// Invoice Parser desktop UI - port of invoice.js from the ASP web app.
// All parsing/prep now happens server-side; this page uploads, reviews and saves.

var poCompareData  = null
var pendingId      = null
var pendingCreated = null
var pendingFileInfo = null
var pendingSaveTimer = null
var pendingDefaultState = null
var lastLlmResult  = null
var rowCandidates  = {}
var pdfLineMap     = null   // [{page, top, h}] per OCR text line; fractions of page height
var isDashboard    = false
var nextRowIndex   = 0      // data-index is a row key, not a position - manual rows get fresh ones

$(document).ready(function () {
    var resumeID = getQueryParam('pending')
    isDashboard = !resumeID

    if (resumeID) {
        $('body').addClass('review-page')
        $('#layout').css('display', 'flex')
        $('#pageMode').text('- Review')
        initPreviewSplit()
        initPreviewZoom()
        var boot = [loadVendors(), loadDepartments(), loadPOList()]
        Promise.all(boot).then(function () { resumePending(resumeID) })
    } else {
        $('#dashboard').show()
        loadDashboard()
        setInterval(loadDashboard, 15000)
    }
    connectEvents()

    $('#fileInput').on('change', handleFilesSelected)
    $('#poSelect').on('change', handlePOChange)
    $('#btnScan').on('click', handleScan)
    $('#btnSave').on('click', handleSave)
    $('#btnDeleteDraft').on('click', handleDeleteDraft)
    $('#btnRestoreDefaults').on('click', handleRestoreDefaults)
    $('#btnAcceptAll').on('click', acceptAllRows)
    $('#btnAddLine').on('click', addBlankRow)
    $('#btnCreateProduct').on('click', handleCreateProduct)
    $('#btnCloseModal').on('click', closeNewProductModal)
    $('#btnParseQueued').on('click', handleParseQueued)
    $('#btnViewParsed').on('click', openParsedModal)
    $('#btnCloseParsed').on('click', closeParsedModal)
    $('#parsedModal').on('click', function (e) { if (e.target === this) closeParsedModal() })
    $(document).on('click', '.parsed-tab', function () {
        $('.parsed-tab').removeClass('active')
        $(this).addClass('active')
        $('.parsed-pane').hide()
        $('#' + $(this).data('pane')).css('display', 'flex')
    })
    $(document).on('keydown', function (e) {
        if (e.key !== 'Escape') return
        closeNewProductModal()
        closeParsedModal()
    })
    $(document).on('input change', '.item-upc,.item-cert,.item-qty,.item-cost', function () {
        if ($('#poSelect').val() && poCompareData) applyPoComparison()
    })
    $(document).on('input change', '#reviewSection input,#reviewSection textarea,#reviewSection select,#ocrText', function () {
        queuePendingStateSave('editing')
    })
    // scroll does not bubble, so the capture phase is the only way to catch
    // the table scroller and drop the fixed-position search dropdown with it.
    // Scrolling inside the dropdown itself must not close it.
    document.addEventListener('scroll', function (e) {
        if (e.target && e.target.nodeType === 1 && e.target.closest('.search-results')) return
        $('.search-results:visible').hide()
    }, true)
    $(document).on('blur', '#np_upc', function () {
        var v = $(this).val().replace(/\D/g, '')
        if (v.length > 0) $(this).val(v.padStart(13, '0'))
    })

    $('#uploadZone').on('dragover', function (e) {
        e.preventDefault()
        $(this).addClass('drag-over')
    }).on('dragleave drop', function (e) {
        e.preventDefault()
        $(this).removeClass('drag-over')
        if (e.type === 'drop') {
            queueFiles(e.originalEvent.dataTransfer.files)
        }
    })
})

// -------------------------------------------------------
// Preview / form split - drag the divider or hide the preview
// entirely so the line-item grid gets the whole window.
// -------------------------------------------------------
function initPreviewSplit() {
    var saved = null
    try { saved = localStorage.getItem('ip_split_pct') } catch (e) {}
    if (saved) $('#leftPanel').css('flex', '0 0 ' + saved + '%')

    var collapsed = false
    try { collapsed = localStorage.getItem('ip_preview_hidden') === '1' } catch (e) {}
    setPreviewCollapsed(collapsed)

    $('#btnTogglePreview').on('click', function () {
        setPreviewCollapsed(!$('#leftPanel').hasClass('collapsed'))
    })

    var dragging = false
    $('#splitter').on('mousedown', function (e) {
        dragging = true
        $(this).addClass('dragging')
        $('body').css('user-select', 'none')
        e.preventDefault()
    })
    $(document).on('mousemove', function (e) {
        if (!dragging) return
        var rect = document.getElementById('layout').getBoundingClientRect()
        var pct  = ((e.clientX - rect.left) / rect.width) * 100
        pct = Math.max(15, Math.min(70, pct))
        $('#leftPanel').css('flex', '0 0 ' + pct.toFixed(1) + '%')
        try { localStorage.setItem('ip_split_pct', pct.toFixed(1)) } catch (err) {}
    }).on('mouseup', function () {
        if (!dragging) return
        dragging = false
        $('#splitter').removeClass('dragging')
        $('body').css('user-select', '')
        applyPreviewZoom()
        renderLineMarkers()
    })
}

// -------------------------------------------------------
// Preview zoom. 1 = fit the page to the panel width; the page
// wrapper is sized in px off the panel, so markers stay in place.
// -------------------------------------------------------
var previewZoom = 1

function initPreviewZoom() {
    var saved = null
    try { saved = parseFloat(localStorage.getItem('ip_preview_zoom')) } catch (e) {}
    if (saved && saved > 0) previewZoom = Math.max(0.25, Math.min(5, saved))

    $('#btnZoomIn').on('click',  function () { setPreviewZoom(previewZoom * 1.25) })
    $('#btnZoomOut').on('click', function () { setPreviewZoom(previewZoom / 1.25) })
    $('#btnZoomFit').on('click', function () { setPreviewZoom(1) })

    $('#canvasWrapper').on('wheel', function (e) {
        var ev = e.originalEvent
        if (!ev.ctrlKey) return
        e.preventDefault()
        setPreviewZoom(previewZoom * (ev.deltaY < 0 ? 1.1 : 1 / 1.1))
    })

    $(window).on('resize', applyPreviewZoom)
    applyPreviewZoom()
}

function setPreviewZoom(z) {
    previewZoom = Math.max(0.25, Math.min(5, z))
    try { localStorage.setItem('ip_preview_zoom', previewZoom) } catch (e) {}
    applyPreviewZoom()
}

function applyPreviewZoom() {
    var wrap = document.getElementById('canvasWrapper')
    $('#zoomLevel').text(Math.round(previewZoom * 100) + '%')
    if (!wrap) return
    // clientWidth already excludes the scrollbar; subtract the 8px padding pair.
    var avail = wrap.clientWidth - 16
    if (avail <= 0) return
    $('#canvasWrapper .page-wrap').css('width', Math.round(avail * previewZoom) + 'px')
}

function setPreviewCollapsed(collapsed) {
    $('#leftPanel').toggleClass('collapsed', !!collapsed)
    $('#btnTogglePreview').html(collapsed ? '&raquo; Show preview' : '&laquo; Hide preview')
    try { localStorage.setItem('ip_preview_hidden', collapsed ? '1' : '0') } catch (e) {}
    if (!collapsed) { applyPreviewZoom(); renderLineMarkers() }
}

// -------------------------------------------------------
// Live updates from the background worker (SSE)
// -------------------------------------------------------
function connectEvents() {
    try {
        var es = new EventSource('/api/events')
        es.onmessage = function (e) {
            var msg
            try { msg = JSON.parse(e.data) } catch (err) { return }
            if (msg.type !== 'stage') return
            if (isDashboard) {
                loadDashboard()
                return
            }
            if (pendingId && msg.id === pendingId) {
                if (msg.stage === 'parsed') {
                    resumePending(pendingId)
                } else if (msg.stage === 'error') {
                    setStatus('Background parsing failed: ' + (msg.error || 'unknown error') + '. Use Scan Invoice to retry.', 'error')
                } else if (msg.stage === 'processing') {
                    setStatus('Parsing in the background...', 'loading')
                }
            }
        }
        es.onerror = function () { /* browser retries automatically */ }
    } catch (e) {
        console.warn('SSE unavailable:', e)
    }
}

// -------------------------------------------------------
// Batch upload: the server stores the file, preps it and
// queues it for background parsing in one round trip.
// -------------------------------------------------------
async function handleFilesSelected(e) {
    await queueFiles(e.target.files)
}

async function queueFiles(fileList) {
    var all = Array.prototype.slice.call(fileList || [])
    if (!all.length) return

    // The accept attribute does not apply to drag-and-drop.
    var rejected = []
    var files = all.filter(function (f) {
        var ok = /\.(pdf|jpe?g|png)$/i.test(f.name)
        if (!ok) rejected.push(f.name)
        return ok
    })
    if (!files.length) {
        setStatus('Not uploaded - only PDF, JPG or PNG files are supported: ' + rejected.join(', '), 'error')
        $('#fileInput').val('')
        return
    }

    setStatus('Uploading ' + files.length + ' file(s)...', 'loading')
    var fd = new FormData()
    files.forEach(function (f) { fd.append('files', f, f.name) })

    try {
        var resp = await fetch('/api/upload', { method: 'POST', body: fd })
        var result = await readJsonResponse(resp, 'upload')
        var ok = 0, fail = 0, failMsgs = []
        ;(result.results || []).forEach(function (r) {
            if (r.ok) ok++
            else { fail++; failMsgs.push((r.file || 'file') + ': ' + (r.error || 'failed')) }
        })
        var msg = 'Queued ' + ok + ' invoice(s)' + (fail ? (', ' + fail + ' failed (' + failMsgs.join('; ') + ')') : '') +
                  '. They parse automatically - check Pending.'
        if (rejected.length) msg += ' Skipped (unsupported type): ' + rejected.join(', ')
        setStatus(msg, (fail || rejected.length) ? 'error' : 'success')
    } catch (err) {
        setStatus('Upload failed: ' + err.message, 'error')
    }
    $('#fileInput').val('')
    if (isDashboard) loadDashboard()
}

// -------------------------------------------------------
// Landing dashboard
// -------------------------------------------------------
async function loadDashboard() {
    try {
        var resp = await fetch('/api/stats')
        var s = await resp.json()
        if (s.error) { showDbError(s.error); return }
        $('#statReady').text(s.ready)
        $('#statQueued').text(s.queued)
        $('#statProcessingSub').text(s.processing ? (s.processing + ' processing') : '')
        $('#statProgress').text(s.in_progress)
        $('#statError').text(s.error)
        $('#statToday').text(s.uploaded_today)
        $('#statArchived').text(s.archived)
        $('#statTotal').text(s.total)
        $('#statValue').text('$' + (parseFloat(s.pending_value) || 0).toFixed(2))
        $('#statLines').text(s.pending_lines)
        $('#dashUpdated').text('Updated ' + new Date().toLocaleTimeString())
    } catch (e) {
        console.warn('Dashboard stats failed:', e)
    }
}

async function handleParseQueued() {
    var btn = $('#btnParseQueued')
    btn.prop('disabled', true)
    try {
        var resp = await fetch('/api/parse-queued', { method: 'POST' })
        var result = await readJsonResponse(resp, 'parse-queued')
        var msg, kind = 'success'
        if (result.queued) {
            msg = 'Queued ' + result.queued + ' invoice(s) for parsing - they process in the background.'
        } else if (result.already_waiting) {
            msg = result.already_waiting + ' invoice(s) are already in the queue and still waiting their turn.'
        } else {
            msg = 'Nothing to parse.'
        }
        setStatus(msg, kind)
    } catch (e) {
        setStatus('Parse failed: ' + e.message, 'error')
    }
    btn.prop('disabled', false)
    loadDashboard()
}

// -------------------------------------------------------
// Scan Invoice = re-parse this draft now (server-side)
// -------------------------------------------------------
async function handleScan() {
    if (!pendingId) return
    if ($('#lineItemsBody tr').length &&
        !confirm('Re-scanning replaces the header and every line item with a fresh parse. Your edits on this draft will be lost. Continue?')) return
    try {
        setStatus('Queued for parsing...', 'loading')
        var resp = await fetch('/api/pending/' + encodeURIComponent(pendingId) + '/parse', { method: 'POST' })
        var result = await readJsonResponse(resp, 'parse')
        if (!result.success) throw new Error(result.error || 'parse failed')
        setStatus('Parsing in the background - this screen updates automatically when it finishes.', 'loading')
    } catch (err) {
        setStatus('Error: ' + err.message, 'error')
    }
}

// -------------------------------------------------------
// Matching
// -------------------------------------------------------
async function callMatch(invoiceData) {
    var fd    = new URLSearchParams()
    fd.append('vendor', invoiceData.vendor_name || '')
    var items = invoiceData.line_items || []
    fd.append('item_count', items.length)
    items.forEach(function (item, i) {
        fd.append('item_' + i + '_upc',  item.upc || '')
        fd.append('item_' + i + '_desc', item.description || '')
        fd.append('item_' + i + '_code', item.product_code || '')
    })
    var resp = await fetch('/api/match', { method: 'POST', body: fd })
    var result = await readJsonResponse(resp, 'match')
    if (result.error) throw new Error(result.error)
    return result
}

// -------------------------------------------------------
// PO dropdown + comparison
// -------------------------------------------------------
async function loadPOList() {
    try {
        var resp = await fetch('/api/polist')
        var pos  = await resp.json()
        if (pos.error) { showDbError(pos.error); return }
        var sel  = $('#poSelect')
        pos.forEach(function (p) {
            var label = 'PO #' + p.po_number
            if (p.vendor_name) label += ' - ' + p.vendor_name
            if (p.po_date)     label += ' (' + p.po_date + ')'
            sel.append('<option value="' + escHtml(p.po_number) + '">' + escHtml(label) + '</option>')
        })
    } catch (e) {
        console.warn('Could not load PO list:', e)
    }
}

async function handlePOChange() {
    var poNum = $('#poSelect').val()
    poCompareData = null
    clearPoComparison()
    if (!poNum) return
    try {
        var resp = await fetch('/api/podetail?po=' + encodeURIComponent(poNum))
        if (!resp.ok) return
        var detail = await resp.json()
        if (detail.error) { showDbError(detail.error); return }
        poCompareData = detail
        if ($('#reviewSection').is(':visible')) applyPoComparison()
        queuePendingStateSave('editing')
    } catch(e) {
        console.warn('PO detail load failed:', e)
    }
}

function normalizeUpc(u) {
    return String(u).replace(/\D/g, '').replace(/^0+/, '')
}

function clearPoComparison() {
    $('#poCompareSummary').text('')
    $('#lineItemsBody tr')
        .removeClass('po-match po-diff po-inv-only')
        .removeAttr('data-po-status')
        .each(function () {
            var row = $(this)
            row.find('.po-cases,.po-pieces,.po-cost')
                .text('-')
                .removeClass('po-cell-diff')
                .addClass('cmp-na')
            row.find('.po-note').remove()
        })
}

function applyPoComparison() {
    var poNum = $('#poSelect').val()
    if (!poNum || !poCompareData) { clearPoComparison(); return }

    clearPoComparison()

    var poPool = poCompareData.map(function(p) { return { used: false, item: p } })
    var matchedCount = 0
    var reviewCount  = 0

    $('#lineItemsBody tr').each(function() {
        var row = $(this)
        var inv = {
            upc:  row.find('.item-upc').val().trim(),
            cert: row.find('.item-cert').val().trim(),
            desc: row.find('.item-desc').val().trim(),
            qty:  parseFloat(row.find('.item-qty').val())  || 0,
            cost: parseFloat(row.find('.item-cost').val()) || 0
        }
        var normInv = normalizeUpc(inv.upc)
        var found   = null

        for (var j = 0; j < poPool.length; j++) {
            if (poPool[j].used) continue
            if (normInv && normalizeUpc(poPool[j].item.upc) === normInv) { found = poPool[j]; break }
        }
        if (!found && inv.cert) {
            for (var j = 0; j < poPool.length; j++) {
                if (poPool[j].used) continue
                if (poPool[j].item.cert_code && poPool[j].item.cert_code.trim() === inv.cert) { found = poPool[j]; break }
            }
        }

        if (found) {
            found.used = true
            matchedCount++
            var po = found.item
            var qDiff = Math.abs(inv.qty - (parseFloat(po.qty || 0))) > 0.005
            var cDiff = Math.abs(inv.cost - (parseFloat(po.cost || 0))) > 0.005
            row.find('.po-cases').text(formatPoNumber(po.qty)).removeClass('cmp-na')
            row.find('.po-pieces').text(formatPoNumber(po.qty_pieces)).removeClass('cmp-na')
            row.find('.po-cost').text(formatMoney(po.cost)).removeClass('cmp-na')
            if (qDiff) row.find('.po-cases').addClass('po-cell-diff')
            if (cDiff) row.find('.po-cost').addClass('po-cell-diff')
            if (qDiff || cDiff) {
                reviewCount++
                row.addClass('po-diff').attr('data-po-status', 'review')
                row.find('.match-badge').last().after('<span class="po-note">VALIDATE DATA</span>')
            } else {
                row.addClass('po-match').attr('data-po-status', 'match')
            }
        } else {
            reviewCount++
            row.addClass('po-inv-only').attr('data-po-status', 'invoice-only')
            row.find('.match-badge').last().after('<span class="po-note">VALIDATE DATA</span>')
        }
    })

    var poOnlyCount = 0
    poPool.forEach(function(p) { if (!p.used) poOnlyCount++ })

    var summary = 'PO #' + poNum + ': ' + matchedCount + ' matched'
    if (reviewCount) summary += ', ' + reviewCount + ' validate'
    if (poOnlyCount) summary += ', ' + poOnlyCount + ' PO-only'
    $('#poCompareSummary').text(summary)
    refreshReviewSummary()
}

function formatPoNumber(v) {
    if (v == null || v === '') return '-'
    var n = parseFloat(v)
    if (isNaN(n)) return String(v)
    return n % 1 === 0 ? String(n) : n.toFixed(2)
}

function formatMoney(v) {
    if (v == null || v === '') return '-'
    var n = parseFloat(v || 0)
    if (isNaN(n)) return String(v)
    return '$' + n.toFixed(2)
}

// -------------------------------------------------------
// Vendor dropdown
// -------------------------------------------------------
async function loadVendors() {
    try {
        var resp    = await fetch('/api/vendors')
        var vendors = await resp.json()
        if (vendors.error) throw new Error(vendors.error)
        var sel     = $('#vendorSelect')
        vendors.forEach(function (v) {
            sel.append('<option value="' + v.id + '">' + escHtml(v.name) + '</option>')
        })
    } catch (e) {
        // Without the list the draft cannot be saved; do not fail silently.
        showDbError('Vendor list failed to load: ' + e.message)
    }
}

// -------------------------------------------------------
// Form population
// -------------------------------------------------------
function populateForm(data, matchData) {
    $('#invoiceNumber').val(data.invoice_number || '')
    $('#invoiceDate').val(data.invoice_date || '')
    $('#invoiceTotal').val(data.total != null ? data.total : '')
    totalLabel = data.total_label || ''
    totalPage  = data.total_page  || ''
    setHint('hintVendor', data.vendor_name)
    setHint('hintInvoiceNumber', data.invoice_number)
    setHint('hintInvoiceDate', data.invoice_date)
    setHint('hintInvoiceTotal', data.total, totalHintSuffix())

    var v = matchData.vendor || {}
    if (v.id != null) {
        $('#vendorSelect').val(v.id)
    }
    if (v.label) {
        var badgeClass = v.label === 'exact' ? 'badge-exact' : v.label === 'fuzzy' ? 'badge-fuzzy' : 'badge-none'
        var badgeText  = v.label === 'exact' ? 'matched' : 'VALIDATE DATA'
        $('#vendorBadge').text(badgeText).attr('class', 'match-badge ' + badgeClass).show()
    }

    var tbody = $('#lineItemsBody')
    tbody.empty()
    var items = data.line_items || []
    items.forEach(function (item, i) {
        var match = (matchData.items && matchData.items[i]) ? matchData.items[i] : {}
        tbody.append(buildRow(i, item, match))
    })
    nextRowIndex = items.length

    recalcAllMargins()
    if ($('#poSelect').val() && poCompareData) applyPoComparison()
    renderLineMarkers()
    refreshReviewSummary()
    pendingDefaultState = collectDraftSnapshot()
}

// -------------------------------------------------------
// Review sanity checks: header total vs line totals, rows that still need
// a decision, and what blocks Save. Cheap enough to run on every edit.
// -------------------------------------------------------
var totalLabel = ''
var totalPage  = ''

function totalHintSuffix() {
    var parts = []
    if (totalLabel) parts.push(totalLabel)
    if (totalPage)  parts.push('page ' + totalPage)
    return parts.length ? ' (' + parts.join(', ') + ')' : ''
}

function rowNeedsAttention(row) {
    var s = row.attr('data-status')
    if (s === 'unmatched' || s === 'fuzzy') return true
    var po = row.attr('data-po-status')
    return po === 'review' || po === 'invoice-only'
}

function refreshReviewSummary() {
    var rows = $('#lineItemsBody tr')
    var attention = 0, unmatched = 0
    rows.each(function () {
        var row = $(this)
        if (rowNeedsAttention(row)) attention++
        var s = row.attr('data-status')
        if (s === 'unmatched' || s === 'fuzzy') unmatched++
    })

    var summary = rows.length + ' line' + (rows.length === 1 ? '' : 's')
    if (rows.length) {
        summary += attention
            ? ' - <span class="attention-count">' + attention + ' need attention</span>'
            : ' - <span class="attention-none">all reviewed</span>'
    }
    $('#lineSummary').html(summary)

    var blockers = $('#saveBlockers')
    if (unmatched) blockers.text(unmatched + ' row' + (unmatched === 1 ? '' : 's') + ' must be matched or accepted before saving').show()
    else blockers.hide()
}

// -------------------------------------------------------
// Source-line markers on the preview (text PDFs only)
// -------------------------------------------------------
function renderLineMarkers() {
    $('#canvasWrapper .line-marker').remove()
    $('#lineItemsBody tr').removeClass('has-source').removeAttr('title')
    if (!pdfLineMap || !pdfLineMap.length) return
    $('#lineItemsBody tr').each(function () {
        var row = $(this)
        var n = parseInt(row.attr('data-source-line'), 10)
        if (isNaN(n) || n < 1 || n > pdfLineMap.length) return
        var line = pdfLineMap[n - 1]
        var pageWrap = $('#canvasWrapper .page-wrap[data-page="' + line.page + '"]')
        if (!pageWrap.length) return
        var desc = row.find('.item-desc').val() || '(no description)'
        $('<div class="line-marker">')
            .css({ top: (line.top * 100) + '%', height: Math.max(line.h * 100, 0.3) + '%' })
            .attr('data-row', row.attr('data-index'))
            .attr('data-tip', 'Row ' + (row.index() + 1) + ': ' + desc)
            .appendTo(pageWrap)
        row.addClass('has-source').attr('title', 'Click to show this line on the invoice preview')
    })
}

// Preview -> row
$(document).on('click', '.line-marker', function () {
    var row = $('tr[data-index="' + $(this).attr('data-row') + '"]')
    if (!row.length) return
    $('#canvasWrapper .line-marker').removeClass('active')
    $(this).addClass('active')
    row[0].scrollIntoView({ behavior: 'smooth', block: 'center' })
    row.removeClass('row-flash')
    void row[0].offsetWidth   // restart the flash animation
    row.addClass('row-flash')
})

// Row -> preview. Clicks on the fields and buttons in the row are left alone.
$(document).on('click', '#lineItemsBody tr.has-source', function (e) {
    if ($(e.target).closest('input,textarea,select,button,.cand-item,.search-results').length) return
    showRowOnPreview($(this))
})

function showRowOnPreview(row) {
    var idx = row.attr('data-index')
    if (!$('#canvasWrapper .line-marker[data-row="' + idx + '"]').length) return

    // Expanding rebuilds the markers, so look the marker up again afterwards.
    if ($('#leftPanel').hasClass('collapsed')) setPreviewCollapsed(false)
    var marker = $('#canvasWrapper .line-marker[data-row="' + idx + '"]')
    if (!marker.length) return

    $('#canvasWrapper .line-marker').removeClass('active')
    marker.addClass('active')

    var wrap = document.getElementById('canvasWrapper')
    var wr = wrap.getBoundingClientRect()
    var mr = marker[0].getBoundingClientRect()
    var top = wrap.scrollTop + (mr.top - wr.top) - (wrap.clientHeight / 2) + (mr.height / 2)
    wrap.scrollTo({ top: Math.max(0, top), behavior: 'smooth' })
}

function buildRow(i, item, match) {
    var parsedUpc  = item.upc             || ''
    var parsedDesc = item.description     || ''
    var parsedCode = item.product_code    || ''
    var parsedSize = item.size            || ''
    var parsedUom  = item.unit_of_measure || 'EA'

    var upc   = match.upc         || parsedUpc
    var desc  = match.description || parsedDesc
    var cert  = match.cert_code   || parsedCode
    var size  = match.size        || parsedSize
    var uom   = match.uom         || parsedUom

    var qty   = item.quantity   != null ? item.quantity   : ''
    var cost  = item.unit_price != null ? item.unit_price : ''
    var total = item.total      != null ? item.total      : ''

    // Retail comes off the product file. Pack prefers the product file and
    // falls back to the invoice's PACK/SIZE column when the product has none.
    var parsedPack = (item.pack != null && item.pack !== '') ? item.pack : ''
    var pack   = match.pack   != null ? match.pack   : parsedPack
    var retail = match.retail != null ? match.retail : ''
    var parsedPackHint = (parsedPack !== '' && String(parsedPack) !== String(pack))
        ? '<small class="parsed-hint" title="Pack printed on the invoice; the box shows the product file value">inv: ' + escHtml(String(parsedPack)) + '</small>'
        : ''

    var label    = match.match_label || 'unmatched'
    var badgeCls = label === 'exact' ? 'badge-exact'
                 : (label === 'fuzzy' || label === 'cert_code' || label === 'upc_norm' || label === 'upc+fuzzy') ? 'badge-fuzzy'
                 : 'badge-none'
    var status    = badgeCls === 'badge-exact' ? 'exact' : badgeCls === 'badge-fuzzy' ? 'fuzzy' : 'unmatched'
    var badgeText = label === 'exact' ? 'matched' : 'VALIDATE DATA'
    var warnHtml  = match.inactive ? '<span class="warn-badge">INACTIVE</span>' : ''

    // The search box is available on every row, matched or not - the suggested
    // product is not always the right one.
    var isUnmatched = (label === 'unmatched')
    var searchHtml  = '<br><button type="button" class="search-toggle" data-item="' + i + '"' +
        (isUnmatched ? ' style="display:none"' : '') + '>Change product</button>' +
        '<div class="search-inline-wrap"' + (isUnmatched ? '' : ' style="display:none"') + '>' +
        buildSearchUI(i) + '</div>' +
        '<br><button type="button" class="btn-new-item" data-item="' + i + '"' +
        ' title="Create this product in posbdat..Products and attach it to this row">+ New item</button>'

    // Only a fuzzy row can be accepted: it already carries a real product.
    // An unmatched row has nothing to accept and must be matched or created.
    var confirmHtml = (status === 'fuzzy')
        ? '<br><button class="btn-confirm" data-index="' + i + '">Accept</button>'
        : ''

    var matchedDesc = match.description || ''
    var toggleHtml  = buildDescToggle(i, parsedDesc, matchedDesc, matchedDesc ? 'matched' : 'parsed')

    var parsedCodeHint = parsedCode ? '<small class="parsed-hint">parsed: ' + escHtml(parsedCode) + '</small>' : ''

    var parsedUpcDiv = (parsedUpc && parsedUpc !== upc)
        ? '<div class="upc-parsed-val">' + escHtml(parsedUpc) + '</div>'
        : ''

    var cands = (match.candidates || []).filter(function (c) { return c.upc !== upc })
    rowCandidates[i] = cands
    var candHtml = ''
    if (cands.length) {
        candHtml = '<div class="cand-list">'
        cands.forEach(function (c, j) {
            candHtml += '<div class="cand-item" data-item="' + i + '" data-cand="' + j + '" title="' + escHtml(c.upc || '') + '">' +
                escHtml(c.description || '') +
                '<span class="cand-meta"> ' + Math.round((c.score || 0) * 100) + '%</span></div>'
        })
        candHtml += '</div>'
    }

    var srcLine = parseInt(item.source_line, 10)

    // Both sides are kept on the row so the parsed-vs-matched view can show
    // what came off the invoice even after the fields have been edited.
    return '<tr data-index="' + i + '" data-status="' + status + '"' +
            ' data-source-line="' + (isNaN(srcLine) ? '' : srcLine) + '"' +
            ' data-parsed-desc="' + escHtml(parsedDesc) + '"' +
            ' data-parsed-upc="'  + escHtml(parsedUpc)  + '"' +
            ' data-parsed-cert="' + escHtml(parsedCode) + '"' +
            ' data-parsed-size="' + escHtml(parsedSize) + '"' +
            ' data-parsed-pack="' + escHtml(String(parsedPack)) + '"' +
            ' data-parsed-uom="'  + escHtml(parsedUom)  + '"' +
            ' data-matched-desc="' + escHtml(matchedDesc) + '"' +
            ' data-matched-upc="'  + escHtml(match.upc || '')       + '"' +
            ' data-matched-cert="' + escHtml(match.cert_code || '') + '"' +
            ' data-matched-size="' + escHtml(match.size || '')      + '"' +
            ' data-matched-uom="'  + escHtml(match.uom || '')       + '">' +
        '<td><div class="upc-matched">' + escHtml(upc) + '</div>' + parsedUpcDiv +
            '<input type="hidden" class="item-upc" value="' + escHtml(upc) + '"></td>' +
        '<td><textarea class="item-desc" rows="2">' + escHtml(desc) + '</textarea>' + toggleHtml + '</td>' +
        '<td><input class="item-cert" value="' + escHtml(cert) + '">' + parsedCodeHint + '</td>' +
        '<td class="po-cases po-value cmp-na">-</td>' +
        '<td class="po-pieces po-value cmp-na">-</td>' +
        '<td class="po-cost po-value cmp-na">-</td>' +
        '<td><input class="item-qty" type="number" step="any" value="' + escHtml(String(qty)) + '"></td>' +
        '<td><input class="item-cost" type="number" step="0.01" value="' + escHtml(String(cost)) + '"></td>' +
        '<td><input class="item-pack" type="number" step="1" min="0" value="' + escHtml(String(pack)) + '">' + parsedPackHint + '</td>' +
        '<td class="item-unitcost calc-cell cmp-na">-</td>' +
        '<td class="item-retail calc-cell cmp-na">-' +
            '<input type="hidden" class="retail-val" value="' + escHtml(String(retail)) + '"></td>' +
        '<td class="item-gm calc-cell gm-cell cmp-na">-</td>' +
        '<td><input class="item-total" type="number" step="0.01" value="' + escHtml(String(total)) + '"></td>' +
        '<td><input class="item-size" value="' + escHtml(size) + '"></td>' +
        '<td><input class="item-uom" value="' + escHtml(uom) + '"></td>' +
        '<td><span class="match-badge ' + badgeCls + '">' + badgeText + '</span>' + warnHtml + confirmHtml + candHtml + searchHtml + '</td>' +
        '<td><button class="btn-remove-row" data-index="' + i + '" title="Remove row">&times;</button></td>' +
    '</tr>'
}

// -------------------------------------------------------
// Gross margin. The invoice bills by the case; the product file prices by the
// unit, so the two only compare after the case cost is divided by the pack.
// A blank or zero pack is treated as 1 (the product file leaves it empty for
// singles) - fix the pack cell when a case row looks impossibly profitable.
// -------------------------------------------------------
function numOrNull(v) {
    var n = parseFloat(v)
    return isNaN(n) ? null : n
}

function recalcMargin(row) {
    var caseCost = numOrNull(row.find('.item-cost').val())
    var pack     = numOrNull(row.find('.item-pack').val())
    var retail   = numOrNull(row.find('.retail-val').val())
    if (!pack || pack <= 0) pack = 1

    var unit = caseCost != null ? caseCost / pack : null
    var unitCell = row.find('.item-unitcost')
    unitCell.text(unit != null ? '$' + unit.toFixed(3) : '-')
            .toggleClass('cmp-na', unit == null)

    var retailCell = row.find('.item-retail')
    retailCell.contents().filter(function () { return this.nodeType === 3 }).remove()
    retailCell.prepend(document.createTextNode(retail != null ? '$' + retail.toFixed(2) : '-'))
    retailCell.toggleClass('cmp-na', retail == null)

    var gmCell = row.find('.item-gm').removeClass('gm-good gm-thin gm-loss')
    if (unit == null || retail == null || retail <= 0) {
        gmCell.text('-').addClass('cmp-na')
        return
    }
    var gm = ((retail - unit) / retail) * 100
    gmCell.text(gm.toFixed(1) + '%').removeClass('cmp-na')
        .addClass(gm < 0 ? 'gm-loss' : gm < 15 ? 'gm-thin' : 'gm-good')
}

function recalcAllMargins() {
    $('#lineItemsBody tr').each(function () { recalcMargin($(this)) })
}

$(document).on('input change', '.item-cost,.item-pack', function () {
    recalcMargin($(this).closest('tr'))
})

// Always rendered, on every row - you should never have to guess whether the
// description in the box came off the invoice or out of the product file.
function buildDescToggle(i, parsedDesc, matchedDesc, active) {
    return '<div class="desc-toggle-row">' +
        descSrcButton(i, 'matched', 'Matched', matchedDesc, active) +
        descSrcButton(i, 'parsed',  'Parsed',  parsedDesc,  active) +
        '</div>'
}

function descSrcButton(i, source, label, value, active) {
    if (!value) {
        return '<button type="button" class="btn-desc-src" disabled ' +
               'title="No ' + source + ' description for this row">' + label + '</button>'
    }
    return '<button type="button" class="btn-desc-src' + (active === source ? ' active' : '') + '" ' +
           'data-item="' + i + '" data-source="' + source + '" ' +
           'title="' + escHtml(value) + '">' + label + '</button>'
}

function buildSearchUI(i) {
    return '<input class="product-search" data-item="' + i + '" ' +
           'placeholder="Search UPC or description...">' +
           '<button type="button" class="btn-search-cancel" data-item="' + i + '">cancel</button>' +
           '<div class="search-results" id="search_' + i + '"></div>'
}

// -------------------------------------------------------
// Manually added line (parser missed a row)
// -------------------------------------------------------
function addBlankRow() {
    var i = nextRowIndex++
    $('#lineItemsBody').append(buildRow(i, { unit_of_measure: 'EA' }, { match_label: 'unmatched' }))
    var row = $('#lineItemsBody tr[data-index="' + i + '"]').addClass('row-added')
    recalcMargin(row)
    refreshReviewSummary()
    row[0].scrollIntoView({ block: 'center' })
    row.find('.product-search').focus()
    if ($('#poSelect').val() && poCompareData) applyPoComparison()
    queuePendingStateSave('editing')
}

// -------------------------------------------------------
// Inline product search
// -------------------------------------------------------
var searchTimers = {}
$(document).on('keyup', '.product-search', function () {
    var inp = $(this)
    var idx = inp.data('item')
    clearTimeout(searchTimers[idx])
    searchTimers[idx] = setTimeout(async function () {
        var q   = inp.val().trim()
        var div = $('#search_' + idx)
        if (q.length < 2) { div.hide().empty(); return }

        try {
            var resp    = await fetch('/api/products/search?q=' + encodeURIComponent(q))
            var results = await resp.json()
            if (results.error) { showDbError(results.error); div.hide().empty(); return }
            div.empty()
            if (results.length === 0) {
                div.html(
                    '<div class="search-result-empty">No results</div>' +
                    '<div class="search-result-new" data-item="' + idx + '">[+ Create new product]</div>'
                ).show()
                positionSearchResults(inp, div)
                return
            }
            results.forEach(function (r) {
                var meta = escHtml(r.upc) +
                    (r.cert_code ? ' / ' + escHtml(r.cert_code) : '') +
                    (r.size ? ' - ' + escHtml(r.size) : '') +
                    (r.cost ? ' ($' + r.cost + ')' : '')
                $('<div class="search-result-item">')
                    .html('<div class="search-result-desc">' + escHtml(r.description) + '</div>' +
                          '<div class="search-result-meta">' + meta + '</div>')
                    .data('product', r)
                    .on('click', function () { applyProduct(idx, $(this).data('product')); div.hide().empty() })
                    .appendTo(div)
            })
            div.show()
            positionSearchResults(inp, div)
        } catch (e) { console.error(e) }
    }, 300)
})

// The dropdown is position:fixed so the scrolling table cannot clip it,
// which means its coordinates have to be set against the input each time.
function positionSearchResults(inp, div) {
    var r = inp[0].getBoundingClientRect()
    var w = div.outerWidth()
    var left = Math.max(6, Math.min(r.left, window.innerWidth - w - 10))
    var top  = r.bottom + 2
    if (top + div.outerHeight() > window.innerHeight - 6) {
        top = Math.max(6, r.top - div.outerHeight() - 2)
    }
    div.css({ left: left + 'px', top: top + 'px' })
}

$(document).on('click', '.search-toggle', function () {
    $(this).hide()
    var td = $(this).closest('td')
    td.find('.search-inline-wrap').show()
    td.find('.product-search').focus()
})

$(document).on('click', '.btn-search-cancel', function () {
    var td = $(this).closest('td')
    td.find('.search-results').hide().empty()
    td.find('.product-search').val('')
    td.find('.search-inline-wrap').hide()
    td.find('.search-toggle').show()
})

$(document).on('click', '.cand-item', function () {
    var i = $(this).data('item')
    var c = (rowCandidates[i] || [])[$(this).data('cand')]
    if (c) applyProduct(i, c)
})

function applyProduct(i, p) {
    var row = $('tr[data-index="' + i + '"]')
    row.attr('data-status', 'exact')

    var matchedDesc = p.description || ''
    var parsedDesc  = row.attr('data-parsed-desc') || ''
    row.attr('data-matched-desc', matchedDesc)
    row.attr('data-matched-upc',  p.upc || '')
    row.attr('data-matched-cert', p.cert_code || '')
    row.attr('data-matched-size', p.size || '')
    row.attr('data-matched-uom',  p.uom || 'EA')

    row.find('.item-upc').val(p.upc || '')
    row.find('.upc-matched').text(p.upc || '')
    row.find('.upc-parsed-val').hide()
    row.find('.item-desc').val(matchedDesc || parsedDesc)
    row.find('.item-cert').val(p.cert_code || '')
    row.find('.item-size').val(p.size || '')
    row.find('.item-uom').val(p.uom || 'EA')
    row.find('.item-pack').val(p.pack != null ? p.pack : '')
    row.find('.retail-val').val(p.retail != null ? p.retail : '')
    recalcMargin(row)

    row.find('.match-badge').text('selected').attr('class', 'match-badge badge-exact')
    row.find('.btn-confirm').remove()
    row.find('.cand-list').remove()
    row.find('.search-results').hide().empty()
    row.find('.product-search').val('')
    row.find('.search-inline-wrap').hide()
    row.find('.search-toggle').show()

    row.find('.desc-toggle-row').remove()
    row.find('.item-desc').after(buildDescToggle(i, parsedDesc, matchedDesc, matchedDesc ? 'matched' : 'parsed'))
    if ($('#poSelect').val() && poCompareData) applyPoComparison()
    refreshReviewSummary()
    queuePendingStateSave('editing')
}

function acceptRow(row, skipSave) {
    row.attr('data-status', 'confirmed')
    row.find('.match-badge').first().text('accepted').attr('class', 'match-badge badge-exact')
    row.find('.btn-confirm').remove()
    row.find('.cand-list').remove()
    if (!skipSave) { refreshReviewSummary(); queuePendingStateSave('editing') }
}

function acceptAllRows() {
    $('#lineItemsBody tr').each(function () {
        if ($(this).attr('data-status') === 'unmatched') return
        acceptRow($(this), true)
    })
    refreshReviewSummary()
    queuePendingStateSave('editing')
}

$(document).on('click', '.btn-confirm', function () {
    var idx = $(this).data('index')
    acceptRow($('tr[data-index="' + idx + '"]'))
})

$(document).on('click', '.btn-remove-row', function () {
    $('tr[data-index="' + $(this).data('index') + '"]').remove()
    if ($('#poSelect').val() && poCompareData) applyPoComparison()
    renderLineMarkers()
    refreshReviewSummary()
    queuePendingStateSave('editing')
})

$(document).on('click', '.btn-desc-src', function () {
    var btn    = $(this)
    var i      = btn.data('item')
    var source = btn.data('source')
    var row    = $('tr[data-index="' + i + '"]')
    var desc   = source === 'parsed' ? row.attr('data-parsed-desc') : row.attr('data-matched-desc')
    if (!desc) return   // never blank the box by switching to a side that has nothing
    row.find('.item-desc').val(desc)
    row.find('.desc-toggle-row .btn-desc-src').removeClass('active')
    btn.addClass('active')
    queuePendingStateSave('editing')
})

$(document).on('click', '.search-result-new', function () {
    var i = $(this).data('item')
    $(this).closest('.search-results').hide().empty()
    openNewProductModal(i)
})

$(document).on('click', '.btn-new-item', function () {
    openNewProductModal($(this).data('item'))
})

// -------------------------------------------------------
// Parsed vs matched - always reachable from the title bar so you can
// check what came off the invoice against the product it was matched to.
// -------------------------------------------------------
function openParsedModal() {
    renderParsedComparison()
    $('#parsedModal').show()
}

function closeParsedModal() {
    $('#parsedModal').hide()
}

function renderParsedComparison() {
    var diffOnly = $('#chkDiffOnly').is(':checked')

    $('#compareHeaderBody').html(
        headerCompareRow('Vendor', stripHint($('#hintVendor').text()), $('#vendorSelect option:selected').text()) +
        headerCompareRow('Invoice #', stripHint($('#hintInvoiceNumber').text()), $('#invoiceNumber').val()) +
        headerCompareRow('Invoice date', stripHint($('#hintInvoiceDate').text()), $('#invoiceDate').val()) +
        headerCompareRow('Total', stripHint($('#hintInvoiceTotal').text()).replace(/\s*\(.*\)$/, ''), $('#invoiceTotal').val())
    )

    var html = ''
    var shown = 0
    $('#lineItemsBody tr').each(function (n) {
        var row = $(this)
        var p = {
            desc: row.attr('data-parsed-desc') || '',
            upc:  row.attr('data-parsed-upc')  || '',
            cert: row.attr('data-parsed-cert') || '',
            size: row.attr('data-parsed-size') || '',
            uom:  row.attr('data-parsed-uom')  || ''
        }
        var m = {
            desc: row.attr('data-matched-desc') || '',
            upc:  row.attr('data-matched-upc')  || '',
            cert: row.attr('data-matched-cert') || '',
            size: row.attr('data-matched-size') || '',
            uom:  row.attr('data-matched-uom')  || ''
        }
        var diff = {
            desc: !sameText(p.desc, m.desc),
            upc:  normalizeUpc(p.upc) !== normalizeUpc(m.upc),
            cert: !sameText(p.cert, m.cert),
            size: !sameText(p.size, m.size),
            uom:  !sameText(p.uom, m.uom)
        }
        var anyDiff = diff.desc || diff.upc || diff.cert || diff.size || diff.uom
        if (diffOnly && !anyDiff) return

        shown++
        var badge = row.find('.match-badge').first()
        html += '<tr data-row="' + row.attr('data-index') + '"' + (anyDiff ? ' class="has-diff"' : '') + '>' +
            '<td>' + (n + 1) + '</td>' +
            '<td>' + compareCell(p, {}) + '</td>' +
            '<td>' + compareCell(m, diff) + '</td>' +
            '<td><span class="' + escHtml(badge.attr('class') || 'match-badge') + '">' +
                escHtml(badge.text() || 'unmatched') + '</span></td>' +
        '</tr>'
    })

    if (!shown) {
        html = '<tr><td colspan="4" class="cmp-none">' +
            (diffOnly ? 'Every line matched the product file exactly.' : 'No line items on this draft.') +
            '</td></tr>'
    }
    $('#compareBody').html(html)
}

function headerCompareRow(label, parsed, current) {
    var diff = !sameText(parsed, current)
    return '<tr><td>' + escHtml(label) + '</td>' +
        '<td>' + cmpVal(parsed, false) + '</td>' +
        '<td>' + cmpVal(current, diff && parsed !== '') + '</td></tr>'
}

// Meta line under the description: only the pieces that exist.
function compareCell(v, diff) {
    var meta = []
    if (v.upc)  meta.push(span(v.upc, diff.upc))
    if (v.cert) meta.push('cert ' + span(v.cert, diff.cert))
    if (v.size) meta.push(span(v.size, diff.size))
    if (v.uom)  meta.push(span(v.uom, diff.uom))
    return '<div class="cmp-desc">' + (v.desc ? span(v.desc, diff.desc) : '<span class="cmp-empty">(none)</span>') + '</div>' +
           (meta.length ? '<div class="cmp-meta">' + meta.join(' &middot; ') + '</div>' : '')
}

function span(text, isDiff) {
    return isDiff ? '<span class="cmp-diff">' + escHtml(text) + '</span>' : escHtml(text)
}

function cmpVal(v, isDiff) {
    if (!v) return '<span class="cmp-empty">(none)</span>'
    return span(v, isDiff)
}

function sameText(a, b) {
    return String(a || '').trim().toLowerCase() === String(b || '').trim().toLowerCase()
}

// Hints render as "scanned: X" on a fresh parse and bare on a restored draft.
function stripHint(s) {
    return String(s || '').replace(/^scanned:\s*/i, '').trim()
}

$(document).on('change', '#chkDiffOnly', renderParsedComparison)

$(document).on('click', '#compareBody tr[data-row]', function () {
    var row = $('#lineItemsBody tr[data-index="' + $(this).attr('data-row') + '"]')
    if (!row.length) return
    closeParsedModal()
    row[0].scrollIntoView({ behavior: 'smooth', block: 'center' })
    row.removeClass('row-flash')
    void row[0].offsetWidth
    row.addClass('row-flash')
})

// -------------------------------------------------------
// New Product modal
// -------------------------------------------------------
var _newProductTargetRow = null

function openNewProductModal(rowIndex) {
    _newProductTargetRow = (rowIndex !== undefined && rowIndex !== null) ? rowIndex : null
    $('#np_upc').val('')
    $('#np_desc').val('')
    $('#np_price').val('')
    $('#np_dept').val('')
    $('#np_tax').val('0')
    $('#np_fs').val('0')
    $('#np_flagsNote').text('from department')
    $('#np_cost').val('')
    $('#np_pack').val('')
    $('#np_size').val('')
    $('#np_code').val('')
    $('#newProductStatus').text('').hide()

    // Seed from the row that asked for it - the invoice already read most of this.
    if (_newProductTargetRow !== null) {
        var row = $('tr[data-index="' + _newProductTargetRow + '"]')
        if (row.length) {
            $('#np_upc').val(row.attr('data-parsed-upc') || row.find('.item-upc').val() || '')
            $('#np_desc').val((row.find('.item-desc').val() || '').slice(0, 30))
            $('#np_code').val(row.find('.item-cert').val() || '')
            $('#np_size').val((row.find('.item-size').val() || '').slice(0, 9))
            $('#np_pack').val(row.find('.item-pack').val() || '')
            var caseCost = parseFloat(row.find('.item-cost').val())
            var pack = parseFloat(row.find('.item-pack').val())
            if (!isNaN(caseCost)) {
                if (isNaN(pack) || pack <= 0) pack = 1
                $('#np_cost').val((caseCost / pack).toFixed(2))
            }
        }
    }

    $('#newProductModal').show()
    $('#np_upc').focus()
}

function closeNewProductModal() {
    $('#newProductModal').hide()
    _newProductTargetRow = null
}

// dept_no -> { tax, fs } from posbdat..Departments; picking a department
// prefills the item's tax and food stamp flags the same way the POS does.
var deptFlags = {}

async function loadDepartments() {
    try {
        var resp  = await fetch('/api/departments')
        var depts = await resp.json()
        if (depts.error) throw new Error(depts.error)
        var sel   = $('#np_dept')
        sel.empty().append('<option value="">-- Select Department --</option>')
        deptFlags = {}
        depts.forEach(function (d) {
            deptFlags[String(d.id)] = { tax: d.tax ? 1 : 0, fs: d.fs ? 1 : 0 }
            sel.append('<option value="' + d.id + '">' + escHtml(d.name) + '</option>')
        })
    } catch (e) {
        showDbError('Department list failed to load: ' + e.message)
    }
}

$(document).on('change', '#np_dept', function () {
    var f = deptFlags[String($(this).val())]
    if (!f) { $('#np_flagsNote').text('from department'); return }
    $('#np_tax').val(String(f.tax))
    $('#np_fs').val(String(f.fs))
    $('#np_flagsNote').text('prefilled from department')
})

async function handleCreateProduct() {
    var upc   = $('#np_upc').val().trim()
    var desc  = $('#np_desc').val().trim()
    var price = $('#np_price').val().trim()
    if (!upc || !desc || !price) {
        $('#newProductStatus').text('UPC, Description, and Price are required.').css('color', '#ff8888').show()
        return
    }
    if (!$('#np_dept').val()) {
        $('#newProductStatus').text('Department is required - it sets tax, food stamp and age checking.').css('color', '#ff8888').show()
        return
    }
    // "2/5.00" = 2 for $5.00; anything else must be a plain amount.
    if (!/^\d+\s*\/\s*\d+(\.\d+)?$/.test(price) && !/^\d+(\.\d+)?$/.test(price)) {
        $('#newProductStatus').text('Price must be an amount like 2.99, or a group price like 2/5.00.').css('color', '#ff8888').show()
        return
    }

    var fd = new URLSearchParams()
    fd.append('upc',          upc)
    fd.append('description',  desc)
    fd.append('normal_price', price)
    fd.append('dept_id',      $('#np_dept').val())
    fd.append('cost',         $('#np_cost').val())
    fd.append('item_code',    $('#np_code').val())
    fd.append('tax',          $('#np_tax').val())
    fd.append('foodstamp',    $('#np_fs').val())
    fd.append('pack',         $('#np_pack').val())
    fd.append('size',         $('#np_size').val())

    $('#newProductStatus').text('Creating...').css('color', '#ffee88').show()
    try {
        var resp   = await fetch('/api/newproduct', { method: 'POST', body: fd })
        var result = await resp.json()
        if (result.success) {
            $('#newProductStatus').text('Created: ' + result.description + ' (' + result.upc + ')').css('color', '#88ff88').show()
            if (_newProductTargetRow !== null) {
                applyProduct(_newProductTargetRow, {
                    upc: result.upc,
                    description: result.description,
                    cert_code: $('#np_code').val() || '',
                    size: $('#np_size').val() || '',
                    uom: 'EA',
                    pack: $('#np_pack').val() !== '' ? parseFloat($('#np_pack').val()) : null,
                    retail: result.retail != null ? result.retail : null
                })
                setTimeout(closeNewProductModal, 800)
            }
        } else {
            $('#newProductStatus').text('Error: ' + result.error).css('color', '#ff8888').show()
        }
    } catch (e) {
        $('#newProductStatus').text('Error: ' + e.message).css('color', '#ff8888').show()
    }
}

// -------------------------------------------------------
// Pending draft state
// -------------------------------------------------------
function getQueryParam(name) {
    var params = new URLSearchParams(window.location.search)
    return params.get(name)
}

function queuePendingStateSave(stage) {
    if (!pendingId) return
    clearTimeout(pendingSaveTimer)
    pendingSaveTimer = setTimeout(function () {
        savePendingState(stage || 'editing').catch(function (e) {
            console.warn('Pending state save failed:', e)
        })
    }, 700)
}

async function savePendingState(stage) {
    if (!pendingId) return
    var state = collectPendingState(stage || 'editing')
    var resp = await fetch('/api/pending/' + encodeURIComponent(pendingId) + '/state', {
        method: 'POST',
        body: JSON.stringify(state),
        headers: { 'Content-Type': 'application/json; charset=utf-8' }
    })
    var result = await resp.json()
    if (!result.success) throw new Error(result.error || 'state save failed')
}

function collectPendingState(stage) {
    var snap = collectDraftSnapshot()
    return {
        version: 1,
        id: pendingId,
        stage: stage || 'editing',
        created_at: pendingCreated || new Date().toISOString(),
        updated_at: new Date().toISOString(),
        source: pendingFileInfo || {},
        parse_mode: _resumedParseMode || '',
        ocr: {
            text: $('#ocrText').val() || '',
            method: $('#ocrMethod').text() || '',
            line_map: pdfLineMap || null
        },
        header: snap.header,
        po_compare_data: snap.po_compare_data,
        line_items: snap.line_items,
        llm: lastLlmResult || null,
        defaults: pendingDefaultState || null
    }
}

var _resumedParseMode = ''

function collectDraftSnapshot() {
    var selectedVendor = $('#vendorSelect option:selected')
    return {
        header: {
            vendor_id: $('#vendorSelect').val() || '',
            vendor_name: selectedVendor.length ? selectedVendor.text() : '',
            vendor_hint: $('#hintVendor').text() || '',
            vendor_badge_text: $('#vendorBadge').is(':visible') ? $('#vendorBadge').text() : '',
            vendor_badge_class: $('#vendorBadge').is(':visible') ? $('#vendorBadge').attr('class') : '',
            invoice_number: $('#invoiceNumber').val() || '',
            invoice_date: $('#invoiceDate').val() || '',
            po_number: $('#poSelect').val() || '',
            invoice_total: $('#invoiceTotal').val() || '',
            total_label: totalLabel || '',
            total_page: totalPage || ''
        },
        po_compare_data: poCompareData || null,
        line_items: collectPendingLineItems()
    }
}

function collectPendingLineItems() {
    var items = []
    $('#lineItemsBody tr').each(function () {
        var row = $(this)
        var badge = row.find('.match-badge').first()
        items.push({
            upc: row.find('.item-upc').val() || '',
            desc: row.find('.item-desc').val() || '',
            cert: row.find('.item-cert').val() || '',
            qty: row.find('.item-qty').val() || '',
            cost: row.find('.item-cost').val() || '',
            pack: row.find('.item-pack').val() || '',
            retail: row.find('.retail-val').val() || '',
            total: row.find('.item-total').val() || '',
            size: row.find('.item-size').val() || '',
            uom: row.find('.item-uom').val() || '',
            source_line: row.attr('data-source-line') || '',
            status: row.attr('data-status') || '',
            parsed_desc: row.attr('data-parsed-desc') || '',
            parsed_upc: row.attr('data-parsed-upc') || '',
            parsed_cert: row.attr('data-parsed-cert') || '',
            parsed_size: row.attr('data-parsed-size') || '',
            parsed_pack: row.attr('data-parsed-pack') || '',
            parsed_uom: row.attr('data-parsed-uom') || '',
            matched_desc: row.attr('data-matched-desc') || '',
            matched_upc: row.attr('data-matched-upc') || '',
            matched_cert: row.attr('data-matched-cert') || '',
            matched_size: row.attr('data-matched-size') || '',
            matched_uom: row.attr('data-matched-uom') || '',
            match_badge_text: badge.text() || '',
            match_badge_class: badge.attr('class') || '',
            po_status: row.attr('data-po-status') || ''
        })
    })
    return items
}

// -------------------------------------------------------
// Resume a pending draft
// -------------------------------------------------------
async function resumePending(id) {
    try {
        showBusy('Loading invoice...')
        setStatus('Loading pending invoice...', 'loading')
        var resp = await fetch('/api/pending/' + encodeURIComponent(id))
        if (!resp.ok) throw new Error('pending load returned ' + resp.status)
        var state = await resp.json()
        if (state.error && !state.stage) throw new Error(state.error)

        pendingId = state.id || id
        pendingCreated = state.created_at || new Date().toISOString()
        pendingFileInfo = state.source || {}
        pendingDefaultState = state.defaults || null
        lastLlmResult = state.llm || null
        _resumedParseMode = state.parse_mode || ''

        try {
            await renderPendingSourcePreview(pendingId)
        } catch (previewErr) {
            console.warn('Pending source preview failed:', previewErr)
            $('#uploadPrompt').text('Pending source file could not be previewed.').show()
        }
        restorePendingState(state)

        if (state.stage === 'parsed' && state.llm && state.llm.parsed) {
            // Background worker did the slow LLM step; finish with the fast match pass.
            await matchAndPopulateFromParsed(state.llm.parsed)
            await savePendingState('review')
            setStatus('Parsed invoice loaded.', 'success')
        } else if (state.stage === 'queued' || state.stage === 'processing') {
            setStatus('This invoice is ' + state.stage + ' for background parsing - this screen updates automatically when it finishes.', 'loading')
        } else if (state.stage === 'error') {
            setStatus('Background parsing failed: ' + (state.error || 'unknown error') +
                '. Use Scan Invoice to retry.', 'error')
        } else {
            setStatus('Pending invoice loaded.', 'success')
        }
    } catch (e) {
        setStatus('Could not load pending invoice: ' + e.message, 'error')
        console.error(e)
    } finally {
        hideBusy()
    }
}

async function matchAndPopulateFromParsed(invoiceData) {
    var count = (invoiceData.line_items || []).length
    showBusy('Matching ' + count + ' line item' + (count === 1 ? '' : 's') + ' against the product file...')
    try {
        var matchData = await callMatch(invoiceData)
        populateForm(invoiceData, matchData)
        $('#reviewSection').css('display', 'flex')
    } finally {
        hideBusy()
    }
}

// Full-panel busy overlay. Opening a parsed invoice does real work (matching
// every line item), and without this the review pane just sits blank.
function showBusy(msg) {
    var el = $('#busyOverlay')
    if (!el.length) {
        el = $('<div id="busyOverlay"><div class="busy-box">' +
              '<div class="busy-spinner"></div><div class="busy-msg"></div>' +
              '</div></div>').appendTo('body')
    }
    el.find('.busy-msg').text(msg || 'Working...')
    el.css('display', 'flex')
}

function hideBusy() {
    $('#busyOverlay').hide()
}

// Preview pages come pre-rendered from the server (PDFium) - no PDF.js.
async function renderPendingSourcePreview(id) {
    var resp = await fetch('/api/pending/' + encodeURIComponent(id) + '/preview')
    var info = await resp.json()
    if (info.error) throw new Error(info.error)

    var wrapper = document.getElementById('canvasWrapper')
    $(wrapper).find('.page-wrap').remove()
    $('#uploadPrompt').hide()

    for (var p = 1; p <= (info.pages || 1); p++) {
        var pageWrap = document.createElement('div')
        pageWrap.className = 'page-wrap'
        pageWrap.setAttribute('data-page', p)
        var img = document.createElement('img')
        img.src = '/api/pending/' + encodeURIComponent(id) + '/preview/' + p + '?ts=' + Date.now()
        pageWrap.appendChild(img)
        wrapper.appendChild(pageWrap)
    }
    applyPreviewZoom()
    $('#scanSection').css('display', 'flex')
}

function restorePendingState(state) {
    var h = state.header || {}
    pdfLineMap = (state.ocr && state.ocr.line_map && state.ocr.line_map.length) ? state.ocr.line_map : null
    $('#ocrText').val('')
    $('#ocrMethod').text('')
    $('#vendorBadge').hide().text('')
    $('#hintVendor,#hintInvoiceNumber,#hintInvoiceDate,#hintInvoiceTotal').hide().text('')
    // A vendor or PO missing from the dropdown (list failed to load, PO
    // outside the TOP 500) would otherwise reset to blank and the next
    // autosave would write that blank back into the draft.
    ensureOption($('#vendorSelect'), h.vendor_id, h.vendor_name)
    ensureOption($('#poSelect'), h.po_number, 'PO #' + h.po_number)
    $('#vendorSelect').val(h.vendor_id || '')
    $('#invoiceNumber').val(h.invoice_number || '')
    $('#invoiceDate').val(h.invoice_date || '')
    $('#invoiceTotal').val(h.invoice_total || '')
    $('#poSelect').val(h.po_number || '')
    totalLabel = h.total_label || ''
    totalPage  = h.total_page  || ''

    if (h.vendor_badge_text) {
        $('#vendorBadge').text(h.vendor_badge_text).attr('class', h.vendor_badge_class || 'match-badge badge-none').show()
    }
    if (h.vendor_hint) $('#hintVendor').text(h.vendor_hint).show()
    if (h.invoice_number) $('#hintInvoiceNumber').text(h.invoice_number).show()
    if (h.invoice_date) $('#hintInvoiceDate').text(h.invoice_date).show()
    if (h.invoice_total) $('#hintInvoiceTotal').text(h.invoice_total + totalHintSuffix()).show()

    if (state.ocr && state.ocr.text) {
        $('#ocrText').val(state.ocr.text)
        $('#ocrMethod').text(state.ocr.method || 'from pending')
    }

    restorePendingRows(state.line_items || [])
    recalcAllMargins()
    poCompareData = state.po_compare_data || null
    if ((state.line_items || []).length) {
        $('#reviewSection').css('display', 'flex')
        if ($('#poSelect').val() && poCompareData) applyPoComparison()
        renderLineMarkers()
    }
    refreshReviewSummary()
}

function ensureOption(sel, value, label) {
    if (!value) return
    var exists = sel.find('option').filter(function () { return this.value === String(value) }).length
    if (!exists) sel.append('<option value="' + escHtml(String(value)) + '">' + escHtml(label || String(value)) + '</option>')
}

function restorePendingRows(items) {
    var tbody = $('#lineItemsBody')
    tbody.empty()
    items.forEach(function (saved, i) {
        var status = saved.status || 'unmatched'
        var matchLabel = (status === 'unmatched' || status === 'fuzzy') ? status : 'exact'
        var item = {
            upc: saved.upc || '',
            description: saved.desc || '',
            product_code: saved.cert || '',
            quantity: saved.qty || '',
            unit_price: saved.cost || '',
            total: saved.total || '',
            size: saved.size || '',
            unit_of_measure: saved.uom || 'EA',
            pack: saved.parsed_pack || '',
            source_line: saved.source_line || ''
        }
        var match = {
            upc: saved.upc || '',
            description: saved.desc || '',
            cert_code: saved.cert || '',
            size: saved.size || '',
            uom: saved.uom || 'EA',
            pack: saved.pack !== '' && saved.pack != null ? saved.pack : null,
            retail: saved.retail !== '' && saved.retail != null ? saved.retail : null,
            match_label: matchLabel
        }
        tbody.append(buildRow(i, item, match))
        var row = tbody.find('tr[data-index="' + i + '"]')
        row.attr('data-status', status)
        row.attr('data-parsed-desc', saved.parsed_desc || saved.desc || '')
        row.attr('data-parsed-upc',  saved.parsed_upc  || saved.upc || '')
        row.attr('data-parsed-cert', saved.parsed_cert || saved.cert || '')
        row.attr('data-parsed-size', saved.parsed_size || saved.size || '')
        row.attr('data-parsed-uom',  saved.parsed_uom  || saved.uom || '')
        row.attr('data-matched-desc', saved.matched_desc || saved.desc || '')
        row.attr('data-matched-upc',  saved.matched_upc  || saved.upc || '')
        row.attr('data-matched-cert', saved.matched_cert || saved.cert || '')
        row.attr('data-matched-size', saved.matched_size || saved.size || '')
        row.attr('data-matched-uom',  saved.matched_uom  || saved.uom || '')
        if (saved.match_badge_text) row.find('.match-badge').first().text(saved.match_badge_text)
        if (saved.match_badge_class) row.find('.match-badge').first().attr('class', saved.match_badge_class)
        if (status !== 'unmatched' && status !== 'fuzzy') row.find('.btn-confirm').remove()
    })
    nextRowIndex = items.length
}

async function handleDeleteDraft() {
    if (!pendingId) return
    if (!confirm('Delete this pending draft? This removes the saved draft and source file.')) return

    var id = pendingId
    clearTimeout(pendingSaveTimer)
    pendingId = null
    try {
        setStatus('Deleting draft...', 'loading')
        var resp = await fetch('/api/pending/' + encodeURIComponent(id), { method: 'DELETE' })
        var result = await resp.json()
        if (!result.success) throw new Error(result.error || 'delete failed')
        window.location.href = 'pending.html'
    } catch (e) {
        pendingId = id
        setStatus('Delete failed: ' + e.message, 'error')
    }
}

async function handleRestoreDefaults() {
    if (!pendingDefaultState) {
        alert('No saved defaults are available for this draft yet.')
        return
    }
    if (!confirm('Restore the original parsed and matched values for this draft?')) return

    var restored = {
        header: pendingDefaultState.header || {},
        line_items: pendingDefaultState.line_items || [],
        po_compare_data: pendingDefaultState.po_compare_data || null,
        ocr: {
            text: $('#ocrText').val() || '',
            method: $('#ocrMethod').text() || '',
            line_map: pdfLineMap
        }
    }
    restorePendingState(restored)
    if (pendingId) {
        try {
            await savePendingState('editing')
        } catch (e) {
            console.warn('Pending state save failed after restore:', e)
        }
    }
    setStatus('Defaults restored.', 'success')
}

// -------------------------------------------------------
// Save
// -------------------------------------------------------
async function handleSave() {
    var vendorId = $('#vendorSelect').val()
    if (!vendorId) { alert('Please select a vendor before saving.'); return }
    if (!$('#invoiceNumber').val().trim()) { alert('Please enter an invoice number before saving.'); return }
    if (!$('#invoiceDate').val()) { alert('Please enter an invoice date before saving.'); return }

    var unconfirmed = []
    $('#lineItemsBody tr').each(function (idx) {
        var s = $(this).attr('data-status')
        if (s === 'unmatched' || s === 'fuzzy') unconfirmed.push(idx + 1)
    })
    if (unconfirmed.length) {
        alert('Row(s) ' + unconfirmed.join(', ') + ' must be matched to an existing product before saving.')
        return
    }

    var fd = new URLSearchParams()
    fd.append('vendor_id',      vendorId)
    fd.append('invoice_number', $('#invoiceNumber').val())
    fd.append('invoice_date',   $('#invoiceDate').val())
    fd.append('po_number',      $('#poSelect').val())
    fd.append('vendor_total',   $('#invoiceTotal').val())
    fd.append('pending_id',     pendingId || '')

    var rows = $('#lineItemsBody tr')
    fd.append('item_count', rows.length)
    rows.each(function (i) {
        var row = $(this)
        fd.append('item_' + i + '_upc',   row.find('.item-upc').val())
        fd.append('item_' + i + '_desc',  row.find('.item-desc').val())
        fd.append('item_' + i + '_cert',  row.find('.item-cert').val())
        fd.append('item_' + i + '_qty',   row.find('.item-qty').val())
        fd.append('item_' + i + '_cost',  row.find('.item-cost').val())
        fd.append('item_' + i + '_total', row.find('.item-total').val())
        fd.append('item_' + i + '_size',  row.find('.item-size').val())
        fd.append('item_' + i + '_uom',   row.find('.item-uom').val())
        // The server divides the case cost by this pack to get the unit cost
        // it compares against the product file, so send the pack on screen.
        fd.append('item_' + i + '_pack',  row.find('.item-pack').val())
    })

    setStatus('Saving...', 'loading')
    try {
        // The server archives the source file inside the save transaction.
        var resp   = await fetch('/api/save', { method: 'POST', body: fd })
        var result = await resp.json()
        if (result.success) {
            var msg = 'Saved successfully' + (result.po_number ? '. PO: ' + result.po_number : '')
            if (result.batch_no) {
                msg += '. Cost batch ' + result.batch_no + ': ' + result.batch_items + ' item'
                     + (result.batch_items === 1 ? '' : 's')
                if (result.batch_flagged) msg += ', ' + result.batch_flagged + ' below target margin'
            }
            setStatus(msg, 'success')
            if (pendingId) {
                // Stop the debounced autosave first: firing after the delete
                // would recreate the draft.
                clearTimeout(pendingSaveTimer)
                var doneId = pendingId
                pendingId = null
                try { await fetch('/api/pending/' + encodeURIComponent(doneId), { method: 'DELETE' }) } catch (e) {}
            }
            // Long enough to read the batch number before the page moves on.
            setTimeout(function () { window.location.href = 'pending.html' }, result.batch_no ? 3000 : 900)
        } else {
            setStatus('Save failed: ' + result.error, 'error')
        }
    } catch (e) {
        setStatus('Save failed: ' + e.message, 'error')
    }
}

// -------------------------------------------------------
// Utilities
// -------------------------------------------------------
function setStatus(msg, type) {
    var el = isDashboard ? $('#dashStatusBar') : $('#statusBar')
    el.text(msg).removeClass('status-loading status-error status-success')
    if (type && msg) el.addClass('status-' + type).show()
    else el.hide()
}

// Persistent banner for database failures. Separate from the status bar,
// which later steps overwrite, so a dead SQL connection stays visible.
function showDbError(msg) {
    var el = $('#dbWarning')
    if (!el.length) el = $('<div id="dbWarning" class="db-warning"></div>').insertAfter('h1')
    el.text(msg).show()
}

async function readJsonResponse(resp, label) {
    var raw = await resp.text()
    if (!resp.ok) {
        throw new Error(label + ' returned ' + resp.status + (raw ? ': ' + raw.slice(0, 300) : ''))
    }
    try {
        return JSON.parse(raw)
    } catch (e) {
        throw new Error(label + ' returned non-JSON: ' + raw.slice(0, 300))
    }
}

function setHint(id, val, suffix) {
    var el = $('#' + id)
    if (val != null && val !== '') el.text('scanned: ' + val + (suffix || '')).show()
    else el.hide()
}

function escHtml(s) {
    return String(s)
        .replace(/&/g, '&amp;')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;')
}