// Orchestration de la transcription PDF → markdown, à l'usage interne de kwikines
// (kwikines_ingest / kwikines_read) : rasterisation page par page puis transcription
// par le modèle de vision. Nécessite un modèle de vision chargé dans LM Studio (en
// plus du chat et de l'embedding).

import type { LMStudioClient } from "@lmstudio/sdk";
import { openPdf, parsePageRange } from "./pdfRender";
import { pickVisionModel, transcribePage } from "./vlClient";
import { concatPages } from "./pdfMarkdown";

export interface PdfTranscribeOptions {
  renderScale: number;
  maxPages: number; // 0 = unlimited
  language: string;
  style: string; // "faithful" | "clean" | "structured"
  vlModelOverride: string;
  pages?: string; // optional 1-indexed page-range spec, e.g. "1-20", "3,5,7"
}

export interface PdfTranscribeContext {
  status: (s: string) => void;
  signal: AbortSignal;
}

export interface PdfTranscribeResult {
  markdown: string;
  model: string;
  pagesProcessed: number;
  pagesFailed: number[];
  warnings: string[];
}

/** Transcribe a whole PDF to markdown by rasterising each page and driving the
 *  loaded vision-language model. Returns { error } if no VL model is available
 *  or nothing could be transcribed. */
export async function transcribePdf(
  client: LMStudioClient,
  absPath: string,
  buffer: Buffer,
  opts: PdfTranscribeOptions,
  ctx: PdfTranscribeContext,
): Promise<PdfTranscribeResult | { error: string }> {
  const warnings: string[] = [];

  ctx.status("Ouverture du PDF…");
  let doc;
  try {
    doc = await openPdf(buffer);
  } catch (e: unknown) {
    return { error: `Failed to open PDF: ${e instanceof Error ? e.message : String(e)}` };
  }
  if (doc.isEncrypted) {
    return { error: "PDF chiffré (protégé par mot de passe) — non supporté." };
  }
  if (doc.numPages === 0) {
    await doc.destroy();
    return { error: "Le PDF ne contient aucune page." };
  }

  let targetPages: number[];
  if (opts.pages && opts.pages.trim()) {
    const parsed = parsePageRange(opts.pages, doc.numPages);
    if (parsed === null) {
      warnings.push(`Plage de pages "${opts.pages}" illisible — toutes les pages prises.`);
      targetPages = range(1, doc.numPages);
    } else {
      targetPages = parsed;
    }
  } else {
    targetPages = range(1, doc.numPages);
  }
  if (opts.maxPages > 0 && targetPages.length > opts.maxPages) {
    warnings.push(`Tronqué de ${targetPages.length} à ${opts.maxPages} pages (plafond pdfMaxPages — précise un paramètre 'pages' ou augmente le plafond).`);
    targetPages = targetPages.slice(0, opts.maxPages);
  }
  const totalPages = targetPages.length;

  ctx.status("Sélection du modèle de vision…");
  const picked = await pickVisionModel(client, opts.vlModelOverride);
  if ("error" in picked) {
    await doc.destroy();
    return { error: picked.error };
  }

  const transcriptions: Array<{ pageNumber: number; markdown: string }> = [];
  const failed: number[] = [];
  let aborted = false;

  for (let i = 0; i < targetPages.length; i++) {
    if (ctx.signal.aborted) {
      aborted = true;
      warnings.push(`Interrompu à la page ${i + 1}/${totalPages}.`);
      break;
    }
    const pageNumber = targetPages[i];
    try {
      ctx.status(`Page ${i + 1}/${totalPages} (p.${pageNumber}) — rendu @ ${opts.renderScale}…`);
      const rendered = await doc.renderPage(pageNumber, opts.renderScale);
      if (ctx.signal.aborted) {
        aborted = true;
        warnings.push(`Interrompu à la page ${i + 1}/${totalPages}.`);
        break;
      }
      ctx.status(`Page ${i + 1}/${totalPages} (p.${pageNumber}) — transcription via ${picked.identifier}…`);
      const md = await transcribePage({
        client,
        model: picked.model,
        pngBase64: rendered.pngBase64,
        pageNumber,
        totalPages,
        language: opts.language,
        style: opts.style,
        abortSignal: ctx.signal,
      });
      transcriptions.push({ pageNumber, markdown: md });
    } catch (e: unknown) {
      if (ctx.signal.aborted) {
        aborted = true;
        warnings.push(`Interrompu à la page ${i + 1}/${totalPages}.`);
        break;
      }
      failed.push(pageNumber);
      warnings.push(`Page ${pageNumber} échouée : ${e instanceof Error ? e.message : String(e)}`);
    }
  }

  await doc.destroy();

  if (transcriptions.length === 0) {
    return {
      error: aborted
        ? "Interrompu avant qu'aucune page n'ait pu être transcrite."
        : failed.length > 0
          ? `Les ${failed.length} pages ont échoué. Vérifie qu'un vrai modèle de vision est chargé.`
          : "Aucune page transcrite.",
    };
  }

  const markdown = concatPages({
    pages: transcriptions,
    includeSeparators: true,
    cleanRepeatedHeaders: opts.style === "clean",
  });

  return {
    markdown,
    model: picked.identifier,
    pagesProcessed: transcriptions.length,
    pagesFailed: failed,
    warnings,
  };
}

function range(start: number, end: number): number[] {
  const out: number[] = [];
  for (let i = start; i <= end; i++) out.push(i);
  return out;
}

// Orchestration de la transcription PDF → markdown, à l'usage interne de kwikines
// (kwikines_ingest / kwikines_read) : rasterisation page par page puis transcription
// par le modèle de vision. Nécessite un modèle de vision chargé dans LM Studio (en
// plus du chat et de l'embedding).

import type { LMStudioClient } from "@lmstudio/sdk";
import { openPdf, parsePageRange } from "./pdfRender";
import { pickVisionModel, transcribePage } from "./vlClient";
import { concatPages } from "./pdfMarkdown";

export interface PdfTranscribeOptions {
  renderScale: number;
  maxPages: number; // 0 = unlimited
  language: string;
  style: string; // "faithful" | "clean" | "structured"
  vlModelOverride: string;
  pages?: string; // optional 1-indexed page-range spec, e.g. "1-20", "3,5,7"
}

export interface PdfTranscribeContext {
  status: (s: string) => void;
  signal: AbortSignal;
}

export interface PdfTranscribeResult {
  markdown: string;
  model: string;
  pagesProcessed: number;
  pagesFailed: number[];
  warnings: string[];
}

/** Transcribe a whole PDF to markdown by rasterising each page and driving the
 *  loaded vision-language model. Returns { error } if no VL model is available
 *  or nothing could be transcribed. */
export async function transcribePdf(
  client: LMStudioClient,
  absPath: string,
  buffer: Buffer,
  opts: PdfTranscribeOptions,
  ctx: PdfTranscribeContext,
): Promise<PdfTranscribeResult | { error: string }> {
  const warnings: string[] = [];

  ctx.status("Ouverture du PDF…");
  let doc;
  try {
    doc = await openPdf(buffer);
  } catch (e: unknown) {
    return { error: `Failed to open PDF: ${e instanceof Error ? e.message : String(e)}` };
  }
  if (doc.isEncrypted) {
    return { error: "PDF chiffré (protégé par mot de passe) — non supporté." };
  }
  if (doc.numPages === 0) {
    await doc.destroy();
    return { error: "Le PDF ne contient aucune page." };
  }

  let targetPages: number[];
  if (opts.pages && opts.pages.trim()) {
    const parsed = parsePageRange(opts.pages, doc.numPages);
    if (parsed === null) {
      warnings.push(`Plage de pages "${opts.pages}" illisible — toutes les pages prises.`);
      targetPages = range(1, doc.numPages);
    } else {
      targetPages = parsed;
    }
  } else {
    targetPages = range(1, doc.numPages);
  }
  if (opts.maxPages > 0 && targetPages.length > opts.maxPages) {
    warnings.push(`Tronqué de ${targetPages.length} à ${opts.maxPages} pages (plafond pdfMaxPages — précise un paramètre 'pages' ou augmente le plafond).`);
    targetPages = targetPages.slice(0, opts.maxPages);
  }
  const totalPages = targetPages.length;

  ctx.status("Sélection du modèle de vision…");
  const picked = await pickVisionModel(client, opts.vlModelOverride);
  if ("error" in picked) {
    await doc.destroy();
    return { error: picked.error };
  }

  const transcriptions: Array<{ pageNumber: number; markdown: string }> = [];
  const failed: number[] = [];
  let aborted = false;

  for (let i = 0; i < targetPages.length; i++) {
    if (ctx.signal.aborted) {
      aborted = true;
      warnings.push(`Interrompu à la page ${i + 1}/${totalPages}.`);
      break;
    }
    const pageNumber = targetPages[i];
    try {
      ctx.status(`Page ${i + 1}/${totalPages} (p.${pageNumber}) — rendu @ ${opts.renderScale}…`);
      const rendered = await doc.renderPage(pageNumber, opts.renderScale);
      if (ctx.signal.aborted) {
        aborted = true;
        warnings.push(`Interrompu à la page ${i + 1}/${totalPages}.`);
        break;
      }
      ctx.status(`Page ${i + 1}/${totalPages} (p.${pageNumber}) — transcription via ${picked.identifier}…`);
      const md = await transcribePage({
        client,
        model: picked.model,
        pngBase64: rendered.pngBase64,
        pageNumber,
        totalPages,
        language: opts.language,
        style: opts.style,
        abortSignal: ctx.signal,
      });
      transcriptions.push({ pageNumber, markdown: md });
    } catch (e: unknown) {
      if (ctx.signal.aborted) {
        aborted = true;
        warnings.push(`Interrompu à la page ${i + 1}/${totalPages}.`);
        break;
      }
      failed.push(pageNumber);
      warnings.push(`Page ${pageNumber} échouée : ${e instanceof Error ? e.message : String(e)}`);
    }
  }

  await doc.destroy();

  if (transcriptions.length === 0) {
    return {
      error: aborted
        ? "Interrompu avant qu'aucune page n'ait pu être transcrite."
        : failed.length > 0
          ? `Les ${failed.length} pages ont échoué. Vérifie qu'un vrai modèle de vision est chargé.`
          : "Aucune page transcrite.",
    };
  }

  const markdown = concatPages({
    pages: transcriptions,
    includeSeparators: true,
    cleanRepeatedHeaders: opts.style === "clean",
  });

  return {
    markdown,
    model: picked.identifier,
    pagesProcessed: transcriptions.length,
    pagesFailed: failed,
    warnings,
  };
}

function range(start: number, end: number): number[] {
  const out: number[] = [];
  for (let i = start; i <= end; i++) out.push(i);
  return out;
}