import { useCallback, useState } from 'react'
import { useDropzone } from 'react-dropzone'
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
import { useNavigate } from 'react-router-dom'
import {
  FileSpreadsheet, CheckCircle, X, Plus,
  Info, PackagePlus, PackageCheck, Ban, FileBox, ArrowRight, Copy,
} from 'lucide-react'
import { toast } from 'sonner'
import { uploadExcel, finalizeExcelImport, getImportValidation } from '../api/uploads'
import type { ExcelPreviewResult, OutputTypeSelection, ImportValidation, ValidationIssue } from '../api/uploads'
import { listOutputTypes } from '../api/outputTypes'
import type { OutputType } from '../api/outputTypes'
import api from '../api/client'
import StepDropzone from '../components/upload/StepDropzone'

function StatCard({ icon, value, label, description, color }: {
  icon: React.ReactNode
  value: number
  label: string
  description: string
  color: string
}) {
  if (value === 0) return null
  return (
    <div className={`flex gap-3 p-3 rounded-lg border ${color}`}>
      <div className="shrink-0 mt-0.5">{icon}</div>
      <div>
        <div className="flex items-baseline gap-1.5">
          <span className="text-lg font-bold">{value}</span>
          <span className="text-sm font-medium">{label}</span>
        </div>
        <p className="text-xs opacity-75 mt-0.5">{description}</p>
      </div>
    </div>
  )
}

export default function UploadPage() {
  const navigate = useNavigate()
  const qc = useQueryClient()

  // Step 1: Excel parsed (preview only — no products created yet)
  const [previewResult, setPreviewResult] = useState<ExcelPreviewResult | null>(null)
  // Step 2: per-row include toggles
  const [includedRows, setIncludedRows] = useState<Record<number, boolean>>({})
  // Step 3: per-row selected output_type_ids
  const [rowOutputTypes, setRowOutputTypes] = useState<Record<number, Record<string, boolean>>>({})
  const [step, setStep] = useState<1 | 2 | 3 | 4>(1)
  const [notes, setNotes] = useState('')
  const [createdOrder, setCreatedOrder] = useState<{ id: string; order_number: string } | null>(null)
  const [createDraftForSkipped, setCreateDraftForSkipped] = useState(false)

  const { data: outputTypes = [] } = useQuery<OutputType[]>({
    queryKey: ['output-types'],
    queryFn: () => listOutputTypes(false),
  })

  const { data: templates } = useQuery({
    queryKey: ['templates'],
    queryFn: async () => {
      const res = await api.get('/templates')
      return res.data as Array<{ id: string; category_key: string; name: string }>
    },
  })

  const [validationId, setValidationId] = useState<string | null>(null)
  const [showValidationDialog, setShowValidationDialog] = useState(false)

  const { data: validationData } = useQuery({
    queryKey: ['validation', validationId],
    queryFn: () => getImportValidation(validationId!),
    enabled: !!validationId && showValidationDialog,
    refetchInterval: (query) => {
      const d = query.state.data as ImportValidation | undefined
      return d?.status === 'completed' || d?.status === 'failed' ? false : 2000
    },
  })

  const saveAlias = useMutation({
    mutationFn: async ({ alias, materialName }: { alias: string; materialName: string }) => {
      await api.post('/materials/seed-aliases', { mappings: [{ display_name: alias, render_name: materialName }] })
    },
    onSuccess: () => toast.success('Alias saved'),
    onError: () => toast.error('Failed to save alias'),
  })

  const uploadMut = useMutation({
    mutationFn: uploadExcel,
    onSuccess: (data) => {
      setPreviewResult(data)
      // Default: include all rows that have an identifier (pim_id or produkt_baureihe)
      // Pre-uncheck duplicate rows so only the first occurrence is included
      const inc: Record<number, boolean> = {}
      const rot: Record<number, Record<string, boolean>> = {}
      data.rows.forEach((row) => {
        const hasId = !!(row.pim_id || row.produkt_baureihe)
        inc[row.row_index] = hasId && !row.is_duplicate
        rot[row.row_index] = {}
      })
      setIncludedRows(inc)
      setRowOutputTypes(rot)
      data.warnings.forEach((w) => toast.warning(w))
      if (data.validation_id) {
        setValidationId(data.validation_id)
        setShowValidationDialog(true)
      }
      setStep(2)
    },
    onError: (e: any) => toast.error(e.response?.data?.detail || 'Upload failed'),
  })

  const finalizeMut = useMutation({
    mutationFn: async () => {
      if (!previewResult) throw new Error('No preview result')
      const templateId = templates?.find(
        (t) => t.category_key === previewResult.category_key,
      )?.id

      const included_row_indices: number[] = []
      const output_type_selections: OutputTypeSelection[] = []

      previewResult.rows.forEach((row) => {
        if (!includedRows[row.row_index]) return
        if (!row.pim_id && !row.produkt_baureihe) return

        included_row_indices.push(row.row_index)

        const selectedTypes = rowOutputTypes[row.row_index] || {}
        const typeIds = Object.entries(selectedTypes)
          .filter(([, checked]) => checked)
          .map(([id]) => id)

        if (typeIds.length > 0) {
          output_type_selections.push({
            row_index: row.row_index,
            output_type_ids: typeIds,
          })
        }
      })

      const primaryOrder = await finalizeExcelImport({
        excel_path: previewResult.excel_path,
        included_row_indices,
        output_type_selections,
        notes: notes || undefined,
        template_id: templateId,
      })

      // Optionally create a tracking-only draft for the unchecked rows
      let draftOrder = null
      if (createDraftForSkipped && excludedWithId.length > 0) {
        const skippedIndices = excludedWithId.map((r) => r.row_index)
        draftOrder = await finalizeExcelImport({
          excel_path: previewResult.excel_path,
          included_row_indices: skippedIndices,
          output_type_selections: [],
          notes: 'Draft — awaiting STEP files',
          template_id: templateId,
        })
      }

      return { primaryOrder, draftOrder }
    },
    onSuccess: ({ primaryOrder, draftOrder }) => {
      qc.invalidateQueries({ queryKey: ['orders'] })
      setCreatedOrder({ id: primaryOrder.id, order_number: primaryOrder.order_number })
      if (draftOrder) {
        const n = draftOrder.items?.length ?? 0
        toast.success(
          `Draft ${draftOrder.order_number} created with ${n} product${n !== 1 ? 's' : ''} awaiting STEP files`,
        )
      }
      setStep(4)
    },
    onError: (e: any) => toast.error(e.response?.data?.detail || 'Failed to create order'),
  })

  const onDrop = useCallback(
    (files: File[]) => { if (files[0]) uploadMut.mutate(files[0]) },
    [uploadMut],
  )
  const { getRootProps, getInputProps, isDragActive } = useDropzone({
    onDrop,
    accept: {
      'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet': ['.xlsx'],
      'application/vnd.ms-excel': ['.xls'],
    },
    multiple: false,
  })

  // Rows that are included and have an identifier
  const includedWithId = previewResult?.rows.filter(
    (r) => includedRows[r.row_index] && (r.pim_id || r.produkt_baureihe),
  ) ?? []

  // Rows that are excluded (have an identifier but not included in the primary order)
  const excludedWithId = previewResult?.rows.filter(
    (r) => !includedRows[r.row_index] && (r.pim_id || r.produkt_baureihe),
  ) ?? []

  // Count how many rows actually have an output type selected
  const rowsWithOutputType = includedWithId.filter((row) => {
    const sel = rowOutputTypes[row.row_index] || {}
    return Object.values(sel).some(Boolean)
  }).length

  function toggleAllOutputType(typeId: string, checked: boolean) {
    setRowOutputTypes((prev) => {
      const updated = { ...prev }
      includedWithId.forEach((row) => {
        updated[row.row_index] = { ...(updated[row.row_index] || {}), [typeId]: checked }
      })
      return updated
    })
  }

  function deselectWithoutStep() {
    if (!previewResult) return
    setIncludedRows((prev) => {
      const updated = { ...prev }
      previewResult.rows.forEach((row) => {
        if (!row.has_step && (row.pim_id || row.produkt_baureihe)) {
          updated[row.row_index] = false
        }
      })
      return updated
    })
  }


  return (
    <div className="p-8 max-w-full mx-auto">
      <div className="mb-6">
        <h1 className="text-2xl font-bold text-content">Upload Order List</h1>
        <p className="text-sm text-content-muted mt-1">
          Import products from Excel and create a new output job order.
        </p>
      </div>

      {/* ── Step 1: Excel drop zone ─────────────────────────────────────── */}
      {step === 1 && (
        <div
          {...getRootProps()}
          className={`card p-16 text-center cursor-pointer border-2 border-dashed transition-colors ${
            isDragActive
              ? 'border-accent bg-accent-light'
              : 'border-border-default hover:border-accent'
          }`}
        >
          <input {...getInputProps()} />
          {uploadMut.isPending ? (
            <div className="text-content-secondary">
              <div className="animate-spin w-8 h-8 border-2 border-accent border-t-transparent rounded-full mx-auto mb-3" />
              Parsing Excel file\u2026
            </div>
          ) : (
            <>
              <FileSpreadsheet size={44} className="text-content-muted mx-auto mb-3" />
              <p className="text-content-secondary font-medium text-lg">
                {isDragActive ? 'Drop the Excel file here' : 'Drag & drop an Excel order list'}
              </p>
              <p className="text-content-muted text-sm mt-1">or click to browse \u2014 .xlsx / .xls</p>
            </>
          )}
        </div>
      )}

      {/* ── Step 2: Product Matching Report ─────────────────────────────── */}
      {step === 2 && previewResult && (
        <div className="space-y-4">
          {/* File info header */}
          <div className="card p-4">
            <div className="flex items-center gap-3">
              <CheckCircle size={20} className="text-green-500 shrink-0" />
              <div className="flex-1 min-w-0">
                <p className="font-semibold text-content truncate">{previewResult.filename}</p>
                <p className="text-sm text-content-secondary">
                  {previewResult.row_count} rows parsed
                  {previewResult.category_key && <> &middot; Primary category: <strong>{previewResult.category_key}</strong></>}
                </p>
              </div>
              <button
                className="btn-secondary text-xs"
                onClick={() => { setPreviewResult(null); setStep(1) }}
                title="Discard this preview and upload a different Excel file"
              >
                <X size={13} /> Replace
              </button>
            </div>
          </div>

          {/* Import summary — explained stats */}
          <div className="card p-4">
            <div className="flex items-center gap-2 mb-3">
              <Info size={15} className="text-content-muted" />
              <h3 className="text-sm font-semibold text-content-secondary">Preview Summary</h3>
            </div>

            <p className="text-xs text-content-secondary mb-3 leading-relaxed">
              No products have been created yet. This is a <strong>preview</strong> of what will happen when you finalize the order.
              Each unique <strong>Product (Series)</strong> in the Excel becomes one product in the library.
            </p>

            <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-3">
              <StatCard
                icon={<PackagePlus size={18} className="text-blue-600" />}
                value={previewResult.new_product_count}
                label="new products"
                description="Will be created when you finalize the order."
                color="bg-status-info-bg border-border-default text-status-info-text"
              />
              <StatCard
                icon={<PackageCheck size={18} className="text-green-600" />}
                value={previewResult.existing_product_count}
                label="existing products"
                description="Already in the library from a previous import."
                color="bg-status-success-bg border-border-default text-status-success-text"
              />
              <StatCard
                icon={<Ban size={18} className="text-amber-600" />}
                value={previewResult.no_pim_id_count}
                label="rows skipped"
                description="No PIM-ID or Product Series found. Cannot be matched to a product."
                color="bg-status-warning-bg border-border-default text-status-warning-text"
              />
              <StatCard
                icon={<Copy size={18} className="text-orange-600" />}
                value={previewResult.duplicate_count}
                label="duplicate Series"
                description="Same Product Series appears multiple times. Pre-unchecked — only first occurrence imported."
                color="bg-status-warning-bg border-border-default text-status-warning-text"
              />
            </div>
          </div>

          {/* Duplicate warning banner */}
          {previewResult.duplicate_count > 0 && (
            <div className="rounded-lg border border-border-default bg-status-warning-bg px-4 py-3">
              <div className="flex items-start gap-2">
                <span className="text-status-warning-text font-bold text-sm shrink-0">⚠</span>
                <div>
                  <p className="text-sm font-semibold text-status-warning-text">
                    {previewResult.duplicate_count} duplicate Product Series row{previewResult.duplicate_count !== 1 ? 's' : ''} detected
                  </p>
                  <p className="text-xs text-status-warning-text mt-0.5">
                    Each product is unique — only the <strong>first occurrence</strong> of a Product Series will be imported.
                    Duplicate rows are pre-unchecked (shown in amber). You can manually re-check them to overwrite the first.
                  </p>
                </div>
              </div>
            </div>
          )}

          {/* Row table */}
          <div className="card overflow-auto">
            <div className="px-4 py-3 border-b border-border-light bg-surface-alt">
              <h3 className="text-sm font-semibold text-content-secondary">Row Details</h3>
              <p className="text-xs text-content-secondary mt-0.5">
                Uncheck rows you don't want to include in the order.
              </p>
            </div>
            <table className="w-full text-sm">
              <thead>
                <tr className="border-b border-border-light text-left">
                  <th className="px-4 py-2 font-medium text-content-secondary w-10">
                    <input
                      type="checkbox"
                      checked={previewResult.rows.every((r) => (!r.pim_id && !r.produkt_baureihe) || includedRows[r.row_index])}
                      onChange={(e) => {
                        const updated: Record<number, boolean> = {}
                        previewResult.rows.forEach((r) => {
                          updated[r.row_index] = (r.pim_id || r.produkt_baureihe) ? e.target.checked : false
                        })
                        setIncludedRows(updated)
                      }}
                      title="Select / deselect all rows"
                    />
                  </th>
                  <th className="px-4 py-2 font-medium text-content-secondary">PIM-ID</th>
                  <th className="px-4 py-2 font-medium text-content-secondary">Series</th>
                  <th className="px-4 py-2 font-medium text-content-secondary"
                    title="Gew\u00e4hltes Produkt \u2014 the specific material/coating variant from the Excel"
                  >Gew. Produkt</th>
                  <th className="px-4 py-2 font-medium text-content-secondary">Category</th>
                  <th className="px-4 py-2 font-medium text-content-secondary">Status</th>
                  <th className="px-4 py-2 font-medium text-content-secondary text-center" title="Whether a STEP/CAD file is already linked to this product">STEP</th>
                </tr>
              </thead>
              <tbody>
                {previewResult.rows.map((row) => {
                  const hasId = !!(row.pim_id || row.produkt_baureihe)
                  return (
                    <tr key={row.row_index} className={`border-b ${row.is_duplicate ? 'bg-status-warning-bg border-border-default hover:bg-status-warning-bg' : 'border-border-light hover:bg-surface-hover'}`}>
                      <td className="px-4 py-2">
                        <input
                          type="checkbox"
                          disabled={!hasId}
                          checked={!!includedRows[row.row_index]}
                          onChange={(e) =>
                            setIncludedRows({ ...includedRows, [row.row_index]: e.target.checked })
                          }
                        />
                      </td>
                      <td className="px-4 py-2 font-mono text-xs">
                        {row.pim_id || <span className="text-content-muted">&mdash;</span>}
                      </td>
                      <td className="px-4 py-2 text-xs">
                        {row.produkt_baureihe || <span className="text-content-muted">&mdash;</span>}
                      </td>
                      <td className="px-4 py-2 text-sm">
                        {row.gewaehltes_produkt || '\u2014'}
                      </td>
                      <td className="px-4 py-2">
                        {row.category_key ? (
                          <span className="text-xs px-2 py-0.5 rounded-full bg-accent-light text-accent font-medium">
                            {row.category_key}
                          </span>
                        ) : (
                          <span className="text-content-muted">&mdash;</span>
                        )}
                      </td>
                      <td className="px-4 py-2">
                        {!hasId ? (
                          <span
                            className="text-xs px-2 py-0.5 rounded-full bg-surface-muted text-content-muted"
                            title="No PIM-ID or Product Series — this row will be skipped"
                          >
                            skipped
                          </span>
                        ) : row.is_duplicate ? (
                          <span
                            className="text-xs px-2 py-0.5 rounded-full bg-status-warning-bg text-status-warning-text font-medium"
                            title={`Duplicate Product Series — first occurrence is row ${row.duplicate_of_row}. Uncheck to exclude.`}
                          >
                            Duplicate of row {row.duplicate_of_row}
                          </span>
                        ) : row.product_exists ? (
                          <span
                            className="text-xs px-2 py-0.5 rounded-full bg-status-success-bg text-status-success-text font-medium"
                            title="This product already exists in the library"
                          >
                            existing
                          </span>
                        ) : (
                          <span
                            className="text-xs px-2 py-0.5 rounded-full bg-status-info-bg text-status-info-text font-medium"
                            title="This product will be created when you finalize"
                          >
                            new (will be created)
                          </span>
                        )}
                      </td>
                      <td className="px-4 py-2 text-center">
                        {!hasId ? null : row.has_step ? (
                          <CheckCircle size={14} className="text-green-500 mx-auto" aria-label="STEP file linked" />
                        ) : (
                          <X size={14} className="text-red-400 mx-auto" aria-label="No STEP file" />
                        )}
                      </td>
                    </tr>
                  )
                })}
              </tbody>
            </table>
          </div>

          <div className="flex justify-end">
            <button
              className="btn-primary"
              disabled={includedWithId.length === 0}
              onClick={() => setStep(3)}
            >
              Next: Select Output Types &rarr;
            </button>
          </div>
        </div>
      )}

      {/* ── Step 4: Upload STEP Files ────────────────────────────────────── */}
      {step === 4 && createdOrder && (
        <div className="space-y-4">
          <div className="card p-4">
            <div className="flex items-center justify-between mb-1">
              <div className="flex items-center gap-2">
                <FileBox size={18} className="text-content-secondary" />
                <h2 className="font-semibold text-content">
                  Upload STEP Files — {createdOrder.order_number}
                </h2>
              </div>
            </div>
            <p className="text-sm text-content-secondary">
              Drop one or more <strong>.stp / .step</strong> files below.
              Each file is matched to an order item by filename stem (case-insensitive).
              You can also skip this and upload STEP files later from the order detail page.
            </p>
          </div>

          <div className="card p-6">
            <StepDropzone
              orderId={createdOrder.id}
              onMatchComplete={() => qc.invalidateQueries({ queryKey: ['order', createdOrder.id] })}
            />
          </div>

          <div className="flex justify-end gap-3">
            <button
              className="btn-secondary"
              onClick={() => navigate(`/orders/${createdOrder.id}`)}
            >
              Skip &mdash; Go to Order
            </button>
            <button
              className="btn-primary"
              onClick={() => navigate(`/orders/${createdOrder.id}`)}
            >
              <ArrowRight size={16} />
              Done &mdash; Go to Order
            </button>
          </div>
        </div>
      )}

      {/* ── Validation Dialog ────────────────────────────────────────────── */}
      {showValidationDialog && (
        <ValidationDialog
          validation={validationData}
          onClose={() => setShowValidationDialog(false)}
          onSaveAlias={(alias, suggestion) => saveAlias.mutate({ alias, materialName: suggestion })}
        />
      )}

      {/* ── Step 3: Output Type Selection ───────────────────────────────── */}
      {step === 3 && previewResult && (
        <div className="space-y-4">
          <div className="card p-4">
            <div className="flex items-center justify-between mb-1">
              <h2 className="font-semibold text-content">Select Output Types</h2>
              <button className="text-sm text-content-muted hover:text-content-secondary" onClick={() => setStep(2)}>
                &larr; Back
              </button>
            </div>
            <p className="text-sm text-content-secondary">
              Choose which output types to request for each included product.
              Leave unchecked to create a tracking-only line.
            </p>
          </div>

          {outputTypes.length > 0 && (
            <div className="card p-4">
              <p className="text-xs font-medium text-content-secondary mb-2">Select/deselect all rows:</p>
              <div className="flex items-center gap-3 flex-wrap">
                {outputTypes.map((ot) => (
                  <div key={ot.id} className="flex items-center gap-1.5">
                    <input
                      type="checkbox"
                      id={`all-ot-${ot.id}`}
                      onChange={(e) => toggleAllOutputType(ot.id, e.target.checked)}
                    />
                    <label htmlFor={`all-ot-${ot.id}`} className="text-sm cursor-pointer">
                      {ot.name}
                    </label>
                  </div>
                ))}
                {includedWithId.some((r) => !r.has_step) && (
                  <button
                    type="button"
                    className="ml-auto flex items-center gap-1.5 text-xs px-3 py-1.5 rounded-md border border-red-200 text-red-700 bg-red-50 hover:bg-red-100"
                    onClick={deselectWithoutStep}
                    title="Uncheck all rows that have no STEP file linked"
                  >
                    <X size={12} />
                    Deselect without STEP
                  </button>
                )}
              </div>
            </div>
          )}

          <div className="card overflow-auto">
            <table className="w-full text-sm">
              <thead>
                <tr className="border-b border-border-light text-left">
                  <th className="px-4 py-2 font-medium text-content-secondary">PIM-ID</th>
                  <th className="px-4 py-2 font-medium text-content-secondary">Product Name</th>
                  <th className="px-4 py-2 font-medium text-content-secondary text-center" title="STEP file linked">STEP</th>
                  {outputTypes.map((ot) => (
                    <th key={ot.id} className="px-4 py-2 font-medium text-content-secondary text-center">
                      {ot.name}
                    </th>
                  ))}
                </tr>
              </thead>
              <tbody>
                {includedWithId.map((row) => (
                  <tr key={row.row_index} className="border-b border-border-light hover:bg-surface-hover">
                    <td className="px-4 py-2 font-mono text-xs">{row.pim_id || '\u2014'}</td>
                    <td className="px-4 py-2">{row.gewaehltes_produkt || row.produkt_baureihe || '\u2014'}</td>
                    <td className="px-4 py-2 text-center">
                      {row.has_step ? (
                        <CheckCircle size={14} className="text-green-500 mx-auto" aria-label="STEP file linked" />
                      ) : (
                        <X size={14} className="text-red-400 mx-auto" aria-label="No STEP file" />
                      )}
                    </td>
                    {outputTypes.map((ot) => (
                      <td key={ot.id} className="px-4 py-2 text-center">
                        <input
                          type="checkbox"
                          checked={!!(rowOutputTypes[row.row_index]?.[ot.id])}
                          onChange={(e) =>
                            setRowOutputTypes((prev) => ({
                              ...prev,
                              [row.row_index]: {
                                ...(prev[row.row_index] || {}),
                                [ot.id]: e.target.checked,
                              },
                            }))
                          }
                        />
                      </td>
                    ))}
                  </tr>
                ))}
              </tbody>
            </table>
          </div>

          {rowsWithOutputType === 0 && includedWithId.length > 0 && (
            <div className="rounded-lg border border-border-default bg-status-warning-bg px-4 py-3 text-sm text-status-warning-text">
              <strong>No output types selected.</strong> This order will be created with tracking-only lines —
              no rendering will be dispatched until output types are added to the order. You can add
              output types later from the order detail page.
            </div>
          )}

          {excludedWithId.length > 0 && (
            <div className="rounded-lg border border-border-default bg-status-info-bg px-4 py-3">
              <label className="flex items-start gap-3 cursor-pointer">
                <input
                  type="checkbox"
                  className="mt-0.5 shrink-0"
                  checked={createDraftForSkipped}
                  onChange={(e) => setCreateDraftForSkipped(e.target.checked)}
                />
                <div>
                  <span className="text-sm font-medium text-status-info-text">
                    Also create a draft for the {excludedWithId.length} skipped product{excludedWithId.length !== 1 ? 's' : ''}
                  </span>
                  <p className="text-xs text-status-info-text mt-0.5">
                    A separate tracking-only draft order will be created for unchecked rows.
                    Upload STEP files there once available, then assign output types.
                  </p>
                </div>
              </label>
            </div>
          )}

          <div className="flex items-end gap-4">
            <div className="flex-1">
              <label className="block text-sm font-medium text-content-secondary mb-1">
                Order Notes <span className="text-content-muted font-normal">(optional)</span>
              </label>
              <textarea
                value={notes}
                onChange={(e) => setNotes(e.target.value)}
                rows={2}
                className="w-full px-3 py-2 border border-border-default rounded-md text-sm focus:outline-none focus:ring-2 focus:ring-accent"
                placeholder="Add any notes for this order\u2026"
              />
            </div>
            <button
              className="btn-primary shrink-0"
              onClick={() => finalizeMut.mutate()}
              disabled={finalizeMut.isPending || includedWithId.length === 0}
            >
              <Plus size={16} />
              {finalizeMut.isPending
                ? 'Creating\u2026'
                : createDraftForSkipped && excludedWithId.length > 0
                  ? `Create 2 Orders (${includedWithId.length} + ${excludedWithId.length} products)`
                  : `Create Order (${includedWithId.length} products)`}
            </button>
          </div>
        </div>
      )}
    </div>
  )
}

// ── ValidationDialog ──────────────────────────────────────────────────────

function ValidationDialog({
  validation,
  onClose,
  onSaveAlias,
}: {
  validation: ImportValidation | undefined
  onClose: () => void
  onSaveAlias: (alias: string, suggestion: string) => void
}) {
  const [expandedRows, setExpandedRows] = useState<Set<number>>(new Set())
  const summary = validation?.summary

  const isLoading =
    !validation || validation.status === 'pending' || validation.status === 'running'

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50">
      <div
        className="rounded-xl shadow-2xl w-full max-w-2xl max-h-[80vh] flex flex-col border"
        style={{ backgroundColor: 'var(--color-bg-surface)', borderColor: 'var(--color-border-default)' }}
      >
        {/* Header */}
        <div
          className="px-6 py-4 border-b flex items-center justify-between"
          style={{ borderColor: 'var(--color-border-default)' }}
        >
          <h2 className="text-lg font-semibold text-content">Import Validation</h2>
          <button
            onClick={onClose}
            className="text-content-muted hover:text-content text-xl leading-none"
          >
            ×
          </button>
        </div>

        <div className="flex-1 overflow-y-auto px-6 py-4 space-y-4">
          {isLoading ? (
            <div className="flex items-center gap-3 text-content-muted">
              <div className="w-5 h-5 border-2 border-accent border-t-transparent rounded-full animate-spin" />
              <span>Validating import...</span>
            </div>
          ) : (
            <>
              {/* Traffic light summary */}
              {summary && (
                <div className="flex gap-4">
                  <div className="flex items-center gap-2 px-4 py-2 bg-green-50 rounded-lg">
                    <div className="w-3 h-3 rounded-full bg-green-500" />
                    <span className="text-sm font-medium text-green-700">{summary.ok} OK</span>
                  </div>
                  <div className="flex items-center gap-2 px-4 py-2 bg-yellow-50 rounded-lg">
                    <div className="w-3 h-3 rounded-full bg-yellow-500" />
                    <span className="text-sm font-medium text-yellow-700">
                      {summary.warnings} Warnings
                    </span>
                  </div>
                  <div className="flex items-center gap-2 px-4 py-2 bg-red-50 rounded-lg">
                    <div className="w-3 h-3 rounded-full bg-red-500" />
                    <span className="text-sm font-medium text-red-700">
                      {summary.errors} Errors
                    </span>
                  </div>
                </div>
              )}

              {/* Rows with issues */}
              {validation.rows &&
                validation.rows
                  .filter((r) => r.issues.length > 0)
                  .map((row) => (
                    <div
                      key={row.row_index}
                      className="rounded-lg overflow-hidden border"
                      style={{ borderColor: 'var(--color-border-default)' }}
                    >
                      <button
                        className={`w-full flex items-center justify-between px-4 py-3 text-left transition-colors ${
                          row.status === 'error'
                            ? 'bg-red-50'
                            : row.status === 'warning'
                              ? 'bg-yellow-50'
                              : ''
                        }`}
                        style={row.status !== 'error' && row.status !== 'warning'
                          ? { backgroundColor: 'var(--color-bg-surface-alt)' }
                          : undefined}
                        onClick={() =>
                          setExpandedRows((prev) => {
                            const next = new Set(prev)
                            next.has(row.row_index)
                              ? next.delete(row.row_index)
                              : next.add(row.row_index)
                            return next
                          })
                        }
                      >
                        <div className="flex items-center gap-3">
                          <div
                            className={`w-2.5 h-2.5 rounded-full ${
                              row.status === 'error'
                                ? 'bg-red-500'
                                : row.status === 'warning'
                                  ? 'bg-yellow-500'
                                  : 'bg-green-500'
                            }`}
                          />
                          <span className="text-sm font-medium text-content">
                            Row {row.row_index + 1}
                            {row.pim_id ? ` — ${row.pim_id}` : ''}
                            {row.produkt_baureihe ? ` (${row.produkt_baureihe})` : ''}
                          </span>
                          <span className="text-xs text-content-muted">
                            {row.issues.length} issue{row.issues.length !== 1 ? 's' : ''}
                          </span>
                        </div>
                        <span className="text-content-muted text-xs">
                          {expandedRows.has(row.row_index) ? '▲' : '▼'}
                        </span>
                      </button>
                      {expandedRows.has(row.row_index) && (
                        <div
                          className="border-t divide-y"
                          style={{ borderColor: 'var(--color-border-default)' }}
                        >
                          {row.issues.map((issue: ValidationIssue, i: number) => (
                            <div
                              key={i}
                              className="px-4 py-3 flex items-start justify-between gap-4"
                              style={{ borderColor: 'var(--color-border-default)' }}
                            >
                              <div>
                                <p className="text-sm text-content">{issue.message}</p>
                                {issue.suggestion && (
                                  <p className="text-xs text-content-muted mt-0.5">
                                    Suggestion: <em>{issue.suggestion}</em>
                                  </p>
                                )}
                              </div>
                              {issue.type === 'material_suggestion' &&
                                issue.value &&
                                issue.suggestion && (
                                  <button
                                    onClick={() =>
                                      onSaveAlias(issue.value!, issue.suggestion!)
                                    }
                                    className="text-xs bg-accent text-white px-3 py-1 rounded whitespace-nowrap"
                                  >
                                    Save as alias
                                  </button>
                                )}
                            </div>
                          ))}
                        </div>
                      )}
                    </div>
                  ))}

              {validation.rows &&
                validation.rows.filter((r) => r.issues.length > 0).length === 0 && (
                  <p className="text-sm text-green-600 font-medium">
                    All rows validated successfully.
                  </p>
                )}
            </>
          )}
        </div>

        <div
          className="px-6 py-4 border-t flex justify-end"
          style={{ borderColor: 'var(--color-border-default)' }}
        >
          <button
            onClick={onClose}
            className="px-4 py-2 text-sm text-content-secondary rounded-lg border border-border-default hover:bg-surface-hover transition-colors"
          >
            Close
          </button>
        </div>
      </div>
    </div>
  )
}