// app/admin/stats-client.tsx
'use client';

import React, { useEffect, useState } from 'react';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Badge } from '@/components/ui/badge';
import { Skeleton } from '@/components/ui/skeleton';
import { AlertCircle } from 'lucide-react';

interface VideoStats {
  id: string;
  title: string;
  playlistTitle: string;
  uploaderName: string;
  views: number;
  totalViewers: number;
  completions: number;
  completionRate: string;
  likes: number;
  comments: number;
  engagement: number;
  avgPercentWatched: number;
  totalSecondsWatched: number;
  totalSegments: number;
  durationSec: number | null;
  createdAt: string;
}

export default function StatsClient() {
  const [stats, setStats] = useState<VideoStats[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [sortBy, setSortBy] = useState<keyof VideoStats>('views');
  const [sortOrder, setSortOrder] = useState<'asc' | 'desc'>('desc');

  useEffect(() => {
    const fetchStats = async () => {
      try {
        setLoading(true);
        const response = await fetch('/api/admin/stats');
        if (!response.ok) throw new Error('Failed to fetch stats');
        const data = await response.json();
        setStats(data);
      } catch (err) {
        setError(err instanceof Error ? err.message : 'An error occurred');
      } finally {
        setLoading(false);
      }
    };

    fetchStats();
  }, []);

  const handleSort = (column: keyof VideoStats) => {
    if (sortBy === column) {
      setSortOrder(sortOrder === 'asc' ? 'desc' : 'asc');
    } else {
      setSortBy(column);
      setSortOrder('desc');
    }
  };

  const sortedStats = [...stats].sort((a, b) => {
    const aVal = a[sortBy];
    const bVal = b[sortBy];

    if (typeof aVal === 'string' && typeof bVal === 'string') {
      return sortOrder === 'asc'
        ? aVal.localeCompare(bVal)
        : bVal.localeCompare(aVal);
    }

    const aNum = typeof aVal === 'number' ? aVal : 0;
    const bNum = typeof bVal === 'number' ? bVal : 0;

    return sortOrder === 'asc' ? aNum - bNum : bNum - aNum;
  });

  const formatDuration = (seconds: number | null) => {
    if (!seconds) return 'N/A';
    const hours = Math.floor(seconds / 3600);
    const minutes = Math.floor((seconds % 3600) / 60);
    const secs = seconds % 60;
    return `${hours}h ${minutes}m ${secs}s`;
  };

  const SortHeader = ({ column, label }: { column: keyof VideoStats; label: string }) => (
    <TableHead
      className="cursor-pointer hover:bg-muted whitespace-nowrap"
      onClick={() => handleSort(column)}
    >
      <div className="flex items-center gap-1">
        {label}
        {sortBy === column && (
          <span className="text-xs">
            {sortOrder === 'asc' ? '↑' : '↓'}
          </span>
        )}
      </div>
    </TableHead>
  );

  if (error) {
    return (
      <div className="flex items-center gap-3 p-4 bg-red-50 border border-red-200 rounded-lg text-red-800">
        <AlertCircle className="w-5 h-5" />
        <div>
          <p className="font-semibold">Error loading stats</p>
          <p className="text-sm">{error}</p>
        </div>
      </div>
    );
  }

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-3xl font-bold tracking-tight mb-2">Video Statistics</h1>
          <p className="text-muted-foreground">
            Performance metrics for all videos in the system
          </p>
        </div>
        <Badge variant="outline" className="text-sm">
          {stats.length} Videos
        </Badge>
      </div>

      {/* Summary Cards */}
      <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4">
        <Card>
          <CardHeader className="pb-2">
            <CardTitle className="text-sm font-medium text-muted-foreground">
              Total Views
            </CardTitle>
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">
              {stats.reduce((sum, s) => sum + s.views, 0).toLocaleString()}
            </div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="pb-2">
            <CardTitle className="text-sm font-medium text-muted-foreground">
              Unique Viewers
            </CardTitle>
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">
              {stats.reduce((sum, s) => sum + s.totalViewers, 0).toLocaleString()}
            </div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="pb-2">
            <CardTitle className="text-sm font-medium text-muted-foreground">
              Total Engagements
            </CardTitle>
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">
              {stats.reduce((sum, s) => sum + s.engagement, 0).toLocaleString()}
            </div>
            <p className="text-xs text-muted-foreground mt-1">
              Likes + Comments
            </p>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="pb-2">
            <CardTitle className="text-sm font-medium text-muted-foreground">
              Avg. Completion Rate
            </CardTitle>
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">
              {(
                stats.reduce((sum, s) => sum + parseFloat(s.completionRate), 0) /
                  (stats.length || 1)
              ).toFixed(1)}
              %
            </div>
          </CardContent>
        </Card>
      </div>

      {/* Data Table */}
      <Card>
        <CardHeader>
          <CardTitle>Video Performance Details</CardTitle>
        </CardHeader>
        <CardContent>
          <div className="w-full overflow-x-auto">
            {loading ? (
              <div className="space-y-2">
                {[...Array(5)].map((_, i) => (
                  <Skeleton key={i} className="h-12 w-full" />
                ))}
              </div>
            ) : stats.length === 0 ? (
              <div className="text-center py-4 text-muted-foreground">
                No videos found
              </div>
            ) : (
              <Table>
                <TableHeader>
                  <TableRow>
                    <SortHeader column="title" label="Title" />
                    <SortHeader column="uploaderName" label="Uploader" />
                    <SortHeader column="views" label="Unlocks" />
                    <SortHeader column="totalViewers" label="Viewers" />
                    <SortHeader column="completions" label="Completions" />
                    <SortHeader column="completionRate" label="Completion %" />
                    <SortHeader column="avgPercentWatched" label="Avg % Watched" />
                    <SortHeader column="engagement" label="Engagement" />
                    <SortHeader column="likes" label="Likes" />
                    <SortHeader column="comments" label="Comments" />
                    <SortHeader column="totalSecondsWatched" label="Total Seconds Watched" />
                    <SortHeader column="durationSec" label="Duration" />
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {sortedStats.map((video) => (
                    <TableRow key={video.id}>
                      <TableCell className="font-medium whitespace-nowrap">
                        <div className="flex flex-col">
                          <span className="max-w-xs truncate">{video.title}</span>
                          <span className="text-xs text-muted-foreground">
                            {video.playlistTitle}
                          </span>
                        </div>
                      </TableCell>
                      <TableCell className="whitespace-nowrap text-sm">
                        {video.uploaderName}
                      </TableCell>
                      <TableCell className="text-sm font-medium">
                        {video.views}
                      </TableCell>
                      <TableCell className="text-sm font-medium">
                        {video.totalViewers}
                      </TableCell>
                      <TableCell className="text-sm">
                        {video.completions}
                      </TableCell>
                      <TableCell className="text-sm font-semibold">
                        <Badge
                          variant={
                            parseFloat(video.completionRate) >= 50
                              ? 'default'
                              : parseFloat(video.completionRate) >= 25
                              ? 'secondary'
                              : 'destructive'
                          }
                        >
                          {video.completionRate}%
                        </Badge>
                      </TableCell>
                      <TableCell className="text-sm">
                        {video.avgPercentWatched.toFixed(1)}%
                      </TableCell>
                      <TableCell className="text-sm font-bold">
                        {video.engagement}
                      </TableCell>
                      <TableCell className="text-sm">
                        <Badge variant="outline">{video.likes}</Badge>
                      </TableCell>
                      <TableCell className="text-sm">
                        <Badge variant="outline">{video.comments}</Badge>
                      </TableCell>
                      <TableCell className="text-sm text-muted-foreground">
                        {video.totalSecondsWatched.toLocaleString()}s
                      </TableCell>
                      <TableCell className="text-sm whitespace-nowrap">
                        {formatDuration(video.durationSec)}
                      </TableCell>
                    </TableRow>
                  ))}
                </TableBody>
              </Table>
            )}
          </div>
        </CardContent>
      </Card>
    </div>
  );
}