import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../../core/theme/accent_choice.dart';
import '../../core/theme/app_colors.dart';
import '../../core/theme/theme_controller.dart';
import '../../core/theme/theme_preference.dart';
import '../../core/widgets/app_icon.dart';
import '../../core/widgets/pressable.dart';
import '../../core/widgets/surface_card.dart';
import '../../data/models/slot_type.dart';
import '../apps/app_picker_sheet.dart';
import '../home/launcher_controller.dart';
import '../lock/lock_controller.dart';
import '../lock/pin_setup_screen.dart';
import 'car_data_section.dart';

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

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    final theme = Theme.of(context);
    final themeController = context.watch<ThemeController>();
    final launcher = context.watch<LauncherController>();
    final lock = context.watch<LockController>();

    return Scaffold(
      backgroundColor: colors.canvas,
      body: Container(
        decoration: homeBackground(colors, Theme.of(context).brightness),
        child: SafeArea(
          child: SingleChildScrollView(
            padding: const EdgeInsets.fromLTRB(32, 22, 32, 32),
            child: Center(
              child: ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 980),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        Pressable(
                          onTap: () => Navigator.of(context).pop(),
                          semanticLabel: 'Back',
                          pressedScale: 0.92,
                          child: Container(
                            width: 46,
                            height: 46,
                            decoration: BoxDecoration(
                              color: colors.surface,
                              shape: BoxShape.circle,
                              border: Border.all(color: colors.border),
                            ),
                            alignment: Alignment.center,
                            child: AppIcon(
                              'assets/icons/arrow-left.svg',
                              size: 20,
                              color: colors.ink,
                            ),
                          ),
                        ),
                        const SizedBox(width: 18),
                        Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(
                              'Settings',
                              style: theme.textTheme.headlineLarge,
                            ),
                            const SizedBox(height: 2),
                            Text(
                              'Theme, car data and access',
                              style: theme.textTheme.bodySmall?.copyWith(
                                color: colors.inkMuted,
                              ),
                            ),
                          ],
                        ),
                      ],
                    ),
                    const SizedBox(height: 32),
                    _SectionTitle(
                      title: 'General',
                      colors: colors,
                      theme: theme,
                    ),
                    const SizedBox(height: 12),
                    SurfaceCard(
                      padding: const EdgeInsets.fromLTRB(26, 22, 26, 18),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Row(
                            children: [
                              Text('Theme', style: theme.textTheme.titleMedium),
                              const Spacer(),
                              _ThemeSelector(
                                selected: themeController.preference,
                                onSelected: themeController.setPreference,
                              ),
                            ],
                          ),
                          const SizedBox(height: 8),
                          Text(
                            themeController.preference ==
                                    ThemePreference.automatic
                                ? 'Switches automatically at the times below.'
                                : themeController.preference ==
                                      ThemePreference.dark
                                ? 'Always dark.'
                                : 'Always light.',
                            style: theme.textTheme.bodySmall?.copyWith(
                              color: colors.inkMuted,
                            ),
                          ),
                          const SizedBox(height: 8),
                          Divider(color: colors.border, height: 24),
                          Row(
                            children: [
                              Text(
                                'Accent',
                                style: theme.textTheme.titleMedium,
                              ),
                              const Spacer(),
                              Text(
                                themeController.accent.label,
                                style: theme.textTheme.labelMedium?.copyWith(
                                  color: colors.inkMuted,
                                ),
                              ),
                            ],
                          ),
                          const SizedBox(height: 10),
                          _AccentSelector(
                            selected: themeController.accent,
                            onSelected: (choice) {
                              themeController.setAccent(choice);
                            },
                          ),
                          if (themeController.preference ==
                              ThemePreference.automatic) ...[
                            const SizedBox(height: 8),
                            Divider(color: colors.border, height: 24),
                            _ActionRow(
                              iconAsset: 'assets/icons/moon.svg',
                              title: 'Dark from',
                              value: _formatMinutes(
                                context,
                                themeController.nightStartMinutes,
                              ),
                              onTap: () => _pickTime(
                                context,
                                themeController,
                                start: true,
                              ),
                            ),
                            const SizedBox(height: 2),
                            _ActionRow(
                              iconAsset: 'assets/icons/sun.svg',
                              title: 'Light from',
                              value: _formatMinutes(
                                context,
                                themeController.nightEndMinutes,
                              ),
                              onTap: () => _pickTime(
                                context,
                                themeController,
                                start: false,
                              ),
                            ),
                          ],
                          Divider(color: colors.border, height: 24),
                          _BatteryToggleRow(
                            value: themeController.showBattery,
                            onChanged: (value) {
                              themeController.setShowBattery(value);
                            },
                          ),
                          Divider(color: colors.border, height: 30),
                          Row(
                            children: [
                              Text(
                                'Home buttons',
                                style: theme.textTheme.titleMedium,
                              ),
                              const Spacer(),
                              Text(
                                '${launcher.homeButtonCount} / '
                                '${LauncherController.maxHomeButtons}',
                                style: theme.textTheme.labelMedium?.copyWith(
                                  color: colors.inkMuted,
                                ),
                              ),
                            ],
                          ),
                          const SizedBox(height: 3),
                          Text(
                            'Turn one off to hide it. All apps is always shown; Settings lives in the top-right status area.',
                            style: theme.textTheme.bodySmall?.copyWith(
                              color: colors.inkMuted,
                            ),
                          ),
                          const SizedBox(height: 4),
                          for (final slot in SlotType.values)
                            _ShortcutToggleRow(
                              slot: slot,
                              launcher: launcher,
                              onPick: () => showAppPicker(context, slot),
                            ),
                          Divider(color: colors.border, height: 30),
                          _HomeRoleRow(launcher: launcher),
                        ],
                      ),
                    ),
                    const SizedBox(height: 30),
                    _SectionTitle(
                      title: 'Car data',
                      colors: colors,
                      theme: theme,
                    ),
                    const SizedBox(height: 12),
                    SurfaceCard(
                      padding: const EdgeInsets.fromLTRB(26, 22, 26, 20),
                      child: const CarDataSection(),
                    ),
                    const SizedBox(height: 30),
                    _SectionTitle(
                      title: 'Security',
                      colors: colors,
                      theme: theme,
                    ),
                    const SizedBox(height: 12),
                    SurfaceCard(
                      padding: const EdgeInsets.fromLTRB(26, 22, 26, 22),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Row(
                            children: [
                              Container(
                                width: 42,
                                height: 42,
                                decoration: BoxDecoration(
                                  color: colors.accentSoft,
                                  borderRadius: BorderRadius.circular(14),
                                ),
                                alignment: Alignment.center,
                                child: AppIcon(
                                  'assets/icons/lock.svg',
                                  size: 20,
                                  color: colors.accent,
                                ),
                              ),
                              const SizedBox(width: 14),
                              Expanded(
                                child: Column(
                                  crossAxisAlignment: CrossAxisAlignment.start,
                                  children: [
                                    Text(
                                      'PIN protection',
                                      style: theme.textTheme.titleMedium,
                                    ),
                                    const SizedBox(height: 2),
                                    Text(
                                      lock.pinSet ? 'On' : 'Off',
                                      style: theme.textTheme.bodySmall
                                          ?.copyWith(
                                            color: lock.pinSet
                                                ? colors.accent
                                                : colors.inkMuted,
                                            fontWeight: FontWeight.w600,
                                          ),
                                    ),
                                  ],
                                ),
                              ),
                              if (!lock.pinSet)
                                _SmallButton(
                                  label: 'Set PIN',
                                  onTap: () =>
                                      _openPinSetup(context, PinSetupMode.set),
                                ),
                            ],
                          ),
                          if (lock.pinSet) ...[
                            const SizedBox(height: 10),
                            Divider(color: colors.border, height: 24),
                            _ActionRow(
                              iconAsset: 'assets/icons/lock.svg',
                              title: 'Change PIN',
                              trailing: const _Chevron(),
                              onTap: () =>
                                  _openPinSetup(context, PinSetupMode.change),
                            ),
                            _ActionRow(
                              iconAsset: 'assets/icons/x.svg',
                              title: 'Remove PIN',
                              trailing: const _Chevron(),
                              onTap: () =>
                                  _openPinSetup(context, PinSetupMode.remove),
                            ),
                          ],
                          const SizedBox(height: 16),
                          Text(
                            'The PIN is requested only when CarDash starts. It does not lock '
                            'again when you switch apps or turn the screen off. It protects the '
                            'launcher, not the device itself.',
                            style: theme.textTheme.bodySmall?.copyWith(
                              color: colors.inkMuted,
                              height: 1.5,
                            ),
                          ),
                        ],
                      ),
                    ),
                    const SizedBox(height: 28),
                    Center(
                      child: Text(
                        'CarDash 0.7.0 · Android 10+',
                        style: theme.textTheme.bodySmall?.copyWith(
                          color: colors.inkFaint,
                        ),
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }

  Future<void> _openPinSetup(BuildContext context, PinSetupMode mode) async {
    final result = await Navigator.of(
      context,
    ).push<bool>(MaterialPageRoute(builder: (_) => PinSetupScreen(mode: mode)));
    if (result != true || !context.mounted) return;
    final message = switch (mode) {
      PinSetupMode.set =>
        'PIN set. It will be requested the next time CarDash starts.',
      PinSetupMode.change => 'PIN changed.',
      PinSetupMode.remove => 'PIN removed.',
    };
    ScaffoldMessenger.of(context)
        .showSnackBar(SnackBar(content: Text(message)));
  }

  Future<void> _pickTime(
    BuildContext context,
    ThemeController controller, {
    required bool start,
  }) async {
    final minutes = start
        ? controller.nightStartMinutes
        : controller.nightEndMinutes;
    final picked = await showTimePicker(
      context: context,
      initialTime: TimeOfDay(hour: minutes ~/ 60, minute: minutes % 60),
      helpText: start ? 'Dark from' : 'Light from',
      builder: (context, child) {
        final theme = Theme.of(context);
        return Theme(
          data: theme.copyWith(
            timePickerTheme: TimePickerThemeData(
              backgroundColor: theme.colorScheme.surface,
              dialBackgroundColor: theme.colorScheme.surfaceContainerHighest,
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(28),
              ),
            ),
          ),
          child: child ?? const SizedBox.shrink(),
        );
      },
    );
    if (picked == null || !context.mounted) return;
    final newValue = picked.hour * 60 + picked.minute;
    await controller.setNightWindow(
      startMinutes: start ? newValue : controller.nightStartMinutes,
      endMinutes: start ? controller.nightEndMinutes : newValue,
    );
  }

  String _formatMinutes(BuildContext context, int minutes) {
    return TimeOfDay(hour: minutes ~/ 60, minute: minutes % 60).format(context);
  }
}

class _SectionTitle extends StatelessWidget {
  const _SectionTitle({
    required this.title,
    required this.colors,
    required this.theme,
  });

  final String title;
  final AppColors colors;
  final ThemeData theme;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(left: 4),
      child: Text(
        title,
        style: theme.textTheme.titleLarge?.copyWith(color: colors.inkMuted),
      ),
    );
  }
}

class _ThemeSelector extends StatelessWidget {
  const _ThemeSelector({required this.selected, required this.onSelected});

  final ThemePreference selected;
  final ValueChanged<ThemePreference> onSelected;

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    return Container(
      padding: const EdgeInsets.all(4),
      decoration: BoxDecoration(
        color: colors.surfaceStrong,
        borderRadius: BorderRadius.circular(999),
        border: Border.all(color: colors.border),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          for (final preference in ThemePreference.values)
            Pressable(
              onTap: () => onSelected(preference),
              semanticLabel: 'Theme ${preference.storageValue}',
              pressedScale: 0.95,
              child: AnimatedContainer(
                duration: const Duration(milliseconds: 160),
                curve: Curves.easeOutCubic,
                padding: const EdgeInsets.symmetric(
                  horizontal: 18,
                  vertical: 9,
                ),
                decoration: BoxDecoration(
                  color: selected == preference
                      ? colors.accent
                      : Colors.transparent,
                  borderRadius: BorderRadius.circular(999),
                ),
                child: Text(
                  switch (preference) {
                    ThemePreference.light => 'Light',
                    ThemePreference.dark => 'Dark',
                    ThemePreference.automatic => 'Auto',
                  },
                  style: Theme.of(context).textTheme.labelMedium?.copyWith(
                    color: selected == preference
                        ? colors.accentInk
                        : colors.inkMuted,
                    fontWeight: FontWeight.w600,
                  ),
                ),
              ),
            ),
        ],
      ),
    );
  }
}

class _AccentSelector extends StatelessWidget {
  const _AccentSelector({required this.selected, required this.onSelected});

  final AccentChoice selected;
  final ValueChanged<AccentChoice> onSelected;

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    final brightness = Theme.of(context).brightness;

    return Wrap(
      spacing: 10,
      runSpacing: 10,
      children: [
        for (final choice in AccentChoice.values)
          Semantics(
            label: '${choice.label} accent',
            selected: choice == selected,
            button: true,
            child: Material(
              color: Colors.transparent,
              shape: const CircleBorder(),
              child: InkWell(
                customBorder: const CircleBorder(),
                onTap: () => onSelected(choice),
                child: Padding(
                  padding: const EdgeInsets.all(3),
                  child: AnimatedContainer(
                    duration: const Duration(milliseconds: 180),
                    width: 30,
                    height: 30,
                    decoration: BoxDecoration(
                      shape: BoxShape.circle,
                      color: choice.accentFor(brightness),
                      border: Border.all(
                        color: choice == selected ? colors.ink : colors.border,
                        width: choice == selected ? 2 : 1,
                      ),
                    ),
                    alignment: Alignment.center,
                    child: choice == selected
                        ? Icon(
                            Icons.check_rounded,
                            size: 16,
                            color: choice.inkFor(brightness),
                          )
                        : null,
                  ),
                ),
              ),
            ),
          ),
      ],
    );
  }
}

class _SettingsSwitch extends StatelessWidget {
  const _SettingsSwitch({
    required this.value,
    required this.onChanged,
    required this.semanticsLabel,
  });

  final bool value;
  final ValueChanged<bool> onChanged;
  final String semanticsLabel;

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    return Semantics(
      label: semanticsLabel,
      child: Switch(
        value: value,
        onChanged: onChanged,
        thumbColor: WidgetStateProperty.resolveWith<Color?>(
          (states) => states.contains(WidgetState.selected)
              ? colors.accentInk
              : colors.inkFaint,
        ),
        trackColor: WidgetStateProperty.resolveWith<Color?>(
          (states) => states.contains(WidgetState.selected)
              ? colors.accent
              : colors.surfaceStrong,
        ),
        trackOutlineColor: WidgetStatePropertyAll(colors.border),
      ),
    );
  }
}

class _BatteryToggleRow extends StatelessWidget {
  const _BatteryToggleRow({required this.value, required this.onChanged});

  final bool value;
  final ValueChanged<bool> onChanged;

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    final theme = Theme.of(context);

    return Row(
      children: [
        Container(
          width: 38,
          height: 38,
          decoration: BoxDecoration(
            color: colors.surfaceStrong,
            borderRadius: BorderRadius.circular(13),
            border: Border.all(color: colors.border),
          ),
          alignment: Alignment.center,
          child: AppIcon(
            'assets/icons/battery-charging.svg',
            size: 18,
            color: colors.inkMuted,
          ),
        ),
        const SizedBox(width: 14),
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text('Battery & charging', style: theme.textTheme.bodyLarge),
              const SizedBox(height: 2),
              Text(
                'Show the battery level and charging bolt.',
                style: theme.textTheme.bodySmall?.copyWith(
                  color: colors.inkMuted,
                ),
              ),
            ],
          ),
        ),
        const SizedBox(width: 8),
        _SettingsSwitch(
          value: value,
          semanticsLabel: value
              ? 'Hide battery and charging status'
              : 'Show battery and charging status',
          onChanged: onChanged,
        ),
      ],
    );
  }
}

class _ActionRow extends StatelessWidget {
  const _ActionRow({
    required this.iconAsset,
    required this.title,
    this.value,
    this.trailing,
    this.onTap,
  });

  final String iconAsset;
  final String title;
  final String? value;
  final Widget? trailing;
  final VoidCallback? onTap;

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    final theme = Theme.of(context);
    final content = Padding(
      padding: const EdgeInsets.symmetric(vertical: 7),
      child: Row(
        children: [
          Container(
            width: 38,
            height: 38,
            decoration: BoxDecoration(
              color: colors.surfaceStrong,
              borderRadius: BorderRadius.circular(13),
              border: Border.all(color: colors.border),
            ),
            alignment: Alignment.center,
            child: AppIcon(iconAsset, size: 18, color: colors.inkMuted),
          ),
          const SizedBox(width: 14),
          Expanded(child: Text(title, style: theme.textTheme.bodyLarge)),
          if (value != null)
            Text(
              value!,
              style: theme.textTheme.labelLarge?.copyWith(
                color: colors.inkMuted,
              ),
            ),
          if (trailing != null) ...[const SizedBox(width: 8), trailing!],
        ],
      ),
    );

    if (onTap == null) return content;
    return Material(
      color: Colors.transparent,
      child: InkWell(
        borderRadius: BorderRadius.circular(14),
        onTap: onTap,
        child: content,
      ),
    );
  }
}

class _ShortcutToggleRow extends StatelessWidget {
  const _ShortcutToggleRow({
    required this.slot,
    required this.launcher,
    required this.onPick,
  });

  final SlotType slot;
  final LauncherController launcher;
  final VoidCallback onPick;

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    final theme = Theme.of(context);
    final enabled = launcher.isSlotEnabled(slot);
    final assignment = launcher.assignmentFor(slot);

    return Row(
      children: [
        Expanded(
          child: Material(
            color: Colors.transparent,
            child: InkWell(
              borderRadius: BorderRadius.circular(14),
              onTap: onPick,
              child: Padding(
                padding: const EdgeInsets.symmetric(vertical: 6),
                child: Row(
                  children: [
                    Opacity(
                      opacity: enabled ? 1 : 0.45,
                      child: Container(
                        width: 38,
                        height: 38,
                        decoration: BoxDecoration(
                          color: colors.surfaceStrong,
                          borderRadius: BorderRadius.circular(13),
                          border: Border.all(color: colors.border),
                        ),
                        alignment: Alignment.center,
                        child: AppIcon(
                          slot.iconAsset,
                          size: 18,
                          color: colors.inkMuted,
                        ),
                      ),
                    ),
                    const SizedBox(width: 14),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            slot.label,
                            style: theme.textTheme.bodyLarge?.copyWith(
                              color: enabled ? colors.ink : colors.inkFaint,
                            ),
                          ),
                          const SizedBox(height: 2),
                          Text(
                            assignment?.label ?? 'Select app',
                            maxLines: 1,
                            overflow: TextOverflow.ellipsis,
                            style: theme.textTheme.bodySmall?.copyWith(
                              color: !enabled
                                  ? colors.inkFaint
                                  : assignment == null
                                  ? colors.accent
                                  : colors.inkMuted,
                              fontWeight: assignment == null && enabled
                                  ? FontWeight.w600
                                  : FontWeight.w400,
                            ),
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ),
        const SizedBox(width: 8),
        _SettingsSwitch(
          value: enabled,
          semanticsLabel: enabled
              ? 'Hide ${slot.label} on Home'
              : 'Show ${slot.label} on Home',
          onChanged: (value) async {
            final error = await launcher.setSlotEnabled(slot, value);
            if (error != null && context.mounted) {
              ScaffoldMessenger.of(context)
                  .showSnackBar(SnackBar(content: Text(error)));
            }
          },
        ),
      ],
    );
  }
}

class _Chevron extends StatelessWidget {
  const _Chevron();

  @override
  Widget build(BuildContext context) {
    return AppIcon(
      'assets/icons/chevron-right.svg',
      size: 18,
      color: context.colors.inkFaint,
    );
  }
}

class _SmallButton extends StatelessWidget {
  const _SmallButton({required this.label, required this.onTap});

  final String label;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    return Pressable(
      onTap: onTap,
      semanticLabel: label,
      pressedScale: 0.95,
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
        decoration: BoxDecoration(
          color: colors.accent,
          borderRadius: BorderRadius.circular(999),
        ),
        child: Text(
          label,
          style: Theme.of(context).textTheme.labelMedium
              ?.copyWith(color: colors.accentInk, fontWeight: FontWeight.w600),
        ),
      ),
    );
  }
}

class _HomeRoleRow extends StatelessWidget {
  const _HomeRoleRow({required this.launcher});

  final LauncherController launcher;

  @override
  Widget build(BuildContext context) {
    final colors = context.colors;
    final theme = Theme.of(context);
    final isDefault = launcher.isDefaultHome;
    return Row(
      children: [
        Container(
          width: 38,
          height: 38,
          decoration: BoxDecoration(
            color: colors.surfaceStrong,
            borderRadius: BorderRadius.circular(13),
            border: Border.all(color: colors.border),
          ),
          alignment: Alignment.center,
          child: AppIcon(
            'assets/icons/smartphone.svg',
            size: 18,
            color: colors.inkMuted,
          ),
        ),
        const SizedBox(width: 14),
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text('Home app', style: theme.textTheme.bodyLarge),
              const SizedBox(height: 2),
              Text(
                launcher.defaultHomeKnown
                    ? (isDefault ? 'CarDash is your home app' : 'Not set')
                    : 'Checking…',
                style: theme.textTheme.bodySmall?.copyWith(
                  color: isDefault ? colors.accent : colors.inkMuted,
                  fontWeight: isDefault ? FontWeight.w600 : FontWeight.w400,
                ),
              ),
            ],
          ),
        ),
        if (launcher.defaultHomeKnown && !isDefault)
          _SmallButton(
            label: 'Set as default',
            onTap: () async {
              final launched = await launcher.requestDefaultHome();
              if (!launched && context.mounted) {
                ScaffoldMessenger.of(context).showSnackBar(
                  const SnackBar(
                    content: Text('Could not open the home app settings.'),
                  ),
                );
              }
            },
          )
        else if (isDefault)
          Icon(Icons.check_circle_rounded, color: colors.accent, size: 22),
      ],
    );
  }
}