import 'dart:async';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../services/ble_service.dart';

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

  @override
  State<CLIScreen> createState() => _CLIScreenState();
}

class _CLIScreenState extends State<CLIScreen> {
  final ScrollController _scrollController = ScrollController();
  final List<String> _logLines = [];
  Timer? _statusTimer;
  bool _autoScroll = true;
  int _lastProcessedPacket = 0;

  @override
  void initState() {
    super.initState();
    _addHeader();
    _startStatusTimer();
  }

  @override
  void dispose() {
    _statusTimer?.cancel();
    _scrollController.dispose();
    super.dispose();
  }

  String _repeatChar(String char, int count) {
    return List.filled(count, char).join();
  }

  void _addHeader() {
    _addLogLine(_repeatChar('=', 70));
    _addLogLine('Enhanced with automatic reconnection');
    _addLogLine(_repeatChar('=', 70));
    _addLogLine('');
  }

  void _addLogLine(String line) {
    setState(() {
      _logLines.add(line);
      // Keep last 5000 lines
      if (_logLines.length > 5000) {
        _logLines.removeAt(0);
      }
    });
    
    if (_autoScroll) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (_scrollController.hasClients) {
          _scrollController.jumpTo(_scrollController.position.maxScrollExtent);
        }
      });
    }
  }

  void _startStatusTimer() {
    _statusTimer = Timer.periodic(const Duration(seconds: 1), (timer) {
      if (mounted) {
        final ble = Provider.of<BLEService>(context, listen: false);
        if (ble.isConnected) {
          _updateStatus(ble);
        }
      }
    });
  }

  void _updateStatus(BLEService ble) {
    final stats = _getStatistics(ble);
    final elapsed = stats['elapsed'] as double;
    final packets = stats['packets'] as int;
    final rate = stats['rate'] as double;
    final connStatus = ble.isConnected ? '✓' : '✗';
    
    // Remove old status line if exists (lines ending with specific pattern)
    if (_logLines.isNotEmpty && _logLines.last.startsWith('[STATUS]')) {
      _logLines.removeLast();
    }
    
    if (packets > 0) {
      _addLogLine(
        '[STATUS] Packets: ${packets.toString().padLeft(5)} | '
        'Rate: ${rate.toStringAsFixed(2).padLeft(5)} pkt/s | '
        'Time: ${elapsed.toStringAsFixed(1).padLeft(7)}s | '
        'Conn: $connStatus',
      );
    } else {
      _addLogLine('[STATUS] Waiting for data... (${elapsed.toStringAsFixed(1)}s)');
    }
  }

  Map<String, dynamic> _getStatistics(BLEService ble) {
    final now = DateTime.now();
    final startTime = ble.streamingDuration != null 
        ? now.subtract(ble.streamingDuration!)
        : now;
    final elapsed = now.difference(startTime).inMilliseconds / 1000.0;
    final packets = ble.packetCount;
    final rate = elapsed > 0 ? packets / elapsed : 0.0;
    
    return {
      'elapsed': elapsed,
      'packets': packets,
      'rate': rate,
    };
  }

  String _formatTimestamp(DateTime dt) {
    return '${dt.hour.toString().padLeft(2, '0')}:'
           '${dt.minute.toString().padLeft(2, '0')}:'
           '${dt.second.toString().padLeft(2, '0')}';
  }

  void _onDataReceived(DataPacket packet) {
    final timestamp = _formatTimestamp(packet.timestamp);
    final hexData = packet.hexString;
    final packetNum = packet.packetNumber;
    final bytes = packet.data.length;
    
    _addLogLine('');
    _addLogLine('[$timestamp] Packet #${packetNum.toString().padLeft(5, '0')}: $hexData ($bytes bytes)');
    
    // Parse data formats (matching Python example)
    if (packet.data.length >= 4) {
      try {
        final valueU32 = packet.value32BitUnsigned;
        final valueS32 = packet.value32BitSigned;
        final valueU16 = packet.value16BitUnsigned;
        final valueS16 = packet.value16BitSigned;
        
        // Commented out like in Python example
        // _addLogLine('         → 32-bit unsigned: ${valueU32.toString().padLeft(10)} | 32-bit signed: ${valueS32.toString().padLeft(10)}');
        // _addLogLine('         → 16-bit unsigned: ${valueU16.toString().padLeft(10)} | 16-bit signed: ${valueS16.toString().padLeft(10)}');
        
        if (valueU32 != null && valueU32 > 0) {
          final floatVal = valueU32 / 100.0;
          // _addLogLine('         → As float (÷100): ${floatVal.toStringAsFixed(2).padLeft(12)}');
        }
      } catch (e) {
        _addLogLine('         → Parse error: $e');
      }
    }
    
    // Show weight as 'timbang' in KG (matching Python example)
    final weightKg = packet.weightKg;
    if (weightKg != null) {
      _addLogLine('         → timbang : ${weightKg.toStringAsFixed(1)} KG');
    } else {
      // Fallback to showing raw bytes in decimal
      final byteStr = packet.data.map((b) => b.toString().padLeft(2, '0')).join(' ');
      _addLogLine('         → timbang : $byteStr');
    }
    
    // Try to decode as ASCII if printable
    final asciiStr = packet.asciiString;
    if (asciiStr != null && asciiStr.isNotEmpty) {
      _addLogLine("         → ASCII: '$asciiStr'");
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.black,
      appBar: AppBar(
        title: const Text('SIAB Bluetooth CLI', style: TextStyle(color: Colors.green)),
        backgroundColor: Colors.grey[900],
        iconTheme: const IconThemeData(color: Colors.green),
        actions: [
          Consumer<BLEService>(
            builder: (context, ble, _) {
              if (ble.isConnected) {
                return IconButton(
                  icon: const Icon(Icons.delete_outline, color: Colors.green),
                  tooltip: 'Clear Log',
                  onPressed: () {
                    setState(() {
                      _logLines.clear();
                      _addHeader();
                    });
                    ble.clearData();
                  },
                );
              }
              return const SizedBox.shrink();
            },
          ),
          IconButton(
            icon: Icon(
              _autoScroll ? Icons.vertical_align_bottom : Icons.vertical_align_center,
              color: Colors.green,
            ),
            tooltip: _autoScroll ? 'Disable Auto-scroll' : 'Enable Auto-scroll',
            onPressed: () {
              setState(() {
                _autoScroll = !_autoScroll;
              });
            },
          ),
        ],
      ),
      body: Consumer<BLEService>(
        builder: (context, ble, _) {
          // Process new data packets
          if (ble.dataPackets.isNotEmpty) {
            final newPackets = ble.dataPackets
                .where((p) => p.packetNumber > _lastProcessedPacket)
                .toList();
            
            for (final packet in newPackets) {
              _onDataReceived(packet);
              _lastProcessedPacket = packet.packetNumber;
            }
          } else {
            _lastProcessedPacket = 0;
          }

          return Column(
            children: [
              // Connection status bar (terminal style)
              Container(
                width: double.infinity,
                padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
                color: Colors.grey[900],
                child: Row(
                  children: [
                    Icon(
                      ble.isConnected ? Icons.bluetooth_connected : Icons.bluetooth_disabled,
                      color: ble.isConnected ? Colors.green : Colors.red,
                      size: 20,
                    ),
                    const SizedBox(width: 8),
                    Text(
                      ble.isConnected 
                          ? 'Connected: ${ble.deviceName ?? ble.deviceAddress ?? "Unknown"}'
                          : 'Disconnected',
                      style: const TextStyle(
                        color: Colors.green,
                        fontFamily: 'monospace',
                        fontSize: 12,
                      ),
                    ),
                    const Spacer(),
                    if (ble.isScanning || ble.isConnecting)
                      const SizedBox(
                        width: 16,
                        height: 16,
                        child: CircularProgressIndicator(
                          strokeWidth: 2,
                          valueColor: AlwaysStoppedAnimation<Color>(Colors.green),
                        ),
                      ),
                  ],
                ),
              ),
              
              // Terminal output area
              Expanded(
                child: Container(
                  color: Colors.black,
                  child: SingleChildScrollView(
                    controller: _scrollController,
                    padding: const EdgeInsets.all(16),
                    child: SelectableText(
                      _logLines.join('\n'),
                      style: const TextStyle(
                        color: Colors.green,
                        fontFamily: 'monospace',
                        fontSize: 12,
                        height: 1.4,
                      ),
                    ),
                  ),
                ),
              ),
              
              // Bottom action bar
              Container(
                width: double.infinity,
                padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
                color: Colors.grey[900],
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: [
                    if (ble.isConnecting || ble.isScanning)
                      const Text(
                        'Connecting...',
                        style: TextStyle(color: Colors.yellow, fontFamily: 'monospace'),
                      )
                    else if (ble.isConnected)
                      ElevatedButton.icon(
                        onPressed: () async {
                          _addLogLine('\n⏹ Disconnecting...');
                          await ble.disconnect();
                          ble.clearData();
                          _addLogLine('✅ Disconnected\n');
                        },
                        icon: const Icon(Icons.bluetooth_disabled, size: 18),
                        label: const Text('Disconnect'),
                        style: ElevatedButton.styleFrom(
                          backgroundColor: Colors.red[900],
                          foregroundColor: Colors.white,
                        ),
                      )
                    else
                      ElevatedButton.icon(
                        onPressed: () async {
                          _addLogLine('\n[1/3] Connecting to SIAB device...');
                          final success = await ble.autoConnect();
                          if (success) {
                            _addLogLine('✅ Connected successfully!');
                            if (ble.deviceAddress != null) {
                              _addLogLine('   Device address: ${ble.deviceAddress}');
                            }
                            _addLogLine('\n[2/3] Enabling streaming data notifications...');
                            _addLogLine('✅ Notifications enabled!');
                            _addLogLine('\n[3/3] Receiving streaming data...');
                            _addLogLine(_repeatChar('=', 70));
                            _addLogLine('Waiting for data packets...');
                            _addLogLine('');
                          } else {
                            _addLogLine('❌ Failed to connect!');
                            _addLogLine('\nTroubleshooting:');
                            _addLogLine('  • Make sure SIAB device is powered on');
                            _addLogLine('  • Check Bluetooth is enabled');
                            _addLogLine('  • Verify device name is \'SIAB\'');
                          }
                        },
                        icon: const Icon(Icons.bluetooth_searching, size: 18),
                        label: const Text('Connect'),
                        style: ElevatedButton.styleFrom(
                          backgroundColor: Colors.green[900],
                          foregroundColor: Colors.white,
                        ),
                      ),
                  ],
                ),
              ),
            ],
          );
        },
      ),
    );
  }
}