/**
 * Admin CSV Rates Management Page
 *
 * ADMIN-only page for:
 * - Uploading CSV rate files
 * - Viewing CSV configurations
 * - Managing carrier rate data
 */

'use client';

import { useEffect, useState } from 'react';
import { useTranslations, useLocale } from 'next-intl';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import { Alert, AlertDescription } from '@/components/ui/alert';
import { Loader2, RefreshCw, Trash2 } from 'lucide-react';
import { CsvUpload } from '@/components/admin/CsvUpload';
import { listCsvFiles, deleteCsvFile, type CsvFileInfo } from '@/lib/api/admin/csv-rates';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';

export default function AdminCsvRatesPage() {
  const t = useTranslations('dashboard.admin.csvRates');
  const locale = useLocale();
  const dateLocale = locale === 'fr' ? 'fr-FR' : 'en-US';

  const [files, setFiles] = useState<CsvFileInfo[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  const fetchFiles = async () => {
    setLoading(true);
    setError(null);

    try {
      const data = await listCsvFiles();
      setFiles(data.files || []);
    } catch (err: any) {
      setError(err?.message || t('loadError'));
    } finally {
      setLoading(false);
    }
  };

  useEffect(() => {
    fetchFiles();
  }, []);

  const handleDelete = async (filename: string) => {
    if (!confirm(t('confirmDelete', { filename }))) {
      return;
    }

    try {
      await deleteCsvFile(filename);
      alert(t('deleteSuccess', { filename }));
      fetchFiles(); // Refresh list
    } catch (err: any) {
      alert(t('deleteError', { message: err?.message || t('deleteFailedFallback') }));
    }
  };

  return (
    <div className="container mx-auto py-8 space-y-6">
      {/* Page Header */}
      <div>
        <h1 className="text-3xl font-bold tracking-tight">{t('title')}</h1>
        <p className="text-muted-foreground mt-2">{t('subtitle')}</p>
        <Badge variant="destructive" className="mt-2">
          {t('adminBadge')}
        </Badge>
      </div>

      {/* Upload Section */}
      <CsvUpload />

      {/* Configurations Table */}
      <Card>
        <CardHeader>
          <div className="flex items-center justify-between">
            <div>
              <CardTitle>{t('cardTitle')}</CardTitle>
              <CardDescription>{t('cardDescription')}</CardDescription>
            </div>
            <Button variant="outline" size="sm" onClick={fetchFiles} disabled={loading}>
              {loading ? (
                <Loader2 className="h-4 w-4 animate-spin" />
              ) : (
                <RefreshCw className="h-4 w-4" />
              )}
            </Button>
          </div>
        </CardHeader>
        <CardContent>
          {error && (
            <Alert variant="destructive" className="mb-4">
              <AlertDescription>{error}</AlertDescription>
            </Alert>
          )}

          {loading ? (
            <div className="flex items-center justify-center py-12">
              <Loader2 className="h-8 w-8 animate-spin text-muted-foreground" />
            </div>
          ) : files.length === 0 ? (
            <div className="text-center py-12 text-muted-foreground">{t('empty')}</div>
          ) : (
            <div className="rounded-md border">
              <Table>
                <TableHeader>
                  <TableRow>
                    <TableHead>{t('table.filename')}</TableHead>
                    <TableHead>{t('table.size')}</TableHead>
                    <TableHead>{t('table.rows')}</TableHead>
                    <TableHead>{t('table.uploadedAt')}</TableHead>
                    <TableHead>{t('table.email')}</TableHead>
                    <TableHead>{t('table.actions')}</TableHead>
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {files.map(file => (
                    <TableRow key={file.filename}>
                      <TableCell className="font-medium font-mono text-xs">
                        {file.filename}
                      </TableCell>
                      <TableCell>{(file.size / 1024).toFixed(2)} KB</TableCell>
                      <TableCell>
                        {file.rowCount ? (
                          <span className="font-semibold">
                            {t('table.rowCount', { count: file.rowCount })}
                          </span>
                        ) : (
                          <span className="text-muted-foreground">-</span>
                        )}
                      </TableCell>
                      <TableCell>
                        <div className="text-xs text-muted-foreground">
                          {new Date(file.uploadedAt).toLocaleDateString(dateLocale)}
                        </div>
                      </TableCell>
                      <TableCell>
                        <div className="text-xs text-muted-foreground">
                          {file.companyEmail ?? '—'}
                        </div>
                      </TableCell>
                      <TableCell>
                        <Button
                          variant="ghost"
                          size="sm"
                          onClick={() => handleDelete(file.filename)}
                        >
                          <Trash2 className="h-4 w-4 text-red-600" />
                        </Button>
                      </TableCell>
                    </TableRow>
                  ))}
                </TableBody>
              </Table>
            </div>
          )}
        </CardContent>
      </Card>

      {/* Info Card */}
      <Card>
        <CardHeader>
          <CardTitle>{t('infoTitle')}</CardTitle>
        </CardHeader>
        <CardContent className="space-y-2 text-sm">
          <p>
            <strong>{t('info.formatLabel')}</strong> {t('info.formatBody')}
          </p>
          <p>
            <strong>{t('info.sizeLabel')}</strong> {t('info.sizeBody')}
          </p>
          <p>
            <strong>{t('info.updateLabel')}</strong> {t('info.updateBody')}
          </p>
          <p>
            <strong>{t('info.validationLabel')}</strong> {t('info.validationBody')}
          </p>
        </CardContent>
      </Card>
    </div>
  );
}