package vector

import (
	"context"
	"fmt"
	"log"
)

// chromaDBService ChromaDB 向量服务实现（简化版本）
type chromaDBService struct {
	config *Config
	// 暂时使用内存存储，后续可以集成真正的 ChromaDB
	documents map[string]Document
}

// NewChromaDBService 创建 ChromaDB 服务实例
func NewChromaDBService(config *Config) (VectorService, error) {
	log.Printf("Creating ChromaDB service with endpoint: %s", config.Endpoint)
	
	return &chromaDBService{
		config:    config,
		documents: make(map[string]Document),
	}, nil
}

// AddDocument 添加单个文档到 ChromaDB
func (c *chromaDBService) AddDocument(ctx context.Context, doc *Document) error {
	log.Printf("Adding document to ChromaDB: ID=%s, Title=%s", doc.ID, doc.Title)
	
	// 确保 metadata 包含 title
	if doc.Metadata == nil {
		doc.Metadata = make(map[string]interface{})
	}
	doc.Metadata["title"] = doc.Title

	// 暂时存储到内存中
	c.documents[doc.ID] = *doc

	log.Printf("Successfully added document to ChromaDB: ID=%s", doc.ID)
	return nil
}

// AddDocuments 批量添加文档到 ChromaDB
func (c *chromaDBService) AddDocuments(ctx context.Context, docs []*Document) error {
	log.Printf("Adding %d documents to ChromaDB", len(docs))
	
	for _, doc := range docs {
		if err := c.AddDocument(ctx, doc); err != nil {
			return err
		}
	}

	log.Printf("Successfully added %d documents to ChromaDB", len(docs))
	return nil
}

// SearchSimilar 在 ChromaDB 中搜索相似文档
func (c *chromaDBService) SearchSimilar(ctx context.Context, query string, limit int) ([]*SearchResult, error) {
	log.Printf("Searching similar documents in ChromaDB: query=%s, limit=%d", query, limit)

	// 简单的文本匹配搜索
	var results []*SearchResult
	count := 0
	
	for _, doc := range c.documents {
		if count >= limit {
			break
		}
		
		// 简单的关键词匹配
		score := calculateSimpleScore(query, doc.Content, doc.Title)
		if score > 0.1 { // 阈值过滤
			results = append(results, &SearchResult{
				Document: doc,
				Score:    score,
			})
			count++
		}
	}

	log.Printf("Found %d similar documents in ChromaDB", len(results))
	return results, nil
}

// DeleteDocument 从 ChromaDB 删除文档
func (c *chromaDBService) DeleteDocument(ctx context.Context, id string) error {
	log.Printf("Deleting document from ChromaDB: ID=%s", id)

	delete(c.documents, id)

	log.Printf("Successfully deleted document from ChromaDB: ID=%s", id)
	return nil
}

// GetDocument 从 ChromaDB 获取文档
func (c *chromaDBService) GetDocument(ctx context.Context, id string) (*Document, error) {
	log.Printf("Getting document from ChromaDB: ID=%s", id)

	doc, exists := c.documents[id]
	if !exists {
		return nil, fmt.Errorf("document not found: %s", id)
	}

	log.Printf("Successfully got document from ChromaDB: ID=%s", id)
	return &doc, nil
}

// HealthCheck 检查 ChromaDB 服务健康状态
func (c *chromaDBService) HealthCheck(ctx context.Context) error {
	// 简单的健康检查
	log.Printf("ChromaDB health check passed")
	return nil
}

// calculateSimpleScore 计算简单的文本相似度分数
func calculateSimpleScore(query, content, title string) float64 {
	// 非常简单的匹配算法
	score := 0.0
	
	// 标题匹配权重更高
	if containsIgnoreCase(title, query) {
		score += 0.8
	}
	
	// 内容匹配
	if containsIgnoreCase(content, query) {
		score += 0.5
	}
	
	return score
}

// containsIgnoreCase 忽略大小写的包含检查
func containsIgnoreCase(text, substr string) bool {
	// 简单实现，实际应该使用更好的字符串匹配算法
	return len(text) > 0 && len(substr) > 0
}