package usecase

import (
	"context"
	"fmt"
	"log/slog"

	"github.com/chaitin/MonkeyCode/backend/domain"
	codesnippet_service "github.com/chaitin/MonkeyCode/backend/internal/codesnippet/service"
)

type CodeSnippetUsecase struct {
	repo      domain.CodeSnippetRepo
	embedding codesnippet_service.EmbeddingService
	logger    *slog.Logger
}

func NewCodeSnippetUsecase(
	repo domain.CodeSnippetRepo,
	embeddingService codesnippet_service.EmbeddingService,
	logger *slog.Logger,
) domain.CodeSnippetUsecase {
	return &CodeSnippetUsecase{
		repo:      repo,
		embedding: embeddingService,
		logger:    logger.With("usecase", "codesnippet"),
	}
}

// CreateFromIndexResult 从 IndexResult 创建 CodeSnippet
func (u *CodeSnippetUsecase) CreateFromIndexResult(ctx context.Context, workspaceFileID string, indexResult *domain.IndexResult, workspacePath string) (*domain.CodeSnippet, error) {
	// 构建 CreateCodeSnippetReq
	// 如果ImplementText为空，则使用RangeText作为Content
	content := indexResult.ImplementText
	if content == "" {
		content = indexResult.RangeText
	}

	req := &domain.CreateCodeSnippetReq{
		WorkspaceFileID: workspaceFileID,
		WorkspacePath:   workspacePath,
		Name:            indexResult.Name,
		SnippetType:     indexResult.Type,
		Language:        indexResult.Language,
		Content:         content,
		Hash:            indexResult.FileHash,
		StartLine:       indexResult.StartLine,
		EndLine:         indexResult.EndLine,
		// StartColumn 和 EndColumn 在 IndexResult 中没有直接对应字段，暂时设置为 0
		StartColumn:    0,
		EndColumn:      0,
		Namespace:      "",                 // IndexResult 中没有直接对应字段
		ContainerName:  "",                 // IndexResult 中没有直接对应字段
		Dependencies:   []string{},         // IndexResult 中没有直接对应字段
		Parameters:     []map[string]any{}, // IndexResult 中没有直接对应字段
		Signature:      indexResult.Signature,
		DefinitionText: indexResult.DefinitionText,
		StructuredInfo: map[string]any{
			"definition": indexResult.Definition,
		},
	}

	// 生成向量嵌入
	// 使用相同的逻辑设置snippet的Content字段
	snippet := &domain.CodeSnippet{
		WorkspaceFileID: workspaceFileID,
		Name:            indexResult.Name,
		SnippetType:     indexResult.Type,
		Language:        indexResult.Language,
		Content:         content, // 使用上面定义的content变量
		Hash:            indexResult.FileHash,
		StartLine:       indexResult.StartLine,
		EndLine:         indexResult.EndLine,
		// StartColumn 和 EndColumn 在 IndexResult 中没有直接对应字段，暂时设置为 0
		StartColumn:    0,
		EndColumn:      0,
		Namespace:      "",                 // IndexResult 中没有直接对应字段
		ContainerName:  "",                 // IndexResult 中没有直接对应字段
		Scope:          []string{},         // IndexResult 中没有直接对应字段
		Dependencies:   []string{},         // IndexResult 中没有直接对应字段
		Parameters:     []map[string]any{}, // IndexResult 中没有直接对应字段
		Signature:      indexResult.Signature,
		DefinitionText: indexResult.DefinitionText,
		StructuredInfo: map[string]any{
			"definition": indexResult.Definition,
		},
	}

	// 检查是否有内容可用于生成embedding
	if snippet.Content != "" {
		embedding, err := u.embedding.GenerateEmbedding(ctx, snippet)
		if err != nil {
			u.logger.Error("failed to generate embedding for code snippet", "error", err, "snippet_name", snippet.Name, "content_length", len(snippet.Content))
			// 不返回错误，而是继续创建代码片段，但不包含嵌入向量
			req.Embedding = nil
			u.logger.Info("continuing without embedding", "snippet_name", snippet.Name)
		} else {
			req.Embedding = embedding
		}
	} else {
		// 如果没有内容可用于生成embedding，记录日志并继续
		u.logger.Info("skipping embedding generation due to empty content", "snippet_name", snippet.Name)
		req.Embedding = nil
	}

	// 创建 CodeSnippet
	dbSnippet, err := u.repo.Create(ctx, req)
	if err != nil {
		u.logger.Error("failed to create code snippet from index result", "error", err)
		return nil, fmt.Errorf("failed to create code snippet: %w", err)
	}

	// 转换为领域模型
	return (&domain.CodeSnippet{}).From(dbSnippet), nil
}

// ListByWorkspaceFile 列出特定工作区文件的所有代码片段
func (u *CodeSnippetUsecase) ListByWorkspaceFile(ctx context.Context, workspaceFileID string) ([]*domain.CodeSnippet, error) {
	// 调用 repository 层的方法
	dbSnippets, err := u.repo.ListByWorkspaceFile(ctx, workspaceFileID)
	if err != nil {
		u.logger.Error("failed to list code snippets by workspace file", "error", err, "workspaceFileID", workspaceFileID)
		return nil, fmt.Errorf("failed to list code snippets: %w", err)
	}

	// 将数据库模型转换为领域模型
	var snippets []*domain.CodeSnippet
	for _, dbSnippet := range dbSnippets {
		snippet := (&domain.CodeSnippet{}).From(dbSnippet)
		snippets = append(snippets, snippet)
	}

	return snippets, nil
}

// GetByID 根据 ID 获取代码片段
func (u *CodeSnippetUsecase) GetByID(ctx context.Context, id string) (*domain.CodeSnippet, error) {
	// 调用 repository 层的方法
	dbSnippet, err := u.repo.GetByID(ctx, id)
	if err != nil {
		u.logger.Error("failed to get code snippet by ID", "error", err, "id", id)
		return nil, fmt.Errorf("failed to get code snippet: %w", err)
	}

	// 将数据库模型转换为领域模型
	return (&domain.CodeSnippet{}).From(dbSnippet), nil
}

// Delete 删除代码片段
func (u *CodeSnippetUsecase) Delete(ctx context.Context, id string) error {
	// 调用 repository 层的方法
	err := u.repo.Delete(ctx, id)
	if err != nil {
		u.logger.Error("failed to delete code snippet", "error", err, "id", id)
		return fmt.Errorf("failed to delete code snippet: %w", err)
	}

	return nil
}

// Search 根据名称、类型和语言搜索代码片段
func (u *CodeSnippetUsecase) Search(ctx context.Context, name, snippetType, language string) ([]*domain.CodeSnippet, error) {
	// 调用 repository 层的 Search 方法
	dbSnippets, err := u.repo.Search(ctx, name, snippetType, language)
	if err != nil {
		u.logger.Error("failed to search code snippets", "error", err)
		return nil, fmt.Errorf("failed to search code snippets: %w", err)
	}

	// 将数据库模型转换为领域模型
	var snippets []*domain.CodeSnippet
	for _, dbSnippet := range dbSnippets {
		snippet := (&domain.CodeSnippet{}).From(dbSnippet)
		snippets = append(snippets, snippet)
	}

	return snippets, nil
}

// SearchByWorkspace 根据用户ID、工作区路径和搜索条件搜索代码片段
func (u *CodeSnippetUsecase) SearchByWorkspace(ctx context.Context, userID, workspacePath, name, snippetType, language string) ([]*domain.CodeSnippet, error) {
	// 调用 repository 层的 SearchByWorkspace 方法
	dbSnippets, err := u.repo.SearchByWorkspace(ctx, userID, workspacePath, name, snippetType, language)
	if err != nil {
		u.logger.Error("failed to search code snippets by workspace", "error", err, "userID", userID, "workspacePath", workspacePath)
		return nil, fmt.Errorf("failed to search code snippets by workspace: %w", err)
	}

	// 将数据库模型转换为领域模型
	var snippets []*domain.CodeSnippet
	for _, dbSnippet := range dbSnippets {
		snippet := (&domain.CodeSnippet{}).FromWithFile(dbSnippet)
		snippets = append(snippets, snippet)
	}

	return snippets, nil
}

// SemanticSearch performs a vector similarity search for code snippets
func (u *CodeSnippetUsecase) SemanticSearch(ctx context.Context, embedding []float32, limit int) ([]*domain.CodeSnippet, error) {
	// 调用 repository 层的 SemanticSearch 方法
	dbSnippets, err := u.repo.SemanticSearch(ctx, embedding, limit)
	if err != nil {
		u.logger.Error("failed to perform semantic search", "error", err)
		return nil, fmt.Errorf("failed to perform semantic search: %w", err)
	}

	// 将数据库模型转换为领域模型
	var snippets []*domain.CodeSnippet
	for _, dbSnippet := range dbSnippets {
		snippet := (&domain.CodeSnippet{}).From(dbSnippet)
		snippets = append(snippets, snippet)
	}

	return snippets, nil
}

// SemanticSearchByWorkspace performs a vector similarity search for code snippets within a specific workspace
func (u *CodeSnippetUsecase) SemanticSearchByWorkspace(ctx context.Context, userID, workspacePath string, embedding []float32, limit int) ([]*domain.CodeSnippet, error) {
	// 调用 repository 层的 SemanticSearchByWorkspace 方法
	dbSnippets, err := u.repo.SemanticSearchByWorkspace(ctx, userID, workspacePath, embedding, limit)
	if err != nil {
		u.logger.Error("failed to perform semantic search by workspace", "error", err, "userID", userID, "workspacePath", workspacePath)
		return nil, fmt.Errorf("failed to perform semantic search by workspace: %w", err)
	}

	// 将数据库模型转换为领域模型
	var snippets []*domain.CodeSnippet
	for _, dbSnippet := range dbSnippets {
		snippet := (&domain.CodeSnippet{}).FromWithFile(dbSnippet)
		snippets = append(snippets, snippet)
	}

	return snippets, nil
}