// lib/services/pdf_snapshot_service.dart

import 'dart:io';
import 'dart:ui' as ui;
import 'package:flutter/foundation.dart';
import 'package:pdf_render/pdf_render.dart';

class PdfSnapshotService {
  /// Merender halaman pertama berkas PDF menjadi berkas gambar PNG lokal.
  /// Mengembalikan path berkas PNG jika berhasil, atau null jika gagal.
  static Future<String?> renderFirstPage({
    required String pdfPath,
    required String outputPngPath,
    double scale = 2.0,
  }) async {
    try {
      final file = File(pdfPath);
      if (!file.existsSync()) {
        debugPrint('PdfSnapshotService: File tidak ditemukan di $pdfPath');
        return null;
      }

      final document = await PdfDocument.openFile(pdfPath);
      if (document.pageCount < 1) {
        await document.dispose();
        return null;
      }

      final page = await document.getPage(1);
      final renderWidth = (page.width * scale).toInt();
      final renderHeight = (page.height * scale).toInt();

      final pageImage = await page.render(
        width: renderWidth,
        height: renderHeight,
      );

      final uiImg = await pageImage.createImageDetached();
      final byteData = await uiImg.toByteData(format: ui.ImageByteFormat.png);
      pageImage.dispose();
      await document.dispose();

      if (byteData != null && byteData.lengthInBytes > 0) {
        final outputFile = File(outputPngPath);
        await outputFile.writeAsBytes(byteData.buffer.asUint8List());
        return outputFile.path;
      }
    } catch (e) {
      debugPrint('PdfSnapshotService.renderFirstPage error: $e');
    }
    return null;
  }

  /// Merender beberapa halaman PDF menjadi daftar berkas gambar PNG lokal.
  static Future<List<String>> renderPages({
    required String pdfPath,
    required String outputBasePngPath,
    double scale = 2.0,
    int maxPages = 5,
  }) async {
    final List<String> renderedPaths = [];
    try {
      final file = File(pdfPath);
      if (!file.existsSync()) return renderedPaths;

      final document = await PdfDocument.openFile(pdfPath);
      final pageCount = document.pageCount;
      final pagesToRender = pageCount < maxPages ? pageCount : maxPages;

      for (int i = 1; i <= pagesToRender; i++) {
        final page = await document.getPage(i);
        final renderWidth = (page.width * scale).toInt();
        final renderHeight = (page.height * scale).toInt();

        final pageImage = await page.render(
          width: renderWidth,
          height: renderHeight,
        );

        final uiImg = await pageImage.createImageDetached();
        final byteData = await uiImg.toByteData(format: ui.ImageByteFormat.png);
        pageImage.dispose();

        if (byteData != null && byteData.lengthInBytes > 0) {
          final targetPath = '${outputBasePngPath}_p$i.png';
          final outputFile = File(targetPath);
          await outputFile.writeAsBytes(byteData.buffer.asUint8List());
          renderedPaths.add(outputFile.path);
        }
      }

      await document.dispose();
    } catch (e) {
      debugPrint('PdfSnapshotService.renderPages error: $e');
    }
    return renderedPaths;
  }
}