import "package:go_router/go_router.dart";
import "package:provider/provider.dart";
import "package:shadcn_flutter/shadcn_flutter.dart";

import "../../../src/project_store.dart";
import "../../providers/chat_provider.dart";
import "../../providers/home_coordinator.dart";
import "../../providers/projects_provider.dart";
import "../../widgets/chat/chat_box.dart";
import "../../widgets/chat/chat_view.dart";
import "../../widgets/common/footer_bar.dart";
import "../../widgets/common/app_header.dart";
import "../../widgets/common/button.dart";
import "../../widgets/sidebar/sidebar.dart";
import "../../widgets/sidebar/sidebar_v2.dart";

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

  @override
  State<NewHomeScreen> createState() => _NewHomeScreenState();
}

Color _centerBgColor(BuildContext context) {
  final theme = Theme.of(context);
  final dark = theme.brightness == Brightness.dark;
  final h = HSLColor.fromColor(theme.colorScheme.border).hue;
  return dark
      ? HSLColor.fromAHSL(1, h, 0.35, 0.13).toColor()
      : HSLColor.fromAHSL(1, h, 0.30, 0.88).toColor();
}


class _NewHomeScreenState extends State<NewHomeScreen> {

  final ScrollController _chatScrollController = ScrollController();

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      context.read<HomeCoordinator>().addListener(_onCoordinatorChanged);
    });
  }

  @override
  void dispose() {
    context.read<HomeCoordinator>().removeListener(_onCoordinatorChanged);
    _chatScrollController.dispose();
    super.dispose();
  }

  void _onCoordinatorChanged() {
    final coordinator = context.read<HomeCoordinator>();
    final err = coordinator.error;
    if (err != null) {
      coordinator.clearError();
      _showError(err);
    }
  }

  Future<void> _showError(String message) {
    return showDialog<void>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: const Text("Heads up"),
        content: Text(message),
        actions: [
          Button.primary(
            onPressed: () => Navigator.of(dialogContext).pop(),
            child: const Text("OK"),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      child: Column(
        children: [

          AppHeader(),

          Expanded(
            child: ColoredBox(
              color: _centerBgColor(context),
              child: Stack(
                children: [

                _ChatArea(scrollController: _chatScrollController),

                Positioned(
                  top: 0,
                  bottom: 0,
                  right: 0,
                  width: 12,
                  child: ChatScrollBar(controller: _chatScrollController),
                ),

                Positioned.fill(
                  child: IgnorePointer(
                    child: CustomPaint(painter: _InsetShadowPainter()),
                  ),
                ),

                Positioned(
                  top: 12,
                  left: 12,
                  bottom: 12,
                  child: _SidebarPane(),
                ),

                ],
              ),
            ),
          ),

          FooterBar(),

        ],
      ),
    );
  }
}


class _ChatArea extends StatelessWidget {

  final ScrollController scrollController;

  const _ChatArea({required this.scrollController});

  @override
  Widget build(BuildContext context) {
    final chatProvider = context.watch<ChatProvider>();

    return Container(
      alignment: Alignment.center,
      // padding: const EdgeInsets.all(16),
      padding: EdgeInsets.only(
        left: 16,
        right: 16
      ),
      child: ConstrainedBox(
        constraints: const BoxConstraints(maxWidth: 700),
        child: Column(
          children: [

            if (chatProvider.messages.isEmpty)...[
              Expanded(
                child: Center(
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      _EmptyChatState(),

                      ChatBox(),
                    ],
                  ),
                )
              ),
            ] else ...[
              Expanded(child: ChatView(scrollController: scrollController)),

              ChatBox(),

              Gap(12),
            ],



          ],
        ),
      ),
    );
  }
}


class _EmptyChatState extends StatelessWidget {

  const _EmptyChatState();

  @override
  Widget build(BuildContext context) {
    final projectsProvider = context.watch<ProjectsProvider>();
    final projects = projectsProvider.projects;
    final selected = projectsProvider.selectedProject;
    final coordinator = context.read<HomeCoordinator>();

    return Center(
      child: Padding(
        padding: const EdgeInsets.all(24),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [

            Text(
              "Lets burn some braincells",
              textAlign: TextAlign.center,
            ).x4Large.extraBold,
            Text(
              "Select a project and thread from the sidebar, or start a new chat.",
              textAlign: TextAlign.center,
            ).textSmall.muted,

          ],
        ),
      ),
    );
  }
}


class _InsetShadowPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    const blur = 12.0;
    final rect = Offset.zero & size;

    canvas.save();
    canvas.clipRect(rect);

    // restrict to outer ring so shadow doesnt bleed into center
    final innerRect = rect.deflate(24);
    final ringClip = Path()
      ..addRect(rect)
      ..addRect(innerRect)
      ..fillType = PathFillType.evenOdd;
    canvas.clipPath(ringClip);

    final path = Path()
      ..addRect(rect.inflate(blur * 2))
      ..addRect(rect)
      ..fillType = PathFillType.evenOdd;

    final paint = Paint()
      ..color = const Color(0x55000000)
      ..maskFilter = const MaskFilter.blur(BlurStyle.normal, blur);

    canvas.drawPath(path, paint);
    canvas.restore();
  }

  @override
  bool shouldRepaint(covariant CustomPainter old) => false;
}


class _SidebarPane extends StatefulWidget {

  const _SidebarPane();

  @override
  State<_SidebarPane> createState() => _SidebarPaneState();
}

class _SidebarPaneState extends State<_SidebarPane> {

  bool _open = true;

  static const _dur = Duration(milliseconds: 220);
  static const _curve = Curves.easeInOut;

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

    return Stack(
      clipBehavior: Clip.none,
      children: [

        AnimatedSlide(
          offset: _open ? Offset.zero : const Offset(-1.1, 0),
          duration: _dur,
          curve: _curve,
          child: AnimatedOpacity(
            opacity: _open ? 1.0 : 0.0,
            duration: _dur,
            curve: _curve,
            child: OutlinedContainer(
              borderRadius: BorderRadius.circular(8),
              boxShadow: [
                BoxShadow(
                  color: Colors.black.withValues(alpha: 0.15),
                  blurRadius: 16,
                  spreadRadius: 2,
                ),
              ],
              child: SidebarV2(onClose: () => setState(() => _open = false)),
            ),
          ),
        ),

        AnimatedOpacity(
          opacity: _open ? 0.0 : 1.0,
          duration: _dur,
          curve: _curve,
          child: IgnorePointer(
            ignoring: _open,
            child: IconButton.ghost(
              onPressed: () => setState(() => _open = true),
              icon: Icon(
                LucideIcons.panelLeftOpen,
                size: 16,
                color: theme.colorScheme.mutedForeground,
              ),
            ),
          ),
        ),

      ],
    );
  }
}


abstract class HomeScreenRoute {
  static const path = '/';
  static const name = 'home';

  static GoRoute get route => GoRoute(
    path: path,
    name: name,
    builder: (context, state) => const NewHomeScreen(),
  );
}