import 'dart:io';
import 'dart:typed_data';
import 'dart:ui' as ui;

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:path_provider/path_provider.dart';
import 'package:intl/date_symbol_data_local.dart';

import 'package:cashumit/models/receipt_item.dart';
import 'package:cashumit/services/invoice_number_service.dart';
import 'package:cashumit/services/media_store_service.dart';
import 'package:cashumit/widgets/invoice_image_widget.dart';

class InvoiceImageService {
  /// Bangun InvoiceData dari konteks struk.
  ///
  /// Jika [invoiceNumber] diberikan, nomor tersebut dipakai ulang (tidak
  /// menambah counter). Jika null, nomor faktur baru dibuat.
  static Future<InvoiceDataBundle> prepare({
    required String storeName,
    required String storeAddress,
    required String adminName,
    required String adminPhone,
    String? logoPath,
    String? qrisPath,
    String disclaimer = '',
    String thankYouText = '',
    String pantunText = '',
    required String customerName,
    required DateTime date,
    required List<ReceiptItem> items,
    double tipAmount = 0.0,
    String? invoiceNumber,
  }) async {
    await initializeDateFormatting('id_ID', null);
    debugPrint('Invoice prepare: items=${items.length} customer=$customerName');
    Uint8List? logoBytes;
    if (logoPath != null) {
      try {
        final f = File(logoPath);
        if (await f.exists()) {
          logoBytes = await f.readAsBytes();
        }
      } catch (_) {}
    }

    Uint8List? qrisBytes;
    if (qrisPath != null) {
      try {
        final f = File(qrisPath);
        if (await f.exists()) {
          qrisBytes = await f.readAsBytes();
        }
      } catch (_) {}
    }

    // Decode lebih dulu agar gambar bisa dirender sinkron saat offscreen.
    final logoImage = await _decodeImage(logoBytes);
    final qrisImage = await _decodeImage(qrisBytes);

    final resolvedInvoiceNumber =
        invoiceNumber ?? InvoiceNumberService.nextNumber(date: date);
    final total =
        items.fold<double>(0.0, (s, i) => s + i.total) + tipAmount;

    final data = InvoiceData(
      invoiceNumber: resolvedInvoiceNumber,
      storeName: storeName,
      storeAddress: storeAddress,
      adminName: adminName,
      adminPhone: adminPhone,
      logoBytes: logoBytes,
      qrisBytes: qrisBytes,
      logoImage: logoImage,
      qrisImage: qrisImage,
      customerName: customerName,
      date: date,
      items: items,
      total: total,
      tipAmount: tipAmount,
      disclaimer: disclaimer,
      thankYouText: thankYouText,
      pantunText: pantunText,
    );

    return InvoiceDataBundle(
        data: data, invoiceNumber: resolvedInvoiceNumber);
  }

  /// Decode bytes gambar menjadi [ui.Image] (sinkron saat dirender).
  static Future<ui.Image?> _decodeImage(Uint8List? bytes) async {
    if (bytes == null || bytes.isEmpty) return null;
    try {
      final codec = await ui.instantiateImageCodec(bytes);
      final frame = await codec.getNextFrame();
      return frame.image;
    } catch (_) {
      return null;
    }
  }

  /// Render widget invoice ke PNG bytes (offscreen).
  static Future<Uint8List> renderToPng(InvoiceData data, {double pixelRatio = 2.5}) async {
    final widget = InvoiceImageWidget(data: data);
    final repaintBoundary = RenderRepaintBoundary();

    final view = WidgetsBinding.instance.platformDispatcher.views.first;
    final renderView = RenderView(
      view: view,
      child: RenderPositionedBox(
        alignment: Alignment.topCenter,
        child: repaintBoundary,
      ),
      configuration: ViewConfiguration(
        logicalConstraints: const BoxConstraints(maxWidth: 420),
        physicalConstraints: const BoxConstraints(maxWidth: 420),
        devicePixelRatio: pixelRatio,
      ),
    );

    final pipelineOwner = PipelineOwner();
    final buildOwner = BuildOwner(focusManager: FocusManager());

    pipelineOwner.rootNode = renderView;
    renderView.prepareInitialFrame();

      final rootElement = RenderObjectToWidgetAdapter<RenderBox>(
       container: repaintBoundary,
       child: Directionality(
         textDirection: TextDirection.ltr,
         child: DefaultTextStyle(
           style: const TextStyle(
             color: Colors.black87,
             fontSize: 14,
             fontFamily: 'CourierPrime, Courier, monospace',
           ),
           child: MediaQuery(
             data: const MediaQueryData(size: Size(420, 4000)),
             child: widget,
           ),
         ),
       ),
     ).attachToRenderTree(buildOwner);

    buildOwner.buildScope(rootElement);
    buildOwner.finalizeTree();

    pipelineOwner.flushLayout();
    pipelineOwner.flushCompositingBits();
    pipelineOwner.flushPaint();

    final ui.Image image = await repaintBoundary.toImage(pixelRatio: pixelRatio);
    final byteData = await image.toByteData(format: ui.ImageByteFormat.png);
    image.dispose();
    if (byteData == null) throw Exception('Gagal merender invoice');
    return byteData.buffer.asUint8List();
  }

  /// Simpan bytes invoice ke penyimpanan lokal dan (opsional) folder Download.
  static Future<InvoiceSaveResult> saveBytes({
    required Uint8List bytes,
    required String invoiceNumber,
    bool alsoSaveToDownloads = false,
  }) async {
    String? localPath;
    try {
      final dir = await getApplicationDocumentsDirectory();
      final invDir = Directory('${dir.path}/invoices');
      if (!await invDir.exists()) await invDir.create(recursive: true);
      final file = File('${invDir.path}/invoice_${invoiceNumber}.png');
      await file.writeAsBytes(bytes);
      localPath = file.path;
    } catch (_) {}

    String? downloadsUri;
    String? downloadsDisplayPath;
    if (alsoSaveToDownloads) {
      final saved = await MediaStoreService.saveToDownloads(
        bytes: bytes,
        fileName: 'invoice_$invoiceNumber.png',
      );
      if (saved != null) {
        downloadsUri = saved.uri;
        downloadsDisplayPath = saved.displayPath;
      }
    }

    return InvoiceSaveResult(
      localPath: localPath,
      downloadsUri: downloadsUri,
      downloadsDisplayPath: downloadsDisplayPath,
    );
  }

  /// Render + simpan salinan lokal, kembalikan bytes + path.
  static Future<InvoiceRenderResult> generate({
    required InvoiceData data,
  }) async {
    debugPrint('Invoice generate: items=${data.items.length}');
    final bytes = await renderToPng(data);
    final saved = await saveBytes(
        bytes: bytes, invoiceNumber: data.invoiceNumber);
    return InvoiceRenderResult(
        bytes: bytes,
        localPath: saved.localPath,
        invoiceNumber: data.invoiceNumber);
  }
}

class InvoiceDataBundle {
  final InvoiceData data;
  final String invoiceNumber;
  InvoiceDataBundle({required this.data, required this.invoiceNumber});
}

class InvoiceRenderResult {
  final Uint8List bytes;
  final String? localPath;
  final String invoiceNumber;
  InvoiceRenderResult({required this.bytes, this.localPath, required this.invoiceNumber});
}

class InvoiceSaveResult {
  final String? localPath;
  final String? downloadsUri;
  final String? downloadsDisplayPath;

  const InvoiceSaveResult({
    this.localPath,
    this.downloadsUri,
    this.downloadsDisplayPath,
  });

  bool get savedAnywhere => localPath != null || downloadsUri != null;
}