import 'package:flutter/material.dart';

import '../models/video_item.dart';
import '../services/app_settings_service.dart';
import '../services/preferred_language_service.dart';
import '../services/youtube_service.dart';
import '../widgets/video_result_card.dart';
import 'video_player_page.dart';

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

  @override
  State<SearchPage> createState() => _SearchPageState();
}

class _SearchPageState extends State<SearchPage> {
  final TextEditingController _controller = TextEditingController();
  final YoutubeService _youtubeService = YoutubeService();

  List<VideoItem> _results = [];
  bool _loading = false;
  String? _error;
  String _lastQuery = '';

  Future<void> _search() async {
    final query = _controller.text.trim();

    if (query.isEmpty || _loading) {
      return;
    }

    FocusScope.of(context).unfocus();

    setState(() {
      _loading = true;
      _error = null;
      _lastQuery = query;
    });

    try {
      final results = await _youtubeService.searchVideos(query);
      final preferredLanguage =
          AppSettingsService.instance.preferredLanguage.value;
      final rankedResults = PreferredLanguageService.rankVideos(
        results,
        preferredLanguage,
      );

      if (!mounted) {
        return;
      }

      setState(() {
        _results = rankedResults;
      });
    } catch (error) {
      if (!mounted) {
        return;
      }

      setState(() {
        _results = [];
        _error =
            'Impossible de récupérer les résultats YouTube.\n'
            'Vérifie ta connexion puis réessaie.';
      });
    } finally {
      if (mounted) {
        setState(() {
          _loading = false;
        });
      }
    }
  }

  void _clear() {
    _controller.clear();

    setState(() {
      _results = [];
      _error = null;
      _lastQuery = '';
    });
  }

  void _openVideo(VideoItem video) {
    Navigator.of(context).push(
      MaterialPageRoute<void>(
        builder: (context) => VideoPlayerPage(video: video),
      ),
    );
  }

  @override
  void dispose() {
    _controller.dispose();
    _youtubeService.close();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Column(
        children: [
          _SearchHeader(
            controller: _controller,
            loading: _loading,
            onSearch: _search,
            onClear: _clear,
          ),
          Expanded(
            child: _buildBody(),
          ),
        ],
      ),
    );
  }

  Widget _buildBody() {
    if (_loading && _results.isEmpty) {
      return Center(
        child: CircularProgressIndicator(),
      );
    }

    if (_error != null) {
      return _ErrorState(
        message: _error!,
        onRetry: _search,
      );
    }

    if (_results.isEmpty) {
      if (_lastQuery.isNotEmpty) {
        return Center(
          child: Padding(
            padding: EdgeInsets.all(24),
            child: Text(
              'Aucune vidéo trouvée pour « $_lastQuery ».',
              textAlign: TextAlign.center,
              style: TextStyle(
                color: Theme.of(context).colorScheme.onSurfaceVariant.withValues(alpha: 0.86),
                fontSize: 16,
              ),
            ),
          ),
        );
      }

      return _EmptySearchState();
    }

    return Column(
      children: [
        Padding(
          padding: EdgeInsets.fromLTRB(20, 4, 20, 6),
          child: Row(
            children: [
              Expanded(
                child: Text(
                  'Résultats pour « $_lastQuery »',
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: TextStyle(
                    color: Theme.of(context).colorScheme.onSurfaceVariant,
                    fontWeight: FontWeight.w500,
                  ),
                ),
              ),
              if (_loading)
                SizedBox(
                  width: 18,
                  height: 18,
                  child: CircularProgressIndicator(strokeWidth: 2),
                ),
            ],
          ),
        ),
        Expanded(
          child: ListView.separated(
            padding: EdgeInsets.fromLTRB(12, 4, 12, 24),
            itemCount: _results.length,
            separatorBuilder: (context, index) => SizedBox(height: 4),
            itemBuilder: (context, index) {
              final video = _results[index];

              return VideoResultCard(
                video: video,
                onTap: () => _openVideo(video),
              );
            },
          ),
        ),
      ],
    );
  }
}

class _SearchHeader extends StatelessWidget {
  const _SearchHeader({
    required this.controller,
    required this.loading,
    required this.onSearch,
    required this.onClear,
  });

  final TextEditingController controller;
  final bool loading;
  final VoidCallback onSearch;
  final VoidCallback onClear;

  @override
  Widget build(BuildContext context) {
    final wide = MediaQuery.sizeOf(context).width >= 700;

    return Padding(
      padding: EdgeInsets.fromLTRB(
        wide ? 28 : 16,
        18,
        wide ? 28 : 16,
        14,
      ),
      child: Center(
        child: ConstrainedBox(
          constraints: BoxConstraints(maxWidth: 900),
          child: Row(
            children: [
              Expanded(
                child: TextField(
                  controller: controller,
                  textInputAction: TextInputAction.search,
                  onSubmitted: (_) => onSearch(),
                  decoration: InputDecoration(
                    hintText: 'Rechercher sur YouTube...',
                    prefixIcon: Icon(Icons.search),
                    suffixIcon: ValueListenableBuilder<TextEditingValue>(
                      valueListenable: controller,
                      builder: (context, value, child) {
                        if (value.text.isEmpty) {
                          return SizedBox.shrink();
                        }

                        return IconButton(
                          tooltip: 'Effacer',
                          onPressed: onClear,
                          icon: Icon(Icons.close),
                        );
                      },
                    ),
                    filled: true,
                    fillColor: Theme.of(context).colorScheme.surfaceContainerHigh,
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(30),
                      borderSide: BorderSide.none,
                    ),
                    enabledBorder: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(30),
                      borderSide: BorderSide(
                        color: Theme.of(context).colorScheme.outlineVariant,
                      ),
                    ),
                    focusedBorder: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(30),
                      borderSide: BorderSide(
                        color: Color(0xFFFF4E45),
                        width: 1.5,
                      ),
                    ),
                  ),
                ),
              ),
              SizedBox(width: 10),
              IconButton.filled(
                tooltip: 'Rechercher',
                onPressed: loading ? null : onSearch,
                icon: Icon(Icons.search),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _EmptySearchState extends StatelessWidget {
  const _EmptySearchState();

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Padding(
        padding: EdgeInsets.all(28),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(
              Icons.youtube_searched_for,
              size: 70,
              color: Theme.of(context).colorScheme.onSurfaceVariant.withValues(alpha: 0.44),
            ),
            SizedBox(height: 18),
            Text(
              'Recherche YouTube',
              style: TextStyle(
                fontSize: 22,
                fontWeight: FontWeight.w600,
              ),
            ),
            SizedBox(height: 8),
            Text(
              'Saisis un titre, une chaîne ou un sujet.',
              textAlign: TextAlign.center,
              style: TextStyle(
                color: Theme.of(context).colorScheme.onSurfaceVariant.withValues(alpha: 0.86),
                fontSize: 15,
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _ErrorState extends StatelessWidget {
  const _ErrorState({
    required this.message,
    required this.onRetry,
  });

  final String message;
  final VoidCallback onRetry;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Padding(
        padding: EdgeInsets.all(28),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(
              Icons.cloud_off_outlined,
              size: 62,
              color: Theme.of(context).colorScheme.onSurfaceVariant.withValues(alpha: 0.62),
            ),
            SizedBox(height: 16),
            Text(
              message,
              textAlign: TextAlign.center,
              style: TextStyle(
                color: Theme.of(context).colorScheme.onSurfaceVariant,
                fontSize: 15,
              ),
            ),
            SizedBox(height: 18),
            FilledButton.icon(
              onPressed: onRetry,
              icon: Icon(Icons.refresh),
              label: Text('Réessayer'),
            ),
          ],
        ),
      ),
    );
  }
}