SpotifyScript.ts

    return playlists_response.public_playlists.map(function (playlist) {
        const image_uri = playlist.image_url
        return new PlatformPlaylist({
            id: new PlatformID(PLATFORM, id_from_uri(playlist.uri), plugin.config.id),
            name: playlist.name,
            author: new PlatformAuthorLink(
                new PlatformID(PLATFORM, id_from_uri(playlist.owner_uri), plugin.config.id),
                playlist.owner_name,
                `${USER_URL_PREFIX}${id_from_uri(playlist.owner_uri)}`,
                // TODO load the owner's image somehow
            ),
            // TODO load the playlist creation or modificiation date somehow datetime?: number
            url: `${PLAYLIST_URL_PREFIX}${id_from_uri(playlist.uri)}`,
            // TODO load the video count somehow videoCount?: number
            thumbnail: url_from_image_uri(image_uri)
        })
    })
}
//#endregion

//#region utilities
function url_from_image_uri(image_uri: string) {
    const match_result = image_uri.match(/^spotify:(image|mosaic):([0-9a-zA-Z:]*)$/)
    if (match_result === null) {
        throw new ScriptException("regex error")
    }
    const image_type: "image" | "mosaic" = match_result[1] as "image" | "mosaic"
    if (image_type === undefined) {
        throw new ScriptException("regex error")
    }
    const uri_id = match_result[2]
    if (uri_id === undefined) {
        throw new ScriptException("regex error")
    }
    switch (image_type) {
        case "image":
            return `https://i.scdn.co/image/${uri_id}`
        case "mosaic":
            return `https://mosaic.scdn.co/300/${uri_id.split(":").join("")}`
        default:
            throw assert_exhaustive(image_type)
    }
}
function id_from_uri(uri: string): string {
    const match_result = uri.match(/^spotify:(show|album|track|artist|playlist|section|episode|user):([0-9a-zA-Z]*)$/)
    if (match_result === null) {
        throw new ScriptException("regex error")
    }
    const uri_id = match_result[2]
    if (uri_id === undefined) {
        throw new ScriptException("regex error")
    }
    return uri_id
}
/**
 * Converts seconds to the timestamp format used in WebVTT
 * @param seconds 
 * @returns 
 */
function milliseconds_to_WebVTT_timestamp(milliseconds: number) {
    return new Date(milliseconds).toISOString().substring(11, 23)
}
function assert_never(value: never) {
    log(value)
}
function log_passthrough<T>(value: T): T {
    log(value)
    return value
}
function assert_exhaustive(value: never): void
function assert_exhaustive(value: never, exception_message: string): ScriptException
function assert_exhaustive(value: never, exception_message?: string): ScriptException | undefined {
    log(["Spotify log:", value])
    if (exception_message !== undefined) {
        return new ScriptException(exception_message)
    }
    return
}
//#endregion

//#region bad

// https://open.spotifycdn.com/cdn/build/web-player/vendor~web-player.391a2438.js
const Z = "0123456789abcdef"
const Q = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
const ee: string[] = []
ee.length = 256
for (let ke = 0; ke < 256; ke++)
    // @ts-expect-error
    ee[ke] = Z[ke >> 4] + Z[15 & ke]
const te: number[] = []
te.length = 128
for (let ke = 0; ke < Q.length; ++ke)
    te[Q.charCodeAt(ke)] = ke

function get_gid(song_uri_id: string) {
    return 22 === song_uri_id.length ? function (e) {
        if (22 !== e.length)
            return null
        const t = 2.3283064365386963e-10
            , n = 4294967296
            , i = 238328
        let o, r, a, s, c
        // @ts-expect-error
        return o = 56800235584 * te[e.charCodeAt(0)] + 916132832 * te[e.charCodeAt(1)] + 14776336 * te[e.charCodeAt(2)] + 238328 * te[e.charCodeAt(3)] + 3844 * te[e.charCodeAt(4)] + 62 * te[e.charCodeAt(5)] + te[e.charCodeAt(6)],
            r = o * t | 0,
            o -= r * n,
            // @ts-expect-error
            c = 3844 * te[e.charCodeAt(7)] + 62 * te[e.charCodeAt(8)] + te[e.charCodeAt(9)],
            o = o * i + c,
            o -= (c = o * t | 0) * n,
            r = r * i + c,
            // @ts-expect-error
            c = 3844 * te[e.charCodeAt(10)] + 62 * te[e.charCodeAt(11)] + te[e.charCodeAt(12)],
            o = o * i + c,
            o -= (c = o * t | 0) * n,
            r = r * i + c,
            r -= (c = r * t | 0) * n,
            a = c,
            // @ts-expect-error
            c = 3844 * te[e.charCodeAt(13)] + 62 * te[e.charCodeAt(14)] + te[e.charCodeAt(15)],
            o = o * i + c,
            o -= (c = o * t | 0) * n,
            r = r * i + c,
            r -= (c = r * t | 0) * n,
            a = a * i + c,
            // @ts-expect-error
            c = 3844 * te[e.charCodeAt(16)] + 62 * te[e.charCodeAt(17)] + te[e.charCodeAt(18)],
            o = o * i + c,
            o -= (c = o * t | 0) * n,
            r = r * i + c,
            r -= (c = r * t | 0) * n,
            a = a * i + c,
            a -= (c = a * t | 0) * n,
            s = c,
            // @ts-expect-error
            c = 3844 * te[e.charCodeAt(19)] + 62 * te[e.charCodeAt(20)] + te[e.charCodeAt(21)],
            o = o * i + c,
            o -= (c = o * t | 0) * n,
            r = r * i + c,
            r -= (c = r * t | 0) * n,
            a = a * i + c,
            a -= (c = a * t | 0) * n,
            s = s * i + c,
            s -= (c = s * t | 0) * n,
            // @ts-expect-error
            c ? null : ee[s >>> 24] + ee[s >>> 16 & 255] + ee[s >>> 8 & 255] + ee[255 & s] + ee[a >>> 24] + ee[a >>> 16 & 255] + ee[a >>> 8 & 255] + ee[255 & a] + ee[r >>> 24] + ee[r >>> 16 & 255] + ee[r >>> 8 & 255] + ee[255 & r] + ee[o >>> 24] + ee[o >>> 16 & 255] + ee[o >>> 8 & 255] + ee[255 & o]
    }(song_uri_id) : song_uri_id
}
//#endregion

// export statements are removed during build step
// used for unit testing in SpotifyScript.test.ts
// export {
    get_gid,
    assert_never,
    log_passthrough
}