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

import 'package:timetrack/features/projects/domain/projects_provider.dart';
import 'package:timetrack/features/settings/data/export_service.dart';

class ExportSheet extends ConsumerStatefulWidget {
  const ExportSheet({super.key});

  static Future<void> show(BuildContext context) {
    return showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
      ),
      builder: (_) => const ExportSheet(),
    );
  }

  @override
  ConsumerState<ExportSheet> createState() => _ExportSheetState();
}

class _ExportSheetState extends ConsumerState<ExportSheet> {
  ExportFormat _format = ExportFormat.csv;
  _Range _range = _Range.thisWeek;
  int? _projectId;
  bool _exporting = false;

  @override
  Widget build(BuildContext context) {
    final projectsAsync = ref.watch(allProjectsProvider);

    return Padding(
      padding: EdgeInsets.only(
        bottom: MediaQuery.of(context).viewInsets.bottom + 16,
        top: 16,
        left: 16,
        right: 16,
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text('Export data', style: Theme.of(context).textTheme.titleLarge),
          const SizedBox(height: 16),

          // Format
          Text('Format', style: Theme.of(context).textTheme.labelLarge),
          const SizedBox(height: 8),
          Wrap(
            spacing: 8,
            children: ExportFormat.values.map((f) {
              final label = f.name.toUpperCase();
              return ChoiceChip(
                label: Text(label),
                selected: _format == f,
                onSelected: (_) => setState(() => _format = f),
              );
            }).toList(),
          ),
          const SizedBox(height: 12),

          // Date range
          Text('Date range', style: Theme.of(context).textTheme.labelLarge),
          const SizedBox(height: 8),
          Wrap(
            spacing: 8,
            children: _Range.values.map((r) {
              return ChoiceChip(
                label: Text(r.label),
                selected: _range == r,
                onSelected: (_) => setState(() => _range = r),
              );
            }).toList(),
          ),
          const SizedBox(height: 12),

          // Project filter
          projectsAsync.when(
            data: (projects) => DropdownButtonFormField<int?>(
              initialValue: _projectId,
              decoration: const InputDecoration(
                border: OutlineInputBorder(),
                labelText: 'Project (optional)',
              ),
              items: [
                const DropdownMenuItem(value: null, child: Text('All projects')),
                ...projects.map((p) => DropdownMenuItem(
                      value: p.id,
                      child: Text(p.name),
                    )),
              ],
              onChanged: (id) => setState(() => _projectId = id),
            ),
            loading: () => const LinearProgressIndicator(),
            error: (e, _) => const SizedBox.shrink(),
          ),

          const SizedBox(height: 20),
          SizedBox(
            width: double.infinity,
            child: FilledButton.icon(
              onPressed: _exporting ? null : _doExport,
              icon: _exporting
                  ? const SizedBox(
                      width: 18,
                      height: 18,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    )
                  : const Icon(Icons.share),
              label: const Text('Share'),
            ),
          ),
        ],
      ),
    );
  }

  Future<void> _doExport() async {
    setState(() => _exporting = true);
    try {
      final (from, to) = _range.bounds;
      await ref.read(exportServiceProvider).export(
            format: _format,
            from: from,
            to: to,
            projectId: _projectId,
          );
      if (mounted) Navigator.pop(context);
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Export failed: $e')),
        );
      }
    } finally {
      if (mounted) setState(() => _exporting = false);
    }
  }
}

enum _Range {
  today('Today'),
  thisWeek('This week'),
  thisMonth('This month');

  const _Range(this.label);
  final String label;

  (DateTime, DateTime) get bounds {
    final now = DateTime.now();
    switch (this) {
      case _Range.today:
        final start = DateTime(now.year, now.month, now.day);
        return (start, start.add(const Duration(days: 1)));
      case _Range.thisWeek:
        final monday = now.subtract(Duration(days: now.weekday - 1));
        final start = DateTime(monday.year, monday.month, monday.day);
        return (start, start.add(const Duration(days: 7)));
      case _Range.thisMonth:
        final start = DateTime(now.year, now.month);
        return (start, DateTime(now.year, now.month + 1));
    }
  }
}