/**
 * The `categories` table: its row type, its guard, and its mapper to the API's
 * {@link Category}.
 *
 * @module
 */

import type { SQLOutputValue } from "node:sqlite";
import type { Category } from "../../shared/category.ts";

/** A row of the `categories` table. */
export interface CategoryRow {
  /** The category's id. */
  id: string;
  /** The category's URL slug, at the site root. */
  slug: string;
  /** The category's display name. */
  name: string;
  /** The category's place in the list, ascending. */
  position: number;
  /** When the category was created. */
  created_at: string;
  /** When the category was last changed, if ever. */
  updated_at: string | null;
  /** Any other column the query selects. */
  [key: string]: SQLOutputValue;
}

/** Checks whether `obj` is a {@link CategoryRow}. */
export function isCategoryRow(obj: unknown): obj is CategoryRow {
  return !!obj && typeof obj === "object" &&
    "id" in obj && typeof obj.id === "string" &&
    "slug" in obj && typeof obj.slug === "string" &&
    "name" in obj && typeof obj.name === "string" &&
    "position" in obj && typeof obj.position === "number" &&
    "created_at" in obj && typeof obj.created_at === "string" &&
    "updated_at" in obj &&
    (typeof obj.updated_at === "string" || obj.updated_at === null);
}

/** Converts a row to the API's {@link Category}. */
export function categoryRowToApi(row: CategoryRow): Category {
  return {
    id: row.id,
    slug: row.slug,
    name: row.name,
    position: row.position,
    createdAt: new Date(row.created_at),
    updatedAt: row.updated_at ? new Date(row.updated_at) : undefined,
  };
}