'use client';

import { useEffect, useState } from 'react';
import Link from 'next/link';
import { Card, CardContent } from '@/components/ui/card';
import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';
import { CheckCircle2, XCircle, Loader2 } from 'lucide-react';
import { useUserTimezone } from '@/lib/hooks/use-user-timezone';

interface ReportSummary {
  id: string;
  generatedAt: string;
  reportTitle: string | null;
  ticketCount: number;
  status: 'pending' | 'running' | 'complete' | 'failed';
  estimatedCostUsd: number | null;
  modelUsed: string | null;
  generatedByUserId: string | null;
}

export default function ReportsListPage() {
  const tz = useUserTimezone();
  const [reports, setReports] = useState<ReportSummary[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    let cancelled = false;
    fetch('/api/analyzer/aggregate-reports')
      .then((r) => (r.ok ? r.json() : Promise.reject(r)))
      .then((data: { reports: ReportSummary[] }) => {
        if (!cancelled) setReports(data.reports);
      })
      .catch((err) => {
        if (!cancelled)
          setError(err instanceof Error ? err.message : 'Failed to load reports');
      })
      .finally(() => {
        if (!cancelled) setLoading(false);
      });
    return () => {
      cancelled = true;
    };
  }, []);

  return (
    <div className="container mx-auto px-4 py-6 space-y-6 max-w-screen-xl">
      <div className="flex items-start justify-between gap-4 flex-wrap">
        <div>
          <h1 className="text-2xl font-semibold tracking-tight">
            Aggregate reports
          </h1>
          <p className="text-muted-foreground text-sm mt-1">
            Cross-ticket pattern analysis. Generate a new one from the browse
            page.
          </p>
        </div>
        <Button asChild>
          <Link href="/analyzer/tickets">Browse tickets</Link>
        </Button>
      </div>

      <Card>
        <CardContent className="p-0">
          {loading ? (
            <div className="p-6 text-sm text-muted-foreground">Loading…</div>
          ) : error ? (
            <div className="p-6 text-sm text-destructive">{error}</div>
          ) : reports.length === 0 ? (
            <div className="p-12 text-center text-muted-foreground">
              <p>No reports yet.</p>
              <p className="text-xs mt-1">
                Pick tickets on the browse page and click{' '}
                <em>Generate aggregate report</em>.
              </p>
            </div>
          ) : (
            <Table>
              <TableHeader>
                <TableRow>
                  <TableHead className="w-[110px]">Status</TableHead>
                  <TableHead>Title</TableHead>
                  <TableHead className="w-[100px]">Tickets</TableHead>
                  <TableHead className="w-[120px]">Model</TableHead>
                  <TableHead className="w-[100px]">Cost</TableHead>
                  <TableHead className="w-[160px]">Generated</TableHead>
                  <TableHead className="w-[100px] text-right">Action</TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {reports.map((r) => (
                  <TableRow key={r.id}>
                    <TableCell>
                      {r.status === 'complete' ? (
                        <Badge
                          variant="outline"
                          className="bg-emerald-500/10 text-emerald-700 dark:text-emerald-400"
                        >
                          <CheckCircle2 className="w-3 h-3 mr-1" />
                          Complete
                        </Badge>
                      ) : r.status === 'failed' ? (
                        <Badge variant="destructive">
                          <XCircle className="w-3 h-3 mr-1" />
                          Failed
                        </Badge>
                      ) : (
                        <Badge variant="secondary">
                          <Loader2 className="w-3 h-3 mr-1 animate-spin" />
                          {r.status}
                        </Badge>
                      )}
                    </TableCell>
                    <TableCell className="text-sm">
                      {r.reportTitle ?? (
                        <span className="text-muted-foreground italic">Untitled</span>
                      )}
                    </TableCell>
                    <TableCell className="text-sm">{r.ticketCount}</TableCell>
                    <TableCell className="text-xs text-muted-foreground">
                      {r.modelUsed ?? '—'}
                    </TableCell>
                    <TableCell className="text-xs">
                      {r.estimatedCostUsd === null
                        ? '—'
                        : `$${r.estimatedCostUsd.toFixed(4)}`}
                    </TableCell>
                    <TableCell className="text-xs text-muted-foreground">
                      {new Date(r.generatedAt).toLocaleString(undefined, { timeZone: tz })}
                    </TableCell>
                    <TableCell className="text-right">
                      <Button variant="outline" size="sm" asChild>
                        <Link href={`/analyzer/reports/${r.id}`}>View</Link>
                      </Button>
                    </TableCell>
                  </TableRow>
                ))}
              </TableBody>
            </Table>
          )}
        </CardContent>
      </Card>
    </div>
  );
}
