import 'package:flutter/material.dart';

import '../../application/focus_seed_controller.dart';
import '../../l10n/l10n.dart';
import '../../models/focus_session.dart';
import '../../models/reflection_entry.dart';
import '../../widgets/seed_illustration.dart';
import '../../widgets/surface_panel.dart';

enum _HistoryView { focus, notes }

class HistoryScreen extends StatefulWidget {
  const HistoryScreen({required this.controller, super.key});

  final FocusSeedController controller;

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

class _HistoryScreenState extends State<HistoryScreen> {
  _HistoryView _view = _HistoryView.focus;

  @override
  Widget build(BuildContext context) {
    final l10n = context.l10n;
    return Scaffold(
      appBar: AppBar(title: Text(l10n.historyTitle)),
      body: SafeArea(
        top: false,
        child: AnimatedBuilder(
          animation: widget.controller,
          builder: (context, _) {
            final state = widget.controller.state!;
            final focusSessions = state.sessions.reversed.toList();
            final reflections = state.reflections.reversed.toList();

            return ListView(
              padding: const EdgeInsets.fromLTRB(20, 8, 20, 28),
              children: [
                _HistorySwitch(
                  value: _view,
                  onChanged: (value) => setState(() => _view = value),
                ),
                const SizedBox(height: 10),
                AnimatedSwitcher(
                  duration: const Duration(milliseconds: 220),
                  switchInCurve: Curves.easeOutCubic,
                  switchOutCurve: Curves.easeInCubic,
                  child:
                      _view == _HistoryView.focus
                          ? _FocusHistoryList(
                            key: const ValueKey('focus-history'),
                            sessions: focusSessions,
                            onStartToday: () => Navigator.of(context).pop(),
                          )
                          : _ReflectionHistoryList(
                            key: const ValueKey('reflection-history'),
                            reflections: reflections,
                            onStartToday: () => Navigator.of(context).pop(),
                          ),
                ),
              ],
            );
          },
        ),
      ),
    );
  }
}

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

  final _HistoryView value;
  final ValueChanged<_HistoryView> onChanged;

  @override
  Widget build(BuildContext context) {
    final l10n = context.l10n;
    final scheme = Theme.of(context).colorScheme;
    return DecoratedBox(
      decoration: BoxDecoration(
        color: scheme.surfaceContainerLow.withValues(alpha: 0.70),
        borderRadius: BorderRadius.circular(16),
        border: Border.all(
          color: scheme.outlineVariant.withValues(alpha: 0.70),
        ),
      ),
      child: Padding(
        padding: const EdgeInsets.all(5),
        child: Row(
          children: [
            Expanded(
              child: _HistorySwitchItem(
                selected: value == _HistoryView.focus,
                icon: Icons.timer_outlined,
                label: l10n.focusHistory,
                onTap: () => onChanged(_HistoryView.focus),
              ),
            ),
            const SizedBox(width: 6),
            Expanded(
              child: _HistorySwitchItem(
                selected: value == _HistoryView.notes,
                icon: Icons.edit_note_rounded,
                label: l10n.notesHistory,
                onTap: () => onChanged(_HistoryView.notes),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _HistorySwitchItem extends StatelessWidget {
  const _HistorySwitchItem({
    required this.selected,
    required this.icon,
    required this.label,
    required this.onTap,
  });

  final bool selected;
  final IconData icon;
  final String label;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final scheme = theme.colorScheme;
    return Material(
      color: Colors.transparent,
      child: InkWell(
        onTap: onTap,
        borderRadius: BorderRadius.circular(12),
        child: AnimatedContainer(
          duration: const Duration(milliseconds: 180),
          curve: Curves.easeOutCubic,
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 12),
          decoration: BoxDecoration(
            color:
                selected
                    ? scheme.primary.withValues(alpha: 0.16)
                    : Colors.transparent,
            borderRadius: BorderRadius.circular(12),
            boxShadow:
                selected
                    ? [
                      BoxShadow(
                        color: scheme.primary.withValues(alpha: 0.16),
                        blurRadius: 12,
                        offset: const Offset(0, 6),
                      ),
                    ]
                    : null,
          ),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Icon(
                icon,
                size: 19,
                color: selected ? scheme.primary : scheme.onSurfaceVariant,
              ),
              const SizedBox(width: 8),
              Flexible(
                child: Text(
                  label,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: theme.textTheme.labelLarge?.copyWith(
                    color:
                        selected ? scheme.onSurface : scheme.onSurfaceVariant,
                    fontWeight: selected ? FontWeight.w900 : FontWeight.w700,
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _FocusHistoryList extends StatelessWidget {
  const _FocusHistoryList({
    required this.sessions,
    required this.onStartToday,
    super.key,
  });

  final List<FocusSession> sessions;
  final VoidCallback onStartToday;

  @override
  Widget build(BuildContext context) {
    final l10n = context.l10n;
    if (sessions.isEmpty) {
      return _EmptyHistory(
        title: l10n.emptyFocusHistoryTitle,
        body: l10n.emptyFocusHistoryBody,
        tone: SeedIllustrationTone.archive,
        onStartToday: onStartToday,
      );
    }
    return Column(
      children: [
        for (var index = 0; index < sessions.length; index++) ...[
          if (index > 0) const SizedBox(height: 8),
          _HistoryTimelineTile(
            leading: Icons.timer_outlined,
            title: l10n.focusMinutes(sessions[index].minutes),
            subtitle: localizedReadableDate(
              context,
              sessions[index].completedAt,
            ),
            trailing: localizedTime(context, sessions[index].completedAt),
          ),
        ],
      ],
    );
  }
}

class _ReflectionHistoryList extends StatelessWidget {
  const _ReflectionHistoryList({
    required this.reflections,
    required this.onStartToday,
    super.key,
  });

  final List<ReflectionEntry> reflections;
  final VoidCallback onStartToday;

  @override
  Widget build(BuildContext context) {
    final l10n = context.l10n;
    if (reflections.isEmpty) {
      return _EmptyHistory(
        title: l10n.emptyNotesHistoryTitle,
        body: l10n.emptyNotesHistoryBody,
        tone: SeedIllustrationTone.data,
        onStartToday: onStartToday,
      );
    }
    return Column(
      children: [
        for (var index = 0; index < reflections.length; index++) ...[
          if (index > 0) const SizedBox(height: 8),
          _HistoryTimelineTile(
            leading: reflections[index].mood.icon,
            title: reflections[index].note,
            subtitle: reflections[index].dateKey,
          ),
        ],
      ],
    );
  }
}

class _EmptyHistory extends StatelessWidget {
  const _EmptyHistory({
    required this.title,
    required this.body,
    required this.tone,
    required this.onStartToday,
  });

  final String title;
  final String body;
  final SeedIllustrationTone tone;
  final VoidCallback onStartToday;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final scheme = theme.colorScheme;
    final minHeight = MediaQuery.sizeOf(context).height * 0.62;
    return SizedBox(
      height: minHeight.clamp(430, 620).toDouble(),
      child: Center(
        child: DecoratedBox(
          decoration: BoxDecoration(
            gradient: RadialGradient(
              center: Alignment.topCenter,
              radius: 1.1,
              colors: [
                scheme.primary.withValues(alpha: 0.16),
                scheme.surfaceContainerLowest.withValues(alpha: 0.76),
                Colors.transparent,
              ],
            ),
            borderRadius: BorderRadius.circular(18),
          ),
          child: Padding(
            padding: const EdgeInsets.fromLTRB(18, 26, 18, 24),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                SeedIllustration(size: 142, tone: tone, hero: true),
                const SizedBox(height: 16),
                Text(
                  title,
                  textAlign: TextAlign.center,
                  style: theme.textTheme.titleLarge?.copyWith(
                    fontWeight: FontWeight.w900,
                  ),
                ),
                const SizedBox(height: 8),
                ConstrainedBox(
                  constraints: const BoxConstraints(maxWidth: 310),
                  child: Text(
                    body,
                    textAlign: TextAlign.center,
                    style: theme.textTheme.bodyMedium?.copyWith(
                      color: scheme.onSurfaceVariant,
                    ),
                  ),
                ),
                const SizedBox(height: 18),
                FilledButton.icon(
                  onPressed: onStartToday,
                  icon: const Icon(Icons.arrow_back_rounded),
                  label: Text(context.l10n.navToday),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class _HistoryTimelineTile extends StatelessWidget {
  const _HistoryTimelineTile({
    required this.leading,
    required this.title,
    required this.subtitle,
    this.trailing,
  });

  final IconData leading;
  final String title;
  final String subtitle;
  final String? trailing;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final scheme = theme.colorScheme;
    return SurfacePanel(
      padding: const EdgeInsets.fromLTRB(13, 12, 14, 12),
      borderColor: scheme.outlineVariant.withValues(alpha: 0.60),
      child: Row(
        children: [
          DecoratedBox(
            decoration: BoxDecoration(
              color: scheme.primary.withValues(alpha: 0.12),
              borderRadius: BorderRadius.circular(12),
            ),
            child: SizedBox.square(
              dimension: 42,
              child: Icon(leading, color: scheme.primary, size: 21),
            ),
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  title,
                  maxLines: 2,
                  overflow: TextOverflow.ellipsis,
                  style: theme.textTheme.titleSmall?.copyWith(
                    fontWeight: FontWeight.w900,
                  ),
                ),
                const SizedBox(height: 3),
                Text(
                  subtitle,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: theme.textTheme.bodySmall?.copyWith(
                    color: scheme.onSurfaceVariant,
                  ),
                ),
              ],
            ),
          ),
          if (trailing != null) ...[
            const SizedBox(width: 10),
            Text(
              trailing!,
              style: theme.textTheme.labelMedium?.copyWith(
                color: scheme.onSurfaceVariant,
                fontWeight: FontWeight.w800,
              ),
            ),
          ],
        ],
      ),
    );
  }
}