Enterprise-Knowledge-Base/internal/application/service/model.go

package service

import (
	"context"
	"errors"

	"github.com/Tencent/WeKnora/internal/logger"
	"github.com/Tencent/WeKnora/internal/models/chat"
	"github.com/Tencent/WeKnora/internal/models/embedding"
	"github.com/Tencent/WeKnora/internal/models/rerank"
	"github.com/Tencent/WeKnora/internal/models/utils/ollama"
	"github.com/Tencent/WeKnora/internal/models/vlm"
	"github.com/Tencent/WeKnora/internal/types"
	"github.com/Tencent/WeKnora/internal/types/interfaces"
)

// ErrModelNotFound is returned when a model cannot be found in the repository
var ErrModelNotFound = errors.New("model not found")

// modelService implements the model service interface
type modelService struct {
	repo          interfaces.ModelRepository
	ollamaService *ollama.OllamaService
	pooler        embedding.EmbedderPooler
}

// NewModelService creates a new model service instance
func NewModelService(repo interfaces.ModelRepository, ollamaService *ollama.OllamaService, pooler embedding.EmbedderPooler) interfaces.ModelService {
	return &modelService{
		repo:          repo,
		ollamaService: ollamaService,
		pooler:        pooler,
	}
}

// CreateModel creates a new model in the repository
// For local models, it initiates an asynchronous download process
// Remote models are immediately set to active status
func (s *modelService) CreateModel(ctx context.Context, model *types.Model) error {
	logger.Infof(ctx, "Creating model: %s, type: %s, source: %s", model.Name, model.Type, model.Source)

	// Handle remote models (e.g., OpenAI, Azure)
	if model.Source == types.ModelSourceRemote {
		logger.Info(ctx, "Remote model detected, setting status to active")
		model.Status = types.ModelStatusActive

		logger.Info(ctx, "Saving remote model to repository")
		err := s.repo.Create(ctx, model)
		if err != nil {
			logger.ErrorWithFields(ctx, err, map[string]interface{}{
				"model_name": model.Name,
				"model_type": model.Type,
			})
			return err
		}

		logger.Infof(ctx, "Remote model created successfully: %s", model.ID)
		return nil
	}

	// Handle local models (e.g., Ollama)
	logger.Info(ctx, "Local model detected, setting status to downloading")
	model.Status = types.ModelStatusDownloading

	logger.Info(ctx, "Saving local model to repository")
	err := s.repo.Create(ctx, model)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_name": model.Name,
			"model_type": model.Type,
		})
		return err
	}

	// Start asynchronous model download
	logger.Infof(ctx, "Starting background download for model: %s", model.Name)
	newCtx := logger.CloneContext(ctx)
	go func() {
		logger.Info(newCtx, "Background download started")
		err := s.ollamaService.PullModel(newCtx, model.Name)
		if err != nil {
			logger.ErrorWithFields(newCtx, err, map[string]interface{}{
				"model_name": model.Name,
			})
			model.Status = types.ModelStatusDownloadFailed
		} else {
			logger.Infof(newCtx, "Model download completed successfully: %s", model.Name)
			model.Status = types.ModelStatusActive
		}
		logger.Infof(newCtx, "Updating model status to: %s", model.Status)
		s.repo.Update(newCtx, model)
	}()

	logger.Infof(ctx, "Model creation initiated successfully: %s", model.ID)
	return nil
}

// GetModelByID retrieves a model by its ID
// Returns an error if the model is not found or is in a non-active state
func (s *modelService) GetModelByID(ctx context.Context, id string) (*types.Model, error) {
	// Check if ID is empty
	if id == "" {
		logger.Error(ctx, "Model ID is empty")
		return nil, errors.New("model ID cannot be empty")
	}

	tenantID := types.MustTenantIDFromContext(ctx)

	// Fetch model from repository
	model, err := s.repo.GetByID(ctx, tenantID, id)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":  id,
			"tenant_id": tenantID,
		})
		return nil, err
	}

	// Check if model exists
	if model == nil {
		logger.Error(ctx, "Model not found")
		return nil, ErrModelNotFound
	}

	logger.Infof(ctx, "Model found, name: %s, status: %s", model.Name, model.Status)

	// Check model status
	if model.Status == types.ModelStatusActive {
		logger.Info(ctx, "Model is active and ready to use")
		return model, nil
	}

	if model.Status == types.ModelStatusDownloading {
		logger.Warn(ctx, "Model is currently downloading")
		return nil, errors.New("model is currently downloading")
	}

	if model.Status == types.ModelStatusDownloadFailed {
		logger.Error(ctx, "Model download failed")
		return nil, errors.New("model download failed")
	}

	logger.Error(ctx, "Model status is abnormal")
	return nil, errors.New("abnormal model status")
}

// ListModels returns all models belonging to the tenant
func (s *modelService) ListModels(ctx context.Context) ([]*types.Model, error) {
	logger.Info(ctx, "Start listing models")

	tenantID := types.MustTenantIDFromContext(ctx)
	logger.Infof(ctx, "Listing models for tenant ID: %d", tenantID)

	// List models from repository with no additional filters
	models, err := s.repo.List(ctx, tenantID, "", "")
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"tenant_id": tenantID,
		})
		return nil, err
	}

	logger.Infof(ctx, "Retrieved %d models successfully", len(models))
	return models, nil
}

// UpdateModel updates an existing model in the repository
func (s *modelService) UpdateModel(ctx context.Context, model *types.Model) error {
	logger.Info(ctx, "Start updating model")
	logger.Infof(ctx, "Updating model ID: %s, name: %s", model.ID, model.Name)

	// Check if the model is builtin - builtin models cannot be updated
	tenantID := types.MustTenantIDFromContext(ctx)
	existingModel, err := s.repo.GetByID(ctx, tenantID, model.ID)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id": model.ID,
		})
		return err
	}
	if existingModel != nil && existingModel.IsBuiltin {
		logger.Warnf(ctx, "Attempted to update builtin model: %s", model.ID)
		return errors.New("builtin models cannot be updated")
	}

	// Update model in repository
	err = s.repo.Update(ctx, model)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":   model.ID,
			"model_name": model.Name,
		})
		return err
	}

	logger.Infof(ctx, "Model updated successfully: %s", model.ID)
	return nil
}

// DeleteModel removes a model from the repository
func (s *modelService) DeleteModel(ctx context.Context, id string) error {
	logger.Info(ctx, "Start deleting model")
	logger.Infof(ctx, "Deleting model ID: %s", id)

	tenantID := types.MustTenantIDFromContext(ctx)
	logger.Infof(ctx, "Tenant ID: %d", tenantID)

	// Check if the model is builtin - builtin models cannot be deleted
	existingModel, err := s.repo.GetByID(ctx, tenantID, id)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id": id,
		})
		return err
	}
	if existingModel != nil && existingModel.IsBuiltin {
		logger.Warnf(ctx, "Attempted to delete builtin model: %s", id)
		return errors.New("builtin models cannot be deleted")
	}

	// Delete model from repository
	err = s.repo.Delete(ctx, tenantID, id)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":  id,
			"tenant_id": tenantID,
		})
		return err
	}

	logger.Infof(ctx, "Model deleted successfully: %s", id)
	return nil
}

// GetEmbeddingModel retrieves and initializes an embedding model instance
// Takes a model ID and returns an Embedder interface implementation
func (s *modelService) GetEmbeddingModel(ctx context.Context, modelId string) (embedding.Embedder, error) {
	// Get the model details
	model, err := s.GetModelByID(ctx, modelId)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id": modelId,
		})
		return nil, err
	}

	logger.Infof(ctx, "Getting embedding model: %s, source: %s", model.Name, model.Source)

	// Initialize the embedder with model configuration
	embedder, err := embedding.NewEmbedder(embedding.Config{
		Source:               model.Source,
		BaseURL:              model.Parameters.BaseURL,
		APIKey:               model.Parameters.APIKey,
		ModelID:              model.ID,
		ModelName:            model.Name,
		Dimensions:           model.Parameters.EmbeddingParameters.Dimension,
		TruncatePromptTokens: model.Parameters.EmbeddingParameters.TruncatePromptTokens,
		Provider:             model.Parameters.Provider,
	}, s.pooler, s.ollamaService)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":   model.ID,
			"model_name": model.Name,
		})
		return nil, err
	}

	logger.Info(ctx, "Embedding model initialized successfully")
	return embedder, nil
}

// GetEmbeddingModelForTenant retrieves and initializes an embedding model for a specific tenant
// This is used for cross-tenant knowledge base sharing where the embedding model from
// the source tenant must be used to ensure vector compatibility
func (s *modelService) GetEmbeddingModelForTenant(ctx context.Context, modelId string, tenantID uint64) (embedding.Embedder, error) {
	// Check if model ID is empty
	if modelId == "" {
		logger.Error(ctx, "Model ID is empty")
		return nil, errors.New("model ID cannot be empty")
	}

	// Fetch model from repository using the specified tenant ID
	model, err := s.repo.GetByID(ctx, tenantID, modelId)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":  modelId,
			"tenant_id": tenantID,
		})
		return nil, err
	}

	if model == nil {
		logger.Error(ctx, "Model not found for specified tenant")
		return nil, ErrModelNotFound
	}

	if model.Status != types.ModelStatusActive {
		logger.Errorf(ctx, "Model is not active, status: %s", model.Status)
		return nil, errors.New("model is not active")
	}

	logger.Infof(ctx, "Getting cross-tenant embedding model: %s, source: %s, tenant: %d", model.Name, model.Source, tenantID)

	// Initialize the embedder with model configuration
	embedder, err := embedding.NewEmbedder(embedding.Config{
		Source:               model.Source,
		BaseURL:              model.Parameters.BaseURL,
		APIKey:               model.Parameters.APIKey,
		ModelID:              model.ID,
		ModelName:            model.Name,
		Dimensions:           model.Parameters.EmbeddingParameters.Dimension,
		TruncatePromptTokens: model.Parameters.EmbeddingParameters.TruncatePromptTokens,
		Provider:             model.Parameters.Provider,
	}, s.pooler, s.ollamaService)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":   model.ID,
			"model_name": model.Name,
			"tenant_id":  tenantID,
		})
		return nil, err
	}

	logger.Info(ctx, "Cross-tenant embedding model initialized successfully")
	return embedder, nil
}

// GetRerankModel retrieves and initializes a reranking model instance
// Takes a model ID and returns a Reranker interface implementation
func (s *modelService) GetRerankModel(ctx context.Context, modelId string) (rerank.Reranker, error) {
	// Get the model details
	model, err := s.GetModelByID(ctx, modelId)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id": modelId,
		})
		return nil, err
	}

	logger.Infof(ctx, "Getting rerank model: %s, source: %s", model.Name, model.Source)

	// Initialize the reranker with model configuration
	reranker, err := rerank.NewReranker(&rerank.RerankerConfig{
		ModelID:   model.ID,
		APIKey:    model.Parameters.APIKey,
		BaseURL:   model.Parameters.BaseURL,
		ModelName: model.Name,
		Source:    model.Source,
	})
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":   model.ID,
			"model_name": model.Name,
		})
		return nil, err
	}

	logger.Info(ctx, "Rerank model initialized successfully")
	return reranker, nil
}

// GetChatModel retrieves and initializes a chat model instance
// Takes a model ID and returns a Chat interface implementation
func (s *modelService) GetChatModel(ctx context.Context, modelId string) (chat.Chat, error) {
	// Check if model ID is empty
	if modelId == "" {
		logger.Error(ctx, "Model ID is empty")
		return nil, errors.New("model ID cannot be empty")
	}

	tenantID := types.MustTenantIDFromContext(ctx)

	// Get the model directly from repository to avoid status checks
	model, err := s.repo.GetByID(ctx, tenantID, modelId)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":  modelId,
			"tenant_id": tenantID,
		})
		return nil, err
	}

	if model == nil {
		logger.Error(ctx, "Chat model not found")
		return nil, ErrModelNotFound
	}

	logger.Infof(ctx, "Getting chat model: %s, source: %s", model.Name, model.Source)

	// Initialize the chat model with model configuration
	chatModel, err := chat.NewChat(&chat.ChatConfig{
		ModelID:   model.ID,
		APIKey:    model.Parameters.APIKey,
		BaseURL:   model.Parameters.BaseURL,
		ModelName: model.Name,
		Source:    model.Source,
	}, s.ollamaService)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":   model.ID,
			"model_name": model.Name,
		})
		return nil, err
	}

	return chatModel, nil
}

// GetVLMModel retrieves and initializes a vision language model instance.
func (s *modelService) GetVLMModel(ctx context.Context, modelId string) (vlm.VLM, error) {
	if modelId == "" {
		return nil, errors.New("model ID cannot be empty")
	}

	tenantID := types.MustTenantIDFromContext(ctx)

	model, err := s.repo.GetByID(ctx, tenantID, modelId)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":  modelId,
			"tenant_id": tenantID,
		})
		return nil, err
	}

	if model == nil {
		return nil, ErrModelNotFound
	}

	logger.Infof(ctx, "Getting VLM model: %s, source: %s", model.Name, model.Source)

	ifType := model.Parameters.InterfaceType
	if ifType == "" {
		if model.Source == types.ModelSourceLocal {
			ifType = "ollama"
		} else {
			ifType = "openai"
		}
	}

	vlmModel, err := vlm.NewVLM(&vlm.Config{
		ModelID:       model.ID,
		APIKey:        model.Parameters.APIKey,
		BaseURL:       model.Parameters.BaseURL,
		ModelName:     model.Name,
		Source:        model.Source,
		InterfaceType: ifType,
	}, s.ollamaService)
	if err != nil {
		logger.ErrorWithFields(ctx, err, map[string]interface{}{
			"model_id":   model.ID,
			"model_name": model.Name,
		})
		return nil, err
	}

	return vlmModel, nil
}

// Note: default model selection logic has been removed; models no longer
// maintain a per-type default flag at the service layer.