wip: rewrite patching process

app/src/main/kotlin/com/aliucord/manager/ManagerApplication.kt

@@ -59,6 +59,7 @@ class ManagerApplication : Application() {
             modules(module {
                 single { providePreferences() }
                 single { provideDownloadManager() }
+                single { providePathManager() }
             })
         }
     }

app/src/main/kotlin/com/aliucord/manager/di/Managers.kt

@@ -2,8 +2,7 @@ package com.aliucord.manager.di
 
 import android.app.Application
 import android.content.Context
-import com.aliucord.manager.manager.DownloadManager
-import com.aliucord.manager.manager.PreferencesManager
+import com.aliucord.manager.manager.*
 import org.koin.core.scope.Scope
 
 fun Scope.providePreferences(): PreferencesManager {
@@ -15,3 +14,8 @@ fun Scope.provideDownloadManager(): DownloadManager {
     val application: Application = get()
     return DownloadManager(application)
 }
+
+fun Scope.providePathManager(): PathManager {
+    val ctx: Context = get()
+    return PathManager(ctx)
+}

app/src/main/kotlin/com/aliucord/manager/installer/steps/KtStepContainer.kt

@@ -0,0 +1,19 @@
+package com.aliucord.manager.installer.steps
+
+import com.aliucord.manager.installer.steps.base.Step
+import com.aliucord.manager.installer.steps.download.*
+import com.aliucord.manager.installer.steps.prepare.FetchInfoStep
+import kotlinx.collections.immutable.persistentListOf
+
+/**
+ * Used for installing the old Kotlin Discord app.
+ */
+class KtStepContainer : StepContainer() {
+    override val steps = persistentListOf<Step>(
+        FetchInfoStep(),
+        DownloadDiscordStep(),
+        DownloadInjectorStep(),
+        DownloadAliuhookStep(),
+        DownloadKotlinStep(),
+    )
+}

app/src/main/kotlin/com/aliucord/manager/installer/steps/StepContainer.kt

@@ -0,0 +1,48 @@
+package com.aliucord.manager.installer.steps
+
+import com.aliucord.manager.installer.steps.base.Step
+import com.aliucord.manager.installer.steps.base.StepState
+import com.aliucord.manager.manager.PreferencesManager
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.coroutines.delay
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
+
+abstract class StepContainer : KoinComponent {
+    private val preferences: PreferencesManager by inject()
+
+    abstract val steps: ImmutableList<Step>
+
+    /**
+     * Get a step that has already been successfully executed.
+     * This is used to retrieve previously executed dependency steps from a later step.
+     */
+    inline fun <reified T : Step> getCompletedStep(): T {
+        val step = steps.asSequence()
+            .filterIsInstance<T>()
+            .filter { it.state == StepState.Success }
+            .firstOrNull()
+
+        if (step == null) {
+            throw IllegalArgumentException("No completed step ${T::class.simpleName} exists in container")
+        }
+
+        return step
+    }
+
+    suspend fun executeAll(): Throwable? {
+        for (step in steps) {
+            val error = step.executeCatching(this@StepContainer)
+            if (error != null) return error
+
+            // Add delay for human psychology and
+            // better group visibility in UI (the active group can change way too fast)
+            if (!preferences.devMode && step.durationMs < 1000) {
+                delay(1000L - step.durationMs)
+            }
+
+        }
+
+        return null
+    }
+}

app/src/main/kotlin/com/aliucord/manager/installer/steps/StepGroup.kt

@@ -0,0 +1,23 @@
+package com.aliucord.manager.installer.steps
+
+import androidx.annotation.StringRes
+import androidx.compose.runtime.Immutable
+import com.aliucord.manager.R
+
+/**
+ * A group of steps that is shown under one section in the install UI.
+ * This has no functional impact.
+ */
+@Immutable
+enum class StepGroup(
+    /**
+     * The UI name to display this group as
+     */
+    @get:StringRes
+    val localizedName: Int,
+) {
+    Prepare(R.string.install_group_prepare),
+    Download(R.string.install_group_download),
+    Patch(R.string.install_group_patch),
+    Install(R.string.install_group_install)
+}

app/src/main/kotlin/com/aliucord/manager/installer/steps/base/DownloadStep.kt

@@ -0,0 +1,85 @@
+package com.aliucord.manager.installer.steps.base
+
+import android.content.Context
+import androidx.compose.runtime.Stable
+import com.aliucord.manager.R
+import com.aliucord.manager.installer.steps.StepContainer
+import com.aliucord.manager.installer.steps.StepGroup
+import com.aliucord.manager.manager.DownloadManager
+import com.aliucord.manager.util.showToast
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
+import java.io.File
+
+@Stable
+abstract class DownloadStep : Step(), KoinComponent {
+    private val context: Context by inject()
+    private val downloads: DownloadManager by inject()
+
+    /**
+     * The remote url to download
+     */
+    abstract val targetUrl: String
+
+    /**
+     * Target path to store the download in. If this file already exists,
+     * then the cached version is used and the step is marked as cancelled/skipped.
+     */
+    abstract val targetFile: File
+
+    /**
+     * Verify that the download completely successfully without errors.
+     * @throws Throwable If verification fails.
+     */
+    open suspend fun verify() {
+        if (!targetFile.exists())
+            throw Error("Downloaded file is missing!")
+
+        if (targetFile.length() <= 0)
+            throw Error("Downloaded file is empty!")
+    }
+
+    override val group = StepGroup.Download
+
+    override suspend fun execute(container: StepContainer) {
+        if (targetFile.exists()) {
+            if (targetFile.length() > 0) {
+                state = StepState.Skipped
+                return
+            }
+
+            targetFile.delete()
+        }
+
+        val result = downloads.download(targetUrl, targetFile) { newProgress ->
+            progress = newProgress ?: -1f
+        }
+
+        when (result) {
+            is DownloadManager.Result.Success -> {
+                try {
+                    verify()
+                } catch (t: Throwable) {
+                    withContext(Dispatchers.Main) {
+                        context.showToast(R.string.installer_dl_verify_fail)
+                    }
+
+                    throw t
+                }
+            }
+
+            is DownloadManager.Result.Error -> {
+                withContext(Dispatchers.Main) {
+                    context.showToast(result.localizedReason)
+                }
+
+                throw Error("Failed to download: ${result.debugReason}")
+            }
+
+            is DownloadManager.Result.Cancelled ->
+                state = StepState.Cancelled
+        }
+    }
+}

app/src/main/kotlin/com/aliucord/manager/installer/steps/base/Step.kt

@@ -0,0 +1,77 @@
+package com.aliucord.manager.installer.steps.base
+
+import androidx.annotation.StringRes
+import androidx.compose.runtime.*
+import com.aliucord.manager.installer.steps.StepGroup
+import com.aliucord.manager.installer.steps.StepContainer
+import org.koin.core.time.measureTimedValue
+import kotlin.math.roundToInt
+
+/**
+ * A base install process step. Steps are single-use
+ */
+@Stable
+abstract class Step {
+    /**
+     * The group this step belongs to.
+     */
+    abstract val group: StepGroup
+
+    /**
+     * The UI name to display this step as
+     */
+    @get:StringRes
+    abstract val localizedName: Int
+
+    /**
+     * Run the step's logic.
+     * It can be assumed that this is executed in the correct order after other steps.
+     */
+    protected abstract suspend fun execute(container: StepContainer)
+
+    /**
+     * The current state of this step in the installation process.
+     */
+    var state by mutableStateOf(StepState.Pending)
+        protected set
+
+    /**
+     * If the current state is [StepState.Running], then the progress of this step.
+     * If the progress isn't currently measurable, then this should be set to `-1`.
+     */
+    var progress by mutableFloatStateOf(-1f)
+        protected set
+
+    /**
+     * The total execution time once this step has finished execution.
+     */
+    // TODO: make this a live value
+    var durationMs by mutableIntStateOf(0)
+        private set
+
+    /**
+     * Thin wrapper over [execute] but handling errors.
+     * @return An exception if the step failed to execute.
+     */
+    suspend fun executeCatching(container: StepContainer): Throwable? {
+        if (state != StepState.Pending)
+            throw IllegalStateException("Cannot execute a step that has already started")
+
+        state = StepState.Running
+
+        // Execute this steps logic while timing it
+        val (error, executionTimeMs) = measureTimedValue {
+            try {
+                execute(container)
+                state = StepState.Success
+                null
+            } catch (t: Throwable) {
+                state = StepState.Error
+                t
+            }
+        }
+
+        durationMs = executionTimeMs.roundToInt()
+        return error
+    }
+}

app/src/main/kotlin/com/aliucord/manager/installer/steps/base/StepState.kt

@@ -0,0 +1,10 @@
+package com.aliucord.manager.installer.steps.base
+
+enum class StepState {
+    Pending,
+    Running,
+    Success,
+    Error,
+    Skipped,
+    Cancelled, // TODO: something like the discord dnd sign except its not red, but gray maybe
+}

app/src/main/kotlin/com/aliucord/manager/installer/steps/download/DownloadAliuhookStep.kt

@@ -0,0 +1,36 @@
+package com.aliucord.manager.installer.steps.download
+
+import androidx.compose.runtime.Stable
+import com.aliucord.manager.R
+import com.aliucord.manager.domain.repository.AliucordMavenRepository
+import com.aliucord.manager.installer.steps.StepContainer
+import com.aliucord.manager.installer.steps.base.DownloadStep
+import com.aliucord.manager.manager.PathManager
+import com.aliucord.manager.network.utils.getOrThrow
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
+
+/**
+ * Download a packaged AAR of the latest Aliuhook build from the Aliucord maven.
+ */
+@Stable
+class DownloadAliuhookStep : DownloadStep(), KoinComponent {
+    private val paths: PathManager by inject()
+    private val maven: AliucordMavenRepository by inject()
+
+    /**
+     * This is populated right before the download starts (ref: [execute])
+     */
+    private lateinit var targetVersion: String
+
+    override val localizedName = R.string.install_step_dl_aliuhook
+    override val targetUrl get() = AliucordMavenRepository.getAliuhookUrl(targetVersion)
+    override val targetFile get() = paths.cachedAliuhookAAR(targetVersion)
+
+    override suspend fun execute(container: StepContainer) {
+        targetVersion = maven.getAliuhookVersion().getOrThrow()
+
+        super.execute(container)
+    }
+}
+

app/src/main/kotlin/com/aliucord/manager/installer/steps/download/DownloadDiscordStep.kt

@@ -0,0 +1,39 @@
+package com.aliucord.manager.installer.steps.download
+
+import androidx.compose.runtime.Stable
+import com.aliucord.manager.BuildConfig
+import com.aliucord.manager.R
+import com.aliucord.manager.installer.steps.base.DownloadStep
+import com.aliucord.manager.manager.PathManager
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
+
+/**
+ * If not already cached, then download the raw unmodified v126.21 (Kotlin) Discord APK
+ * from a redirect to an APK mirror site provided by the Aliucord backend.
+ */
+@Stable
+class DownloadDiscordStep : DownloadStep(), KoinComponent {
+    private val paths: PathManager by inject()
+
+    override val localizedName = R.string.install_step_dl_kt_apk
+    override val targetUrl = getDiscordApkUrl(DISCORD_KT_VERSION)
+    override val targetFile = paths.discordApkVersionCache(DISCORD_KT_VERSION)
+        .resolve("discord.apk")
+
+    override suspend fun verify() {
+        super.verify()
+
+        // TODO: verify signature
+    }
+
+    private companion object {
+        /**
+         * Last version of Discord before the RN transition.
+         */
+        const val DISCORD_KT_VERSION = 126021
+
+        fun getDiscordApkUrl(version: Int) =
+            "${BuildConfig.BACKEND_URL}/download/discord?v=$version"
+    }
+}