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

import type { SQLOutputValue } from "node:sqlite";
import type { Playlist } from "../../shared/playlist.ts";

/**
 * A row of the `playlists` table. Queries may add `dump_count` and
 * `owner_username`, which {@link playlistRowToApi} carries over.
 */
export interface PlaylistRow {
  /** The playlist's id. */
  id: string;
  /** The owner's id. */
  user_id: string;
  /** The playlist's title. */
  title: string;
  /** The playlist's URL slug. */
  slug: string | null;
  /** The owner's description, in Markdown. */
  description: string | null;
  /** 1 when anyone may see the playlist, 0 when only its owner does. */
  is_public: number;
  /** When the playlist was created. */
  created_at: string;
  /** When the playlist was last changed, if ever. */
  updated_at: string | null;
  /** The cover image's type, null without one. */
  image_mime: string | null;
  /** Any other column the query selects. */
  [key: string]: SQLOutputValue;
}

/** Checks whether `obj` is a {@link PlaylistRow}. */
export function isPlaylistRow(
  obj: unknown,
): obj is PlaylistRow {
  return !!obj && typeof obj === "object" &&
    "id" in obj && typeof obj.id === "string" &&
    "user_id" in obj && typeof obj.user_id === "string" &&
    "title" in obj && typeof obj.title === "string" &&
    "slug" in obj && (typeof obj.slug === "string" || obj.slug === null) &&
    "description" in obj &&
    (typeof obj.description === "string" || obj.description === null) &&
    "is_public" in obj && typeof obj.is_public === "number" &&
    "created_at" in obj && typeof obj.created_at === "string" &&
    "updated_at" in obj &&
    (typeof obj.updated_at === "string" || obj.updated_at === null) &&
    "image_mime" in obj &&
    (typeof obj.image_mime === "string" || obj.image_mime === null);
}

/** Converts a row to the API's {@link Playlist}. */
export function playlistRowToApi(row: PlaylistRow): Playlist {
  return {
    id: row.id,
    userId: row.user_id,
    title: row.title,
    slug: row.slug ?? undefined,
    description: row.description ?? undefined,
    isPublic: Boolean(row.is_public),
    createdAt: new Date(row.created_at),
    updatedAt: row.updated_at ? new Date(row.updated_at) : undefined,
    imageMime: row.image_mime ?? undefined,
    dumpCount: typeof row.dump_count === "number" ? row.dump_count : undefined,
    ownerUsername: typeof row.owner_username === "string"
      ? row.owner_username
      : undefined,
  };
}