import 'package:auto_route/auto_route.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:trainhub_flutter/core/constants/ui_constants.dart';
import 'package:trainhub_flutter/core/theme/app_colors.dart';
import 'package:trainhub_flutter/domain/entities/program_workout.dart';
import 'package:trainhub_flutter/presentation/common/widgets/app_empty_state.dart';
import 'package:trainhub_flutter/presentation/common/widgets/app_stat_card.dart';
import 'package:trainhub_flutter/presentation/home/home_controller.dart';
import 'package:trainhub_flutter/presentation/home/home_state.dart';

@RoutePage()
class HomePage extends ConsumerWidget {
  const HomePage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final asyncState = ref.watch(homeControllerProvider);

    return asyncState.when(
      loading: () => const Center(child: CircularProgressIndicator()),
      error: (e, _) => Center(
        child: Padding(
          padding: const EdgeInsets.all(UIConstants.pagePadding),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Icon(
                Icons.error_outline,
                size: 48,
                color: AppColors.destructive,
              ),
              const SizedBox(height: UIConstants.spacing16),
              Text(
                'Something went wrong',
                style: GoogleFonts.inter(
                  fontSize: 16,
                  fontWeight: FontWeight.w600,
                  color: AppColors.textPrimary,
                ),
              ),
              const SizedBox(height: UIConstants.spacing8),
              Text(
                '$e',
                style: GoogleFonts.inter(
                  fontSize: 13,
                  color: AppColors.textMuted,
                ),
                textAlign: TextAlign.center,
              ),
              const SizedBox(height: UIConstants.spacing24),
              FilledButton.icon(
                onPressed: () =>
                    ref.read(homeControllerProvider.notifier).refresh(),
                icon: const Icon(Icons.refresh, size: 18),
                label: const Text('Retry'),
              ),
            ],
          ),
        ),
      ),
      data: (data) {
        if (data.activeProgramName == null) {
          return AppEmptyState(
            icon: Icons.calendar_today_outlined,
            title: 'No active program',
            subtitle:
                'Head to Calendar to create or select a training program to get started.',
            actionLabel: 'Go to Calendar',
            onAction: () {
              AutoTabsRouter.of(context).setActiveIndex(3);
            },
          );
        }
        return _HomeContent(data: data);
      },
    );
  }
}

class _HomeContent extends StatelessWidget {
  final HomeState data;

  const _HomeContent({required this.data});

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      padding: const EdgeInsets.all(UIConstants.pagePadding),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // -- Welcome header --
          _WelcomeHeader(programName: data.activeProgramName!),
          const SizedBox(height: UIConstants.spacing24),

          // -- Stat cards row --
          _StatCardsRow(
            completed: data.completedWorkouts,
            total: data.totalWorkouts,
          ),
          const SizedBox(height: UIConstants.spacing24),

          // -- Next workout banner --
          if (data.nextWorkoutName != null) ...[
            _NextWorkoutBanner(workoutName: data.nextWorkoutName!),
            const SizedBox(height: UIConstants.spacing24),
          ],

          // -- Quick actions --
          _QuickActionsRow(),
          const SizedBox(height: UIConstants.spacing32),

          // -- Recent activity --
          _RecentActivitySection(activity: data.recentActivity),
        ],
      ),
    );
  }
}

// ---------------------------------------------------------------------------
// Welcome header
// ---------------------------------------------------------------------------
class _WelcomeHeader extends StatelessWidget {
  final String programName;

  const _WelcomeHeader({required this.programName});

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          'Welcome back',
          style: GoogleFonts.inter(
            fontSize: 14,
            fontWeight: FontWeight.w500,
            color: AppColors.textMuted,
          ),
        ),
        const SizedBox(height: UIConstants.spacing4),
        Row(
          children: [
            Expanded(
              child: Text(
                programName,
                style: GoogleFonts.inter(
                  fontSize: 28,
                  fontWeight: FontWeight.w700,
                  color: AppColors.textPrimary,
                ),
              ),
            ),
            Container(
              padding: const EdgeInsets.symmetric(
                horizontal: UIConstants.spacing12,
                vertical: 6,
              ),
              decoration: BoxDecoration(
                color: AppColors.accentMuted,
                borderRadius: UIConstants.smallCardBorderRadius,
              ),
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  const Icon(
                    Icons.fitness_center,
                    size: 14,
                    color: AppColors.accent,
                  ),
                  const SizedBox(width: 6),
                  Text(
                    'Active Program',
                    style: GoogleFonts.inter(
                      fontSize: 12,
                      fontWeight: FontWeight.w600,
                      color: AppColors.accent,
                    ),
                  ),
                ],
              ),
            ),
          ],
        ),
      ],
    );
  }
}

// ---------------------------------------------------------------------------
// Stat cards row
// ---------------------------------------------------------------------------
class _StatCardsRow extends StatelessWidget {
  final int completed;
  final int total;

  const _StatCardsRow({required this.completed, required this.total});

  @override
  Widget build(BuildContext context) {
    final progress = total == 0 ? 0 : (completed / total * 100).round();

    return Row(
      children: [
        Expanded(
          child: AppStatCard(
            title: 'Completed',
            value: '$completed',
            icon: Icons.check_circle_outline,
            accentColor: AppColors.success,
          ),
        ),
        const SizedBox(width: UIConstants.spacing16),
        Expanded(
          child: AppStatCard(
            title: 'Total Workouts',
            value: '$total',
            icon: Icons.list_alt,
            accentColor: AppColors.info,
          ),
        ),
        const SizedBox(width: UIConstants.spacing16),
        Expanded(
          child: AppStatCard(
            title: 'Progress',
            value: '$progress%',
            icon: Icons.trending_up,
            accentColor: AppColors.purple,
          ),
        ),
      ],
    );
  }
}

// ---------------------------------------------------------------------------
// Next workout banner
// ---------------------------------------------------------------------------
class _NextWorkoutBanner extends StatelessWidget {
  final String workoutName;

  const _NextWorkoutBanner({required this.workoutName});

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(UIConstants.cardPadding),
      decoration: BoxDecoration(
        color: AppColors.surfaceContainer,
        borderRadius: UIConstants.cardBorderRadius,
        border: Border.all(color: AppColors.border),
      ),
      child: Row(
        children: [
          Container(
            width: 40,
            height: 40,
            decoration: BoxDecoration(
              color: AppColors.accentMuted,
              borderRadius: UIConstants.smallCardBorderRadius,
            ),
            child: const Icon(
              Icons.play_arrow_rounded,
              color: AppColors.accent,
              size: 22,
            ),
          ),
          const SizedBox(width: UIConstants.spacing12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  'Up Next',
                  style: GoogleFonts.inter(
                    fontSize: 12,
                    fontWeight: FontWeight.w500,
                    color: AppColors.textMuted,
                  ),
                ),
                const SizedBox(height: 2),
                Text(
                  workoutName,
                  style: GoogleFonts.inter(
                    fontSize: 15,
                    fontWeight: FontWeight.w600,
                    color: AppColors.textPrimary,
                  ),
                ),
              ],
            ),
          ),
          Icon(
            Icons.chevron_right,
            color: AppColors.textMuted,
            size: 20,
          ),
        ],
      ),
    );
  }
}

// ---------------------------------------------------------------------------
// Quick actions row
// ---------------------------------------------------------------------------
class _QuickActionsRow extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          'Quick Actions',
          style: GoogleFonts.inter(
            fontSize: 16,
            fontWeight: FontWeight.w600,
            color: AppColors.textPrimary,
          ),
        ),
        const SizedBox(height: UIConstants.spacing12),
        Row(
          children: [
            _QuickActionButton(
              icon: Icons.play_arrow_rounded,
              label: 'New Workout',
              color: AppColors.accent,
              onTap: () {
                AutoTabsRouter.of(context).setActiveIndex(1);
              },
            ),
            const SizedBox(width: UIConstants.spacing12),
            _QuickActionButton(
              icon: Icons.description_outlined,
              label: 'View Plans',
              color: AppColors.info,
              onTap: () {
                AutoTabsRouter.of(context).setActiveIndex(1);
              },
            ),
            const SizedBox(width: UIConstants.spacing12),
            _QuickActionButton(
              icon: Icons.chat_bubble_outline,
              label: 'AI Chat',
              color: AppColors.purple,
              onTap: () {
                AutoTabsRouter.of(context).setActiveIndex(4);
              },
            ),
          ],
        ),
      ],
    );
  }
}

class _QuickActionButton extends StatefulWidget {
  final IconData icon;
  final String label;
  final Color color;
  final VoidCallback onTap;

  const _QuickActionButton({
    required this.icon,
    required this.label,
    required this.color,
    required this.onTap,
  });

  @override
  State<_QuickActionButton> createState() => _QuickActionButtonState();
}

class _QuickActionButtonState extends State<_QuickActionButton> {
  bool _isHovered = false;

  @override
  Widget build(BuildContext context) {
    return MouseRegion(
      onEnter: (_) => setState(() => _isHovered = true),
      onExit: (_) => setState(() => _isHovered = false),
      child: AnimatedContainer(
        duration: UIConstants.animationDuration,
        decoration: BoxDecoration(
          color: _isHovered
              ? widget.color.withValues(alpha: 0.08)
              : Colors.transparent,
          borderRadius: UIConstants.smallCardBorderRadius,
          border: Border.all(
            color: _isHovered ? widget.color.withValues(alpha: 0.4) : AppColors.border,
          ),
        ),
        child: Material(
          color: Colors.transparent,
          child: InkWell(
            onTap: widget.onTap,
            borderRadius: UIConstants.smallCardBorderRadius,
            child: Padding(
              padding: const EdgeInsets.symmetric(
                horizontal: UIConstants.spacing24,
                vertical: UIConstants.spacing12,
              ),
              child: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Icon(
                    widget.icon,
                    size: 18,
                    color: widget.color,
                  ),
                  const SizedBox(width: UIConstants.spacing8),
                  Text(
                    widget.label,
                    style: GoogleFonts.inter(
                      fontSize: 13,
                      fontWeight: FontWeight.w500,
                      color: _isHovered
                          ? widget.color
                          : AppColors.textSecondary,
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}

// ---------------------------------------------------------------------------
// Recent activity section
// ---------------------------------------------------------------------------
class _RecentActivitySection extends StatelessWidget {
  final List<ProgramWorkoutEntity> activity;

  const _RecentActivitySection({required this.activity});

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Row(
          children: [
            Expanded(
              child: Text(
                'Recent Activity',
                style: GoogleFonts.inter(
                  fontSize: 16,
                  fontWeight: FontWeight.w600,
                  color: AppColors.textPrimary,
                ),
              ),
            ),
            if (activity.isNotEmpty)
              Text(
                '${activity.length} workout${activity.length == 1 ? '' : 's'}',
                style: GoogleFonts.inter(
                  fontSize: 12,
                  color: AppColors.textMuted,
                ),
              ),
          ],
        ),
        const SizedBox(height: UIConstants.spacing12),
        if (activity.isEmpty)
          _EmptyActivity()
        else
          _ActivityList(activity: activity),
      ],
    );
  }
}

class _EmptyActivity extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.symmetric(
        vertical: 40,
        horizontal: UIConstants.spacing24,
      ),
      decoration: BoxDecoration(
        color: AppColors.surfaceContainer,
        borderRadius: UIConstants.cardBorderRadius,
        border: Border.all(color: AppColors.border),
      ),
      child: Column(
        children: [
          Icon(
            Icons.history,
            size: 32,
            color: AppColors.textMuted,
          ),
          const SizedBox(height: UIConstants.spacing12),
          Text(
            'No completed workouts yet',
            style: GoogleFonts.inter(
              fontSize: 14,
              fontWeight: FontWeight.w500,
              color: AppColors.textSecondary,
            ),
          ),
          const SizedBox(height: UIConstants.spacing4),
          Text(
            'Your recent workout history will appear here.',
            style: GoogleFonts.inter(
              fontSize: 13,
              color: AppColors.textMuted,
            ),
          ),
        ],
      ),
    );
  }
}

class _ActivityList extends StatelessWidget {
  final List<ProgramWorkoutEntity> activity;

  const _ActivityList({required this.activity});

  @override
  Widget build(BuildContext context) {
    return Container(
      decoration: BoxDecoration(
        color: AppColors.surfaceContainer,
        borderRadius: UIConstants.cardBorderRadius,
        border: Border.all(color: AppColors.border),
      ),
      child: ClipRRect(
        borderRadius: UIConstants.cardBorderRadius,
        child: Column(
          children: [
            for (int i = 0; i < activity.length; i++) ...[
              if (i > 0)
                const Divider(
                  height: 1,
                  thickness: 1,
                  color: AppColors.border,
                ),
              _ActivityItem(workout: activity[i]),
            ],
          ],
        ),
      ),
    );
  }
}

class _ActivityItem extends StatefulWidget {
  final ProgramWorkoutEntity workout;

  const _ActivityItem({required this.workout});

  @override
  State<_ActivityItem> createState() => _ActivityItemState();
}

class _ActivityItemState extends State<_ActivityItem> {
  bool _isHovered = false;

  Color get _typeColor {
    switch (widget.workout.type.toLowerCase()) {
      case 'strength':
        return AppColors.accent;
      case 'cardio':
        return AppColors.info;
      case 'flexibility':
      case 'mobility':
        return AppColors.purple;
      case 'rest':
        return AppColors.textMuted;
      default:
        return AppColors.success;
    }
  }

  IconData get _typeIcon {
    switch (widget.workout.type.toLowerCase()) {
      case 'strength':
        return Icons.fitness_center;
      case 'cardio':
        return Icons.directions_run;
      case 'flexibility':
      case 'mobility':
        return Icons.self_improvement;
      case 'rest':
        return Icons.bedtime_outlined;
      default:
        return Icons.check_circle;
    }
  }

  @override
  Widget build(BuildContext context) {
    return MouseRegion(
      onEnter: (_) => setState(() => _isHovered = true),
      onExit: (_) => setState(() => _isHovered = false),
      child: AnimatedContainer(
        duration: UIConstants.animationDuration,
        color: _isHovered
            ? AppColors.surfaceContainerHigh.withValues(alpha: 0.5)
            : Colors.transparent,
        padding: const EdgeInsets.symmetric(
          horizontal: UIConstants.cardPadding,
          vertical: UIConstants.spacing12,
        ),
        child: Row(
          children: [
            // Leading icon with color coding
            Container(
              width: 36,
              height: 36,
              decoration: BoxDecoration(
                color: widget.workout.completed
                    ? _typeColor.withValues(alpha: 0.15)
                    : AppColors.zinc800,
                borderRadius: UIConstants.smallCardBorderRadius,
              ),
              child: Icon(
                widget.workout.completed ? _typeIcon : Icons.circle_outlined,
                size: 18,
                color: widget.workout.completed
                    ? _typeColor
                    : AppColors.textMuted,
              ),
            ),
            const SizedBox(width: UIConstants.spacing12),

            // Workout info
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    widget.workout.name ?? 'Workout',
                    style: GoogleFonts.inter(
                      fontSize: 14,
                      fontWeight: FontWeight.w500,
                      color: AppColors.textPrimary,
                    ),
                  ),
                  const SizedBox(height: 2),
                  Text(
                    'Week ${widget.workout.weekId}  ·  Day ${widget.workout.day}',
                    style: GoogleFonts.inter(
                      fontSize: 12,
                      color: AppColors.textMuted,
                    ),
                  ),
                ],
              ),
            ),

            // Type badge
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
              decoration: BoxDecoration(
                color: _typeColor.withValues(alpha: 0.12),
                borderRadius: BorderRadius.circular(6),
              ),
              child: Text(
                widget.workout.type,
                style: GoogleFonts.inter(
                  fontSize: 11,
                  fontWeight: FontWeight.w500,
                  color: _typeColor,
                ),
              ),
            ),
            const SizedBox(width: UIConstants.spacing12),

            // Status indicator
            if (widget.workout.completed)
              const Icon(
                Icons.check_circle,
                size: 18,
                color: AppColors.success,
              )
            else
              const Icon(
                Icons.radio_button_unchecked,
                size: 18,
                color: AppColors.textMuted,
              ),
          ],
        ),
      ),
    );
  }
}