commonMain.Lyrics.kt Maven / Gradle / Ivy

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package dev.schlaubi.lyrics

import dev.schlaubi.lyrics.internal.model.*
import dev.schlaubi.lyrics.internal.util.*
import dev.schlaubi.lyrics.protocol.Lyrics
import dev.schlaubi.lyrics.protocol.SearchTrack
import dev.schlaubi.lyrics.protocol.TextLyrics
import dev.schlaubi.lyrics.protocol.TimedLyrics
import io.ktor.client.*
import io.ktor.client.call.*
import io.ktor.client.plugins.*
import io.ktor.client.plugins.contentnegotiation.*
import io.ktor.client.plugins.resources.*
import io.ktor.client.request.*
import io.ktor.http.*
import io.ktor.serialization.kotlinx.json.*
import io.ktor.utils.io.core.*
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.SupervisorJob
import kotlinx.coroutines.cancel
import kotlinx.serialization.json.JsonArray
import kotlinx.serialization.json.JsonObject
import kotlinx.serialization.json.jsonArray
import kotlinx.serialization.json.jsonObject
import kotlin.coroutines.CoroutineContext

internal expect fun newClient(config: HttpClientConfig<*>.() -> Unit): HttpClient

/**
 * Client for retrieving lyrics from the YouTube API.
 */
public class LyricsClient : Closeable, CoroutineScope {
    override val coroutineContext: CoroutineContext = Dispatchers.IO + SupervisorJob()
    private val client = newClient {
        install(ContentNegotiation) {
            json()
        }
        install(Resources)
        defaultRequest {
            url.takeFrom("https://music.youtube.com/")
        }
    }

    /**
     * Requests the [Lyrics] for [videoId].
     */
    public suspend fun requestLyrics(videoId: String): Lyrics {
        val nextPage = requestNextPage(videoId)
        val browseId = nextPage.browseEndpoint ?: throw LyricsNotFoundException()

        val browseResult = request(MusicApi.Browse(), BrowseRequest(mobileYoutubeMusicContext, browseId))

        val lyricsData = browseResult.lyricsData
        val albumArt = nextPage.thumbnails?.map { it.jsonObject.toAlbumArt() } ?: emptyList()
        return if (lyricsData != null) {
            val source = lyricsData.source
            TimedLyrics(nextPage.getTracks(albumArt), source, lyricsData.lines)
        } else {
            val renderer = browseResult.musicDescriptionShelfRenderer ?: notFound()
            val text = renderer.getRunningText("description")!!
            val source = renderer.getRunningText("footer")!!
            TextLyrics(nextPage.getTracks(albumArt), source, text)
        }
    }

    /**
     * Searches for [query].
     *
     * @param region the region used for the search
     *
     * @see SearchTrack
     */
    public suspend fun search(query: String, region: String? = null): List {
        val result = request(MusicApi.Search(), SearchRequest(mobileYoutubeMusicContext(region), query, onlyTracksSearchParam))

        // /contents/tabbedSearchResultsRenderer/tabs/0/tabRenderer/content/sectionListRenderer/contents/1/musicCardShelfRenderer/title/runs/0/navigationEndpoint/watchEndpoint/videoId
        val section = result
            .getJsonObject("contents")
            ?.getJsonObject("tabbedSearchResultsRenderer")
            ?.getJsonArray("tabs")
            ?.getJsonObject(0)
            ?.getJsonObject("tabRenderer")
            ?.getJsonObject("content")
            ?.getJsonObject("sectionListRenderer")
            ?.getJsonArray("contents") ?: JsonArray(emptyList())

        val otherResults = ((section.firstOrNull {
            it.jsonObject.getJsonObject("musicShelfRenderer")
                ?.getJsonArray("contents")?.any { content ->
                    content.jsonObject.getJsonObject("musicTwoColumnItemRenderer")
                        ?.getJsonObject("navigationEndpoint")
                        ?.getJsonObject("watchEndpoint")
                        ?.getString("videoId") != null
                } == true
        }?.jsonObject?.getJsonObject("musicShelfRenderer")?.getJsonArray("contents") ?: JsonArray(emptyList())))
            .map { item ->
                val renderer = item.jsonObject
                    .getJsonObject("musicTwoColumnItemRenderer") ?: error("")
                val title = renderer.getRunningText("title")!!
                val videoId =
                    renderer.getJsonObject("navigationEndpoint")
                        ?.getJsonObject("watchEndpoint")
                        ?.getString("videoId")!!

                SearchTrack(videoId, title)
            }

        return otherResults
    }

    override fun close() {
        client.close()
        cancel()
    }

    private suspend inline fun  request(resource: T, body: B) =
        client.post(resource) {
            contentType(ContentType.Application.Json)
            setBody(body)
        }.body()

    private suspend fun requestNextPage(videoId: String) =
        request(MusicApi.Next(), NextRequest(mobileYoutubeMusicContext, videoId))
}