data: implement HuggingFace data model, data source with Retrofit API

examples/llama.android/app/src/main/java/com/example/llama/revamp/data/remote/HuggingFaceApiService.kt

@@ -0,0 +1,29 @@
+package com.example.llama.revamp.data.remote
+
+import okhttp3.ResponseBody
+import retrofit2.http.GET
+import retrofit2.http.Path
+import retrofit2.http.Query
+import retrofit2.http.Streaming
+
+interface HuggingFaceApiService {
+    @GET("api/models")
+    suspend fun getModels(
+        @Query("search") search: String? = null,
+        @Query("author") author: String? = null,
+        @Query("filter") filter: String? = null,
+        @Query("sort") sort: String? = null,
+        @Query("direction") direction: String? = null,
+        @Query("limit") limit: Int? = null
+    ): List<HuggingFaceModel>
+
+    @GET("api/models/{modelId}")
+    suspend fun getModelDetails(@Path("modelId") modelId: String): HuggingFaceModel
+
+    @GET("{modelId}/resolve/main/{filePath}")
+    @Streaming
+    suspend fun downloadModelFile(
+        @Path("modelId") modelId: String,
+        @Path("filePath") filePath: String
+    ): ResponseBody
+}

examples/llama.android/app/src/main/java/com/example/llama/revamp/data/remote/HuggingFaceModel.kt

@@ -0,0 +1,14 @@
+package com.example.llama.revamp.data.remote
+
+data class HuggingFaceModel(
+    val id: String,
+    val modelId: String,
+    val likes: Int?,
+    val trendingScore: Int?,
+    val private: Boolean?,
+    val downloads: Int?,
+    val tags: List<String>?,
+    val pipeline_tag: String?,
+    val library_name: String?,
+    val createdAt: String?
+)

examples/llama.android/app/src/main/java/com/example/llama/revamp/data/remote/HuggingFaceRemoteDataSource.kt

@@ -0,0 +1,79 @@
+package com.example.llama.revamp.data.remote
+
+import android.util.Log
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.File
+import javax.inject.Inject
+import javax.inject.Singleton
+
+interface HuggingFaceRemoteDataSource {
+    suspend fun searchModels(
+        query: String? = "gguf",
+        filter: String? = "text-generation", // Only generative models,
+        sort: String? = "downloads",
+        direction: String? = "-1",
+        limit: Int? = 20
+    ): List<HuggingFaceModel>
+
+    suspend fun getModelDetails(modelId: String): HuggingFaceModel
+
+    suspend fun downloadModelFile(modelId: String, filePath: String, outputFile: File): Result<File>
+}
+
+@Singleton
+class HuggingFaceRemoteDataSourceImpl @Inject constructor(
+    private val apiService: HuggingFaceApiService
+) : HuggingFaceRemoteDataSource {
+
+    override suspend fun searchModels(
+        query: String?,
+        filter: String?,
+        sort: String?,
+        direction: String?,
+        limit: Int?
+    ) = withContext(Dispatchers.IO) {
+        apiService.getModels(
+            search = query,
+            filter = filter,
+            sort = sort,
+            direction = direction,
+            limit = limit
+        )
+    }
+
+    override suspend fun getModelDetails(
+        modelId: String
+    ) = withContext(Dispatchers.IO) {
+        apiService.getModelDetails(modelId)
+    }
+
+    override suspend fun downloadModelFile(
+        modelId: String,
+        filePath: String,
+        outputFile: File
+    ): Result<File> = withContext(Dispatchers.IO) {
+        try {
+            val response = apiService.downloadModelFile(modelId, filePath)
+
+            // Create parent directories if needed
+            outputFile.parentFile?.mkdirs()
+
+            // Save the file
+            response.byteStream().use { input ->
+                outputFile.outputStream().use { output ->
+                    input.copyTo(output)
+                }
+            }
+
+            Result.success(outputFile)
+        } catch (e: Exception) {
+            Log.e(TAG, "Error downloading file $filePath: ${e.message}")
+            Result.failure(e)
+        }
+    }
+
+    companion object {
+        private val TAG = HuggingFaceRemoteDataSourceImpl::class.java.simpleName
+    }
+}

examples/llama.android/app/src/main/java/com/example/llama/revamp/di/AppModule.kt

@@ -4,16 +4,19 @@ import android.content.Context
 import android.llama.cpp.InferenceEngine
 import android.llama.cpp.LLamaAndroid
 import com.example.llama.revamp.data.local.AppDatabase
+import com.example.llama.revamp.data.remote.HuggingFaceApiService
+import com.example.llama.revamp.data.remote.HuggingFaceRemoteDataSource
+import com.example.llama.revamp.data.remote.HuggingFaceRemoteDataSourceImpl
 import com.example.llama.revamp.data.repository.ModelRepository
 import com.example.llama.revamp.data.repository.ModelRepositoryImpl
 import com.example.llama.revamp.data.repository.SystemPromptRepository
 import com.example.llama.revamp.data.repository.SystemPromptRepositoryImpl
 import com.example.llama.revamp.engine.BenchmarkService
 import com.example.llama.revamp.engine.ConversationService
-import com.example.llama.revamp.engine.StubInferenceEngine
 import com.example.llama.revamp.engine.InferenceService
 import com.example.llama.revamp.engine.InferenceServiceImpl
 import com.example.llama.revamp.engine.ModelLoadingService
+import com.example.llama.revamp.engine.StubInferenceEngine
 import com.example.llama.revamp.monitoring.PerformanceMonitor
 import dagger.Binds
 import dagger.Module
@@ -21,6 +24,10 @@ import dagger.Provides
 import dagger.hilt.InstallIn
 import dagger.hilt.android.qualifiers.ApplicationContext
 import dagger.hilt.components.SingletonComponent
+import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import retrofit2.Retrofit
+import retrofit2.converter.gson.GsonConverterFactory
 import javax.inject.Singleton
 
 @Module
@@ -45,9 +52,13 @@ internal abstract class AppModule {
     @Binds
     abstract fun bindsSystemPromptRepository(impl: SystemPromptRepositoryImpl): SystemPromptRepository
 
+    @Binds
+    abstract fun bindHuggingFaceRemoteDataSource(
+        impl: HuggingFaceRemoteDataSourceImpl
+    ): HuggingFaceRemoteDataSource
+
     companion object {
         @Provides
-        @Singleton
         fun provideInferenceEngine(): InferenceEngine {
             val useRealEngine = true
             return if (useRealEngine) LLamaAndroid.instance() else StubInferenceEngine()
@@ -64,5 +75,22 @@ internal abstract class AppModule {
 
         @Provides
         fun providesSystemPromptDao(appDatabase: AppDatabase) = appDatabase.systemPromptDao()
+
+        @Provides
+        @Singleton
+        fun provideOkhttpClient() = OkHttpClient.Builder()
+            .addInterceptor(HttpLoggingInterceptor().apply {
+                level = HttpLoggingInterceptor.Level.BODY
+            }).build()
+
+        @Provides
+        @Singleton
+        fun provideHuggingFaceApiService(okHttpClient: OkHttpClient): HuggingFaceApiService =
+            Retrofit.Builder()
+                .baseUrl("https://huggingface.co/")
+                .client(okHttpClient)
+                .addConverterFactory(GsonConverterFactory.create())
+                .build()
+                .create(HuggingFaceApiService::class.java)
     }
 }