package cache

import (
	"electricity_bill_calc/global"
	"fmt"
	"strings"
)

func assembleEntityKey(entityName, id string) string {
	var keys = make([]string, 0)
	keys = append(keys, strings.ToUpper(entityName), id)
	var b strings.Builder
	b.WriteString(TAG_ENTITY)
	for _, s := range keys {
		fmt.Fprintf(&b, ":%s", s)
	}
	return b.String()
}

// 缓存模型名称明确的，使用ID进行检索的实体内容。
func CacheEntity[T any](instance T, relationNames []string, entityName, id string) error {
	entityKey := assembleEntityKey(entityName, id)
	err := Cache(entityKey, &instance, 0)
	for _, relationName := range relationNames {
		CacheRelation(relationName, STORE_TYPE_KEY, entityKey)
	}
	return err
}

// 从缓存中取出模型名称明确的，使用ID进行检索的实体内容。
func RetreiveEntity[T any](entityName, id string) (*T, error) {
	entityKey := assembleEntityKey(entityName, id)
	instance, err := Retreive[T](entityKey)
	return instance, err
}

// 精确的从缓存中删除指定模型名称、指定ID的实体内容。
func AbolishSpecificEntity(entityName, id string) (bool, error) {
	entityKey := assembleEntityKey(entityName, id)
	return Delete(entityKey)
}

// 从缓存中删除指定模型名称的所有内容。
func AbolishEntity(entityName string) error {
	var (
		cursor uint64
		keys   = make([]string, 0)
	)
	pattern := fmt.Sprintf("%s:%s:*", TAG_ENTITY, strings.ToUpper(entityName))
	for {
		k, cursor, err := global.RedisConn.Scan(global.Ctx, cursor, pattern, 20).Result()
		if err != nil {
			return err
		}
		keys = append(keys, k...)
		if cursor == 0 {
			break
		}
	}
	pipeline := global.RedisConn.Pipeline()
	pipeline.Del(global.Ctx, keys...)
	_, err := pipeline.Exec(global.Ctx)
	return err
}