import { Fragment } from "react";
import { useTranslation } from "react-i18next";
import { type Column } from "./ui/DataTable";
import VirtualGrid from "./ui/VirtualGrid";
import { CHANNEL_LAYOUT_SPEC } from "../lib/channelLayout";
import { navItemAttrs } from "../lib/listNav";
import { SURFACE } from "./ui/surfaces";

// The channel manager's `cards` layout (E4 S3), built by reusing the SAME `Column<T>` render closures
// the DataTable draws — so the subscribed and discovery tables (which have different columns) both get
// the card view for free, and a cell's behaviour (priority bump, tag toggle, sync, actions) is defined
// once. The `table` layout keeps DataTable; this renders only when the manager's layout is `cards`.
//
// Named slots place the columns that need bespoke positions; everything else flows in the meta line.
// Unlike DataTable's cramped narrow-screen card fallback, the desktop card is roomy, so it shows the
// `hideInCard` columns too (About, priority) — the user wants those affordances in every layout.
//
// Each card is a keyboard item (lib/listNav): `j`/`k` and the arrows walk the cards, and Enter opens
// the channel — the name ChannelLink renders is the card's open element.

interface ChannelLayoutGridProps<T> {
  rows: T[];
  columns: Column<T>[];
  rowKey: (row: T) => string;
  /** Column key docked at the top-right of the card (the priority stepper). */
  leadKey?: string;
  /** Column key rendered as a full-width description line (the About cell + its hover overlay). */
  aboutKey?: string;
  /** Column key rendered as the action cluster, pinned to the card's bottom edge. */
  actionsKey?: string;
  /** Column key docked at the top-right corner after the lead: the card's "…" (E28 C1), which
   *  belongs beside the name it acts on, not under the card's last line. */
  moreKey?: string;
  rowClassName?: (row: T) => string;
  /** Extra DOM props per card — same escape hatch, same single consumer, as `DataTable.rowProps`, so
   *  a channel answers the right-click in the card layout exactly as it does in the table. */
  rowProps?: (row: T) => Record<string, unknown>;
  emptyText?: string;
}

export default function ChannelLayoutGrid<T>({
  rows,
  columns,
  rowKey,
  leadKey,
  aboutKey,
  actionsKey,
  moreKey,
  rowClassName,
  rowProps,
  emptyText,
}: ChannelLayoutGridProps<T>) {
  const { t } = useTranslation();
  const spec = CHANNEL_LAYOUT_SPEC.cards;

  const slotted = new Set([leadKey, aboutKey, actionsKey, moreKey].filter(Boolean) as string[]);
  const primary = columns.filter((c) => c.cardPrimary);
  const lead = leadKey ? columns.find((c) => c.key === leadKey) : undefined;
  const about = aboutKey ? columns.find((c) => c.key === aboutKey) : undefined;
  const actions = actionsKey ? columns.find((c) => c.key === actionsKey) : undefined;
  const more = moreKey ? columns.find((c) => c.key === moreKey) : undefined;
  // Everything else flows in the meta line: not the heading, not a slotted column.
  const meta = columns.filter((c) => !c.cardPrimary && !slotted.has(c.key));

  const renderCard = (row: T, index: number) => (
    <div
      {...rowProps?.(row)}
      {...navItemAttrs(index)}
      className={`${SURFACE.card} p-3 h-full flex flex-col gap-2 ${rowClassName?.(row) ?? ""}`}
    >
      <div className="flex items-start justify-between gap-2">
        <div className="min-w-0 flex-1 font-medium">
          {primary.map((col) => (
            <Fragment key={col.key}>{col.render(row)}</Fragment>
          ))}
        </div>
        {lead && <div className="shrink-0">{lead.render(row)}</div>}
        {more && <div className="shrink-0 -my-1">{more.render(row)}</div>}
      </div>
      {about && <div className="min-w-0 text-sm">{about.render(row)}</div>}
      <div className="flex flex-wrap items-center gap-x-3 gap-y-1.5 text-sm min-w-0">
        {meta.map((col) => (
          <span key={col.key} className="inline-flex items-center gap-1">
            {col.cardLabel !== false && <span className="text-muted text-xs">{col.header}</span>}
            {col.render(row)}
          </span>
        ))}
      </div>
      {actions && <div className="mt-auto pt-1">{actions.render(row)}</div>}
    </div>
  );

  if (rows.length === 0) {
    return (
      <div className="text-muted py-8 text-center text-sm">{emptyText ?? t("datatable.empty")}</div>
    );
  }

  return (
    <VirtualGrid
      items={rows}
      getKey={rowKey}
      minCol={spec.minCol}
      colMaxWidth={null}
      rowEst={spec.rowEst}
      keyboardNav
      renderItem={(row, _itemWidth, index) => renderCard(row, index)}
    />
  );
}