package api

import (
	"sync"

	"git.pyer.club/kingecg/godocdb/document"
	"git.pyer.club/kingecg/godocdb/index" // "fmt"
)

// "go.mongodb.org/mongo-driver/bson"

// Collection MongoDB兼容的集合结构
type Collection struct {
	name          string
	indexStore    *index.IndexStore
	documentStore *document.DocumentStore
}

var (
	indexStores  = make(map[string]*index.IndexStore)
	indexStoreMu sync.RWMutex
)

// NewCollection 创建新的集合实例
func NewCollection(name string, storagePath string) (*Collection, error) {
	ds, err := document.NewDocumentStore(storagePath)
	if err != nil {
		return nil, err
	}

	is, err := getIndexStore(storagePath)
	if err != nil {
		return nil, err
	}

	return &Collection{
		name:          name,
		documentStore: ds,
		indexStore:    is,
	}, nil
}

// InsertOne 插入单个文档
func (coll *Collection) InsertOne(doc interface{}) error {
	// 自动生成文档ID
	// docID := generateID()

	// 将collection信息传递给文档管理层和索引管理层
	if err := coll.documentStore.StoreDocument(coll.name, "", doc); err != nil {
		return err
	}

	// 创建相关索引（需要实现generateID）
	return coll.createRelatedIndexes(doc)
}

// Find 查询文档
func (coll *Collection) Find(filter interface{}) (*Cursor, error) {
	// 使用collection信息进行索引查询
	fieldValue := extractFilterValue(filter) // 需要实现过滤器解析
	docIDs, err := coll.indexStore.GetIndexedDocuments(coll.name, "default_index", fieldValue)
	if err != nil {
		return nil, err
	}

	// 获取实际文档数据
	docs := make([]interface{}, 0, len(docIDs))
	for _, id := range docIDs {
		var doc interface{}
		if err := coll.documentStore.GetDocument(coll.name, id, &doc); err == nil {
			docs = append(docs, doc)
		}
	}

	return newCursor(docs), nil
}

// 以下为简化实现，需要补充完整

func (coll *Collection) createRelatedIndexes(doc interface{}) error {
	// 实现自动创建相关索引（根据注解或配置）
	return nil
}

func getIndexStore(path string) (*index.IndexStore, error) {
	indexStoreMu.RLock()
	if is, ok := indexStores[path]; ok {
		indexStoreMu.RUnlock()
		return is, nil
	}
	indexStoreMu.RUnlock()

	indexStoreMu.Lock()
	defer indexStoreMu.Unlock()

	// Double-check in case it was added before acquiring the lock
	if is, ok := indexStores[path]; ok {
		return is, nil
	}

	is, err := index.NewIndexStore(path)
	if err != nil {
		return nil, err
	}

	indexStores[path] = is
	return is, nil
}

func generateID() string {
	// 生成唯一文档ID
	return "doc_123456"
}

func extractFilterValue(filter interface{}) interface{} {
	// 解析过滤条件获取字段值
	return nil
}

// Cursor 游标用于遍历查询结果
type Cursor struct {
	// ... 实现细节 ...
}

func newCursor(docs []interface{}) *Cursor {
	// 创建新的游标实例
	return &Cursor{}
}