joystream-lib/media.ts

import { ApiPromise } from "@polkadot/api";
import { Vec, Option } from "@polkadot/types";
import { Hash } from "@joystream/types/common";
import { Entity } from "@joystream/types/content-directory";
import { ContentId, DataObject } from "@joystream/types/media";
import { getNextEntity, getEntity, getDataObject } from "./api";
import { Channel, Media } from "./types";

const CHANNEL_CLASS_iD = 1;
const VIDEO_CLASS_iD = 10;

const getEntities = async (
  api: ApiPromise,
  blockHash: Hash
): Promise<Map<number, Entity>> => {
  let nrEntities: number = await getNextEntity(api, blockHash);
  let entities = new Map<number, Entity>();
  for (let i = 0; i < nrEntities; ++i) {
    const entity: Entity = await getEntity(api, blockHash, i);
    entities.set(i, entity);
  }
  return entities;
};

export const computeUsedSpaceInMbs = async (
  api: ApiPromise,
  contentIds: Vec<ContentId>
): Promise<number> => {
  let space = 0;
  for (let contentId of contentIds) {
    const dataObject: Option<DataObject> = await getDataObject(api, contentId);
    space += dataObject.unwrap().size_in_bytes.toNumber();
  }
  return space / 1024 / 1024;
};

export const parseVideos = async (
  entities: Map<number, Entity>
): Promise<Media[]> => {
  let videos: Media[] = [];
  for (let [key, entity] of entities) {
    if (entity.class_id.toNumber() != VIDEO_CLASS_iD || entity.values.isEmpty)
      continue;
    let values = Array.from(entity.getField("values").entries());
    if (values.length < 2 || values[2].length < 1) continue;

    let title = values[2][1].getValue().toString();
    videos.push(new Media(key, title));
  }

  return videos;
};

const parseChannels = async (
  entities: Map<number, Entity>
): Promise<Channel[]> => {
  let channels: Channel[] = [];

  for (let [key, entity] of entities) {
    if (
      entity.class_id.toNumber() != CHANNEL_CLASS_iD ||
      entity.values.isEmpty
    ) {
      continue;
    }
    let values = Array.from(entity.getField("values").entries());

    let title = values[0][1].getValue().toString();
    channels.push(new Channel(key, title));
  }
  return channels;
};