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

import '../../../models/programmer_task.model.dart';
import '../../../providers/programmer_tasks_provider.dart';
import '../../../utils/programmer_task_ledger.dart';
import '../../../widgets/m3_card.dart';
import '../../../widgets/tech_chip.dart';
import '../programmer_task_actions.dart';

/// Hero card at the top of the programmer dashboard showing the currently
/// running task (or an idle state when nothing is running).
class NowWorkingCard extends ConsumerWidget {
  const NowWorkingCard({
    super.key,
    required this.running,
    required this.nextUp,
    required this.todayOnTask,
    required this.totalOnTask,
    required this.readOnly,
  });

  /// The currently running task, or null when nothing is running.
  final ProgrammerTask? running;

  /// First queued (not-started) task, shown as a start target when idle.
  final ProgrammerTask? nextUp;

  /// How long the user has worked on [running] today.
  final Duration todayOnTask;

  /// Total worked time on [running] across all days.
  final Duration totalOnTask;

  final bool readOnly;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return M3Card.elevated(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: running != null
            ? _RunningView(
                task: running!,
                todayOnTask: todayOnTask,
                totalOnTask: totalOnTask,
                readOnly: readOnly,
              )
            : _IdleView(nextUp: nextUp, readOnly: readOnly),
      ),
    );
  }
}

class _RunningView extends ConsumerWidget {
  const _RunningView({
    required this.task,
    required this.todayOnTask,
    required this.totalOnTask,
    required this.readOnly,
  });

  final ProgrammerTask task;
  final Duration todayOnTask;
  final Duration totalOnTask;
  final bool readOnly;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final tt = Theme.of(context).textTheme;
    final cs = Theme.of(context).colorScheme;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          task.title,
          style: tt.titleMedium?.copyWith(fontWeight: FontWeight.w600),
          maxLines: 2,
          overflow: TextOverflow.ellipsis,
        ),
        const SizedBox(height: 8),
        Wrap(
          spacing: 8,
          runSpacing: 4,
          crossAxisAlignment: WrapCrossAlignment.center,
          children: [
            TechChip(task.category, icon: Icons.category_outlined, dense: true),
            Text(
              'Today ${formatDurationHm(todayOnTask)} · '
              'Total ${formatDurationHm(totalOnTask)}',
              style: tt.bodySmall?.copyWith(color: cs.onSurfaceVariant),
            ),
          ],
        ),
        if (!readOnly) ...[
          const SizedBox(height: 12),
          Row(
            mainAxisAlignment: MainAxisAlignment.end,
            children: [
              OutlinedButton.icon(
                onPressed: () => ref
                    .read(programmerTasksControllerProvider)
                    .pauseTask(taskId: task.id),
                icon: const Icon(Icons.pause_rounded, size: 18),
                label: const Text('Pause'),
              ),
              const SizedBox(width: 8),
              FilledButton.icon(
                onPressed: () =>
                    completeProgrammerTaskWithConfirm(context, ref, task),
                icon: const Icon(Icons.check_rounded, size: 18),
                label: const Text('Complete'),
              ),
            ],
          ),
        ],
      ],
    );
  }
}

class _IdleView extends ConsumerWidget {
  const _IdleView({required this.nextUp, required this.readOnly});

  final ProgrammerTask? nextUp;
  final bool readOnly;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final tt = Theme.of(context).textTheme;
    final cs = Theme.of(context).colorScheme;

    return Row(
      children: [
        Expanded(
          child: Text(
            'Nothing running',
            style: tt.bodyLarge?.copyWith(color: cs.onSurfaceVariant),
          ),
        ),
        if (nextUp != null && !readOnly)
          FilledButton.icon(
            onPressed: () =>
                startProgrammerTaskWithPausePrompt(context, ref, nextUp!),
            icon: const Icon(Icons.play_arrow_rounded, size: 18),
            label: const Text('Start'),
          ),
      ],
    );
  }
}