feat: added google drive service.

Signed-off-by: KaiserBh <kaiserbh@proton.me>

app/build.gradle.kts

@@ -257,6 +257,9 @@ dependencies {
     // For detecting memory leaks; see https://square.github.io/leakcanary/
     // debugImplementation(libs.leakcanary.android)
     implementation(libs.leakcanary.plumber)
+
+    implementation(libs.google.api.services.drive)
+    implementation(libs.google.api.client.oauth)
 }
 
 androidComponents {

app/proguard-rules.pro

@@ -73,4 +73,10 @@
 
 # Firebase
 -keep class com.google.firebase.installations.** { *; }
--keep interface com.google.firebase.installations.** { *; }
+-keep interface com.google.firebase.installations.** { *; }
+
+# Google Drive
+-keep class com.google.api.services.** { *; }
+
+# Google OAuth
+-keep class com.google.api.client.** { *; }

app/src/main/AndroidManifest.xml

@@ -183,6 +183,20 @@
                     android:scheme="tachiyomi" />
             </intent-filter>
         </activity>
+        <activity
+            android:name=".ui.setting.track.GoogleDriveLoginActivity"
+            android:label="GoogleDrive"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+
+                <data
+                    android:scheme="eu.kanade.google.oauth" />
+            </intent-filter>
+        </activity>
 
         <receiver
             android:name=".data.notification.NotificationReceiver"

app/src/main/assets/client_secrets.json

@@ -0,0 +1 @@
+{"installed":{"client_id":"1046609911130-tbp79niehhuii976ekep1us06e9a8lne.apps.googleusercontent.com","project_id":"tachiyomi","auth_uri":"https://accounts.google.com/o/oauth2/auth","token_uri":"https://oauth2.googleapis.com/token","auth_provider_x509_cert_url":"https://www.googleapis.com/oauth2/v1/certs"}}

app/src/main/java/eu/kanade/presentation/more/settings/screen/SettingsBackupAndSyncScreen.kt

@@ -52,6 +52,8 @@ import eu.kanade.tachiyomi.data.backup.BackupRestoreJob
 import eu.kanade.tachiyomi.data.backup.models.Backup
 import eu.kanade.tachiyomi.data.sync.SyncDataJob
 import eu.kanade.tachiyomi.data.sync.SyncManager
+import eu.kanade.tachiyomi.data.sync.service.GoogleDriveService
+import eu.kanade.tachiyomi.data.sync.service.GoogleDriveSyncService
 import eu.kanade.tachiyomi.util.storage.DiskUtil
 import eu.kanade.tachiyomi.util.system.DeviceUtil
 import eu.kanade.tachiyomi.util.system.copyToClipboard
@@ -94,6 +96,7 @@ object SettingsBackupAndSyncScreen : SearchableSettings {
                         entries = mapOf(
                             SyncManager.SyncService.NONE.value to stringResource(R.string.off),
                             SyncManager.SyncService.SYNCYOMI.value to stringResource(R.string.syncyomi),
+                            SyncManager.SyncService.GOOGLE_DRIVE.value to stringResource(R.string.google_drive),
                         ),
                         onValueChanged = { true },
                     ),
@@ -448,6 +451,7 @@ object SettingsBackupAndSyncScreen : SearchableSettings {
         return when (syncServiceType) {
             SyncManager.SyncService.NONE -> emptyList()
             SyncManager.SyncService.SYNCYOMI -> getSelfHostPreferences(syncPreferences)
+            SyncManager.SyncService.GOOGLE_DRIVE -> getGoogleDrivePreferences()
         } +
             if (syncServiceType == SyncManager.SyncService.NONE) {
                 emptyList()
@@ -456,6 +460,74 @@ object SettingsBackupAndSyncScreen : SearchableSettings {
             }
     }
 
+    @Composable
+    private fun getGoogleDrivePreferences(): List<Preference> {
+        val context = LocalContext.current
+        val googleDriveSync = Injekt.get<GoogleDriveService>()
+        return listOf(
+            Preference.PreferenceItem.TextPreference(
+                title = stringResource(R.string.pref_google_drive_sign_in),
+                onClick = {
+                    val intent = googleDriveSync.getSignInIntent()
+                    context.startActivity(intent)
+                },
+            ),
+            getGoogleDrivePurge(),
+        )
+    }
+
+    @Composable
+    private fun getGoogleDrivePurge(): Preference.PreferenceItem.TextPreference {
+        val scope = rememberCoroutineScope()
+        val showPurgeDialog = remember { mutableStateOf(false) }
+        val context = LocalContext.current
+        val googleDriveSync = remember { GoogleDriveSyncService(context) }
+
+        if (showPurgeDialog.value) {
+            PurgeConfirmationDialog(
+                onConfirm = {
+                    showPurgeDialog.value = false
+                    scope.launch {
+                        val result = googleDriveSync.deleteSyncDataFromGoogleDrive()
+                        if (result) {
+                            context.toast(R.string.google_drive_sync_data_purged)
+                        } else {
+                            context.toast(R.string.google_drive_sync_data_not_found)
+                        }
+                    }
+                },
+                onDismissRequest = { showPurgeDialog.value = false },
+            )
+        }
+
+        return Preference.PreferenceItem.TextPreference(
+            title = stringResource(R.string.pref_google_drive_purge_sync_data),
+            onClick = { showPurgeDialog.value = true },
+        )
+    }
+
+    @Composable
+    fun PurgeConfirmationDialog(
+        onConfirm: () -> Unit,
+        onDismissRequest: () -> Unit,
+    ) {
+        AlertDialog(
+            onDismissRequest = onDismissRequest,
+            title = { Text(text = stringResource(R.string.pref_purge_confirmation_title)) },
+            text = { Text(text = stringResource(R.string.pref_purge_confirmation_message)) },
+            dismissButton = {
+                TextButton(onClick = onDismissRequest) {
+                    Text(text = stringResource(R.string.action_cancel))
+                }
+            },
+            confirmButton = {
+                TextButton(onClick = onConfirm) {
+                    Text(text = stringResource(android.R.string.ok))
+                }
+            },
+        )
+    }
+
     @Composable
     private fun getSelfHostPreferences(syncPreferences: SyncPreferences): List<Preference> {
         return listOf(

app/src/main/java/eu/kanade/tachiyomi/AppModule.kt

@@ -19,6 +19,7 @@ import eu.kanade.tachiyomi.data.download.DownloadCache
 import eu.kanade.tachiyomi.data.download.DownloadManager
 import eu.kanade.tachiyomi.data.download.DownloadProvider
 import eu.kanade.tachiyomi.data.saver.ImageSaver
+import eu.kanade.tachiyomi.data.sync.service.GoogleDriveService
 import eu.kanade.tachiyomi.data.track.TrackManager
 import eu.kanade.tachiyomi.extension.ExtensionManager
 import eu.kanade.tachiyomi.network.JavaScriptEngine
@@ -151,6 +152,8 @@ class AppModule(val app: Application) : InjektModule {
 
             get<DownloadManager>()
         }
+
+        addSingletonFactory { GoogleDriveService(app) }
     }
 }
 

app/src/main/java/eu/kanade/tachiyomi/data/sync/SyncManager.kt

@@ -13,6 +13,7 @@ import eu.kanade.tachiyomi.data.backup.models.BackupManga
 import eu.kanade.tachiyomi.data.sync.models.SyncData
 import eu.kanade.tachiyomi.data.sync.models.SyncDevice
 import eu.kanade.tachiyomi.data.sync.models.SyncStatus
+import eu.kanade.tachiyomi.data.sync.service.GoogleDriveSyncService
 import eu.kanade.tachiyomi.data.sync.service.SyncYomiSyncService
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.protobuf.ProtoBuf
@@ -56,6 +57,7 @@ class SyncManager(
     enum class SyncService(val value: Int) {
         NONE(0),
         SYNCYOMI(1),
+        GOOGLE_DRIVE(2),
         ;
 
         companion object {
@@ -107,6 +109,10 @@ class SyncManager(
                 )
             }
 
+            SyncService.GOOGLE_DRIVE -> {
+                GoogleDriveSyncService(context, json, syncPreferences)
+            }
+
             else -> {
                 logcat(LogPriority.ERROR) { "Invalid sync service type: $syncService" }
                 null

app/src/main/java/eu/kanade/tachiyomi/data/sync/service/GoogleDriveSyncService.kt

@@ -0,0 +1,332 @@
+package eu.kanade.tachiyomi.data.sync.service
+
+import android.app.Activity
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import android.util.Log
+import com.google.api.client.auth.oauth2.TokenResponseException
+import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow
+import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeTokenRequest
+import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets
+import com.google.api.client.googleapis.auth.oauth2.GoogleCredential
+import com.google.api.client.googleapis.auth.oauth2.GoogleTokenResponse
+import com.google.api.client.http.ByteArrayContent
+import com.google.api.client.http.javanet.NetHttpTransport
+import com.google.api.client.json.JsonFactory
+import com.google.api.client.json.jackson2.JacksonFactory
+import com.google.api.services.drive.Drive
+import com.google.api.services.drive.DriveScopes
+import com.google.api.services.drive.model.File
+import eu.kanade.tachiyomi.data.sync.models.SyncData
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import logcat.LogPriority
+import tachiyomi.core.util.system.logcat
+import tachiyomi.domain.sync.SyncPreferences
+import uy.kohesive.injekt.Injekt
+import uy.kohesive.injekt.api.get
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+import java.io.IOException
+import java.io.InputStreamReader
+import java.util.zip.GZIPInputStream
+import java.util.zip.GZIPOutputStream
+
+class GoogleDriveSyncService(context: Context, json: Json, syncPreferences: SyncPreferences) : SyncService(context, json, syncPreferences) {
+    constructor(context: Context) : this(
+        context,
+        Json {
+            encodeDefaults = true
+            ignoreUnknownKeys = true
+        },
+        Injekt.get<SyncPreferences>(),
+    )
+
+    private val remoteFileName = "tachiyomi_sync_data.gz"
+
+    private val googleDriveService = GoogleDriveService(context)
+
+    override suspend fun beforeSync() = googleDriveService.refreshToken()
+
+    override suspend fun pushSyncData(): SyncData? {
+        val drive = googleDriveService.googleDriveService
+
+        // Check if the Google Drive service is initialized
+        if (drive == null) {
+            logcat(LogPriority.ERROR) { "Google Drive service not initialized" }
+            return null
+        }
+
+        val fileList = getFileList(drive)
+
+        if (fileList.isEmpty()) {
+            return null
+        }
+        val gdriveFileId = fileList[0].id
+
+        val outputStream = ByteArrayOutputStream()
+        drive.files().get(gdriveFileId).executeMediaAndDownloadTo(outputStream)
+        val jsonString = withContext(Dispatchers.IO) {
+            val gzipInputStream = GZIPInputStream(ByteArrayInputStream(outputStream.toByteArray()))
+            gzipInputStream.bufferedReader(Charsets.UTF_8).use { it.readText() }
+        }
+
+        return json.decodeFromString(SyncData.serializer(), jsonString)
+    }
+
+    override suspend fun pullSyncData(syncData: SyncData) {
+        val jsonData = json.encodeToString(syncData)
+
+        val drive = googleDriveService.googleDriveService
+
+        // Check if the Google Drive service is initialized
+        if (drive == null) {
+            logcat(LogPriority.ERROR) { "Google Drive service not initialized" }
+            return
+        }
+
+        // delete file if exists
+        val fileList = getFileList(drive)
+        if (fileList.isNotEmpty()) {
+            drive.files().delete(fileList[0].id).execute()
+        }
+
+        val fileMetadata = File()
+        fileMetadata.name = remoteFileName
+        fileMetadata.mimeType = "application/gzip"
+
+        val byteArrayOutputStream = ByteArrayOutputStream()
+
+        withContext(Dispatchers.IO) {
+            val gzipOutputStream = GZIPOutputStream(byteArrayOutputStream)
+            gzipOutputStream.write(jsonData.toByteArray(Charsets.UTF_8))
+            gzipOutputStream.close()
+        }
+
+        val byteArrayContent = ByteArrayContent("application/octet-stream", byteArrayOutputStream.toByteArray())
+        val uploadedFile = drive.files().create(fileMetadata, byteArrayContent)
+            .setFields("id")
+            .execute()
+
+        logcat(LogPriority.DEBUG) { "Created sync data file in Google Drive with file ID: ${uploadedFile.id}" }
+    }
+
+    private fun getFileList(drive: Drive): MutableList<File> {
+        // Search for the existing file by name
+        val query = "mimeType='application/gzip' and trashed = false and name = '$remoteFileName'"
+        val fileList = drive.files().list().setQ(query).execute().files
+        Log.d("GoogleDrive", "File list: $fileList")
+
+        return fileList
+    }
+
+    suspend fun deleteSyncDataFromGoogleDrive(): Boolean {
+        val drive = googleDriveService.googleDriveService
+
+        if (drive == null) {
+            logcat(LogPriority.ERROR) { "Google Drive service not initialized" }
+            return false
+        }
+        googleDriveService.refreshToken()
+
+        return withContext(Dispatchers.IO) {
+            val query = "mimeType='application/gzip' and trashed = false and name = '$remoteFileName'"
+            val fileList = drive.files().list().setQ(query).execute().files
+
+            if (fileList.isNullOrEmpty()) {
+                logcat(LogPriority.DEBUG) { "No sync data file found in Google Drive" }
+                false
+            } else {
+                val fileId = fileList[0].id
+                drive.files().delete(fileId).execute()
+                logcat(LogPriority.DEBUG) { "Deleted sync data file in Google Drive with file ID: $fileId" }
+                true
+            }
+        }
+    }
+}
+
+class GoogleDriveService(private val context: Context) {
+    var googleDriveService: Drive? = null
+    private val syncPreferences = Injekt.get<SyncPreferences>()
+
+    init {
+        initGoogleDriveService()
+    }
+
+    /**
+     * Initializes the Google Drive service by obtaining the access token and refresh token from the SyncPreferences
+     * and setting up the service using the obtained tokens.
+     */
+    private fun initGoogleDriveService() {
+        val accessToken = syncPreferences.getGoogleDriveAccessToken()
+        val refreshToken = syncPreferences.getGoogleDriveRefreshToken()
+
+        if (accessToken == "" || refreshToken == "") {
+            googleDriveService = null
+            return
+        }
+
+        setupGoogleDriveService(accessToken, refreshToken)
+    }
+
+    /**
+     * Launches an Intent to open the user's default browser for Google Drive sign-in.
+     * The Intent carries the authorization URL, which prompts the user to sign in
+     * and grant the application permission to access their Google Drive account.
+     * @return An Intent configured to launch a browser for Google Drive OAuth sign-in.
+     */
+    fun getSignInIntent(): Intent {
+        val authorizationUrl = generateAuthorizationUrl()
+
+        return Intent(Intent.ACTION_VIEW).apply {
+            data = Uri.parse(authorizationUrl)
+            addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+        }
+    }
+
+    /**
+     * Generates the authorization URL required for the user to grant the application permission to access their Google Drive account.
+     * Sets the approval prompt to "force" to ensure that the user is always prompted to grant access, even if they have previously granted access.
+     * @return The authorization URL.
+     */
+    private fun generateAuthorizationUrl(): String {
+        val jsonFactory: JsonFactory = JacksonFactory.getDefaultInstance()
+        val secrets = GoogleClientSecrets.load(
+            jsonFactory,
+            InputStreamReader(context.assets.open("client_secrets.json")),
+        )
+
+        val flow = GoogleAuthorizationCodeFlow.Builder(
+            NetHttpTransport(),
+            jsonFactory,
+            secrets,
+            listOf(DriveScopes.DRIVE_FILE),
+        ).setAccessType("offline").build()
+
+        return flow.newAuthorizationUrl()
+            .setRedirectUri("eu.kanade.google.oauth:/oauth2redirect")
+            .setApprovalPrompt("force")
+            .build()
+    }
+    internal suspend fun refreshToken() = withContext(Dispatchers.IO) {
+        val jsonFactory: JsonFactory = JacksonFactory.getDefaultInstance()
+        val secrets = GoogleClientSecrets.load(
+            jsonFactory,
+            InputStreamReader(context.assets.open("client_secrets.json")),
+        )
+
+        val credential = GoogleCredential.Builder()
+            .setJsonFactory(jsonFactory)
+            .setTransport(NetHttpTransport())
+            .setClientSecrets(secrets)
+            .build()
+
+        credential.refreshToken = syncPreferences.getGoogleDriveRefreshToken()
+
+        logcat(LogPriority.DEBUG) { "Refreshing access token with: ${syncPreferences.getGoogleDriveRefreshToken()}" }
+
+        try {
+            credential.refreshToken()
+            val newAccessToken = credential.accessToken
+            val oldAccessToken = syncPreferences.getGoogleDriveAccessToken()
+            // Save the new access token
+            syncPreferences.setGoogleDriveAccessToken(newAccessToken)
+            setupGoogleDriveService(newAccessToken, credential.refreshToken)
+            logcat(LogPriority.DEBUG) { "Google Access token refreshed old: $oldAccessToken new: $newAccessToken" }
+        } catch (e: TokenResponseException) {
+            if (e.details.error == "invalid_grant") {
+                // The refresh token is invalid, prompt the user to sign in again
+                logcat(LogPriority.ERROR) { "Refresh token is invalid, prompt user to sign in again" }
+                throw e.message?.let { Exception(it) } ?: Exception("Unknown error")
+            } else {
+                // Token refresh failed; handle this situation
+                logcat(LogPriority.ERROR) { "Failed to refresh access token ${e.message}" }
+                logcat(LogPriority.ERROR) { "Google Drive sync will be disabled" }
+            }
+        } catch (e: IOException) {
+            // Token refresh failed; handle this situation
+            logcat(LogPriority.ERROR) { "Failed to refresh access token ${e.message}" }
+            logcat(LogPriority.ERROR) { "Google Drive sync will be disabled" }
+        }
+    }
+
+    /**
+     * Sets up the Google Drive service using the provided access token and refresh token.
+     * @param accessToken The access token obtained from the SyncPreferences.
+     * @param refreshToken The refresh token obtained from the SyncPreferences.
+     */
+    private fun setupGoogleDriveService(accessToken: String, refreshToken: String) {
+        val jsonFactory: JsonFactory = JacksonFactory.getDefaultInstance()
+        val secrets = GoogleClientSecrets.load(
+            jsonFactory,
+            InputStreamReader(context.assets.open("client_secrets.json")),
+        )
+
+        val credential = GoogleCredential.Builder()
+            .setJsonFactory(jsonFactory)
+            .setTransport(NetHttpTransport())
+            .setClientSecrets(secrets)
+            .build()
+
+        credential.accessToken = accessToken
+        credential.refreshToken = refreshToken
+
+        googleDriveService = Drive.Builder(
+            NetHttpTransport(),
+            jsonFactory,
+            credential,
+        ).setApplicationName("Tachiyomi")
+            .build()
+    }
+
+    /**
+     * Handles the authorization code returned after the user has granted the application permission to access their Google Drive account.
+     * It obtains the access token and refresh token using the authorization code, saves the tokens to the SyncPreferences,
+     * sets up the Google Drive service using the obtained tokens, and initializes the service.
+     * @param authorizationCode The authorization code obtained from the OAuthCallbackServer.
+     * @param activity The current activity.
+     * @param onSuccess A callback function to be called on successful authorization.
+     * @param onFailure A callback function to be called on authorization failure.
+     */
+    fun handleAuthorizationCode(authorizationCode: String, activity: Activity, onSuccess: () -> Unit, onFailure: (String) -> Unit) {
+        val jsonFactory: JsonFactory = JacksonFactory.getDefaultInstance()
+        val secrets = GoogleClientSecrets.load(
+            jsonFactory,
+            InputStreamReader(context.assets.open("client_secrets.json")),
+        )
+
+        val tokenResponse: GoogleTokenResponse = GoogleAuthorizationCodeTokenRequest(
+            NetHttpTransport(),
+            jsonFactory,
+            secrets.installed.clientId,
+            secrets.installed.clientSecret,
+            authorizationCode,
+            "eu.kanade.google.oauth:/oauth2redirect",
+        ).setGrantType("authorization_code").execute()
+
+        try {
+            // Save the access token and refresh token
+            val accessToken = tokenResponse.accessToken
+            val refreshToken = tokenResponse.refreshToken
+
+            // Save the tokens to SyncPreferences
+            syncPreferences.setGoogleDriveAccessToken(accessToken)
+            syncPreferences.setGoogleDriveRefreshToken(refreshToken)
+
+            setupGoogleDriveService(accessToken, refreshToken)
+            initGoogleDriveService()
+
+            activity.runOnUiThread {
+                onSuccess()
+            }
+        } catch (e: Exception) {
+            activity.runOnUiThread {
+                onFailure(e.localizedMessage ?: "Unknown error")
+            }
+        }
+    }
+}

app/src/main/java/eu/kanade/tachiyomi/data/sync/service/SyncService.kt

@@ -106,8 +106,8 @@ abstract class SyncService(
         localMangaMap.forEach { (key, localManga) ->
             val remoteManga = remoteMangaMap[key]
             if (remoteManga != null) {
-                val localInstant = localManga.lastModifiedAt?.let { Instant.ofEpochMilli(it) }
-                val remoteInstant = remoteManga.lastModifiedAt?.let { Instant.ofEpochMilli(it) }
+                val localInstant = localManga.lastModifiedAt.let { Instant.ofEpochMilli(it) }
+                val remoteInstant = remoteManga.lastModifiedAt.let { Instant.ofEpochMilli(it) }
 
                 val mergedManga = if ((localInstant ?: Instant.MIN) >= (
                     remoteInstant
@@ -164,8 +164,8 @@ abstract class SyncService(
         localChapterMap.forEach { (url, localChapter) ->
             val remoteChapter = remoteChapterMap[url]
             if (remoteChapter != null) {
-                val localInstant = localChapter.lastModifiedAt?.let { Instant.ofEpochMilli(it) }
-                val remoteInstant = remoteChapter.lastModifiedAt?.let { Instant.ofEpochMilli(it) }
+                val localInstant = localChapter.lastModifiedAt.let { Instant.ofEpochMilli(it) }
+                val remoteInstant = remoteChapter.lastModifiedAt.let { Instant.ofEpochMilli(it) }
 
                 val mergedChapter =
                     if ((localInstant ?: Instant.MIN) >= (remoteInstant ?: Instant.MIN)) {

app/src/main/java/eu/kanade/tachiyomi/ui/setting/track/GoogleDriveLoginActivity.kt

@@ -0,0 +1,52 @@
+package eu.kanade.tachiyomi.ui.setting.track
+
+import android.net.Uri
+import android.widget.Toast
+import androidx.lifecycle.lifecycleScope
+import eu.kanade.tachiyomi.data.sync.service.GoogleDriveService
+import tachiyomi.core.util.lang.launchIO
+import uy.kohesive.injekt.Injekt
+import uy.kohesive.injekt.api.get
+
+class GoogleDriveLoginActivity : BaseOAuthLoginActivity() {
+    private val googleDriveService = Injekt.get<GoogleDriveService>()
+    override fun handleResult(data: Uri?) {
+        val code = data?.getQueryParameter("code")
+        val error = data?.getQueryParameter("error")
+        if (code != null) {
+            lifecycleScope.launchIO {
+                googleDriveService.handleAuthorizationCode(
+                    code,
+                    this@GoogleDriveLoginActivity,
+                    onSuccess = {
+                        Toast.makeText(
+                            this@GoogleDriveLoginActivity,
+                            "Authorization successful.",
+                            Toast.LENGTH_LONG,
+                        ).show()
+
+                        returnToSettings()
+                    },
+                    onFailure = { error ->
+                        Toast.makeText(
+                            this@GoogleDriveLoginActivity,
+                            "Authorization failed: $error",
+                            Toast.LENGTH_LONG,
+                        ).show()
+                        returnToSettings()
+                    },
+                )
+            }
+        } else if (error != null) {
+            Toast.makeText(
+                this@GoogleDriveLoginActivity,
+                "Authorization failed: $error",
+                Toast.LENGTH_LONG,
+            ).show()
+
+            returnToSettings()
+        } else {
+            returnToSettings()
+        }
+    }
+}

domain/src/main/java/tachiyomi/domain/sync/SyncPreferences.kt

@@ -15,4 +15,20 @@ class SyncPreferences(
     fun deviceName() = preferenceStore.getString("device_name", android.os.Build.MANUFACTURER + android.os.Build.PRODUCT)
 
     fun syncService() = preferenceStore.getInt("sync_service", 0)
+
+    private fun googleDriveAccessToken() = preferenceStore.getString("google_drive_access_token", "")
+
+    fun setGoogleDriveAccessToken(accessToken: String) {
+        googleDriveAccessToken().set(accessToken)
+    }
+
+    fun getGoogleDriveAccessToken() = googleDriveAccessToken().get()
+
+    private fun googleDriveRefreshToken() = preferenceStore.getString("google_drive_refresh_token", "")
+
+    fun setGoogleDriveRefreshToken(refreshToken: String) {
+        googleDriveRefreshToken().set(refreshToken)
+    }
+
+    fun getGoogleDriveRefreshToken() = googleDriveRefreshToken().get()
 }

gradle/libs.versions.toml

@@ -91,6 +91,9 @@ voyager-navigator = { module = "cafe.adriel.voyager:voyager-navigator", version.
 voyager-tab-navigator = { module = "cafe.adriel.voyager:voyager-tab-navigator", version.ref = "voyager" }
 voyager-transitions = { module = "cafe.adriel.voyager:voyager-transitions", version.ref = "voyager" }
 
+google-api-services-drive = "com.google.apis:google-api-services-drive:v3-rev197-1.25.0"
+google-api-client-oauth = "com.google.oauth-client:google-oauth-client:1.34.1"
+
 kotlinter = "org.jmailen.gradle:kotlinter-gradle:3.13.0"
 
 [bundles]

i18n/src/main/res/values/strings.xml

@@ -530,6 +530,18 @@
     <string name="syncyomi">SyncYomi</string>
     <string name="sync_completed_message">Done in %1$s</string>
     <string name="last_synchronization">Last Synchronization: %1$s</string>
+    <string name="google_drive">Google Drive</string>
+    <string name="pref_google_drive_sign_in">Sign in</string>
+    <string name="google_drive_sign_in_success">Signed in successfully</string>
+    <string name="google_drive_sign_in_failed">Sign in failed</string>
+    <string name="authentication">Authentication</string>
+    <string name="pref_google_drive_purge_sync_data">Clear Sync Data from Google Drive</string>
+    <string name="google_drive_sync_data_purged">Sync data purged from Google Drive</string>
+    <string name="google_drive_sync_data_not_found">No sync data found in Google Drive</string>
+    <string name="google_drive_not_signed_in">Not signed in to Google Drive</string>
+    <string name="pref_purge_confirmation_title">Purge confirmation</string>
+    <string name="pref_purge_confirmation_message">Purging sync data will delete all your sync data from Google Drive. Are you sure you want to continue?</string>
+
 
     <!-- Advanced section -->
     <string name="label_network">Network</string>