import 'package:flutter/material.dart';
import 'package:trainhub_flutter/core/theme/app_colors.dart';
import 'package:trainhub_flutter/core/constants/ui_constants.dart';
import 'package:trainhub_flutter/core/utils/id_generator.dart';
import 'package:trainhub_flutter/domain/entities/program_week.dart';
import 'package:trainhub_flutter/domain/entities/program_workout.dart';
import 'package:trainhub_flutter/domain/entities/training_plan.dart';

class ProgramWeekView extends StatelessWidget {
  final ProgramWeekEntity week;
  final List<ProgramWorkoutEntity> workouts;
  final List<TrainingPlanEntity> availablePlans;
  final Function(ProgramWorkoutEntity) onAddWorkout;
  final Function(String) onDeleteWorkout;

  const ProgramWeekView({
    super.key,
    required this.week,
    required this.workouts,
    required this.availablePlans,
    required this.onAddWorkout,
    required this.onDeleteWorkout,
  });

  @override
  Widget build(BuildContext context) {
    return Card(
      margin: const EdgeInsets.only(bottom: 24),
      elevation: 2,
      child: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              'Week ${week.position}',
              style: Theme.of(context).textTheme.headlineSmall,
            ),
            const Divider(),
            SizedBox(
              height: 500,
              child: Row(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: List.generate(7, (dayIndex) {
                  final dayNum = dayIndex + 1;
                  final dayWorkouts = workouts
                      .where((w) => w.day == dayNum.toString())
                      .toList();

                  return Expanded(
                    child: _DayColumn(
                      dayNum: dayNum,
                      dayIndex: dayIndex,
                      dayWorkouts: dayWorkouts,
                      availablePlans: availablePlans,
                      week: week,
                      onAddWorkout: onAddWorkout,
                      onDeleteWorkout: onDeleteWorkout,
                    ),
                  );
                }),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _DayColumn extends StatelessWidget {
  final int dayNum;
  final int dayIndex;
  final List<ProgramWorkoutEntity> dayWorkouts;
  final List<TrainingPlanEntity> availablePlans;
  final ProgramWeekEntity week;
  final Function(ProgramWorkoutEntity) onAddWorkout;
  final Function(String) onDeleteWorkout;

  const _DayColumn({
    required this.dayNum,
    required this.dayIndex,
    required this.dayWorkouts,
    required this.availablePlans,
    required this.week,
    required this.onAddWorkout,
    required this.onDeleteWorkout,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
        border: dayIndex < 6
            ? const Border(
                right: BorderSide(color: Colors.grey, width: 0.5),
              )
            : null,
        color: dayIndex % 2 == 0
            ? Theme.of(context).colorScheme.surfaceContainerLow
            : null,
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Container(
            padding: const EdgeInsets.all(8),
            decoration: BoxDecoration(
              color: Theme.of(context).colorScheme.surfaceContainerHigh,
              border: const Border(
                bottom: BorderSide(color: Colors.grey, width: 0.5),
              ),
            ),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(
                  _getDayName(dayNum),
                  style: const TextStyle(fontWeight: FontWeight.bold),
                ),
                InkWell(
                  onTap: () => _showAddWorkoutSheet(context),
                  borderRadius: BorderRadius.circular(16),
                  child: const Icon(Icons.add_circle_outline, size: 20),
                ),
              ],
            ),
          ),
          Expanded(
            child: SingleChildScrollView(
              padding: const EdgeInsets.all(4),
              child: Column(
                children: [
                  if (dayWorkouts.isEmpty)
                    Padding(
                      padding: const EdgeInsets.only(top: 16.0),
                      child: Center(
                        child: Text(
                          'Rest',
                          style: TextStyle(
                            color: Theme.of(
                              context,
                            ).colorScheme.onSurfaceVariant,
                            fontSize: 12,
                          ),
                        ),
                      ),
                    )
                  else
                    ...dayWorkouts.map(
                      (workout) => _WorkoutCard(
                        workout: workout,
                        onDelete: () => onDeleteWorkout(workout.id),
                      ),
                    ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  String _getDayName(int day) {
    const days = [
      'Mon',
      'Tue',
      'Wed',
      'Thu',
      'Fri',
      'Sat',
      'Sun',
    ];
    if (day >= 1 && day <= 7) return days[day - 1];
    return 'Day $day';
  }

  void _showAddWorkoutSheet(BuildContext context) {
    showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      builder: (context) => _AddWorkoutSheet(
        availablePlans: availablePlans,
        week: week,
        dayNum: dayNum,
        onAddWorkout: (workout) {
          onAddWorkout(workout);
          Navigator.pop(context);
        },
      ),
    );
  }
}

class _WorkoutCard extends StatelessWidget {
  final ProgramWorkoutEntity workout;
  final VoidCallback onDelete;

  const _WorkoutCard({required this.workout, required this.onDelete});

  @override
  Widget build(BuildContext context) {
    final isNote = workout.type == 'note';

    return Card(
      margin: const EdgeInsets.only(bottom: 4),
      color: isNote
          ? AppColors.info.withValues(alpha: 0.08)
          : null,
      child: ListTile(
        contentPadding: const EdgeInsets.symmetric(
          horizontal: 8,
          vertical: 0,
        ),
        visualDensity: VisualDensity.compact,
        leading: Icon(
          isNote ? Icons.sticky_note_2_outlined : Icons.fitness_center,
          size: 14,
          color: isNote ? AppColors.info : AppColors.textMuted,
        ),
        title: Text(
          workout.name ?? 'Untitled',
          style: const TextStyle(fontSize: 12),
          maxLines: 2,
          overflow: TextOverflow.ellipsis,
        ),
        subtitle: workout.description != null && workout.description!.isNotEmpty
            ? Text(
                workout.description!,
                style: const TextStyle(fontSize: 10),
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
              )
            : null,
        trailing: InkWell(
          onTap: onDelete,
          borderRadius: BorderRadius.circular(12),
          child: const Icon(Icons.close, size: 14),
        ),
      ),
    );
  }
}

class _AddWorkoutSheet extends StatefulWidget {
  final List<TrainingPlanEntity> availablePlans;
  final ProgramWeekEntity week;
  final int dayNum;
  final Function(ProgramWorkoutEntity) onAddWorkout;

  const _AddWorkoutSheet({
    required this.availablePlans,
    required this.week,
    required this.dayNum,
    required this.onAddWorkout,
  });

  @override
  State<_AddWorkoutSheet> createState() => _AddWorkoutSheetState();
}

class _AddWorkoutSheetState extends State<_AddWorkoutSheet>
    with SingleTickerProviderStateMixin {
  late final TabController _tabController;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 2, vsync: this);
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(vertical: 16),
      constraints: BoxConstraints(
        maxHeight: MediaQuery.of(context).size.height * 0.6,
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 8),
            child: Text(
              'Add to Schedule',
              style: Theme.of(context).textTheme.titleMedium,
            ),
          ),
          TabBar(
            controller: _tabController,
            tabs: const [
              Tab(
                icon: Icon(Icons.fitness_center, size: 16),
                text: 'Training Plan',
              ),
              Tab(
                icon: Icon(Icons.sticky_note_2_outlined, size: 16),
                text: 'Note',
              ),
            ],
          ),
          const Divider(height: 1),
          Expanded(
            child: TabBarView(
              controller: _tabController,
              children: [
                _PlanPickerTab(
                  availablePlans: widget.availablePlans,
                  week: widget.week,
                  dayNum: widget.dayNum,
                  onAddWorkout: widget.onAddWorkout,
                ),
                _NoteTab(
                  week: widget.week,
                  dayNum: widget.dayNum,
                  onAddWorkout: widget.onAddWorkout,
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

class _PlanPickerTab extends StatelessWidget {
  final List<TrainingPlanEntity> availablePlans;
  final ProgramWeekEntity week;
  final int dayNum;
  final Function(ProgramWorkoutEntity) onAddWorkout;

  const _PlanPickerTab({
    required this.availablePlans,
    required this.week,
    required this.dayNum,
    required this.onAddWorkout,
  });

  @override
  Widget build(BuildContext context) {
    if (availablePlans.isEmpty) {
      return const Padding(
        padding: EdgeInsets.all(16.0),
        child: Center(
          child: Text('No training plans available. Create one first!'),
        ),
      );
    }

    return ListView.builder(
      itemCount: availablePlans.length,
      itemBuilder: (context, index) {
        final plan = availablePlans[index];
        return ListTile(
          leading: const Icon(Icons.fitness_center),
          title: Text(plan.name),
          subtitle: Text('${plan.totalExercises} exercises'),
          onTap: () {
            final newWorkout = ProgramWorkoutEntity(
              id: IdGenerator.generate(),
              programId: week.programId,
              weekId: week.id,
              day: dayNum.toString(),
              type: 'workout',
              name: plan.name,
              refId: plan.id,
              description: '${plan.sections.length} sections',
              completed: false,
            );
            onAddWorkout(newWorkout);
          },
        );
      },
    );
  }
}

class _NoteTab extends StatefulWidget {
  final ProgramWeekEntity week;
  final int dayNum;
  final Function(ProgramWorkoutEntity) onAddWorkout;

  const _NoteTab({
    required this.week,
    required this.dayNum,
    required this.onAddWorkout,
  });

  @override
  State<_NoteTab> createState() => _NoteTabState();
}

class _NoteTabState extends State<_NoteTab> {
  final TextEditingController _titleController = TextEditingController();
  final TextEditingController _contentController = TextEditingController();

  @override
  void dispose() {
    _titleController.dispose();
    _contentController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(UIConstants.spacing16),
      child: Column(
        children: [
          TextField(
            controller: _titleController,
            decoration: const InputDecoration(
              labelText: 'Title',
              hintText: 'e.g. Active Recovery',
            ),
            autofocus: true,
          ),
          const SizedBox(height: UIConstants.spacing12),
          TextField(
            controller: _contentController,
            decoration: const InputDecoration(
              labelText: 'Note (optional)',
              hintText: 'Additional details...',
            ),
            maxLines: 3,
          ),
          const SizedBox(height: UIConstants.spacing16),
          SizedBox(
            width: double.infinity,
            child: FilledButton.icon(
              onPressed: () {
                if (_titleController.text.isEmpty) return;
                final newWorkout = ProgramWorkoutEntity(
                  id: IdGenerator.generate(),
                  programId: widget.week.programId,
                  weekId: widget.week.id,
                  day: widget.dayNum.toString(),
                  type: 'note',
                  name: _titleController.text,
                  description: _contentController.text.isEmpty
                      ? null
                      : _contentController.text,
                  completed: false,
                );
                widget.onAddWorkout(newWorkout);
              },
              icon: const Icon(Icons.add),
              label: const Text('Add Note'),
            ),
          ),
        ],
      ),
    );
  }
}