const xe = require("xe-utils")
/**
 * 状态机-编排复杂的流程状态业务
 * @param  {string} listName 列名.
 */
module.exports = class Status {
    constructor(listName, status, data) {
        this.data = data
        this.status = status
        this.listName = listName
        this.list = []
    }

    /**
     * 返回上个状态
     */
    back() {
        let index = this.getStatusIndex(this.listName, this.status)
        const res = this.getList(this.listName)
        if ((index - 1) < 0) {
            return null
        }
        const status = res.status[index - 1]
        if (res.listName && status.name) {
            this.go(res.listName, status.name)
        }
        return this
    }

    /**
     * 下一个状态
     */
    next() {
        let index = this.getStatusIndex(this.listName, this.status)
        const res = this.getList(this.listName)
        if (res.status.length <= (index + 1)) {
            return null
        }
        const status = res.status[index + 1]
        if (res.listName && status.name) {
            this.go(res.listName, status.name)
        }
        return this
    }

    /**
     * 触发成功事件
     */
    success() {
        const index = this.getStatusIndex(this.listName, this.status)
        const res = this.getList(this.listName)
        const status = res.status[index]
        if (status.success.event) { this.emitEvent(status.success.event) }
        if (status.success.listName && status.success.status) {
            this.go(status.success.listName, status.success.status)
        }
        return this
    }

    emitEvent(eventName) {
        console.log("emitEvent:", eventName);
    }

    fail() {
        const index = this.getStatusIndex(this.listName, this.status)
        const res = this.getList(this.listName)
        const status = res.status[index]
        if (status.fail.event) { this.emitEvent(status.fail.event) }
        if (status.fail.listName && status.fail.status) {
            this.go(status.fail.listName, status.fail.status)
        }
        return this
    }

    go(listName, status) {
        this.status = status
        this.listName = listName
        return this
    }

    getStatusIndex(listName, status) {
        const res = this.getList(listName)
        let index = xe.findKey(res.status, item => item.name === status)
        return index ? Number(index) : null
    }

    getList(listName) {
        const res = this.list.filter(item => item.listName === listName)
        if (res.length <= 0) { return false }
        return res[0]
    }

    push({status, success, fail}) {
        const res = this.getList(this.listName)
        if (res) {
            success = success || {}
            success["listName"] = success["listName"] || ""
            success["status"] = success["status"] || ""
            success["event"] = success["event"] || ""
            fail = fail || {}
            fail["listName"] = fail["listName"] || ""
            fail["status"] = fail["status"] || ""
            fail["event"] = fail["event"] || ""

            res.status.push({
                name   : status,
                success: success,
                fail   : fail,
            })
        }
        else {return false}
        return this
    }

    create(listName) {
        if (!listName) { return false }
        const res = this.getList(listName)
        if (res) { return false }
        this.list.push({
            listName: listName,
            status  : []
        })
        this.listName = listName
        return this
    }
}
//
// const s = new Status()
//
// s.create("ord")
//  .push({
//      status : "start",
//      success: {
//          listName: "ord", //成功后切换到的listName
//          status  : "pay", //成功后切换到的status
//          event   : "ord.start",
//      },
//      fail   : {
//          listName: "", //失败后切换到的listName
//          status  : "", //失败后切换到的status
//          event   : "",
//      },
//  })
//  .push({
//      status : "pay",
//      success: {
//          listName: "ord", //成功后切换到的listName
//          status  : "end", //成功后切换到的status
//          event   : "ord.pay",
//      },
//      fail   : {
//          listName: "refund", //失败后切换到的listName
//          status  : "start", //失败后切换到的status
//          event   : "",
//      },
//  })
//  .push({
//      status : "end",
//      success: {
//          listName: "", //成功后切换到的listName
//          status  : "", //成功后切换到的status
//          event   : "ord.end",
//      },
//      fail   : {
//          listName: "", //失败后切换到的listName
//          status  : "", //失败后切换到的status
//          event   : "",
//      },
//  })
// s.create("refund")
//  .push({
//      status : "start",
//      success: {
//          listName: "refund", //成功后切换到的listName
//          status  : "ret", //成功后切换到的status
//          event   : "refund.start",
//      },
//      fail   : {
//          listName: "", //失败后切换到的listName
//          status  : "", //失败后切换到的status
//          event   : "",
//      },
//  })
//  .push({
//      status : "ret",
//      success: {
//          listName: "refund", //成功后切换到的listName
//          status  : "end", //成功后切换到的status
//          event   : "refund.ret",
//      },
//      fail   : {
//          listName: "", //失败后切换到的listName
//          status  : "", //失败后切换到的status
//          event   : "",
//      },
//  })
//  .push({
//      status : "end",
//      success: {
//          listName: "", //成功后切换到的listName
//          status  : "", //成功后切换到的status
//          event   : "refund.end",
//      },
//      fail   : {
//          listName: "", //失败后切换到的listName
//          status  : "", //失败后切换到的status
//          event   : "",
//      },
//  })
// // console.log(s);
//
// s.go("ord", "start")
// console.log(s.listName, s.status);
// s.success()
// console.log(s.listName, s.status);
// s.fail()
// console.log(s.listName, s.status);
// s.success()
// console.log(s.listName, s.status);
// s.success()
// console.log(s.listName, s.status);
// s.success()
// console.log(s.listName, s.status);
// s.next()
// console.log(s.listName, s.status);