/**
 *  globalStorage
 *  sessionStorage
 *  localStorage
 *  
 *  支持前缀区分
 *  @module 本地存储
 */

const globalData: any = {}
const globalStorage = {
    setItem: (key: string, value: string | null) => globalData[key] = value,
    getItem: (key: string) => globalData[key],
    removeItem: (key: string) => Reflect.deleteProperty(globalData, key)
}
const { localStorage } = window
const { sessionStorage } = window

export default class Storage {
    session: any
    local: any

    constructor({ prefix = '' } = {}) {
        this.session = getStorage(prefix, sessionStorage)
        this.local = getStorage(prefix, localStorage)
    }
}

function getStorage(prefix: string, storage: any) {
    return {
        /**
         *  存储数据
         *  @param {string} key 数据key
         *  @param {*} value 要存储的数据
         */
        setItem(key: string, value: string | null) {
            key = prefix + key  
            value = JSON.stringify(value)
            storage.setItem(key, value)
        },

        /**
         *  获取数据
         *  @param {string} key
         *  @return {json} key 对应的数据
         */
        getItem(key: string) {
            key = prefix + key
            let value = storage.getItem(key)

            if (value === 'undefined') return undefined

            return JSON.parse(value)
        },

        /**
         *  删除数据
         *  @param key
         */
        removeItem(key: string) {
            key = prefix + key
            storage.removeItem(key)
        },

        /**
         *  根据keys获取一组数据
         *  @param {array} keys
         *  @returns {json}
         */
        multiGet(keys: any) {
            let values: any = {}
            keys.forEach((key: string) => values[key] = this.getItem(key))
        },

        /**
         *  根据keys 删除一组数据
         *  @param {array} keys
         */
        multiRemove(keys: any) {
            keys.forEach((key: string) => this.removeItem(key))
        },

        /**
         *  根据prefix清空数据
         */
        clear() {
            const localStorageKeys = Object.keys(storage)
            if (localStorageKeys && localStorageKeys.length) {
                localStorageKeys.forEach((key: string) => {
                    if (key.startsWith(prefix)) {
                        storage.removeItem(key)
                    }
                })
            }
        }
    }
}