// ── Shared: Data Table Component ──
// Generic data table powered by @tanstack/react-table.
// Supports sorting, filtering, row selection, column visibility, faceted values, and pagination.
// Renders loading skeletons (5 rows) while data is loading.

"use client"

import * as React from "react"
import {
  ColumnDef,
  ColumnFiltersState,
  SortingState,
  VisibilityState,
  flexRender,
  getCoreRowModel,
  getFacetedRowModel,
  getFacetedUniqueValues,
  getFilteredRowModel,
  getPaginationRowModel,
  getSortedRowModel,
  useReactTable,
} from "@tanstack/react-table"
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table"
import { DataTablePagination } from "./data-table-pagination"
import { cn } from "@/lib/utils"

interface DataTableProps<TData, TValue> {
  columns: ColumnDef<TData, TValue>[]
  data: TData[]
  toolbar?: React.ReactNode
  loading?: boolean
  emptyMessage?: string
}

/**
 * DataTable — fully featured generic table with TanStack Table.
 * Manages sorting, column filters, row selection, visibility, and pagination internally.
 * Shows skeleton placeholders when `loading` is true.
 */
export function DataTable<TData, TValue>({
  columns,
  data,
  toolbar,
  loading,
  emptyMessage = "No results found.",
}: DataTableProps<TData, TValue>) {
  const [rowSelection, setRowSelection] = React.useState({})
  const [columnVisibility, setColumnVisibility] = React.useState<VisibilityState>({})
  const [columnFilters, setColumnFilters] = React.useState<ColumnFiltersState>([])
  const [sorting, setSorting] = React.useState<SortingState>([])

  const table = useReactTable({
    data,
    columns,
    state: {
      sorting,
      columnVisibility,
      rowSelection,
      columnFilters,
    },
    enableRowSelection: true,
    onRowSelectionChange: setRowSelection,
    onSortingChange: setSorting,
    onColumnFiltersChange: setColumnFilters,
    onColumnVisibilityChange: setColumnVisibility,
    getCoreRowModel: getCoreRowModel(),
    getFilteredRowModel: getFilteredRowModel(),
    getPaginationRowModel: getPaginationRowModel(),
    getSortedRowModel: getSortedRowModel(),
    getFacetedRowModel: getFacetedRowModel(),
    getFacetedUniqueValues: getFacetedUniqueValues(),
  })

  return (
    <div className="space-y-4">
      {toolbar && <div className="flex items-center justify-between gap-4">{toolbar}</div>}
      <div className="rounded-md border">
        <Table>
          <TableHeader>
            {table.getHeaderGroups().map((headerGroup) => (
              <TableRow key={headerGroup.id}>
                {headerGroup.headers.map((header) => (
                  <TableHead key={header.id} colSpan={header.colSpan}>
                    {header.isPlaceholder
                      ? null
                      : flexRender(header.column.columnDef.header, header.getContext())}
                  </TableHead>
                ))}
              </TableRow>
            ))}
          </TableHeader>
          <TableBody>
            {loading ? (
              Array.from({ length: 5 }).map((_, i) => (
                <TableRow key={i}>
                  {columns.map((_, ci) => (
                    <TableCell key={ci}>
                      <div className="h-4 animate-pulse rounded bg-muted" />
                    </TableCell>
                  ))}
                </TableRow>
              ))
            ) : table.getRowModel().rows?.length ? (
              table.getRowModel().rows.map((row) => (
                <TableRow
                  key={row.id}
                  data-state={row.getIsSelected() && "selected"}
                  className={cn("cursor-pointer")}
                >
                  {row.getVisibleCells().map((cell) => (
                    <TableCell key={cell.id}>
                      {flexRender(cell.column.columnDef.cell, cell.getContext())}
                    </TableCell>
                  ))}
                </TableRow>
              ))
            ) : (
              <TableRow>
                <TableCell colSpan={columns.length} className="h-24 text-center">
                  <div className="flex flex-col items-center gap-2 text-muted-foreground">
                    <p>{emptyMessage}</p>
                  </div>
                </TableCell>
              </TableRow>
            )}
          </TableBody>
        </Table>
      </div>
      <DataTablePagination table={table} />
    </div>
  )
}