const fs = require('fs');
const path = require('path');
const axios = require('axios');
const logger = require('../utils/logger');

class PdfStorage {
  constructor(baseDir) {
    this.baseDir = baseDir || path.join(process.cwd(), 'data', 'pdfs');
    this.sessionFile = path.join(this.baseDir, 'sessions.json');
    this.ensureDir();
  }

  ensureDir() {
    fs.mkdirSync(this.baseDir, { recursive: true });
  }

  async downloadPdf(url) {
    const response = await axios.get(url, { responseType: 'arraybuffer' });
    const fileName = `pdf-${Date.now()}-${Math.random().toString(36).slice(2)}.pdf`;
    const targetPath = path.join(this.baseDir, fileName);
    fs.writeFileSync(targetPath, response.data);
    return targetPath;
  }

  writeImageFile(buffer, pageIndex) {
    const fileName = `page-${pageIndex}-${Date.now()}-${Math.random().toString(36).slice(2)}.png`;
    const targetPath = path.join(this.baseDir, fileName);
    fs.writeFileSync(targetPath, buffer);
    return targetPath;
  }

  loadSessions() {
    try {
      if (!fs.existsSync(this.sessionFile)) return [];
      const raw = fs.readFileSync(this.sessionFile, 'utf8');
      return JSON.parse(raw);
    } catch (e) {
      logger.error('Erreur lors du chargement des sessions PDF persistées:', e);
      return [];
    }
  }

  saveSessions(data) {
    try {
      fs.writeFileSync(this.sessionFile, JSON.stringify(data, null, 2), 'utf8');
    } catch (e) {
      logger.error('Erreur lors de la sauvegarde des sessions PDF:', e);
    }
  }

  deleteFiles(paths) {
    paths.forEach(p => {
      if (p && fs.existsSync(p)) {
        try { fs.unlinkSync(p); } catch (e) { logger.warn('Erreur suppression fichier PDF/PNG', e); }
      }
    });
  }
}

module.exports = PdfStorage;