// ---------------------------------------------------------------------------
// DataTable — pre-built sortable, paginated table wired to AnyDB
// ---------------------------------------------------------------------------
// PRE-INSTALLED. CodeWriterAgent just uses:
//   import { DataTable } from "@/components/DataTable"
//   <DataTable
//     collection="orders"
//     columns={[
//       { key: 'customer', label: 'Customer' },
//       { key: 'total_cents', label: 'Amount', render: (v) => `$${(v/100).toFixed(2)}` },
//       { key: 'status', label: 'Status', render: (v) => <Badge>{v}</Badge> },
//       { key: 'created_at', label: 'Date', render: (v) => new Date(v).toLocaleDateString() },
//     ]}
//     filter={{ status: 'active' }}
//     pageSize={10}
//     searchField="customer"
//   />
// ---------------------------------------------------------------------------

import { useState, useMemo } from "react";
import { useCollection } from "@/hooks/use-anydb";
import { Input } from "@/components/ui/input";
import { Button } from "@/components/ui/button";
import { Skeleton } from "@/components/ui/skeleton";
import { ChevronUp, ChevronDown, Search, ChevronLeft, ChevronRight } from "lucide-react";

interface Column<T = any> {
  key: string;
  label: string;
  sortable?: boolean;
  render?: (value: any, row: T) => React.ReactNode;
  className?: string;
}

interface DataTableProps<T = any> {
  collection: string;
  columns: Column<T>[];
  filter?: Record<string, any>;
  pageSize?: number;
  searchField?: string;
  searchPlaceholder?: string;
  onRowClick?: (row: T) => void;
  emptyMessage?: string;
  className?: string;
}

export function DataTable<T extends Record<string, any> = any>({
  collection,
  columns,
  filter = {},
  pageSize = 10,
  searchField,
  searchPlaceholder = "Search...",
  onRowClick,
  emptyMessage = "No data found",
  className = "",
}: DataTableProps<T>) {
  const [page, setPage] = useState(0);
  const [sortKey, setSortKey] = useState<string | null>(null);
  const [sortDir, setSortDir] = useState<1 | -1>(-1);
  const [search, setSearch] = useState("");

  const queryFilter = useMemo(() => {
    const f = { ...filter };
    if (searchField && search.trim()) {
      f[searchField] = { $regex: search.trim(), $options: "i" };
    }
    return f;
  }, [filter, searchField, search]);

  const sort = sortKey ? { [sortKey]: sortDir } : { created_at: -1 as const };

  const { data, total, loading, error } = useCollection<T>(collection, {
    filter: queryFilter,
    sort,
    limit: pageSize,
    skip: page * pageSize,
  });

  const totalPages = Math.ceil(total / pageSize);

  const handleSort = (key: string) => {
    if (sortKey === key) {
      setSortDir(d => (d === 1 ? -1 : 1));
    } else {
      setSortKey(key);
      setSortDir(-1);
    }
    setPage(0);
  };

  if (error) {
    return (
      <div className="text-center py-8 text-destructive">
        <p>Failed to load data: {error}</p>
        <Button variant="outline" size="sm" className="mt-2" onClick={() => window.location.reload()}>
          Retry
        </Button>
      </div>
    );
  }

  return (
    <div className={`rounded-lg border bg-card ${className}`}>
      {/* Search bar */}
      {searchField && (
        <div className="p-4 border-b">
          <div className="relative max-w-sm">
            <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
            <Input
              placeholder={searchPlaceholder}
              value={search}
              onChange={(e) => { setSearch(e.target.value); setPage(0); }}
              className="pl-9 h-10"
            />
          </div>
        </div>
      )}

      {/* Table */}
      <div className="overflow-x-auto">
        <table className="w-full text-sm">
          <thead>
            <tr className="border-b bg-muted/50">
              {columns.map((col) => (
                <th
                  key={col.key}
                  className={`px-4 py-3 text-left font-medium text-muted-foreground ${
                    col.sortable !== false ? "cursor-pointer select-none hover:text-foreground transition-colors" : ""
                  } ${col.className || ""}`}
                  onClick={() => col.sortable !== false && handleSort(col.key)}
                >
                  <div className="flex items-center gap-1">
                    {col.label}
                    {col.sortable !== false && sortKey === col.key && (
                      sortDir === 1 ? <ChevronUp className="h-3 w-3" /> : <ChevronDown className="h-3 w-3" />
                    )}
                  </div>
                </th>
              ))}
            </tr>
          </thead>
          <tbody>
            {loading ? (
              Array.from({ length: pageSize }).map((_, i) => (
                <tr key={i} className="border-b">
                  {columns.map((col) => (
                    <td key={col.key} className="px-4 py-3">
                      <Skeleton className="h-5 w-full" />
                    </td>
                  ))}
                </tr>
              ))
            ) : data.length === 0 ? (
              <tr>
                <td colSpan={columns.length} className="px-4 py-12 text-center text-muted-foreground">
                  {emptyMessage}
                </td>
              </tr>
            ) : (
              data.map((row, i) => (
                <tr
                  key={row._id || i}
                  className={`border-b transition-colors hover:bg-muted/30 ${
                    onRowClick ? "cursor-pointer" : ""
                  }`}
                  onClick={() => onRowClick?.(row)}
                >
                  {columns.map((col) => (
                    <td key={col.key} className={`px-4 py-3 ${col.className || ""}`}>
                      {col.render ? col.render(row[col.key], row) : String(row[col.key] ?? "")}
                    </td>
                  ))}
                </tr>
              ))
            )}
          </tbody>
        </table>
      </div>

      {/* Pagination */}
      {totalPages > 1 && (
        <div className="flex items-center justify-between px-4 py-3 border-t">
          <p className="text-sm text-muted-foreground">
            Showing {page * pageSize + 1}–{Math.min((page + 1) * pageSize, total)} of {total}
          </p>
          <div className="flex items-center gap-2">
            <Button
              variant="outline"
              size="sm"
              disabled={page === 0}
              onClick={() => setPage(p => p - 1)}
              className="h-8"
            >
              <ChevronLeft className="h-4 w-4" />
            </Button>
            <span className="text-sm tabular-nums">
              {page + 1} / {totalPages}
            </span>
            <Button
              variant="outline"
              size="sm"
              disabled={page >= totalPages - 1}
              onClick={() => setPage(p => p + 1)}
              className="h-8"
            >
              <ChevronRight className="h-4 w-4" />
            </Button>
          </div>
        </div>
      )}
    </div>
  );
}