import 'package:flutter/material.dart';
import 'package:rimworld_modman/modloader.dart';
import 'dart:io';

// Global variable to store loaded mods for access across the app
late ModList modManager;

void main() {
  // Initialize the mod manager
  modManager = ModList(path: modsRoot);
  
  // Start the app
  runApp(const RimWorldModManager());
}

class RimWorldModManager extends StatelessWidget {
  const RimWorldModManager({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Rimworld Mod Manager',
      theme: ThemeData.dark().copyWith(
        primaryColor: const Color(0xFF3D4A59),
        colorScheme: ColorScheme.fromSeed(
          seedColor: const Color(0xFF3D4A59),
          brightness: Brightness.dark,
        ),
        scaffoldBackgroundColor: const Color(0xFF1E262F),
        cardColor: const Color(0xFF2A3440),
        appBarTheme: const AppBarTheme(
          backgroundColor: Color(0xFF2A3440),
          foregroundColor: Colors.white,
        ),
      ),
      home: const ModManagerHomePage(),
    );
  }
}

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

  @override
  State<ModManagerHomePage> createState() => _ModManagerHomePageState();
}

class _ModManagerHomePageState extends State<ModManagerHomePage> {
  int _selectedIndex = 0;

  final List<Widget> _pages = [
    const ModListPage(),
    const LoadOrderPage(),
    const TroubleshootingPage(),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Rimworld Mod Manager')),
      body: _pages[_selectedIndex],
      bottomNavigationBar: BottomNavigationBar(
        currentIndex: _selectedIndex,
        onTap: (index) {
          setState(() {
            _selectedIndex = index;
          });
        },
        items: const [
          BottomNavigationBarItem(icon: Icon(Icons.extension), label: 'Mods'),
          BottomNavigationBarItem(
            icon: Icon(Icons.reorder),
            label: 'Load Order',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.build),
            label: 'Troubleshoot',
          ),
        ],
      ),
    );
  }
}

// Page to display all installed mods with enable/disable toggles
class ModListPage extends StatefulWidget {
  const ModListPage({super.key});

  @override
  State<ModListPage> createState() => _ModListPageState();
}

class _ModListPageState extends State<ModListPage> {
  final List<Mod> _loadedMods = [];
  bool _isLoading = false;
  String _loadingStatus = '';
  int _totalModsFound = 0;
  bool _skipFileCount = false; // Skip file counting by default for faster loading

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: _loadedMods.isEmpty && !_isLoading
          ? _buildEmptyState()
          : _buildModList(),
    );
  }

  Widget _buildEmptyState() {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          const Icon(Icons.extension, size: 64),
          const SizedBox(height: 16),
          Text('Mod List', style: Theme.of(context).textTheme.headlineMedium),
          const SizedBox(height: 16),
          Text(
            'Ready to scan for Rimworld mods.',
            style: Theme.of(context).textTheme.bodyLarge,
          ),
          const SizedBox(height: 12),
          Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              Checkbox(
                value: _skipFileCount,
                onChanged: (value) {
                  setState(() {
                    _skipFileCount = value ?? true;
                  });
                },
              ),
              const Text('Skip file counting (faster loading)'),
            ],
          ),
          const SizedBox(height: 24),
          ElevatedButton(
            onPressed: _startLoadingMods,
            child: const Text('Scan for Mods'),
          ),
        ],
      ),
    );
  }

  Widget _buildModList() {
    return Column(
      children: [
        if (_isLoading)
          Padding(
            padding: const EdgeInsets.all(16.0),
            child: Column(
              children: [
                LinearProgressIndicator(
                  value:
                      _totalModsFound > 0
                          ? _loadedMods.length / _totalModsFound
                          : null,
                ),
                const SizedBox(height: 8),
                Text(
                  _loadingStatus,
                  style: Theme.of(context).textTheme.bodyMedium,
                ),
              ],
            ),
          ),
        Expanded(
          child: ListView.builder(
            itemCount: _loadedMods.length,
            itemBuilder: (context, index) {
              final mod = _loadedMods[index];
              return Card(
                margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
                child: ListTile(
                  title: Text(mod.name),
                  subtitle: Text(
                    'ID: ${mod.id}\nSize: ${mod.size} files',
                    style: Theme.of(context).textTheme.bodySmall,
                  ),
                  trailing: Icon(
                    Icons.circle,
                    color:
                        mod.hardDependencies.isNotEmpty
                            ? Colors.orange
                            : Colors.green,
                    size: 12,
                  ),
                  onTap: () {
                    // TODO: Show mod details
                  },
                ),
              );
            },
          ),
        ),
        if (!_isLoading && _loadedMods.isNotEmpty)
          Padding(
            padding: const EdgeInsets.all(16.0),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text('${_loadedMods.length} mods loaded'),
                ElevatedButton(
                  onPressed: _startLoadingMods,
                  child: const Text('Reload'),
                ),
              ],
            ),
          ),
      ],
    );
  }

  void _startLoadingMods() {
    setState(() {
      _loadedMods.clear();
      _isLoading = true;
      _loadingStatus = 'Scanning for mods...';
    });

    // First get the mod directories to know the total count
    final directory = Directory(modsRoot);
    if (directory.existsSync()) {
      final List<FileSystemEntity> entities = directory.listSync();
      final List<String> modDirectories =
          entities.whereType<Directory>().map((dir) => dir.path).toList();
      
      setState(() {
        _totalModsFound = modDirectories.length;
        _loadingStatus = 'Found $_totalModsFound mod directories. Loading...';
      });
    }

    // Use the serial loading with our skipFileCount option
    modManager
        .load(skipFileCount: _skipFileCount)
        .listen(
          (mod) {
            setState(() {
              _loadedMods.add(mod);
              _loadingStatus = 'Loaded ${_loadedMods.length}/$_totalModsFound mods...';
            });
          },
          onError: (error) {
            setState(() {
              _isLoading = false;
              _loadingStatus = 'Error loading mods: $error';
            });
          },
          onDone: () {
            setState(() {
              _isLoading = false;
              _loadingStatus = 'Completed! ${_loadedMods.length} mods loaded.';

              // Sort mods by name for better display
              _loadedMods.sort((a, b) => a.name.compareTo(b.name));
            });
          },
        );
  }
}

// Page to manage mod load order with dependency visualization
class LoadOrderPage extends StatefulWidget {
  const LoadOrderPage({super.key});

  @override
  State<LoadOrderPage> createState() => _LoadOrderPageState();
}

class _LoadOrderPageState extends State<LoadOrderPage> {
  bool _isLoading = false;
  String _statusMessage = '';
  List<Mod> _sortedMods = [];
  bool _hasCycles = false;
  List<String>? _cycleInfo;
  List<List<String>> _incompatibleMods = [];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              'Mod Load Order',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
            const SizedBox(height: 16),
            Text(
              'Automatically sort mods based on dependencies, prioritizing larger mods.',
              style: Theme.of(context).textTheme.bodyLarge,
            ),
            const SizedBox(height: 24),
            Row(
              children: [
                ElevatedButton(
                  onPressed: _isLoading ? null : _sortMods,
                  child: const Text('Auto-sort Mods'),
                ),
                const SizedBox(width: 8),
                Chip(
                  backgroundColor: Colors.amber.withOpacity(0.2),
                  label: const Text(
                    'Larger mods prioritized',
                    style: TextStyle(fontSize: 12),
                  ),
                ),
                const SizedBox(width: 16),
                ElevatedButton(
                  onPressed: _isLoading || _sortedMods.isEmpty ? null : _saveModOrder,
                  child: const Text('Save Load Order'),
                ),
              ],
            ),
            const SizedBox(height: 16),
            if (_isLoading)
              const LinearProgressIndicator(),
            if (_statusMessage.isNotEmpty)
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 8.0),
                child: Text(
                  _statusMessage,
                  style: TextStyle(
                    color: _hasCycles || _incompatibleMods.isNotEmpty
                        ? Colors.orange
                        : Colors.green,
                  ),
                ),
              ),
            if (_hasCycles && _cycleInfo != null) 
              Padding(
                padding: const EdgeInsets.only(top: 8.0),
                child: Text(
                  'Dependency cycle detected: ${_cycleInfo!.join(" -> ")}',
                  style: TextStyle(color: Colors.orange),
                ),
              ),
            if (_incompatibleMods.isNotEmpty)
              Padding(
                padding: const EdgeInsets.only(top: 8.0),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      'Incompatible mods detected:',
                      style: TextStyle(color: Colors.orange),
                    ),
                    ...List.generate(_incompatibleMods.length > 5 ? 5 : _incompatibleMods.length, (index) {
                      final pair = _incompatibleMods[index];
                      return Text(
                        '- ${modManager.mods[pair[0]]?.name} and ${modManager.mods[pair[1]]?.name}',
                        style: TextStyle(color: Colors.orange),
                      );
                    }),
                    if (_incompatibleMods.length > 5)
                      Text('...and ${_incompatibleMods.length - 5} more'),
                  ],
                ),
              ),
            const SizedBox(height: 16),
            if (_sortedMods.isNotEmpty) 
              Container(
                padding: const EdgeInsets.all(8),
                decoration: BoxDecoration(
                  color: Colors.grey.withOpacity(0.1),
                  borderRadius: BorderRadius.circular(8),
                ),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text('Legend:', style: TextStyle(fontWeight: FontWeight.bold)),
                    const SizedBox(height: 4),
                    Row(
                      children: [
                        Icon(Icons.link, color: Colors.orange, size: 16),
                        const SizedBox(width: 4),
                        Text('Hard dependencies', style: TextStyle(fontSize: 12)),
                        const SizedBox(width: 12),
                        Icon(Icons.link_off, color: Colors.blue, size: 16),
                        const SizedBox(width: 4),
                        Text('Soft dependencies', style: TextStyle(fontSize: 12)),
                      ],
                    ),
                    const SizedBox(height: 4),
                    Row(
                      children: [
                        Container(width: 12, height: 12, color: Colors.amber),
                        const SizedBox(width: 4),
                        Text('Very large mod (>1000 files)', style: TextStyle(fontSize: 12)),
                        const SizedBox(width: 12),
                        Container(width: 12, height: 12, color: Colors.yellow.shade600),
                        const SizedBox(width: 4),
                        Text('Large mod (>500 files)', style: TextStyle(fontSize: 12)),
                      ],
                    ),
                  ],
                ),
              ),
            Expanded(
              child: _sortedMods.isEmpty
                  ? Center(
                      child: Text(
                        'Click "Auto-sort Mods" to generate a load order based on dependencies.',
                        textAlign: TextAlign.center,
                      ),
                    )
                  : ListView.builder(
                      itemCount: _sortedMods.length,
                      itemBuilder: (context, index) {
                        final mod = _sortedMods[index];
                        return Card(
                          margin: const EdgeInsets.symmetric(vertical: 4),
                          child: ListTile(
                            leading: Column(
                              mainAxisAlignment: MainAxisAlignment.center,
                              children: [
                                Text('${index + 1}'),
                                const SizedBox(height: 2),
                                if (mod.size > 0) Text('${mod.size}', style: TextStyle(fontSize: 10, color: Colors.grey)),
                              ],
                            ),
                            title: Text(mod.name),
                            subtitle: Column(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                Text(mod.id, style: TextStyle(fontSize: 10)),
                                if (mod.hardDependencies.isNotEmpty)
                                  Text(
                                    'Hard dependencies: ${mod.hardDependencies.length}',
                                    style: TextStyle(fontSize: 10, color: Colors.orange),
                                  ),
                                if (mod.softDependencies.isNotEmpty)
                                  Text(
                                    'Soft dependencies: ${mod.softDependencies.length}',
                                    style: TextStyle(fontSize: 10, color: Colors.blue),
                                  ),
                              ],
                            ),
                            isThreeLine: mod.hardDependencies.isNotEmpty || mod.softDependencies.isNotEmpty,
                            trailing: Row(
                              mainAxisSize: MainAxisSize.min,
                              children: [
                                if (mod.hardDependencies.isNotEmpty)
                                  Icon(Icons.link, color: Colors.orange, size: 16),
                                const SizedBox(width: 4),
                                if (mod.softDependencies.isNotEmpty)
                                  Icon(Icons.link_off, color: Colors.blue, size: 16),
                                const SizedBox(width: 4),
                                Text(
                                  '${mod.size} files',
                                  style: TextStyle(
                                    fontSize: 12,
                                    fontWeight: mod.size > 1000 ? FontWeight.bold : FontWeight.normal,
                                    color: mod.size > 1000 
                                      ? Colors.amber
                                      : mod.size > 500 
                                        ? Colors.yellow.shade600
                                        : Colors.grey,
                                  ),
                                ),
                              ],
                            ),
                          ),
                        );
                      },
                    ),
            ),
          ],
        ),
      ),
    );
  }

  void _sortMods() async {
    if (modManager.mods.isEmpty) {
      setState(() {
        _statusMessage = 'No mods have been loaded yet. Please load mods first.';
      });
      return;
    }

    setState(() {
      _isLoading = true;
      _statusMessage = 'Sorting mods based on dependencies...';
      _hasCycles = false;
      _cycleInfo = null;
      _incompatibleMods = [];
    });

    // This could be slow so run in a separate isolate or compute
    await Future.delayed(Duration.zero); // Allow UI to update

    try {
      // Check for cycles first
      final hardGraph = modManager.buildDependencyGraph();
      final cycle = modManager.detectCycle(hardGraph);
      
      if (cycle != null) {
        setState(() {
          _hasCycles = true;
          _cycleInfo = cycle;
        });
      }
      
      // Get incompatibilities
      _incompatibleMods = modManager.findIncompatibilities();

      // Get the sorted mods
      final sortedMods = modManager.getModsInLoadOrder();

      setState(() {
        _sortedMods = sortedMods;
        _isLoading = false;
        _statusMessage = 'Sorting complete! ${sortedMods.length} mods sorted.';
        if (_hasCycles) {
          _statusMessage += ' Warning: Dependency cycles were found and fixed.';
        }
        if (_incompatibleMods.isNotEmpty) {
          _statusMessage += ' Warning: ${_incompatibleMods.length} incompatible mod pairs found.';
        }
      });
    } catch (e) {
      setState(() {
        _isLoading = false;
        _statusMessage = 'Error sorting mods: $e';
      });
    }
  }

  void _saveModOrder() async {
    if (_sortedMods.isEmpty) return;

    setState(() {
      _isLoading = true;
      _statusMessage = 'Saving mod load order...';
    });

    try {
      // Create a ConfigFile instance
      final configFile = ConfigFile(path: configPath);
      
      // Load the current config
      configFile.load();
      
      // Replace the mods with our sorted list
      // We need to convert our Mods to the format expected by the config file
      configFile.mods.clear();
      for (final mod in _sortedMods) {
        configFile.mods.add(mod);
      }
      
      // Save the updated config
      configFile.save();
      
      setState(() {
        _isLoading = false;
        _statusMessage = 'Mod load order saved successfully!';
      });
    } catch (e) {
      setState(() {
        _isLoading = false;
        _statusMessage = 'Error saving mod load order: $e';
      });
    }
  }
}

// Page for troubleshooting problematic mods
class TroubleshootingPage extends StatelessWidget {
  const TroubleshootingPage({super.key});

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          const Icon(Icons.build, size: 64),
          const SizedBox(height: 16),
          Text(
            'Troubleshooting',
            style: Theme.of(context).textTheme.headlineMedium,
          ),
          const SizedBox(height: 16),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 32.0),
            child: Text(
              'Find problematic mods with smart batch testing.',
              style: Theme.of(context).textTheme.bodyLarge,
              textAlign: TextAlign.center,
            ),
          ),
          const SizedBox(height: 24),
          ElevatedButton(
            onPressed: () {
              // TODO: Implement troubleshooting wizard
            },
            child: const Text('Start Troubleshooting'),
          ),
        ],
      ),
    );
  }
}