import { useState } from 'react';
import { AdminLayout } from '@/components/layout/AdminLayout';
import { AdminPageLayout } from '@/components/admin';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Badge } from '@/components/ui/badge';
import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';
import {
  useMaintenanceTables,
  useVacuumTable,
  useAnalyzeTable,
  useReindexTable,
} from '@/hooks/admin/useDatabaseMaintenance';
import { Database, RefreshCw, Zap, Settings, AlertTriangle } from 'lucide-react';
import { Skeleton } from '@/components/ui/skeleton';

export default function DatabaseMaintenance() {
  const { data: tables, isLoading, refetch } = useMaintenanceTables();
  const vacuumMutation = useVacuumTable();
  const analyzeMutation = useAnalyzeTable();
  const reindexMutation = useReindexTable();

  const [selectedTable, setSelectedTable] = useState<string | null>(null);

  const handleVacuum = (tableName: string) => {
    setSelectedTable(tableName);
    vacuumMutation.mutate(tableName);
  };

  const handleAnalyze = (tableName: string) => {
    setSelectedTable(tableName);
    analyzeMutation.mutate(tableName);
  };

  const handleReindex = (tableName: string) => {
    setSelectedTable(tableName);
    reindexMutation.mutate(tableName);
  };

  const isOperationPending = (tableName: string) => {
    return (
      selectedTable === tableName &&
      (vacuumMutation.isPending || analyzeMutation.isPending || reindexMutation.isPending)
    );
  };

  return (
    <AdminLayout>
      <AdminPageLayout
        title="Database Maintenance"
        description="Run vacuum, analyze, and reindex operations on database tables"
      >
        <Alert variant="default" className="mb-6">
          <AlertTriangle className="h-4 w-4" />
          <AlertTitle>Superuser Access Required</AlertTitle>
          <AlertDescription>
            These operations require superuser privileges. They can help improve database
            performance by reclaiming storage, updating statistics, and rebuilding indexes.
          </AlertDescription>
        </Alert>

        <div className="grid gap-6 mb-6 md:grid-cols-3">
          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">VACUUM</CardTitle>
              <Database className="h-4 w-4 text-muted-foreground" />
            </CardHeader>
            <CardContent>
              <CardDescription className="text-xs">
                Reclaims storage occupied by dead tuples and makes space available for reuse
              </CardDescription>
            </CardContent>
          </Card>

          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">ANALYZE</CardTitle>
              <Zap className="h-4 w-4 text-muted-foreground" />
            </CardHeader>
            <CardContent>
              <CardDescription className="text-xs">
                Updates statistics used by the query planner for optimal query execution plans
              </CardDescription>
            </CardContent>
          </Card>

          <Card>
            <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
              <CardTitle className="text-sm font-medium">REINDEX</CardTitle>
              <Settings className="h-4 w-4 text-muted-foreground" />
            </CardHeader>
            <CardContent>
              <CardDescription className="text-xs">
                Rebuilds indexes to eliminate bloat and restore optimal index performance
              </CardDescription>
            </CardContent>
          </Card>
        </div>

        <Card>
          <CardHeader>
            <div className="flex items-center justify-between">
              <div>
                <CardTitle>Database Tables</CardTitle>
                <CardDescription>
                  Select maintenance operations to perform on each table
                </CardDescription>
              </div>
              <Button
                variant="outline"
                size="sm"
                onClick={() => refetch()}
                disabled={isLoading}
              >
                <RefreshCw className={`mr-2 h-4 w-4 ${isLoading ? 'animate-spin' : ''}`} />
                Refresh
              </Button>
            </div>
          </CardHeader>
          <CardContent>
            {isLoading ? (
              <div className="space-y-4">
                {Array.from({ length: 5 }).map((_, i) => (
                  <Skeleton key={i} className="h-12 w-full" />
                ))}
              </div>
            ) : tables && tables.length > 0 ? (
              <div className="rounded-md border">
                <Table>
                  <TableHeader>
                    <TableRow>
                      <TableHead>Table Name</TableHead>
                      <TableHead className="text-right">Rows</TableHead>
                      <TableHead className="text-right">Table Size</TableHead>
                      <TableHead className="text-right">Indexes Size</TableHead>
                      <TableHead className="text-right">Total Size</TableHead>
                      <TableHead className="text-right">Actions</TableHead>
                    </TableRow>
                  </TableHeader>
                  <TableBody>
                    {tables.map((table) => (
                      <TableRow key={table.table_name}>
                        <TableCell className="font-medium">
                          <code className="text-sm">{table.table_name}</code>
                        </TableCell>
                        <TableCell className="text-right">
                          {table.row_count?.toLocaleString() || 'N/A'}
                        </TableCell>
                        <TableCell className="text-right">
                          <Badge variant="secondary">{table.table_size}</Badge>
                        </TableCell>
                        <TableCell className="text-right">
                          <Badge variant="secondary">{table.indexes_size}</Badge>
                        </TableCell>
                        <TableCell className="text-right">
                          <Badge variant="outline">{table.total_size}</Badge>
                        </TableCell>
                        <TableCell className="text-right">
                          <div className="flex gap-2 justify-end">
                            <Button
                              variant="outline"
                              size="sm"
                              onClick={() => handleVacuum(table.table_name)}
                              disabled={isOperationPending(table.table_name)}
                            >
                              {isOperationPending(table.table_name) &&
                              vacuumMutation.isPending ? (
                                <RefreshCw className="h-3 w-3 animate-spin" />
                              ) : (
                                'Vacuum'
                              )}
                            </Button>
                            <Button
                              variant="outline"
                              size="sm"
                              onClick={() => handleAnalyze(table.table_name)}
                              disabled={isOperationPending(table.table_name)}
                            >
                              {isOperationPending(table.table_name) &&
                              analyzeMutation.isPending ? (
                                <RefreshCw className="h-3 w-3 animate-spin" />
                              ) : (
                                'Analyze'
                              )}
                            </Button>
                            <Button
                              variant="outline"
                              size="sm"
                              onClick={() => handleReindex(table.table_name)}
                              disabled={isOperationPending(table.table_name)}
                            >
                              {isOperationPending(table.table_name) &&
                              reindexMutation.isPending ? (
                                <RefreshCw className="h-3 w-3 animate-spin" />
                              ) : (
                                'Reindex'
                              )}
                            </Button>
                          </div>
                        </TableCell>
                      </TableRow>
                    ))}
                  </TableBody>
                </Table>
              </div>
            ) : (
              <div className="text-center py-12 text-muted-foreground">
                No tables available
              </div>
            )}
          </CardContent>
        </Card>
      </AdminPageLayout>
    </AdminLayout>
  );
}