import "package:provider/provider.dart";
import "package:shadcn_flutter/shadcn_flutter.dart";
import '../../../src/session/session_types.dart';
import '../../providers/chat_provider.dart';
import '../../providers/home_coordinator.dart';
import '../../providers/projects_provider.dart';
import '../../providers/session_provider.dart';
import 'app_logo.dart';
import 'project_section.dart';
import 'thread_button.dart';

class Sidebar extends StatelessWidget {

  const Sidebar({super.key});

  @override
  Widget build(BuildContext context) {
    final projectsProvider = context.watch<ProjectsProvider>();
    final sessionProvider = context.watch<SessionProvider>();
    final chatProvider = context.watch<ChatProvider>();
    final coordinator = context.read<HomeCoordinator>();

    return Container(
      width: 300,
      color: Theme.of(context).colorScheme.input.scaleAlpha(0.3),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [

          Container(
            height: 100,
            alignment: Alignment.centerLeft,
            padding: EdgeInsets.symmetric(horizontal: 16),
            child: AppLogo(),
          ),

          Divider(),

          Gap(16),

          Padding(
            padding: EdgeInsets.symmetric(horizontal: 8),
            child: _fixedSection(context, coordinator, chatProvider),
          ),

          Gap(16),

          Divider(),

          Gap(16),

          Expanded(
            child: Padding(
              padding: EdgeInsets.symmetric(horizontal: 8),
              child: _projectsSection(context, projectsProvider, sessionProvider, coordinator, chatProvider),
            ),
          ),

        ],
      ),
    );
  }

  Widget _fixedSection(BuildContext context, HomeCoordinator coordinator, ChatProvider chatProvider) {
    return Column(
      children: [
        SizedBox(
          width: double.infinity,
          child: Button.ghost(
            style: ButtonStyle.ghost().copyWith(
              padding: (context, state, edgeInsets) {
                return EdgeInsets.only(
                  top: 8,
                  left: 8,
                  bottom: 8,
                  right: 10
                );
              }
            ),
            onPressed: chatProvider.isLoading ? null : coordinator.createNewChat,
            disableFocusOutline: true,
            leading: Icon(LucideIcons.squarePen).iconSmall,
            alignment: Alignment.centerLeft,
            child: Text("New Chat"),
          ),
        ),

        SizedBox(
          width: double.infinity,
          child: Button.ghost(
            style: ButtonStyle.ghost().copyWith(
              padding: (context, state, edgeInsets) {
                return EdgeInsets.only(
                  top: 8,
                  left: 8,
                  bottom: 8,
                  right: 10
                );
              }
            ),
            onPressed: coordinator.pickProjectDirectory,
            disableFocusOutline: true,
            leading: Icon(LucideIcons.folderPlus).iconSmall,
            alignment: Alignment.centerLeft,
            child: Text("New Project"),
          ),
        ),
      ],
    );
  }

  Widget _projectsSection(BuildContext context, ProjectsProvider projectsProvider, SessionProvider sessionProvider, HomeCoordinator coordinator, ChatProvider chatProvider) {
    if (projectsProvider.projects.isEmpty) {
      return Padding(
        padding: EdgeInsets.symmetric(horizontal: 8, vertical: 6),
        child: Text("No projects yet").textSmall.muted,
      );
    }

    // group sessions by working directory
    final sessionsByProject = <String, List<SessionSummary>>{};
    for (final session in sessionProvider.sessions) {
      final dir = session.workingDirectory ?? '';
      sessionsByProject.putIfAbsent(dir, () => []).add(session);
    }

    // sort sessions within each project newest first
    final sorted = <String, List<SessionSummary>>{};
    sessionsByProject.forEach((dir, sessions) {
      sorted[dir] = List<SessionSummary>.from(sessions)
        ..sort((a, b) => b.updated.compareTo(a.updated));
    });

    final projects = List.of(projectsProvider.projects)
      ..sort((a, b) {
        final aLatest = sorted[a.workingDirectory]?.firstOrNull?.updated;
        final bLatest = sorted[b.workingDirectory]?.firstOrNull?.updated;

        if (aLatest == null && bLatest == null) return 0;
        if (aLatest == null) return 1;
        if (bLatest == null) return -1;
        return bLatest.compareTo(aLatest);
      });

    return ListView(
      padding: EdgeInsets.zero,
      children: [

        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 8),
          child: Text("Projects").textMuted,
        ),

        Gap(8),

        for (final project in projects) ...[

          ProjectSection(
            projectLabel: project.name,
            children: [
              if (sorted[project.workingDirectory]?.isEmpty ?? true)
                ThreadButton(
                  label: "No threads yet",
                  muted: true,
                )
              else
                for (final session in sorted[project.workingDirectory]!)
                  ThreadButton(
                    label: session.name,
                    lastMessage: session.updated,
                    selected: sessionProvider.currentSessionId == session.id,
                    isRunning: chatProvider.isSessionRunning(session.id),
                    onPressed: () => coordinator.openSession(session),
                    onDelete: () => coordinator.deleteSession(session),
                  ),
            ],
          ),

          Gap(2),

        ],

      ],
    );
  }

}