package modelrepo

import "sync"

// Repo管理
type repoManager struct {
	repoMap map[string]Repo
	lock    sync.Mutex
}

var defaultManager = &repoManager{
	repoMap: make(map[string]Repo),
}

// 获取Repo
func GetRepo(id string) Repo {
	manager := defaultManager
	manager.lock.Lock()
	defer manager.lock.Unlock()
	r, ok := manager.repoMap[id]
	if !ok {
		return nil
	}
	return r
}

// 保存Repo
func SaveRepo(r Repo) {
	manager := defaultManager
	manager.lock.Lock()
	defer manager.lock.Unlock()
	manager.repoMap[r.Id()] = r
}

// 移除Repo
func RemoveRepo(id string) {
	manager := defaultManager
	manager.lock.Lock()
	defer manager.lock.Unlock()
	delete(manager.repoMap, id)
}

// 获取或构建Repo,若存在则返回已存在的,若不存在则构建保存并返回
func GetOrBuildRepo(id string, builder func() (Repo, error)) (Repo, error) {
	r := GetRepo(id)
	if r == nil {
		// 构建模型Repo
		r, err := builder()
		// 构建出错直接返回
		if err != nil {
			return nil, err
		}
		// 保存
		SaveRepo(r)
	}
	return r, nil
}