4NK_IA_front/src/services/fileExtract.ts

// Chargements dynamiques locaux (pdfjs-dist/tesseract.js)
let _pdfjsLib: any | null = null
async function getPdfJs() {
  if (_pdfjsLib) return _pdfjsLib
  const pdfjsLib: any = await import('pdfjs-dist')
  try {
    // Utilise un worker module réel pour éviter le fake worker
    const workerUrl = new URL('pdfjs-dist/build/pdf.worker.min.mjs', import.meta.url)
    // @ts-expect-error - API v4
    pdfjsLib.GlobalWorkerOptions.workerPort = new Worker(workerUrl, { type: 'module' })
  } catch {
    // ignore si worker introuvable
  }
  _pdfjsLib = pdfjsLib
  return _pdfjsLib
}

export async function extractTextFromFile(file: File): Promise<string> {
  const mime = file.type || ''
  if (mime.includes('pdf') || file.name.toLowerCase().endsWith('.pdf')) {
    return extractFromPdf(file)
  }
  if (mime.startsWith('image/') || ['.png', '.jpg', '.jpeg'].some((ext) => file.name.toLowerCase().endsWith(ext))) {
    return extractFromImage(file)
  }
  // Fallback: lecture texte brut
  try {
    return await file.text()
  } catch {
    return ''
  }
}

async function extractFromPdf(file: File): Promise<string> {
  const pdfjsLib = await getPdfJs().catch(() => null)
  if (!pdfjsLib) return ''
  const arrayBuffer = await file.arrayBuffer()
  const pdf = await pdfjsLib.getDocument({ data: new Uint8Array(arrayBuffer) }).promise
  const texts: string[] = []
  const numPages = Math.min(pdf.numPages, 50)
  for (let i = 1; i <= numPages; i += 1) {
    const page = await pdf.getPage(i)
    const content = await page.getTextContent()
    const pageText = content.items.map((it: any) => (it.str ? it.str : '')).join(' ')
    if (pageText.trim()) texts.push(pageText)
  }
  return texts.join('\n')
}

async function extractFromImage(file: File): Promise<string> {
  const { createWorker } = await import('tesseract.js')

  // Pré-redimensionne l'image si trop petite (largeur minimale 300px)
  const imgBitmap = await createImageBitmap(file)
  let source: Blob = file
  // Normalisation pour CNI: contraste, gris, upscaling plus agressif
  const minWidth = /recto|verso|cni|carte/i.test(file.name) ? 1200 : 300
  if (imgBitmap.width < minWidth) {
    const scale = minWidth / Math.max(1, imgBitmap.width)
    const canvas = document.createElement('canvas')
    canvas.width = Math.max(300, Math.floor(imgBitmap.width * scale))
    canvas.height = Math.floor(imgBitmap.height * scale)
    const ctx = canvas.getContext('2d')!
    ctx.imageSmoothingEnabled = true
    ctx.imageSmoothingQuality = 'high'
    ctx.drawImage(imgBitmap, 0, 0, canvas.width, canvas.height)
    // Conversion en niveaux de gris + amélioration du contraste
    const imgData = ctx.getImageData(0, 0, canvas.width, canvas.height)
    const data = imgData.data
    for (let i = 0; i < data.length; i += 4) {
      const r = data[i], g = data[i + 1], b = data[i + 2]
      // luma
      let y = 0.299 * r + 0.587 * g + 0.114 * b
      // contraste simple
      y = Math.max(0, Math.min(255, (y - 128) * 1.2 + 128))
      data[i] = data[i + 1] = data[i + 2] = y
    }
    ctx.putImageData(imgData, 0, 0)
    source = await new Promise<Blob>((resolve) => canvas.toBlob((b) => resolve(b || file))!)
  }

  const worker = await createWorker()
  try {
    // Configure le logger après création pour éviter DataCloneError
    // eslint-disable-next-line no-console
    worker.setLogger?.((m: any) => {
      if (m?.progress != null) console.info('[OCR]', Math.round(m.progress * 100) + '%')
    })
    await worker.load()
    await worker.loadLanguage('fra+eng')
    await worker.initialize('fra+eng')
    // Essaie plusieurs PSM et orientations (0/90/180/270) et garde le meilleur résultat
    const rotations = [0, 90, 180, 270]
    const psmModes = ['6', '7', '11'] // 6: block, 7: single line, 11: sparse text
    let bestText = ''
    let bestScore = -1

    for (const psm of psmModes) {
      await worker.setParameters({ tessedit_pageseg_mode: psm })
      for (const deg of rotations) {
        const rotatedBlob = await rotateBlob(source, deg)
        const { data } = await worker.recognize(rotatedBlob)
        const text = data.text || ''
        const len = text.replace(/\s+/g, ' ').trim().length
        const score = (data.confidence || 0) * Math.log(len + 1)
        if (score > bestScore) {
          bestScore = score
          bestText = text
        }
        // Court-circuit si très bon
        if (data.confidence >= 85 && len > 40) break
      }
    }

    return bestText
  } finally {
    await worker.terminate()
  }
}

async function rotateBlob(blob: Blob, deg: number): Promise<Blob> {
  if (deg % 360 === 0) return blob
  const bmp = await createImageBitmap(blob)
  const rad = (deg * Math.PI) / 180
  const sin = Math.abs(Math.sin(rad))
  const cos = Math.abs(Math.cos(rad))
  const w = bmp.width
  const h = bmp.height
  const newW = Math.floor(w * cos + h * sin)
  const newH = Math.floor(w * sin + h * cos)
  const canvas = document.createElement('canvas')
  canvas.width = newW
  canvas.height = newH
  const ctx = canvas.getContext('2d')!
  ctx.imageSmoothingEnabled = true
  ctx.imageSmoothingQuality = 'high'
  ctx.translate(newW / 2, newH / 2)
  ctx.rotate(rad)
  ctx.drawImage(bmp, -w / 2, -h / 2)
  return await new Promise<Blob>((resolve) => canvas.toBlob((b) => resolve(b || blob))!)
}