// pages/login_page.dart
import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';
//import 'package:audioplayers/audioplayers.dart';
import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:http/http.dart' as http;
import 'package:just_audio/just_audio.dart';
import 'package:path_provider/path_provider.dart';
import 'package:MakerBook/pages/epub_page.dart';
import 'package:MakerBook/pages/qr_code_scanner.dart';
import 'package:MakerBook/utils/encrypt.dart';
import 'package:MakerBook/widgets/web_viewer.dart';
import 'package:MakerBook/utils/global.dart';
import '../widgets/animated_button.dart';
import 'pdf_page.dart';
import 'home_page.dart';
import 'package:crypto/crypto.dart';

class LoginPage extends StatefulWidget {
  const LoginPage({Key? key}) : super(key: key);

  @override
  _LoginPageState createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
  final TextEditingController _codeController = TextEditingController();
  bool loading = false;

  Future<void> _login() async {
    if (loading) return;

    if (_codeController.text.isNotEmpty) {
      setState(() => loading = true);

      final url = Uri.parse('$apiEndpoint/auth/loginBook');
      final response = await http.post(
        url,
        headers: {'Content-Type': 'application/json'},
        body: jsonEncode({'accesskey': _codeController.text}),
      );

      if (response.statusCode == 200) {
        final data = jsonDecode(response.body)['results'][1][0];
        if (data['success'] == 1) {
          final ext = data['ext'];
          final book_id = data['courseId'];
          final courseName = data['courseName'];
          final modifiedAt = data['modifiedAt'];

          final directory = await getApplicationDocumentsDirectory();
          final file = File('${directory.path}/$book_id$ext');

          await baixarOuAtualizarArquivo(book_id, bookPath, ext, modifiedAt);

          //final player = AudioPlayer();
          //await player.play(AssetSource('sounds/open_book.mp3'));
          final player = AudioPlayer();
          await player.setAsset('assets/sounds/open_book.mp3');
          await player.play();

          Navigator.push(
            context,
            MaterialPageRoute(
              builder: (context) => ext == ".pdf"
                  ? PdfPage(pdfBytes: file.readAsBytesSync(), courseName: courseName, book_id: book_id,)
                  : ext == ".epub"
                      ? EpubPage(epubBytes: [], book_id: book_id, courseName: courseName)
                      : ext == ".web"
                          ? WebViewer(book_id: book_id.toString())
                          : const LoginPage(),
            ),
          ).then((_) async {
            final directory = await getTemporaryDirectory();
            final tempFile = File('${directory.path}/${book_id}_temp$ext');
            if (await tempFile.exists()) {
              await tempFile.delete();
            }
          });
        } else {
          _showSnackBar('Login falhou');
        }
      } else {
        _showSnackBar('Erro na requisição');
      }
    } else {
      _showSnackBar('Por favor, insira o código de acesso');
    }

    setState(() => loading = false);
  }

  Future<void> baixarOuAtualizarArquivo(
    int bookId,
    String bookPath,
    String ext,
    String? serverModifiedAtStr,
  ) async {
    final directory = await getApplicationDocumentsDirectory();
    final file = File('${directory.path}/$bookId$ext');
    final jsonFile = File('${directory.path}/$bookId.json');

    print("[LOG] Diretorio Json: ${'${directory.path}/$bookId.json'}");

    DateTime? serverModifiedAt = DateTime.tryParse(serverModifiedAtStr ?? "");

    // Verifica se já existe o JSON com a modifiedAt local
    if (await jsonFile.exists()) {
      final jsonData = jsonDecode(await jsonFile.readAsString());
      final localModifiedAt = DateTime.tryParse(jsonData['modifiedAt'] ?? '');

      if (serverModifiedAt != null && localModifiedAt != null) {
        if (!serverModifiedAt.isAfter(localModifiedAt)) {
          print("[LOG] Arquivo já está atualizado (por modifiedAt).");
          return;
        } else {
          print("[LOG] Arquivo modificado no servidor. Baixando...");
        }
      }
    }

    // Baixa o arquivo
    final bookUrl = Uri.parse("$bookPath/course_$bookId$ext");
    final resBook = await http.get(bookUrl);

    if (resBook.statusCode != 200) {
      _showSnackBar('[LOG] Falha ao carregar o livro');
      return;
    }

    Uint8List conteudoProtegidoBytes;

    if (ext == ".epub") {
      String protegido = await protectFile(resBook.bodyBytes, null);
      conteudoProtegidoBytes = Uint8List.fromList(utf8.encode(protegido));
    } else {
      conteudoProtegidoBytes = resBook.bodyBytes;
    }

    bool arquivoMudou = true;

    // Compara com arquivo local, se existir
    if (await file.exists()) {
      final localBytes = await file.readAsBytes();
      final hashNovo = md5.convert(conteudoProtegidoBytes);
      final hashLocal = md5.convert(localBytes);

      if (hashNovo == hashLocal) {
        arquivoMudou = false;
        print("[LOG] Hashs iguais. Nada a fazer.");
      } else {
        print("[LOG] Arquivo realmente mudou. Substituindo.");
      }
    } else {
      print("[LOG] Arquivo ainda não existe. Salvando.");
    }

    if (arquivoMudou) {
      // Salva o arquivo EPUB
      await file.writeAsBytes(conteudoProtegidoBytes);  
    }
    
    // Atualiza o JSON com nova modifiedAt, mantendo o lastLocation se já existir
    Map<String, dynamic> newJson = {
      "modifiedAt": serverModifiedAtStr,
      "lastLocation": null,
    };

    if (await jsonFile.exists()) {
      final conteudo = await jsonFile.readAsString();
      print("[LOG] Conteudo Json Original: ${conteudo}");
      final oldJson = jsonDecode(conteudo);
      if (oldJson['lastLocation'] != null) {
        newJson['lastLocation'] = oldJson['lastLocation'];
      }
    }

    await jsonFile.writeAsString(jsonEncode(newJson));

    print("[LOG] Arquivo e JSON atualizados.");
  }

  void _showSnackBar(String msg) {
    ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(msg)));
  }

  Future<void> _scanQRCode() async {
    if (!loading) {
      final result = await Navigator.push(
        context,
        MaterialPageRoute(
          builder: (context) => const QRCodeScannerPage(),
        ),
      );

      if (result != null) {
        setState(() {
          _codeController.text = result;
        });
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final alturaTela = MediaQuery.of(context).size.height;

    return Scaffold(
      body: Stack(
        children: [
          // Fundo
          Container(
            decoration: const BoxDecoration(
              image: DecorationImage(
                image: AssetImage('assets/images/background.png'),
                fit: BoxFit.cover,
              ),
            ),
          ),
          SafeArea(
            child: Stack(
              children: [
                // Conteúdo com rolagem e centralização
                SingleChildScrollView(
                  padding: const EdgeInsets.symmetric(horizontal: 16),
                  child: ConstrainedBox(
                    constraints: BoxConstraints(minHeight: alturaTela * 0.9),
                    child: Center(
                      child: Column(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: [
                          const SizedBox(height: 40),
                          Image.asset('assets/images/icon.png', width: 160),
                          const SizedBox(height: 40),

                          // Campo de código
                          Container(
                            width: 300,
                            padding: const EdgeInsets.symmetric(horizontal: 20),
                            decoration: BoxDecoration(
                              border: Border.all(color: Colors.lightBlueAccent, width: 2),
                              borderRadius: BorderRadius.circular(25),
                              color: Colors.white,
                            ),
                            child: TextField(
                              enabled: !loading,
                              controller: _codeController,
                              textAlign: TextAlign.center,
                              style: GoogleFonts.fredoka(
                                fontSize: 20,
                                fontWeight: FontWeight.bold,
                              ),
                              decoration: const InputDecoration(
                                hintText: 'DIGITE O CÓDIGO DO LIVRO',
                                border: InputBorder.none,
                              ),
                            ),
                          ),

                          const SizedBox(height: 20),

                          // Botão abrir livro com mãozinha
                          Stack(
                            clipBehavior: Clip.none,
                            alignment: Alignment.center,
                            children: [
                              AnimatedButton(
                                onTap: loading ? () {} : _login,
                                child: ElevatedButton(
                                  onPressed: _login,
                                  style: ElevatedButton.styleFrom(
                                    backgroundColor: Colors.orange,
                                    shape: RoundedRectangleBorder(
                                      borderRadius: BorderRadius.circular(25),
                                    ),
                                    padding: const EdgeInsets.symmetric(horizontal: 60, vertical: 16),
                                  ),
                                  child: Text(
                                    loading ? 'ENTRANDO...' : 'ABRIR LIVRO',
                                    style: GoogleFonts.fredoka(
                                      fontSize: 18,
                                      fontWeight: FontWeight.bold,
                                      color: Colors.white,
                                    ),
                                  ),
                                ),
                              ),
                              Positioned(
                                right: -30,
                                bottom: -25,
                                child: const AnimatedHand(size: 50),
                              )
                            ],
                          ),

                          const SizedBox(height: 40),
                          Text(
                            'PREFERE USAR A CÂMERA?',
                            style: GoogleFonts.fredoka(
                              fontSize: 19,
                              fontWeight: FontWeight.bold,
                              color: Colors.white,
                            ),
                          ),
                          const SizedBox(height: 20),

                          // Botão QR
                          AnimatedButton(
                            onTap: _scanQRCode,
                            child: ElevatedButton.icon(
                              onPressed: _scanQRCode,
                              icon: const Icon(Icons.qr_code, color: Colors.black),
                              label: Text(
                                'ESCANEAR QR CODE',
                                style: GoogleFonts.fredoka(
                                  fontSize: 15,
                                  fontWeight: FontWeight.bold,
                                  color: Colors.black,
                                ),
                              ),
                              style: ElevatedButton.styleFrom(
                                backgroundColor: Colors.white,
                                shape: RoundedRectangleBorder(
                                  borderRadius: BorderRadius.circular(25),
                                  side: const BorderSide(color: Colors.lightBlueAccent, width: 2),
                                ),
                                padding: const EdgeInsets.symmetric(horizontal: 30, vertical: 14),
                              ),
                            ),
                          ),

                          const SizedBox(height: 30),
                          if (loading) const CircularProgressIndicator(),
                          const SizedBox(height: 40),
                        ],
                      ),
                    ),
                  ),
                ),
                // 👉 Botão de voltar por cima
                Positioned(
                  top: 10,
                  left: 10,
                  child: IconButton(
                    icon: const Icon(Icons.arrow_back, color: Colors.white),
                    onPressed: () {
                      Navigator.pushReplacement(
                        context,
                        MaterialPageRoute(builder: (_) => const HomePage()),
                      );
                    },
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}