'use client';

import { useState } from 'react';
import { useTasks } from '@/lib/hooks/use-tasks';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Skeleton } from '@/components/ui/skeleton';
import { Alert, AlertDescription } from '@/components/ui/alert';
import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
import { TaskCard } from './task-card';
import { TaskQuickAdd } from './task-quick-add';
import { WorkItemStatus } from '@/types/project';

interface TaskListProps {
  storyId: string;
}

type FilterType = 'all' | 'active' | 'completed';
type SortType = 'recent' | 'alphabetical' | 'status';

export function TaskList({ storyId }: TaskListProps) {
  const { data: tasks, isLoading, error } = useTasks(storyId);
  const [filter, setFilter] = useState<FilterType>('all');
  const [sort, setSort] = useState<SortType>('recent');

  if (isLoading) {
    return (
      <Card>
        <CardHeader>
          <Skeleton className="h-8 w-48" />
        </CardHeader>
        <CardContent>
          <div className="space-y-4">
            {[1, 2, 3].map((i) => (
              <Skeleton key={i} className="h-24 w-full" />
            ))}
          </div>
        </CardContent>
      </Card>
    );
  }

  if (error) {
    return (
      <Card>
        <CardContent className="pt-6">
          <Alert variant="destructive">
            <AlertDescription>
              Failed to load tasks. Please try again.
            </AlertDescription>
          </Alert>
        </CardContent>
      </Card>
    );
  }

  const filteredTasks = tasks?.filter(task => {
    if (filter === 'active') return task.status !== 'Done';
    if (filter === 'completed') return task.status === 'Done';
    return true;
  }) || [];

  const sortedTasks = [...filteredTasks].sort((a, b) => {
    if (sort === 'alphabetical') return a.title.localeCompare(b.title);
    if (sort === 'status') return a.status.localeCompare(b.status);
    return new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime();
  });

  const completedCount = tasks?.filter(t => t.status === 'Done').length || 0;
  const totalCount = tasks?.length || 0;
  const progressPercentage = totalCount > 0 ? (completedCount / totalCount) * 100 : 0;

  return (
    <div className="space-y-6">
      <Card>
        <CardHeader>
          <div className="flex items-center justify-between">
            <div>
              <CardTitle>Tasks</CardTitle>
              <CardDescription>
                {completedCount} of {totalCount} completed
              </CardDescription>
            </div>
            <div className="flex items-center gap-4">
              <Select value={filter} onValueChange={(v) => setFilter(v as FilterType)}>
                <SelectTrigger className="w-[140px]">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="all">All</SelectItem>
                  <SelectItem value="active">Active</SelectItem>
                  <SelectItem value="completed">Completed</SelectItem>
                </SelectContent>
              </Select>
              <Select value={sort} onValueChange={(v) => setSort(v as SortType)}>
                <SelectTrigger className="w-[160px]">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="recent">Recent</SelectItem>
                  <SelectItem value="alphabetical">Alphabetical</SelectItem>
                  <SelectItem value="status">By Status</SelectItem>
                </SelectContent>
              </Select>
            </div>
          </div>
          {/* Progress bar */}
          <div className="mt-4">
            <div className="h-2 bg-secondary rounded-full overflow-hidden">
              <div
                className="h-full bg-primary transition-all duration-300"
                style={{ width: `${progressPercentage}%` }}
              />
            </div>
          </div>
        </CardHeader>
        <CardContent className="space-y-4">
          <TaskQuickAdd storyId={storyId} />

          {sortedTasks.length === 0 ? (
            <div className="text-center py-12">
              <p className="text-muted-foreground">
                {filter === 'all'
                  ? 'No tasks yet. Create your first task above!'
                  : `No ${filter} tasks found.`}
              </p>
            </div>
          ) : (
            <div className="space-y-3">
              {sortedTasks.map(task => (
                <TaskCard key={task.id} task={task} storyId={storyId} />
              ))}
            </div>
          )}
        </CardContent>
      </Card>
    </div>
  );
}