// F∆I Studio — desktop GUI for the F∆I hub.
//
// Visual language: warm minimalism / deep tech with soul.
// Tokens in lib/theme/, primitives in lib/widgets/.

import 'dart:async';

import 'package:flutter/material.dart';

import 'data/hub.dart';
import 'pages/approvals.dart';
import 'pages/audit.dart';
import 'pages/doctor.dart';
import 'pages/modules.dart';
import 'theme/theme.dart';
import 'theme/tokens.dart';
import 'widgets/widgets.dart';

/// Studio's own build version. Bump on every UI commit so the
/// running app self-identifies — visible in the sidebar header
/// and quick-glance proof that you're seeing the current build.
const String kStudioVersion = '0.7.1';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  // Restore the persisted endpoint and theme mode before the
  // first frame so neither flicker on startup.
  await HubService.instance.loadPersistedEndpoint();
  final themeMode = await HubService.instance.loadThemeMode();
  runApp(StudioApp(initialThemeMode: themeMode));
}

class StudioApp extends StatefulWidget {
  final ThemeModeValue initialThemeMode;

  const StudioApp({super.key, required this.initialThemeMode});

  /// Lookup helper so descendants can flip the theme without
  /// passing callbacks down through every level.
  static StudioAppState? of(BuildContext context) =>
      context.findAncestorStateOfType<StudioAppState>();

  @override
  State<StudioApp> createState() => StudioAppState();
}

class StudioAppState extends State<StudioApp> {
  late ThemeModeValue _mode;

  ThemeModeValue get mode => _mode;

  Future<void> setMode(ThemeModeValue m) async {
    setState(() => _mode = m);
    await HubService.instance.saveThemeMode(m);
  }

  @override
  void initState() {
    super.initState();
    _mode = widget.initialThemeMode;
  }

  ThemeMode _flutterMode() {
    switch (_mode) {
      case ThemeModeValue.system:
        return ThemeMode.system;
      case ThemeModeValue.light:
        return ThemeMode.light;
      case ThemeModeValue.dark:
        return ThemeMode.dark;
    }
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'F∆I Studio',
      debugShowCheckedModeBanner: false,
      theme: FaiTheme.light(),
      darkTheme: FaiTheme.dark(),
      themeMode: _flutterMode(),
      home: const StudioShell(),
    );
  }
}

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

  @override
  State<StudioShell> createState() => _StudioShellState();
}

class _StudioShellState extends State<StudioShell> {
  int _selectedIndex = 0;
  bool? _connected; // null = unknown, polled on a timer
  Timer? _healthPoll;

  static const _pages = <_NavPage>[
    _NavPage(
      label: 'Doctor',
      icon: Icons.health_and_safety_outlined,
      selectedIcon: Icons.health_and_safety,
      page: DoctorPage(),
    ),
    _NavPage(
      label: 'Modules',
      icon: Icons.extension_outlined,
      selectedIcon: Icons.extension,
      page: ModulesPage(),
    ),
    _NavPage(
      label: 'Audit',
      icon: Icons.timeline_outlined,
      selectedIcon: Icons.timeline,
      page: AuditPage(),
    ),
    _NavPage(
      label: 'Approvals',
      icon: Icons.inbox_outlined,
      selectedIcon: Icons.inbox,
      page: ApprovalsPage(),
    ),
  ];

  @override
  void initState() {
    super.initState();
    _checkHealth();
    _healthPoll = Timer.periodic(
      const Duration(seconds: 5),
      (_) => _checkHealth(),
    );
  }

  Future<void> _checkHealth() async {
    final ok = await HubService.instance.healthy();
    if (!mounted) return;
    if (_connected != ok) setState(() => _connected = ok);
  }

  @override
  void dispose() {
    _healthPoll?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Scaffold(
      body: Row(
        children: [
          _Sidebar(
            selectedIndex: _selectedIndex,
            onSelect: (i) => setState(() => _selectedIndex = i),
            pages: _pages,
            connected: _connected,
            endpointLabel: HubService.instance.endpointLabel,
          ),
          Container(
            width: 1,
            color: theme.colorScheme.outlineVariant,
          ),
          Expanded(
            child: AnimatedSwitcher(
              duration: FaiMotion.base,
              switchInCurve: FaiMotion.easing,
              switchOutCurve: FaiMotion.easing,
              transitionBuilder: (child, anim) => FadeTransition(
                opacity: anim,
                child: SlideTransition(
                  position: Tween<Offset>(
                    begin: const Offset(0, 0.02),
                    end: Offset.zero,
                  ).animate(anim),
                  child: child,
                ),
              ),
              child: KeyedSubtree(
                key: ValueKey(_selectedIndex),
                child: _pages[_selectedIndex].page,
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class _Sidebar extends StatelessWidget {
  final int selectedIndex;
  final ValueChanged<int> onSelect;
  final List<_NavPage> pages;
  final bool? connected;
  final String endpointLabel;

  const _Sidebar({
    required this.selectedIndex,
    required this.onSelect,
    required this.pages,
    required this.connected,
    required this.endpointLabel,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final mode = connected == true ? FaiDeltaMode.live : FaiDeltaMode.idle;
    return Container(
      width: 220,
      color: theme.colorScheme.surfaceContainerLow,
      padding: const EdgeInsets.symmetric(vertical: FaiSpace.xl),
      child: Column(
        children: [
          // Brand mark.
          FaiDeltaMark(color: theme.colorScheme.primary, mode: mode),
          const SizedBox(height: FaiSpace.md),
          Text(
            'F∆I Studio',
            style: theme.textTheme.titleMedium?.copyWith(
              fontWeight: FontWeight.w600,
            ),
          ),
          const SizedBox(height: 2),
          Text(
            'v$kStudioVersion · warm-minimalism',
            style: FaiTheme.mono(
              size: 10,
              color: theme.colorScheme.primary,
            ),
          ),
          const SizedBox(height: FaiSpace.md),
          // Connection pill.
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: FaiSpace.lg),
            child: _ConnectionPill(
              connected: connected,
              label: endpointLabel,
            ),
          ),
          const SizedBox(height: FaiSpace.xxl),
          // Destinations.
          Expanded(
            child: ListView(
              padding: const EdgeInsets.symmetric(horizontal: FaiSpace.md),
              children: [
                for (var i = 0; i < pages.length; i++)
                  _SidebarItem(
                    page: pages[i],
                    selected: i == selectedIndex,
                    onTap: () => onSelect(i),
                  ),
              ],
            ),
          ),
          // Footer: theme toggle + settings.
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: FaiSpace.md),
            child: Row(
              children: [
                _ThemeToggle(),
                const Spacer(),
                IconButton(
                  icon: const Icon(Icons.settings_outlined, size: 16),
                  tooltip: 'Hub endpoint…',
                  visualDensity: VisualDensity.compact,
                  onPressed: () async {
                    final saved = await FaiSettingsDialog.show(context);
                    if (saved && context.mounted) {
                      // Force a sidebar rebuild so the new endpoint
                      // shows in the connection pill.
                      (context as Element).markNeedsBuild();
                    }
                  },
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

class _ConnectionPill extends StatelessWidget {
  final bool? connected;
  final String label;

  const _ConnectionPill({required this.connected, required this.label});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final dotColor = connected == true
        ? FaiColors.success
        : connected == false
            ? FaiColors.danger
            : FaiColors.muted;
    final caption = connected == true
        ? 'connected'
        : connected == false
            ? 'unreachable'
            : 'connecting…';
    return Container(
      padding: const EdgeInsets.symmetric(
        horizontal: FaiSpace.sm,
        vertical: 6,
      ),
      decoration: BoxDecoration(
        color: theme.colorScheme.surfaceContainerHigh,
        borderRadius: BorderRadius.circular(FaiRadius.sm),
        border: Border.all(color: theme.colorScheme.outlineVariant),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        mainAxisSize: MainAxisSize.min,
        children: [
          Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              FaiStatusDot(color: dotColor, pulsing: connected == true),
              const SizedBox(width: 6),
              Text(
                caption,
                style: theme.textTheme.labelSmall?.copyWith(
                  color: dotColor == FaiColors.danger
                      ? theme.colorScheme.error
                      : theme.colorScheme.onSurface,
                  fontWeight: FontWeight.w500,
                ),
              ),
            ],
          ),
          const SizedBox(height: 2),
          Text(
            label,
            style: FaiTheme.mono(
              size: 10,
              color: theme.colorScheme.onSurfaceVariant,
            ),
          ),
        ],
      ),
    );
  }
}

class _SidebarItem extends StatefulWidget {
  final _NavPage page;
  final bool selected;
  final VoidCallback onTap;

  const _SidebarItem({
    required this.page,
    required this.selected,
    required this.onTap,
  });

  @override
  State<_SidebarItem> createState() => _SidebarItemState();
}

class _SidebarItemState extends State<_SidebarItem> {
  bool _hovered = false;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final color = widget.selected
        ? theme.colorScheme.primary
        : _hovered
            ? theme.colorScheme.onSurface
            : theme.colorScheme.onSurfaceVariant;
    final bg = widget.selected
        ? theme.colorScheme.primary.withValues(alpha: 0.08)
        : _hovered
            ? theme.colorScheme.surfaceContainerHigh
            : Colors.transparent;
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 2),
      child: MouseRegion(
        onEnter: (_) => setState(() => _hovered = true),
        onExit: (_) => setState(() => _hovered = false),
        cursor: SystemMouseCursors.click,
        child: GestureDetector(
          behavior: HitTestBehavior.opaque,
          onTap: widget.onTap,
          child: AnimatedContainer(
            duration: FaiMotion.fast,
            padding: const EdgeInsets.symmetric(
              horizontal: FaiSpace.md,
              vertical: FaiSpace.md,
            ),
            decoration: BoxDecoration(
              color: bg,
              borderRadius: BorderRadius.circular(FaiRadius.sm),
            ),
            child: Row(
              children: [
                Icon(
                  widget.selected ? widget.page.selectedIcon : widget.page.icon,
                  size: 18,
                  color: color,
                ),
                const SizedBox(width: FaiSpace.md),
                Text(
                  widget.page.label,
                  style: theme.textTheme.labelMedium?.copyWith(color: color),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class _NavPage {
  final String label;
  final IconData icon;
  final IconData selectedIcon;
  final Widget page;

  const _NavPage({
    required this.label,
    required this.icon,
    required this.selectedIcon,
    required this.page,
  });
}

class _ThemeToggle extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final app = StudioApp.of(context);
    final mode = app?.mode ?? ThemeModeValue.system;
    final icon = switch (mode) {
      ThemeModeValue.system => Icons.brightness_auto_outlined,
      ThemeModeValue.light => Icons.light_mode_outlined,
      ThemeModeValue.dark => Icons.dark_mode_outlined,
    };
    final tooltip = switch (mode) {
      ThemeModeValue.system => 'theme: follow system',
      ThemeModeValue.light => 'theme: light',
      ThemeModeValue.dark => 'theme: dark',
    };
    return IconButton(
      icon: Icon(icon, size: 16),
      tooltip: tooltip,
      visualDensity: VisualDensity.compact,
      onPressed: () {
        final next = switch (mode) {
          ThemeModeValue.system => ThemeModeValue.light,
          ThemeModeValue.light => ThemeModeValue.dark,
          ThemeModeValue.dark => ThemeModeValue.system,
        };
        app?.setMode(next);
      },
    );
  }
}