data: update Model data repository to support fetching HuggingFace models

examples/llama.android/app/src/main/java/com/example/llama/revamp/data/repository/ModelRepository.kt

@@ -7,8 +7,11 @@ import android.util.Log
 import com.example.llama.revamp.data.local.dao.ModelDao
 import com.example.llama.revamp.data.local.entity.ModelEntity
 import com.example.llama.revamp.data.model.ModelInfo
+import com.example.llama.revamp.data.remote.HuggingFaceModel
+import com.example.llama.revamp.data.remote.HuggingFaceRemoteDataSource
 import com.example.llama.revamp.data.repository.ModelRepository.ImportProgressTracker
 import com.example.llama.revamp.monitoring.StorageMetrics
+import com.example.llama.revamp.util.GgufMetadata
 import com.example.llama.revamp.util.GgufMetadataReader
 import com.example.llama.revamp.util.copyWithBuffer
 import com.example.llama.revamp.util.copyWithChannels
@@ -77,6 +80,24 @@ interface ModelRepository {
      */
     suspend fun deleteModel(modelId: String)
     suspend fun deleteModels(modelIds: List<String>)
+
+    /**
+     * Search models on HuggingFace
+     */
+    suspend fun searchHuggingFaceModels(limit: Int = 20): List<HuggingFaceModel>
+
+    /**
+     * Obtain the model details from HuggingFace
+     */
+    suspend fun getHuggingFaceModelDetails(modelId: String): HuggingFaceModel
+
+    /**
+     * Download and import a HuggingFace model
+     */
+    suspend fun importHuggingFaceModel(
+        model: HuggingFaceModel,
+        progressTracker: (Float) -> Unit
+    ): ModelInfo
 }
 
 class InsufficientStorageException(message: String) : IOException(message)
@@ -85,6 +106,7 @@ class InsufficientStorageException(message: String) : IOException(message)
 class ModelRepositoryImpl @Inject constructor(
     @ApplicationContext private val context: Context,
     private val modelDao: ModelDao,
+    private val huggingFaceRemoteDataSource: HuggingFaceRemoteDataSource,
 ) : ModelRepository {
 
     private val modelsDir = File(context.filesDir, INTERNAL_STORAGE_PATH)
@@ -93,6 +115,17 @@ class ModelRepositoryImpl @Inject constructor(
         if (!modelsDir.exists()) { modelsDir.mkdirs() }
     }
 
+    val modelsSizeBytes: Long
+        get() = modelsDir.listFiles()?.fold(0L) { totalSize, file ->
+            totalSize + if (file.isFile) file.length() else 0
+        } ?: 0L
+
+    val availableSpaceBytes: Long
+        get() = StatFs(context.filesDir.path).availableBytes
+
+    val totalSpaceBytes: Long
+        get() = StatFs(context.filesDir.path).totalBytes
+
     override fun getStorageMetrics(): Flow<StorageMetrics> = flow {
         while (true) {
             emit(
@@ -306,16 +339,128 @@ class ModelRepositoryImpl @Inject constructor(
         }
     }
 
-    val modelsSizeBytes: Long
-        get() = modelsDir.listFiles()?.fold(0L) { totalSize, file ->
-            totalSize + if (file.isFile) file.length() else 0
-        } ?: 0L
+    override suspend fun searchHuggingFaceModels(
+        limit: Int
+    ): List<HuggingFaceModel> = withContext(Dispatchers.Default) {
+        huggingFaceRemoteDataSource.searchModels(limit = limit)
+    }
 
-    val availableSpaceBytes: Long
-        get() = StatFs(context.filesDir.path).availableBytes
+    override suspend fun getHuggingFaceModelDetails(
+        modelId: String
+    ) = withContext(Dispatchers.Default) {
+        huggingFaceRemoteDataSource.getModelDetails(modelId)
+    }
 
-    val totalSpaceBytes: Long
-        get() = StatFs(context.filesDir.path).totalBytes
+    override suspend fun importHuggingFaceModel(
+        model: HuggingFaceModel,
+        progressTracker: (Float) -> Unit
+    ): ModelInfo = withContext(Dispatchers.IO) {
+        try {
+            // Find GGUF files in the model repository
+            val modelFiles = findGgufFiles(model.id)
+            if (modelFiles.isEmpty()) {
+                throw IOException("No GGUF files found for model ${model.id}")
+            }
+
+            // Create directory for the model
+            val modelDir = File(modelsDir, model.id.replace("/", "_"))
+            if (!modelDir.exists()) {
+                modelDir.mkdirs()
+            }
+
+            var totalDownloaded = 0L
+            var fileIndex = 0
+            val totalFiles = modelFiles.size
+
+            // Download each GGUF file
+            modelFiles.forEach { filePath ->
+                fileIndex++
+                progressTracker(fileIndex.toFloat() / totalFiles)
+
+                val outputFile = File(modelDir, filePath.substringAfterLast("/"))
+                huggingFaceRemoteDataSource.downloadModelFile(
+                    model.id, filePath, outputFile
+                ).onSuccess { file ->
+                    totalDownloaded += file.length()
+                }
+            }
+
+            // Create and save the model entity
+            val modelEntity = ModelEntity(
+                id = UUID.randomUUID().toString(), // Generate a new ID for local storage
+                name = model.modelId.split("/").last(),
+                path = modelDir.absolutePath,
+                sizeInBytes = totalDownloaded,
+                metadata = createGgufMetadataFromHfModel(model),
+                dateAdded = System.currentTimeMillis(),
+                dateLastUsed = null
+            )
+
+            modelDao.insertModel(modelEntity)
+            return@withContext modelEntity.toModelInfo()
+
+        } catch (e: Exception) {
+            // Clean up if download fails
+            File(modelsDir, model.id.replace("/", "_")).let {
+                if (it.exists()) {
+                    it.deleteRecursively()
+                }
+            }
+            throw e
+        }
+    }
+
+    // TODO-han.yin: replace this heuristic approach with API call
+    private suspend fun findGgufFiles(modelId: String): List<String> = withContext(Dispatchers.IO) {
+        // In a real implementation, we would query the Hugging Face API or use Git APIs
+        // to get the file listing. For now, we'll use a simpler approach:
+
+        // 1. Try standard filenames first
+        val standardNames = listOf(
+            "model.gguf",
+            "model-q4_0.gguf",
+            "model-q4_k_m.gguf",
+            "model-q5_k_m.gguf",
+            "model-q8_0.gguf"
+        )
+
+        // 2. Check if standard files exist (would require separate API call)
+        // For now, just return the standard names as a fallback
+        standardNames
+    }
+
+    /**
+     * Convert HuggingFace model metadata to GgufMetadata format
+     *
+     * TODO-han.yin: improve this conversion coverage
+     */
+    private fun createGgufMetadataFromHfModel(model: HuggingFaceModel) =
+        GgufMetadata(
+            version = GgufMetadata.GgufVersion.VALIDATED_V3,
+            tensorCount = 0,
+            kvCount = 0,
+            basic = GgufMetadata.BasicInfo(
+                uuid = model.id,
+                name = model.modelId.split("/").last(),
+                nameLabel = model.modelId,
+                sizeLabel = extractModelSize(model.tags)
+            ),
+            additional = GgufMetadata.AdditionalInfo(
+                type = model.pipeline_tag,
+                description = null,
+                tags = model.tags,
+                languages = model.tags?.filter { it.length <= 3 } // language codes
+            )
+        )
+
+    private fun extractModelSize(tags: List<String>?): String? {
+        // Try to extract model size from tags
+        if (tags == null) return null
+
+        // Common model size patterns: 7B, 13B, 70B, etc.
+        val sizePattern = Regex("\\d+(\\.\\d+)?[Bb]")
+        return tags.find { it.matches(sizePattern) }
+    }
 
     companion object {
         private val TAG = ModelRepository::class.java.simpleName
@@ -332,9 +477,6 @@ class ModelRepositoryImpl @Inject constructor(
         private const val DEFAULT_BUFFER_SIZE = 4 * 1024 * 1024
         private const val DEFAULT_YIELD_SIZE = 16 * 1024 * 1024
         private const val CANCEL_LOCAL_MODEL_IMPORT_TIMEOUT = 500L
-
-        private const val DEFAULT_CONTEXT_SIZE = 8192
-
     }
 }