/**
 *  把对象转换为 JSON 支持循环引用
 */
export function json(data: any, space = 2): string {
    return stringify(data, null, space)
}

/**
 *  把 JSON 转换为对象 支持循环引用
 */
export function fromJson(data: any): any {
    return parse(data)
}

//  https://github.com/yyx990803/circular-json-es6

function encode(data: any, replacer: any, list: any, seen: any) {
    var stored: any, key, value, i, l
    var seenIndex = seen.get(data)
    if (seenIndex != null) {
        return seenIndex
    }
    var index = list.length
    var proto = Object.prototype.toString.call(data)
    if (proto === "[object Object]") {
        stored = {}
        seen.set(data, index)
        list.push(stored)
        var keys = Object.keys(data)
        for (i = 0, l = keys.length; i < l; i++) {
            key = keys[i]
            value = data[key]
            if (replacer) value = replacer.call(data, key, value)
            stored[key] = encode(value, replacer, list, seen)
        }
    } else if (proto === "[object Array]") {
        stored = []
        seen.set(data, index)
        list.push(stored)
        for (i = 0, l = data.length; i < l; i++) {
            value = data[i]
            if (replacer) value = replacer.call(data, i, value)
            stored[i] = encode(value, replacer, list, seen)
        }
    } else {
        list.push(data)
    }
    return index
}

function decode(list: any, reviver: any) {
    var i = list.length
    var j, k, data, key, value, proto
    while (i--) {
        data = list[i]
        proto = Object.prototype.toString.call(data)
        if (proto === "[object Object]") {
            var keys = Object.keys(data)
            for (j = 0, k = keys.length; j < k; j++) {
                key = keys[j]
                value = list[data[key]]
                if (reviver) value = reviver.call(data, key, value)
                data[key] = value
            }
        } else if (proto === "[object Array]") {
            for (j = 0, k = data.length; j < k; j++) {
                value = list[data[j]]
                if (reviver) value = reviver.call(data, j, value)
                data[j] = value
            }
        }
    }
}

function stringify(data: any, replacer: any, space: any) {
    try {
        return arguments.length === 1 ? JSON.stringify(data) : JSON.stringify(data, replacer, space)
    } catch (e) {
        return stringifyStrict(data, replacer, space)
    }
}

function parse(data: any, reviver?: any) {
    var hasCircular = /^\s/.test(data)
    if (!hasCircular) {
        return arguments.length === 1 ? JSON.parse(data) : JSON.parse(data, reviver)
    } else {
        var list = JSON.parse(data)
        decode(list, reviver)
        return list[0]
    }
}
function stringifyStrict(data: any, replacer: any, space: any) {
    var list: any = []
    encode(data, replacer, list, new Map())
    return space ? " " + JSON.stringify(list, null, space) : " " + JSON.stringify(list)
}