import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../services/chat_service.dart';
import '../services/reverb_socket_service.dart';
import '../services/dio_client.dart';
import '../providers/chat_unread_provider.dart';
import 'package:url_launcher/url_launcher.dart';
import 'dart:io';
import 'package:file_selector/file_selector.dart';
import 'chat_file_viewer.dart';
import '../widgets/chat_file_preview.dart';




class ChatScreen extends StatefulWidget {
  const ChatScreen({super.key});

  @override
  State<ChatScreen> createState() => _ChatScreenState();
}

class _ChatScreenState extends State<ChatScreen> {
  final TextEditingController _messageCtrl = TextEditingController();
  final ScrollController _scrollCtrl = ScrollController();
  Map<String, dynamic>? uploadingMessage;

  late ChatService _chatService;
  final ReverbSocketService _socket = ReverbSocketService();

  int? ticketId;
  List<Map<String, dynamic>> messages = [];
  bool isLoading = true;

  // ============================
  // INIT STATE
  // ============================
  @override
  void initState() {
    super.initState();

    _chatService = ChatService(DioClient.getInstance(context));

    // 🔔 Mark chat as OPEN (important)
    WidgetsBinding.instance.addPostFrameCallback((_) {
      context.read<ChatUnreadProvider>().setChatOpen(true);
    });

    _initChat();
  }
  String _guessMimeType(String path) {
    final lower = path.toLowerCase();
    if (lower.endsWith('.jpg') || lower.endsWith('.png')) return 'image/*';
    if (lower.endsWith('.mp4')) return 'video/*';
    if (lower.endsWith('.pdf')) return 'application/pdf';
    return 'application/octet-stream';
  }

  Future<void> _pickAndSendFile() async {
    final XFile? picked = await openFile();
    if (picked == null || ticketId == null) return;

    final file = File(picked.path);

    // 1️⃣ Show uploading UI
    setState(() {
      uploadingMessage = {
        'local_file': file,
        'file_type': _guessMimeType(file.path),
        'progress': 0.0,
      };
    });

    // 2️⃣ Upload (NO adding message)
    await _chatService.sendFile(
      ticketId!,
      file,
      onProgress: (progress) {
        if (!mounted) return;
        setState(() {
          uploadingMessage!['progress'] = progress;
        });
      },
    );

    // 3️⃣ Remove sending bubble ONLY
    if (!mounted) return;
    setState(() {
      uploadingMessage = null;
    });

    // 🚫 DO NOT add message here
    // WebSocket will handle it
  }




  // ============================
  // INIT CHAT
  // ============================
  Future<void> _initChat() async {
    // 1️⃣ Start chat
    final ticketRes = await _chatService.startChat();
    ticketId = ticketRes['ticket']['id'];

    // 2️⃣ Load messages
    final msgs = await _chatService.getMessages(ticketId!);
    messages = List<Map<String, dynamic>>.from(msgs);

    // 3️⃣ Realtime socket
    await _socket.connect(
      context: context,
      ticketId: ticketId!,
      onMessage: (msg) {
        final incomingClientId = msg['client_id'];

        setState(() {
          // 🧹 Remove local temp message with same client_id
          messages.removeWhere(
                (m) => m['client_id'] != null &&
                m['client_id'] == incomingClientId,
          );

          // ✅ Add confirmed socket message
          messages.add(msg);
        });

        _scrollToBottom();
      },


      onAdminMessage: () {
        if (!mounted) {
          context.read<ChatUnreadProvider>().increment();
        }
      },
    );




    if (!mounted) return;
    setState(() => isLoading = false);
    _scrollToBottom();
  }

  // ============================
  // SCROLL
  // ============================
  void _scrollToBottom() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (_scrollCtrl.hasClients) {
        _scrollCtrl.jumpTo(_scrollCtrl.position.maxScrollExtent);
      }
    });
  }

  // ============================
  // SEND MESSAGE
  // ============================
  Future<void> _sendMessage() async {
    final text = _messageCtrl.text.trim();
    if (text.isEmpty || ticketId == null) return;

    _messageCtrl.clear();

    final clientId = DateTime.now().millisecondsSinceEpoch.toString();

    // 1️⃣ ADD LOCAL MESSAGE IMMEDIATELY
    setState(() {
      messages.add({
        'client_id': clientId,
        'sender_type': 'App\\Models\\User',
        'message': text,
        'file_path': null,
        'file_type': null,
        'sending': true,
      });
    });

    _scrollToBottom();

    // 2️⃣ SEND TO SERVER
    await _chatService.sendMessage(
      ticketId!,
      message: text,
      clientId: clientId,
    );
  }


  // ============================
  // DISPOSE
  // ============================
  @override
  void dispose() {
    // 🔕 Mark chat CLOSED
    context.read<ChatUnreadProvider>().setChatOpen(false);

    _socket.disconnect();
    _messageCtrl.dispose();
    _scrollCtrl.dispose();
    super.dispose();
  }

  // ============================
  // UI
  // ============================
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text("Support Chat")),
      body: isLoading
          ? const Center(child: CircularProgressIndicator())
          : Column(
        children: [
          Expanded(child: _buildMessages()),
          _buildInput(),
        ],
      ),
    );
  }


  // Future<void> _openUrl(String url) async {
  //   final uri = Uri.parse(url);
  //
  //   if (await canLaunchUrl(uri)) {
  //     await launchUrl(
  //       uri,
  //       mode: LaunchMode.externalApplication,
  //     );
  //   } else {
  //     debugPrint("❌ Cannot launch URL: $url");
  //   }
  // }



  Widget _buildMessageContent({
    String? message,
    String? filePath,
    String? fileType,
    required bool isUser,
  }) {
    final textColor = isUser ? Colors.white : Colors.black;

    if (filePath == null) {
      return Text(message ?? '', style: TextStyle(color: textColor));
    }

    final url = "${DioClient.baseUrl}/storage/$filePath";

    return GestureDetector(
      onTap: () {
        ChatFileViewer.open(
          context,
          url: url,
          fileType: fileType ?? '',
        );
      },
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(_iconForFile(fileType), color: textColor),
          const SizedBox(width: 8),
          Text(
            _labelForFile(fileType),
            style: TextStyle(color: textColor),
          ),
        ],
      ),
    );
  }

  IconData _iconForFile(String? type) {
    if (type == null) return Icons.insert_drive_file;
    if (type.startsWith('image/')) return Icons.image;
    if (type.startsWith('video/')) return Icons.play_circle_fill;
    if (type == 'application/pdf') return Icons.picture_as_pdf;
    return Icons.insert_drive_file;
  }

  String _labelForFile(String? type) {
    if (type == null) return "File";
    if (type.startsWith('image/')) return "Image";
    if (type.startsWith('video/')) return "Video";
    if (type == 'application/pdf') return "PDF";
    return "Download file";
  }




  Widget _buildMessages() {
    return ListView(
      controller: _scrollCtrl,
      padding: const EdgeInsets.all(12),
      children: [
        // EXISTING MESSAGES
        ...messages.map((msg) {
          final isUser = msg['sender_type'] == 'App\\Models\\User';

          return Align(
            alignment: isUser ? Alignment.centerRight : Alignment.centerLeft,
            child: Container(
              margin: const EdgeInsets.symmetric(vertical: 6),
              padding: const EdgeInsets.all(10),
              decoration: BoxDecoration(
                color: isUser ? Colors.blue : Colors.grey.shade300,
                borderRadius: BorderRadius.circular(12),
              ),
              child: msg['file_path'] == null
                  ? Text(
                msg['message'] ?? '',
                style: TextStyle(
                  color: isUser ? Colors.white : Colors.black,
                ),
              )
                  : ChatFilePreview(
                filePath: msg['file_path'],
                fileType: msg['file_type'] ?? '',
                isUser: isUser,
              ),
            ),
          );
        }),

        // ⏳ UPLOADING MESSAGE
        if (uploadingMessage != null)
          Align(
            alignment: Alignment.centerRight,
            child: Container(
              margin: const EdgeInsets.symmetric(vertical: 6),
              padding: const EdgeInsets.all(10),
              decoration: BoxDecoration(
                color: Colors.blue,
                borderRadius: BorderRadius.circular(12),
              ),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  ChatFilePreview(
                    filePath: uploadingMessage!['local_file'].path,
                    fileType: uploadingMessage!['file_type'],
                    isUser: true,
                    isLocal: true,
                  ),
                  const SizedBox(height: 8),
                  LinearProgressIndicator(
                    value: uploadingMessage!['progress'],
                    backgroundColor: Colors.white24,
                    valueColor:
                    const AlwaysStoppedAnimation(Colors.white),
                  ),
                  const SizedBox(height: 4),
                  const Text(
                    "Sending…",
                    style: TextStyle(
                      color: Colors.white,
                      fontSize: 12,
                    ),
                  ),
                ],
              ),
            ),
          ),
      ],
    );
  }


  Widget _buildInput() {
    return SafeArea(
      child: Row(
        children: [
          IconButton(
            icon: const Icon(Icons.attach_file),
            onPressed: _pickAndSendFile,
          ),
          Expanded(
            child: TextField(
              controller: _messageCtrl,
              decoration: const InputDecoration(
                hintText: "Type message",
                border: InputBorder.none,
              ),
            ),
          ),
          IconButton(
            icon: const Icon(Icons.send),
            onPressed: _sendMessage,
          ),
        ],
      ),
    );
  }

}