import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import '../../core/constants/app_constants.dart';
import '../../core/theme/app_theme.dart';
import '../../data/models/session.dart';
import '../../data/models/target_type.dart';
import '../../data/repositories/session_repository.dart';
import 'session_detail_screen.dart';
import 'widgets/session_list_item.dart';
import 'widgets/history_chart.dart';

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

  @override
  State<HistoryScreen> createState() => _HistoryScreenState();
}

class _HistoryScreenState extends State<HistoryScreen> {
  List<Session> _sessions = [];
  bool _isLoading = true;
  TargetType? _filterType;

  // --- MODIFICATION : Remplacement de DateTime par DateTimeRange ---
  DateTimeRange? _selectedDateRange;

  @override
  void initState() {
    super.initState();
    _loadSessions();
  }

  Future<void> _loadSessions() async {
    if (!mounted) return;
    setState(() => _isLoading = true);

    try {
      final repository = context.read<SessionRepository>();
      final sessions = await repository.getAllSessions();

      if (mounted) {
        setState(() {
          _sessions = sessions;

          // --- LOGIQUE DE FILTRAGE PAR PÉRIODE ---
          if (_selectedDateRange != null) {
            _sessions = _sessions.where((s) {
              // On compare uniquement les dates (sans les heures) pour éviter les bugs
              final sessionDate = DateTime(
                s.createdAt.year,
                s.createdAt.month,
                s.createdAt.day,
              );
              final startDate = DateTime(
                _selectedDateRange!.start.year,
                _selectedDateRange!.start.month,
                _selectedDateRange!.start.day,
              );
              final endDate = DateTime(
                _selectedDateRange!.end.year,
                _selectedDateRange!.end.month,
                _selectedDateRange!.end.day,
              );

              return sessionDate.isAtSameMomentAs(startDate) ||
                  sessionDate.isAtSameMomentAs(endDate) ||
                  (sessionDate.isAfter(startDate) &&
                      sessionDate.isBefore(endDate));
            }).toList();
          }
          _isLoading = false;
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() => _isLoading = false);
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Erreur: $e'),
            backgroundColor: AppTheme.errorColor,
          ),
        );
      }
    }
  }

  // --- MODIFICATION : Fonction DateRangePicker ---
  Future<void> _pickDateRange() async {
    final DateTimeRange? picked = await showDateRangePicker(
      context: context,
      initialDateRange: _selectedDateRange,
      firstDate: DateTime(2020),
      lastDate: DateTime.now().add(const Duration(days: 1)),
      locale: const Locale('fr', 'FR'),
      builder: (context, child) {
        return Theme(
          data: ThemeData.light().copyWith(
            colorScheme: ColorScheme.light(
              primary: AppTheme.primaryColor,   // En-tête et sélection
              onPrimary: Colors.white,          // Texte sur en-tête/sélection
              surface: Colors.white,            // Fond du calendrier
              onSurface: Colors.black87,        // Texte des dates (Noir sur Blanc)
              secondary: AppTheme.primaryColor,
            ),
            dialogBackgroundColor: Colors.white,
            textButtonTheme: TextButtonThemeData(
              style: TextButton.styleFrom(foregroundColor: AppTheme.primaryColor),
            ),
          ),
          child: child!,
        );
      },
    );

    if (picked != null) {
      setState(() => _selectedDateRange = picked);
      _loadSessions();
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Historique'),
        actions: [
          PopupMenuButton<TargetType?>(
            icon: const Icon(Icons.filter_list),
            onSelected: (type) {
              setState(() => _filterType = type);
              _loadSessions();
            },
            itemBuilder: (context) => [
              const PopupMenuItem(value: null, child: Text('Tous')),
              ...TargetType.values.map(
                (type) =>
                    PopupMenuItem(value: type, child: Text(type.displayName)),
              ),
            ],
          ),
        ],
      ),
      body: Column(
        children: [
          Expanded(
            child: _isLoading
                ? const Center(child: CircularProgressIndicator())
                : _sessions.isEmpty
                ? _buildEmptyState()
                : _buildContent(),
          ),
          _buildBottomFilterBar(),
        ],
      ),
    );
  }

  Widget _buildBottomFilterBar() {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
      decoration: BoxDecoration(
        color: Theme.of(context).cardColor,
        boxShadow: const [
          BoxShadow(
            color: Colors.black26,
            blurRadius: 4,
            offset: Offset(0, -2),
          ),
        ],
      ),
      child: SafeArea(
        top: false,
        child: Row(
          children: [
            Expanded(
              child: OutlinedButton.icon(
                onPressed: _pickDateRange,
                icon: const Icon(Icons.date_range, size: 18),
                label: Text(
                  _selectedDateRange == null
                      ? 'Choisir une période'
                      : '${DateFormat('dd/MM/yy').format(_selectedDateRange!.start)} - ${DateFormat('dd/MM/yy').format(_selectedDateRange!.end)}',
                ),
              ),
            ),
            if (_selectedDateRange != null)
              IconButton(
                icon: const Icon(Icons.close, color: AppTheme.errorColor),
                onPressed: () {
                  setState(() => _selectedDateRange = null);
                  _loadSessions();
                },
              ),
          ],
        ),
      ),
    );
  }

  Widget _buildEmptyState() {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(Icons.history, size: 64, color: Colors.grey[400]),
          const SizedBox(height: 16),
          const Text('Aucune session sur cette période'),
        ],
      ),
    );
  }

  Widget _buildContent() {
    return RefreshIndicator(
      onRefresh: _loadSessions,
      child: CustomScrollView(
        slivers: [
          if (_sessions.length >= 2 && _selectedDateRange == null)
            SliverToBoxAdapter(
              child: Padding(
                padding: const EdgeInsets.all(AppConstants.defaultPadding),
                child: HistoryChart(sessions: _sessions),
              ),
            ),
          SliverPadding(
            padding: const EdgeInsets.all(AppConstants.defaultPadding),
            sliver: SliverList(
              delegate: SliverChildBuilderDelegate((context, index) {
                final session = _sessions[index];
                return Padding(
                  padding: const EdgeInsets.only(bottom: 12),
                  child: SessionListItem(
                    session: session,
                    onTap: () => _openSessionDetail(session),
                    onDelete: () => _deleteSession(session),
                  ),
                );
              }, childCount: _sessions.length),
            ),
          ),
        ],
      ),
    );
  }

  void _openSessionDetail(Session session) async {
    await Navigator.push(
      context,
      MaterialPageRoute(builder: (_) => SessionDetailScreen(session: session)),
    );
    _loadSessions();
  }

  Future<void> _deleteSession(Session session) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Supprimer'),
        content: Text(
          'Supprimer la session du ${DateFormat('dd/MM/yyyy').format(session.createdAt)}?',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('Annuler'),
          ),
          TextButton(
            onPressed: () => Navigator.pop(context, true),
            child: const Text(
              'Supprimer',
              style: TextStyle(color: AppTheme.errorColor),
            ),
          ),
        ],
      ),
    );

    if (confirmed == true && mounted) {
      try {
        final repository = context.read<SessionRepository>();
        await repository.deleteSession(session.id);
        _loadSessions();
      } catch (e) {
        debugPrint('Erreur suppression: $e');
      }
    }
  }
}