Error Handling WIP

2024-11-22 09:04:32 +01:00 · 2021-06-21 17:55:35 +05:30 · 2021-06-21 17:55:35 +05:30 · 8d5e9cdccc
commit 8d5e9cdccc
parent 0b7b93ba63
17 changed files with 235 additions and 177 deletions
--- a/common/data-models/src/commonMain/kotlin/com/shabinder/common/models/SpotiFlyerException.kt
+++ b/common/data-models/src/commonMain/kotlin/com/shabinder/common/models/SpotiFlyerException.kt
@ -3,6 +3,7 @@ package com.shabinder.common.models
 sealed class SpotiFlyerException(override val message: String): Exception(message) {

    data class FeatureNotImplementedYet(override val message: String = "Feature not yet implemented."): SpotiFlyerException(message)
+    data class NoInternetException(override val message: String = "Check Your Internet Connection"): SpotiFlyerException(message)

    data class NoMatchFound(
        val trackName: String? = null,
@ -14,6 +15,15 @@ sealed class SpotiFlyerException(override val message: String): Exception(messag
        override val message: String = "No Downloadable link found for videoID: $videoID"
    ): SpotiFlyerException(message)

+    data class DownloadLinkFetchFailed(
+        val trackName: String,
+        val jioSaavnError: Throwable,
+        val ytMusicError: Throwable,
+        override val message: String = "No Downloadable link found for track: $trackName," +
+                " \n JioSaavn Error's StackTrace: ${jioSaavnError.stackTraceToString()} \n " +
+                " \n YtMusic Error's StackTrace: ${ytMusicError.stackTraceToString()} \n "
+    ): SpotiFlyerException(message)
+
    data class LinkInvalid(
        val link: String? = null,
        override val message: String = "Entered Link is NOT Valid!\n ${link ?: ""}"
--- a/common/data-models/src/commonMain/kotlin/com/shabinder/common/models/event/Event.kt
+++ b/common/data-models/src/commonMain/kotlin/com/shabinder/common/models/event/Event.kt
@ -1,5 +1,8 @@
 package com.shabinder.common.models.event

+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+
 inline fun <reified X> Event<*, *>.getAs() = when (this) {
    is Event.Success -> value as? X
    is Event.Failure -> error as? X
@ -128,7 +131,7 @@ inline fun <V, E : Throwable> Event<V, E>.unwrapError(success: (V) -> Nothing):
    apply { component1()?.let(success) }.component2()!!


-sealed class Event<out V : Any?, out E : Throwable> {
+sealed class Event<out V : Any?, out E : Throwable>: ReadOnlyProperty<Any?, V> {

    open operator fun component1(): V? = null
    open operator fun component2(): E? = null
@ -138,13 +141,11 @@ sealed class Event<out V : Any?, out E : Throwable> {
        is Failure -> failure(this.error)
    }

-    abstract fun get(): V
+    abstract val value: V

-    class Success<out V : Any?>(val value: V) : Event<V, Nothing>() {
+    class Success<out V : Any?>(override val value: V) : Event<V, Nothing>() {
        override fun component1(): V? = value

-        override fun get(): V = value
-
        override fun toString() = "[Success: $value]"

        override fun hashCode(): Int = value.hashCode()
@ -153,12 +154,14 @@ sealed class Event<out V : Any?, out E : Throwable> {
            if (this === other) return true
            return other is Success<*> && value == other.value
        }
+
+        override fun getValue(thisRef: Any?, property: KProperty<*>): V = value
    }

    class Failure<out E : Throwable>(val error: E) : Event<Nothing, E>() {
-        override fun component2(): E? = error
+        override fun component2(): E = error

-        override fun get() = throw error
+        override val value: Nothing = throw error

        fun getThrowable(): E = error

@ -170,6 +173,8 @@ sealed class Event<out V : Any?, out E : Throwable> {
            if (this === other) return true
            return other is Failure<*> && error == other.error
        }
+
+        override fun getValue(thisRef: Any?, property: KProperty<*>): Nothing = value
    }

    companion object {
--- a/common/data-models/src/commonMain/kotlin/com/shabinder/common/models/event/coroutines/SuspendableEvent.kt
+++ b/common/data-models/src/commonMain/kotlin/com/shabinder/common/models/event/coroutines/SuspendableEvent.kt
@ -1,5 +1,8 @@
 package com.shabinder.common.models.event.coroutines

+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+
 inline fun <reified X> SuspendableEvent<*, *>.getAs() = when (this) {
    is SuspendableEvent.Success -> value as? X
    is SuspendableEvent.Failure -> error as? X
@ -52,16 +55,24 @@ suspend inline fun <V : Any?, U : Any?, E : Throwable> SuspendableEvent<V, E>.fl

 suspend inline fun <V : Any?, E : Throwable, E2 : Throwable> SuspendableEvent<V, E>.mapError(
    crossinline transform: suspend (E) -> E2
-) = when (this) {
+) = try {
+    when (this) {
        is SuspendableEvent.Success -> SuspendableEvent.Success<V, E2>(value)
        is SuspendableEvent.Failure -> SuspendableEvent.Failure<V, E2>(transform(error))
+    }
+} catch (ex: Throwable) {
+    SuspendableEvent.error(ex as E)
 }

 suspend inline fun <V : Any?, E : Throwable, E2 : Throwable> SuspendableEvent<V, E>.flatMapError(
    crossinline transform: suspend (E) -> SuspendableEvent<V, E2>
-) = when (this) {
+) = try {
+    when (this) {
        is SuspendableEvent.Success -> SuspendableEvent.Success(value)
        is SuspendableEvent.Failure -> transform(error)
+    }
+} catch (ex: Throwable) {
+    SuspendableEvent.error(ex as E)
 }

 suspend inline fun <V : Any?, E : Throwable> SuspendableEvent<V, E>.any(
@ -89,7 +100,7 @@ suspend fun <V : Any?, E : Throwable> List<SuspendableEvent<V, E>>.lift(): Suspe
    }
 }

-sealed class SuspendableEvent<out V : Any?, out E : Throwable> {
+sealed class SuspendableEvent<out V : Any?, out E : Throwable>: ReadOnlyProperty<Any?,V> {

    abstract operator fun component1(): V?
    abstract operator fun component2(): E?
@ -115,6 +126,8 @@ sealed class SuspendableEvent<out V : Any?, out E : Throwable> {
            if (this === other) return true
            return other is Success<*, *> && value == other.value
        }
+
+        override fun getValue(thisRef: Any?, property: KProperty<*>): V = value
    }

    class Failure<out V : Any?, out E : Throwable>(val error: E) : SuspendableEvent<V, E>() {
@ -133,6 +146,8 @@ sealed class SuspendableEvent<out V : Any?, out E : Throwable> {
            if (this === other) return true
            return other is Failure<*, *> && error == other.error
        }
+
+        override fun getValue(thisRef: Any?, property: KProperty<*>): V = value
    }

    companion object {
@ -143,14 +158,14 @@ sealed class SuspendableEvent<out V : Any?, out E : Throwable> {
            return value?.let { Success<V, Nothing>(it) } ?: error(fail())
        }

-        suspend inline fun <V : Any?, E : Throwable> of(crossinline f: suspend () -> V): SuspendableEvent<V, E> = try {
-            Success(f())
+        suspend inline fun <V : Any?, E : Throwable> of(crossinline block: suspend () -> V): SuspendableEvent<V, E> = try {
+            Success(block())
        } catch (ex: Throwable) {
            Failure(ex as E)
        }

-        suspend inline operator fun <V : Any?> invoke(crossinline f: suspend () -> V): SuspendableEvent<V, Throwable> = try {
-            Success(f())
+        suspend inline operator fun <V : Any?> invoke(crossinline block: suspend () -> V): SuspendableEvent<V, Throwable> = try {
+            Success(block())
        } catch (ex: Throwable) {
            Failure(ex)
        }
--- a/common/dependency-injection/src/androidMain/kotlin/com/shabinder/common/di/worker/ForegroundService.kt
+++ b/common/dependency-injection/src/androidMain/kotlin/com/shabinder/common/di/worker/ForegroundService.kt
@ -76,7 +76,6 @@ class ForegroundService : Service(), CoroutineScope {

    private lateinit var downloadManager: DownloadManager
    private lateinit var downloadService: ParallelExecutor
-    private val ytDownloader get() = fetcher.youtubeProvider.ytDownloader
    private val fetcher: FetchPlatformQueryResult by inject()
    private val logger: Kermit by inject()
    private val dir: Dir by inject()
@ -161,15 +160,17 @@ class ForegroundService : Service(), CoroutineScope {
        trackList.forEach {
            launch(Dispatchers.IO) {
                downloadService.execute {
-                    val url = fetcher.findMp3DownloadLink(it)
-                    if (!url.isNullOrBlank()) { // Successfully Grabbed Mp3 URL
+                    fetcher.findMp3DownloadLink(it).fold(
+                        success = { url ->
                            enqueueDownload(url, it)
-                    } else {
+                        },
+                        failure = { _ ->
                            sendTrackBroadcast(Status.FAILED.name, it)
                            failed++
                            updateNotification()
                            allTracksStatus[it.title] = DownloadStatus.Failed
                        }
+                    )
                }
            }
        }
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/FetchPlatformQueryResult.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/FetchPlatformQueryResult.kt
@ -26,25 +26,33 @@ import com.shabinder.common.di.providers.YoutubeMusic
 import com.shabinder.common.di.providers.YoutubeProvider
 import com.shabinder.common.di.providers.get
 import com.shabinder.common.models.PlatformQueryResult
+import com.shabinder.common.models.SpotiFlyerException
 import com.shabinder.common.models.TrackDetails
+import com.shabinder.common.models.event.coroutines.SuspendableEvent
+import com.shabinder.common.models.event.coroutines.flatMap
+import com.shabinder.common.models.event.coroutines.flatMapError
+import com.shabinder.common.models.event.coroutines.success
 import com.shabinder.common.models.spotify.Source
+import com.shabinder.common.requireNotNull
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch

 class FetchPlatformQueryResult(
    private val gaanaProvider: GaanaProvider,
-    val spotifyProvider: SpotifyProvider,
-    val youtubeProvider: YoutubeProvider,
+    private val spotifyProvider: SpotifyProvider,
+    private val youtubeProvider: YoutubeProvider,
    private val saavnProvider: SaavnProvider,
-    val youtubeMusic: YoutubeMusic,
-    val youtubeMp3: YoutubeMp3,
-    val audioToMp3: AudioToMp3,
+    private val youtubeMusic: YoutubeMusic,
+    private val youtubeMp3: YoutubeMp3,
+    private val audioToMp3: AudioToMp3,
    val dir: Dir
 ) {
    private val db: DownloadRecordDatabaseQueries?
        get() = dir.db?.downloadRecordDatabaseQueries

-    suspend fun query(link: String): PlatformQueryResult? {
+    suspend fun authenticateSpotifyClient() = spotifyProvider.authenticateSpotifyClient()
+
+    suspend fun query(link: String): SuspendableEvent<PlatformQueryResult,Throwable> {
        val result = when {
            // SPOTIFY
            link.contains("spotify", true) ->
@ -63,13 +71,13 @@ class FetchPlatformQueryResult(
                gaanaProvider.query(link)

            else -> {
-                null
+                SuspendableEvent.error(SpotiFlyerException.LinkInvalid(link))
            }
        }
-        if (result != null) {
+        result.success {
            addToDatabaseAsync(
                link,
-                result.copy() // Send a copy in order to not to freeze Result itself
+                it.copy() // Send a copy in order to not to freeze Result itself
            )
        }
        return result
@ -79,33 +87,51 @@ class FetchPlatformQueryResult(
    // 2) If Not found try finding on Youtube Music
    suspend fun findMp3DownloadLink(
        track: TrackDetails
-    ): String? =
+    ): SuspendableEvent<String,Throwable> =
        if (track.videoID != null) {
            // We Already have VideoID
            when (track.source) {
                Source.JioSaavn -> {
-                    saavnProvider.getSongFromID(track.videoID!!).media_url?.let { m4aLink ->
-                        audioToMp3.convertToMp3(m4aLink)
+                    saavnProvider.getSongFromID(track.videoID.requireNotNull()).flatMap { song ->
+                        song.media_url?.let { audioToMp3.convertToMp3(it) } ?: findHighestQualityMp3Link(track)
                    }
                }
                Source.YouTube -> {
-                    youtubeMp3.getMp3DownloadLink(track.videoID!!)
-                        ?: youtubeProvider.ytDownloader?.getVideo(track.videoID!!)?.get()?.url?.let { m4aLink ->
+                    youtubeMp3.getMp3DownloadLink(track.videoID.requireNotNull()).flatMapError {
+                        youtubeProvider.ytDownloader.getVideo(track.videoID!!).get()?.url?.let { m4aLink ->
                            audioToMp3.convertToMp3(m4aLink)
+                        } ?: throw SpotiFlyerException.YoutubeLinkNotFound(track.videoID)
                    }
                }
                else -> {
-                    null/* Do Nothing, We should never reach here for now*/
+                    /*We should never reach here for now*/
+                    findHighestQualityMp3Link(track)
                }
            }
        } else {
-            // First Try Getting A Link From JioSaavn
-            saavnProvider.findSongDownloadURL(
+            findHighestQualityMp3Link(track)
+        }
+
+    private suspend fun findHighestQualityMp3Link(
+        track: TrackDetails
+    ):SuspendableEvent<String,Throwable> {
+        // Try Fetching Track from Jio Saavn
+        return saavnProvider.findMp3SongDownloadURL(
            trackName = track.title,
            trackArtists = track.artists
-            )
+        ).flatMapError { saavnError ->
            // Lets Try Fetching Now From Youtube Music
-                ?: youtubeMusic.findSongDownloadURL(track)
+            youtubeMusic.findMp3SongDownloadURLYT(track).flatMapError { ytMusicError ->
+                // If Both Failed Bubble the Exception Up with both StackTraces
+                SuspendableEvent.error(
+                    SpotiFlyerException.DownloadLinkFetchFailed(
+                        trackName =  track.title,
+                        jioSaavnError = saavnError,
+                        ytMusicError = ytMusicError
+                    )
+                )
+            }
+        }
    }

    private fun addToDatabaseAsync(link: String, result: PlatformQueryResult) {
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/TokenStore.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/TokenStore.kt
@ -43,7 +43,7 @@ class TokenStore(
        logger.d { "System Time:${Clock.System.now().epochSeconds} , Token Expiry:${token?.expiry}" }
        if (Clock.System.now().epochSeconds > token?.expiry ?: 0 || token == null) {
            logger.d { "Requesting New Token" }
-            token = authenticateSpotify()
+            token = authenticateSpotify().component1()
            GlobalScope.launch { token?.access_token?.let { save(token) } }
        }
        return token
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/audioToMp3/AudioToMp3.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/audioToMp3/AudioToMp3.kt
@ -2,14 +2,12 @@ package com.shabinder.common.di.audioToMp3

 import co.touchlab.kermit.Kermit
 import com.shabinder.common.models.AudioQuality
-import io.ktor.client.HttpClient
-import io.ktor.client.request.forms.formData
-import io.ktor.client.request.forms.submitFormWithBinaryData
-import io.ktor.client.request.get
-import io.ktor.client.request.header
-import io.ktor.client.request.headers
-import io.ktor.client.statement.HttpStatement
-import io.ktor.http.isSuccess
+import com.shabinder.common.models.event.coroutines.SuspendableEvent
+import io.ktor.client.*
+import io.ktor.client.request.*
+import io.ktor.client.request.forms.*
+import io.ktor.client.statement.*
+import io.ktor.http.*
 import kotlinx.coroutines.delay

 interface AudioToMp3 {
@ -32,9 +30,9 @@ interface AudioToMp3 {
    suspend fun convertToMp3(
        URL: String,
        audioQuality: AudioQuality = AudioQuality.getQuality(URL.substringBeforeLast(".").takeLast(3)),
-    ): String? {
-        val activeHost = getHost() // ex - https://hostveryfast.onlineconverter.com/file/send
-        val jobLink = convertRequest(URL, activeHost, audioQuality) // ex - https://www.onlineconverter.com/convert/309a0f2bbaeb5687b04f96b6d65b47bfdd
+    ): SuspendableEvent<String,Throwable> = SuspendableEvent {
+        val activeHost by getHost() // ex - https://hostveryfast.onlineconverter.com/file/send
+        val jobLink by convertRequest(URL, activeHost, audioQuality) // ex - https://www.onlineconverter.com/convert/309a0f2bbaeb5687b04f96b6d65b47bfdd

        // (jobStatus.contains("d")) == COMPLETION
        var jobStatus: String
@ -54,10 +52,7 @@ interface AudioToMp3 {
            if (!jobStatus.contains("d")) delay(400) // Add Delay , to give Server Time to process audio
        } while (!jobStatus.contains("d", true) && retryCount != 0)

-        return if (jobStatus.equals("d", true)) {
-            // Return MP3 Download Link
        "${activeHost.removeSuffix("send")}${jobLink.substringAfterLast("/")}/download"
-        } else null
    }

    /*
@ -68,8 +63,8 @@ interface AudioToMp3 {
        URL: String,
        host: String? = null,
        audioQuality: AudioQuality = AudioQuality.KBPS160,
-    ): String {
-        val activeHost = host ?: getHost()
+    ): SuspendableEvent<String,Throwable> = SuspendableEvent {
+        val activeHost = host ?: getHost().value
        val res = client.submitFormWithBinaryData<String>(
            url = activeHost,
            formData = formData {
@ -87,7 +82,7 @@ interface AudioToMp3 {
                header("Referer", "https://www.onlineconverter.com/")
            }
        }.run {
-            logger.d { this }
+            // logger.d { this }
            dropLast(3) // last 3 are useless unicode char
        }

@ -97,18 +92,20 @@ interface AudioToMp3 {
            }
        }.execute()
        logger.i("Schedule Conversion Job") { job.status.isSuccess().toString() }
-        return res
+
+        res
    }

    // Active Host free to process conversion
    // ex - https://hostveryfast.onlineconverter.com/file/send
-    private suspend fun getHost(): String {
-        return client.get<String>("https://www.onlineconverter.com/get/host") {
+    private suspend fun getHost(): SuspendableEvent<String,Throwable> = SuspendableEvent {
+        client.get<String>("https://www.onlineconverter.com/get/host") {
            headers {
                header("Host", "www.onlineconverter.com")
            }
-        }.also { logger.i("Active Host") { it } }
+        }//.also { logger.i("Active Host") { it } }
    }
+
    // Extract full Domain from URL
    // ex - hostveryfast.onlineconverter.com
    private fun String.getHostDomain(): String {
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/providers/SaavnProvider.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/providers/SaavnProvider.kt
@ -33,7 +33,7 @@ class SaavnProvider(
        ).apply {
            when (fullLink.substringAfter("saavn.com/").substringBefore("/")) {
                "song" -> {
-                    getSong(fullLink).let {
+                    getSong(fullLink).value.let {
                        folderType = "Tracks"
                        subFolder = ""
                        trackList = listOf(it).toTrackDetails(folderType, subFolder)
@ -42,7 +42,7 @@ class SaavnProvider(
                    }
                }
                "album" -> {
-                    getAlbum(fullLink)?.let {
+                    getAlbum(fullLink).value.let {
                        folderType = "Albums"
                        subFolder = removeIllegalChars(it.title)
                        trackList = it.songs.toTrackDetails(folderType, subFolder)
@ -51,7 +51,7 @@ class SaavnProvider(
                    }
                }
                "featured" -> { // Playlist
-                    getPlaylist(fullLink)?.let {
+                    getPlaylist(fullLink).value.let {
                        folderType = "Playlists"
                        subFolder = removeIllegalChars(it.listname)
                        trackList = it.songs.toTrackDetails(folderType, subFolder)
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/providers/SpotifyProvider.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/providers/SpotifyProvider.kt
@ -48,9 +48,9 @@ class SpotifyProvider(
 ) : SpotifyRequests {

    override suspend fun authenticateSpotifyClient(override: Boolean) {
-        val token = if (override) authenticateSpotify() else tokenStore.getToken()
+        val token = if (override) authenticateSpotify().component1() else tokenStore.getToken()
        if (token == null) {
-            logger.d { "Please Check your Network Connection" }
+            logger.d { "Spotify Auth Failed: Please Check your Network Connection" }
        } else {
            logger.d { "Spotify Provider Created with $token" }
            HttpClient {
@ -183,8 +183,10 @@ class SpotifyProvider(
                    coverUrl = playlistObject.images?.firstOrNull()?.url.toString()
                }
                "episode" -> { // TODO
+                    throw SpotiFlyerException.FeatureNotImplementedYet()
                }
                "show" -> { // TODO
+                    throw SpotiFlyerException.FeatureNotImplementedYet()
                }
                else -> {
                    throw SpotiFlyerException.LinkInvalid("Provide: Spotify, Type:$type -> Link:$link")
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/providers/YoutubeMusic.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/providers/YoutubeMusic.kt
@ -46,28 +46,29 @@ import kotlin.math.absoluteValue
 class YoutubeMusic constructor(
    private val logger: Kermit,
    private val httpClient: HttpClient,
-    private val youtubeMp3: YoutubeMp3,
    private val youtubeProvider: YoutubeProvider,
+    private val youtubeMp3: YoutubeMp3,
    private val audioToMp3: AudioToMp3
 ) {
-
    companion object {
        const val apiKey = "AIzaSyC9XL3ZjWddXya6X74dJoCTL-WEYFDNX30"
        const val tag = "YT Music"
    }

-    suspend fun findSongDownloadURL(
+    // Get Downloadable Link
+    suspend fun findMp3SongDownloadURLYT(
        trackDetails: TrackDetails
    ): SuspendableEvent<String, Throwable> {
-        val bestMatchVideoID = getYTIDBestMatch(trackDetails)
-        return bestMatchVideoID.flatMap { videoID ->
-            // Get Downloadable Link
+        return getYTIDBestMatch(trackDetails).flatMap { videoID ->
+            // 1 Try getting Link from Yt1s
            youtubeMp3.getMp3DownloadLink(videoID).flatMapError {
-                SuspendableEvent {
+                // 2 if Yt1s failed , Extract Manually
                youtubeProvider.ytDownloader.getVideo(videoID).get()?.url?.let { m4aLink ->
                    audioToMp3.convertToMp3(m4aLink)
-                    } ?: throw SpotiFlyerException.YoutubeLinkNotFound(videoID)
-                }
+                } ?: throw SpotiFlyerException.YoutubeLinkNotFound(
+                    videoID,
+                    message = "Caught Following Errors While Finding Downloadable Link for $videoID :   \n${it.stackTraceToString()}"
+                )
            }
        }
    }
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/saavn/JioSaavnRequests.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/saavn/JioSaavnRequests.kt
@ -4,17 +4,20 @@ import co.touchlab.kermit.Kermit
 import com.shabinder.common.di.audioToMp3.AudioToMp3
 import com.shabinder.common.di.globalJson
 import com.shabinder.common.models.corsApi
+import com.shabinder.common.models.event.coroutines.SuspendableEvent
+import com.shabinder.common.models.event.coroutines.map
+import com.shabinder.common.models.event.coroutines.success
 import com.shabinder.common.models.saavn.SaavnAlbum
 import com.shabinder.common.models.saavn.SaavnPlaylist
 import com.shabinder.common.models.saavn.SaavnSearchResult
 import com.shabinder.common.models.saavn.SaavnSong
+import com.shabinder.common.requireNotNull
 import io.github.shabinder.fuzzywuzzy.diffutils.FuzzySearch
 import io.github.shabinder.utils.getBoolean
 import io.github.shabinder.utils.getJsonArray
 import io.github.shabinder.utils.getJsonObject
 import io.github.shabinder.utils.getString
 import io.ktor.client.*
-import io.ktor.client.features.*
 import io.ktor.client.request.*
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.JsonArray
@ -32,63 +35,64 @@ interface JioSaavnRequests {
    val httpClient: HttpClient
    val logger: Kermit

-    suspend fun findSongDownloadURL(
+    suspend fun findMp3SongDownloadURL(
        trackName: String,
        trackArtists: List<String>,
-    ): String? {
-        val songs = searchForSong(trackName)
+    ): SuspendableEvent<String,Throwable> = searchForSong(trackName).map { songs ->
        val bestMatches = sortByBestMatch(songs, trackName, trackArtists)
-        val m4aLink: String? = bestMatches.keys.firstOrNull()?.let {
-            getSongFromID(it).media_url
+
+        val m4aLink: String by getSongFromID(bestMatches.keys.first()).map { song ->
+            song.media_url.requireNotNull()
        }
-        val mp3Link = m4aLink?.let { audioToMp3.convertToMp3(it) }
-        return mp3Link
+
+        val mp3Link by audioToMp3.convertToMp3(m4aLink)
+
+        mp3Link
    }

    suspend fun searchForSong(
        query: String,
        includeLyrics: Boolean = false
-    ): List<SaavnSearchResult> {
-        /*if (query.startsWith("http") && query.contains("saavn.com")) {
-            return listOf(getSong(query))
-        }*/
+    ): SuspendableEvent<List<SaavnSearchResult>,Throwable> = SuspendableEvent {

        val searchURL = search_base_url + query
        val results = mutableListOf<SaavnSearchResult>()
-        try {
-            (globalJson.parseToJsonElement(httpClient.get(searchURL)) as JsonObject).getJsonObject("songs").getJsonArray("data")?.forEach {
-                (it as? JsonObject)?.formatData()?.let { jsonObject ->
+
+        (globalJson.parseToJsonElement(httpClient.get(searchURL)) as JsonObject)
+            .getJsonObject("songs")
+            .getJsonArray("data").requireNotNull().forEach {
+                (it as JsonObject).formatData().let { jsonObject ->
                    results.add(globalJson.decodeFromJsonElement(SaavnSearchResult.serializer(), jsonObject))
                }
        }
-        }catch (e: ServerResponseException) {}
-        return results
+
+        results
    }

-    suspend fun getLyrics(ID: String): String? {
-        return try {
+    suspend fun getLyrics(ID: String): SuspendableEvent<String,Throwable> = SuspendableEvent {
        (Json.parseToJsonElement(httpClient.get(lyrics_base_url + ID)) as JsonObject)
-                .getString("lyrics")
-        }catch (e:Exception) { null }
+            .getString("lyrics").requireNotNull()
    }

    suspend fun getSong(
        URL: String,
        fetchLyrics: Boolean = false
-    ): SaavnSong {
+    ): SuspendableEvent<SaavnSong,Throwable> = SuspendableEvent {
        val id = getSongID(URL)
        val data = ((globalJson.parseToJsonElement(httpClient.get(song_details_base_url + id)) as JsonObject)[id] as JsonObject)
            .formatData(fetchLyrics)
-        return globalJson.decodeFromJsonElement(SaavnSong.serializer(), data)
+
+        globalJson.decodeFromJsonElement(SaavnSong.serializer(), data)
    }

    suspend fun getSongFromID(
        ID: String,
        fetchLyrics: Boolean = false
-    ): SaavnSong {
+    ): SuspendableEvent<SaavnSong,Throwable> = SuspendableEvent {
        val data = ((globalJson.parseToJsonElement(httpClient.get(song_details_base_url + ID)) as JsonObject)[ID] as JsonObject)
            .formatData(fetchLyrics)
-        return globalJson.decodeFromJsonElement(SaavnSong.serializer(), data)
+
+        globalJson.decodeFromJsonElement(SaavnSong.serializer(), data)
    }

    private suspend fun getSongID(
@ -105,24 +109,19 @@ interface JioSaavnRequests {
    suspend fun getPlaylist(
        URL: String,
        includeLyrics: Boolean = false
-    ): SaavnPlaylist? {
-        return try {
+    ): SuspendableEvent<SaavnPlaylist,Throwable> = SuspendableEvent {
        globalJson.decodeFromJsonElement(
            SaavnPlaylist.serializer(),
-                (globalJson.parseToJsonElement(httpClient.get(playlist_details_base_url + getPlaylistID(URL))) as JsonObject)
+            (globalJson.parseToJsonElement(httpClient.get(playlist_details_base_url + getPlaylistID(URL).value)) as JsonObject)
                .formatData(includeLyrics)
        )
-        } catch (e: Exception) {
-            e.printStackTrace()
-            null
-        }
    }

    private suspend fun getPlaylistID(
        URL: String
-    ): String {
+    ): SuspendableEvent<String,Throwable> = SuspendableEvent {
        val res = httpClient.get<String>(URL)
-        return try {
+        try {
            res.split("\"type\":\"playlist\",\"id\":\"")[1].split('"')[0]
        } catch (e: IndexOutOfBoundsException) {
            res.split("\"page_id\",\"")[1].split("\",\"")[0]
@ -132,24 +131,19 @@ interface JioSaavnRequests {
    suspend fun getAlbum(
        URL: String,
        includeLyrics: Boolean = false
-    ): SaavnAlbum? {
-        return try {
+    ): SuspendableEvent<SaavnAlbum,Throwable> = SuspendableEvent {
        globalJson.decodeFromJsonElement(
            SaavnAlbum.serializer(),
-                (globalJson.parseToJsonElement(httpClient.get(album_details_base_url + getAlbumID(URL))) as JsonObject)
+            (globalJson.parseToJsonElement(httpClient.get(album_details_base_url + getAlbumID(URL).value)) as JsonObject)
                .formatData(includeLyrics)
        )
-        } catch (e: Exception) {
-            e.printStackTrace()
-            null
-        }
    }

    private suspend fun getAlbumID(
        URL: String
-    ): String {
+    ): SuspendableEvent<String,Throwable> = SuspendableEvent {
        val res = httpClient.get<String>(URL)
-        return try {
+        try {
            res.split("\"album_id\":\"")[1].split('"')[0]
        } catch (e: IndexOutOfBoundsException) {
            res.split("\"page_id\",\"")[1].split("\",\"")[0]
@ -215,8 +209,10 @@ interface JioSaavnRequests {
            // Fetch Lyrics if Requested
            // Lyrics is HTML Based
            if (includeLyrics) {
-                if (getBoolean("has_lyrics") == true) {
-                    put("lyrics", getString("id")?.let { getLyrics(it) })
+                if (getBoolean("has_lyrics") == true && containsKey("id")) {
+                    getLyrics(getString("id").requireNotNull()).success {
+                        put("lyrics", it)
+                    }
                } else {
                    put("lyrics", "")
                }
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/spotify/SpotifyAuth.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/spotify/SpotifyAuth.kt
@ -17,6 +17,8 @@
 package com.shabinder.common.di.spotify

 import com.shabinder.common.di.globalJson
+import com.shabinder.common.models.SpotiFlyerException
+import com.shabinder.common.models.event.coroutines.SuspendableEvent
 import com.shabinder.common.models.methods
 import com.shabinder.common.models.spotify.TokenData
 import io.ktor.client.*
@ -29,15 +31,12 @@ import io.ktor.client.request.forms.*
 import io.ktor.http.*
 import kotlin.native.concurrent.SharedImmutable

-suspend fun authenticateSpotify(): TokenData? {
-    return try {
-        if (methods.value.isInternetAvailable) spotifyAuthClient.post("https://accounts.spotify.com/api/token") {
+suspend fun authenticateSpotify(): SuspendableEvent<TokenData,Throwable> = SuspendableEvent {
+    if (methods.value.isInternetAvailable) {
+        spotifyAuthClient.post("https://accounts.spotify.com/api/token") {
            body = FormDataContent(Parameters.build { append("grant_type", "client_credentials") })
-        } else null
-    } catch (e: Exception) {
-        e.printStackTrace()
-        null
        }
+    } else throw SpotiFlyerException.NoInternetException()
 }

@SharedImmutable
--- a/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/youtubeMp3/Yt1sMp3.kt
+++ b/common/dependency-injection/src/commonMain/kotlin/com/shabinder/common/di/youtubeMp3/Yt1sMp3.kt
@ -19,6 +19,8 @@ package com.shabinder.common.di.youtubeMp3
 import co.touchlab.kermit.Kermit
 import com.shabinder.common.models.corsApi
 import com.shabinder.common.models.event.coroutines.SuspendableEvent
+import com.shabinder.common.models.event.coroutines.flatMap
+import com.shabinder.common.models.event.coroutines.map
 import com.shabinder.common.requireNotNull
 import io.ktor.client.*
 import io.ktor.client.request.*
@ -39,13 +41,12 @@ interface Yt1sMp3 {
    /*
    * Downloadable Mp3 Link for YT videoID.
    * */
-    suspend fun getLinkFromYt1sMp3(videoID: String): SuspendableEvent<String,Throwable> = SuspendableEvent {
-        getConvertedMp3Link(
-            videoID,
-            getKey(videoID).value
-        ).value["dlink"].requireNotNull()
+    suspend fun getLinkFromYt1sMp3(videoID: String): SuspendableEvent<String,Throwable> = getKey(videoID).flatMap { key ->
+        getConvertedMp3Link(videoID, key).map {
+            it["dlink"].requireNotNull()
                .jsonPrimitive.content.replace("\"", "")
        }
+    }

    /*
    * POST:https://yt1s.com/api/ajaxSearch/index
--- a/common/list/src/commonMain/kotlin/com/shabinder/common/list/SpotiFlyerList.kt
+++ b/common/list/src/commonMain/kotlin/com/shabinder/common/list/SpotiFlyerList.kt
@ -83,7 +83,7 @@ interface SpotiFlyerList {
        val queryResult: PlatformQueryResult? = null,
        val link: String = "",
        val trackList: List<TrackDetails> = emptyList(),
-        val errorOccurred: Exception? = null,
+        val errorOccurred: Throwable? = null,
        val askForDonation: Boolean = false,
    )
 }
--- a/common/list/src/commonMain/kotlin/com/shabinder/common/list/store/SpotiFlyerListStoreProvider.kt
+++ b/common/list/src/commonMain/kotlin/com/shabinder/common/list/store/SpotiFlyerListStoreProvider.kt
@ -59,7 +59,7 @@ internal class SpotiFlyerListStoreProvider(
        data class ResultFetched(val result: PlatformQueryResult, val trackList: List<TrackDetails>) : Result()
        data class UpdateTrackList(val list: List<TrackDetails>) : Result()
        data class UpdateTrackItem(val item: TrackDetails) : Result()
-        data class ErrorOccurred(val error: Exception) : Result()
+        data class ErrorOccurred(val error: Throwable) : Result()
        data class AskForDonation(val isAllowed: Boolean) : Result()
    }

@ -90,19 +90,17 @@ internal class SpotiFlyerListStoreProvider(
        override suspend fun executeIntent(intent: Intent, getState: () -> State) {
            when (intent) {
                is Intent.SearchLink -> {
-                    try {
-                        val result = fetchQuery.query(link)
-                        if (result != null) {
+                    val resp = fetchQuery.query(link)
+                    resp.fold(
+                        success = { result ->
                            result.trackList = result.trackList.toMutableList()
                            dispatch((Result.ResultFetched(result, result.trackList.updateTracksStatuses(downloadProgressFlow.replayCache.getOrElse(0) { hashMapOf() }))))
                            executeIntent(Intent.RefreshTracksStatuses, getState)
-                        } else {
-                            throw Exception("An Error Occurred, Check your Link / Connection")
-                        }
-                    } catch (e: Exception) {
-                        e.printStackTrace()
-                        dispatch(Result.ErrorOccurred(e))
+                        },
+                        failure = {
+                            dispatch(Result.ErrorOccurred(it))
                        }
+                    )
                }

                is Intent.StartDownloadAll -> {
--- a/common/root/src/commonMain/kotlin/com/shabinder/common/root/integration/SpotiFlyerRootImpl.kt
+++ b/common/root/src/commonMain/kotlin/com/shabinder/common/root/integration/SpotiFlyerRootImpl.kt
@ -28,7 +28,7 @@ import com.arkivanov.decompose.statekeeper.Parcelable
 import com.arkivanov.decompose.statekeeper.Parcelize
 import com.arkivanov.decompose.value.Value
 import com.shabinder.common.di.Dir
-import com.shabinder.common.di.providers.SpotifyProvider
+import com.shabinder.common.di.dispatcherIO
 import com.shabinder.common.list.SpotiFlyerList
 import com.shabinder.common.main.SpotiFlyerMain
 import com.shabinder.common.models.Actions
@ -39,7 +39,6 @@ import com.shabinder.common.root.SpotiFlyerRoot.Analytics
 import com.shabinder.common.root.SpotiFlyerRoot.Child
 import com.shabinder.common.root.SpotiFlyerRoot.Dependencies
 import com.shabinder.common.root.callbacks.SpotiFlyerRootCallBacks
-import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.launch
@ -77,8 +76,8 @@ internal class SpotiFlyerRootImpl(
    ) {
        instanceKeeper.ensureNeverFrozen()
        methods.value = dependencies.actions.freeze()
-        /*Authenticate Spotify Client*/
-        authenticateSpotify(dependencies.fetchPlatformQueryResult.spotifyProvider)
+        /*Init App Launch & Authenticate Spotify Client*/
+        initAppLaunchAndAuthenticateSpotify(dependencies.fetchPlatformQueryResult::authenticateSpotifyClient)
    }

    private val router =
@ -129,11 +128,11 @@ internal class SpotiFlyerRootImpl(
            }
        }

-    private fun authenticateSpotify(spotifyProvider: SpotifyProvider) {
-        GlobalScope.launch(Dispatchers.Default) {
+    private fun initAppLaunchAndAuthenticateSpotify(authenticator: suspend () -> Unit) {
+        GlobalScope.launch(dispatcherIO) {
            analytics.appLaunchEvent()
            /*Authenticate Spotify Client*/
-            spotifyProvider.authenticateSpotifyClient()
+            authenticator()
        }
    }

--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@ -30,3 +30,11 @@ include(
    ":console-app",
    ":maintenance-tasks"
 )
+
+includeBuild("mosaic") {
+    dependencySubstitution {
+        substitute(module("com.jakewharton.mosaic:mosaic-gradle-plugin")).with(project(":mosaic-gradle-plugin"))
+        substitute(module("com.jakewharton.mosaic:mosaic-runtime")).with(project(":mosaic-runtime"))
+        substitute(module("com.jakewharton.mosaic:compose-compiler")).with(project(":compose:compiler"))
+    }
+}