# pmSeries.mjs

    import drop from 'lodash/drop'
    import each from 'lodash/each'
    import genPm from './genPm.mjs'
    import isarr from './isarr.mjs'
    import isobj from './isobj.mjs'
    import isfun from './isfun.mjs'

    /**
     * Promise的mapSeries，循序執行Promise
     *
     * 若輸入rs為資料陣列則fn需將數據處理並回傳Promise，若輸入rs為Promise陣列則fn可不給，並循序執行各Promise。
     * 使用函數執行時，等同於pmMap使用函數執行且takeLimit=1，promise依序執行完畢才會調用下一個promise。
     * 先行產生promise時，等同於pmMap使用函數執行且takeLimit=0，或是等同於pmMap先行產生promise，各promise直接執行視各自執行時間結束。
     *
     * Unit Test: {@link https://github.com/yuda-lyu/wsemi/blob/master/test/pmSeries.test.mjs Github}
     * @memberOf wsemi
     * @param {Array} rs 輸入資料陣列，若不給fn則rs需要為Promise陣列
     * @param {Function} fun 輸入循序執行值的呼叫函數
     * @returns {Promise} 回傳Promise，resolve為成功結果，reject為失敗結果
     * @example
     *
     * async function topAsync() {
     *
     *     async function test1() {
     *         return new Promise((resolve, reject) => {
     *             let ms = []
     *
     *             //通過function調用產生promise, 各promise循序調用
     *             pmSeries([1, 2, 3, 4, 5], function (v, k) {
     *                 return new Promise(function(resolve, reject) {
     *                     let d = 400 - ((v ** 2) * 10 + 50)
     *                     console.log('call', v)
     *                     ms.push({ call: v })
     *                     setTimeout(function() {
     *                         console.log('resolve', v, 'd', d)
     *                         ms.push({ resolve: v, d })
     *                         resolve('#' + v)
     *                     }, d)
     *                 })
     *             })
     *                 .then(function(res) {
     *                     console.log('then', JSON.stringify(res))
     *                     ms.push({ res })
     *                     resolve(ms)
     *                 })
     *                 .catch(function(err) {
     *                     console.log('catch', JSON.stringify(err))
     *                     ms.push({ err })
     *                     resolve(ms)
     *                 })
     *
     *         })
     *
     *     }
     *     console.log('test1')
     *     let r1 = await test1()
     *     console.log(JSON.stringify(r1))
     *     // test1
     *     // call 1
     *     // resolve 1 d 340
     *     // call 2
     *     // resolve 2 d 310
     *     // call 3
     *     // resolve 3 d 260
     *     // call 4
     *     // resolve 4 d 190
     *     // call 5
     *     // resolve 5 d 100
     *     // then ["#1","#2","#3","#4","#5"]
     *     // [{"call":1},{"resolve":1,"d":340},{"call":2},{"resolve":2,"d":310},{"call":3},{"resolve":3,"d":260},{"call":4},{"resolve":4,"d":190},{"call":5},{"resolve":5,"d":100},{"res":["#1","#2","#3","#4","#5"]}]
     *
     *     async function test2() {
     *         return new Promise((resolve, reject) => {
     *             let ms = []
     *
     *             //通過function調用產生promise, 各promise循序調用, 於3會觸發reject而跳出pmSeries
     *             pmSeries([1, 2, 3, 4, 5], function (v, k) {
     *                 return new Promise(function(resolve, reject) {
     *                     let d = 400 - ((v ** 2) * 10 + 50)
     *                     console.log('call', v)
     *                     ms.push({ call: v })
     *                     setTimeout(function() {
     *                         if (v === 3) {
     *                             console.log('reject', v, 'd', d)
     *                             ms.push({ reject: v, d })
     *                             reject('#' + v)
     *                         }
     *                         else {
     *                             console.log('resolve', v, 'd', d)
     *                             ms.push({ resolve: v, d })
     *                             resolve('#' + v)
     *                         }
     *                     }, d)
     *                 })
     *             })
     *                 .then(function(res) {
     *                     console.log('then', JSON.stringify(res))
     *                     ms.push({ res })
     *                     resolve(ms)
     *                 })
     *                 .catch(function(err) {
     *                     console.log('catch', JSON.stringify(err))
     *                     ms.push({ err })
     *                     resolve(ms)
     *                 })
     *
     *         })
     *
     *     }
     *     console.log('test2')
     *     let r2 = await test2()
     *     console.log(JSON.stringify(r2))
     *     // test2
     *     // call 1
     *     // resolve 1 d 340
     *     // call 2
     *     // resolve 2 d 310
     *     // call 3
     *     // reject 3 d 260
     *     // catch "#3"
     *     // [{"call":1},{"resolve":1,"d":340},{"call":2},{"resolve":2,"d":310},{"call":3},{"reject":3,"d":260},{"err":"#3"}]
     *
     *     async function test3() {
     *         return new Promise((resolve, reject) => {
     *             let ms = []
     *
     *             //先產生promise, 因事先初始化故各promise會依照各自執行時間結束
     *             let rs = [1, 2, 3, 4, 5].map(function (v, k) {
     *                 return new Promise(function(resolve, reject) {
     *                     let d = 400 - ((v ** 2) * 10 + 50)
     *                     console.log('call', v)
     *                     ms.push({ call: v })
     *                     setTimeout(function() {
     *                         console.log('resolve', v, 'd', d)
     *                         ms.push({ resolve: v, d })
     *                         resolve('#' + v)
     *                     }, d)
     *                 })
     *             })
     *             pmSeries(rs, null)
     *                 .then(function(res) {
     *                     console.log('then', JSON.stringify(res))
     *                     ms.push({ res })
     *                     resolve(ms)
     *                 })
     *                 .catch(function(err) {
     *                     console.log('catch', JSON.stringify(err))
     *                     ms.push({ err })
     *                     resolve(ms)
     *                 })
     *
     *         })
     *
     *     }
     *     console.log('test3')
     *     let r3 = await test3()
     *     console.log(JSON.stringify(r3))
     *     // test3
     *     // call 1
     *     // call 2
     *     // call 3
     *     // call 4
     *     // call 5
     *     // resolve 5 d 100
     *     // resolve 4 d 190
     *     // resolve 3 d 260
     *     // resolve 2 d 310
     *     // resolve 1 d 340
     *     // then ["#1","#2","#3","#4","#5"]
     *     // [{"call":1},{"call":2},{"call":3},{"call":4},{"call":5},{"resolve":5,"d":100},{"resolve":4,"d":190},{"resolve":3,"d":260},{"resolve":2,"d":310},{"resolve":1,"d":340},{"res":["#1","#2","#3","#4","#5"]}]
     *
     *     async function test4() {
     *         return new Promise((resolve, reject) => {
     *             let ms = []
     *
     *             //通過function調用產生promise, 各promise循序調用
     *             pmSeries({
     *                 t1: 1,
     *                 t2: 2.345,
     *                 t3: 'abc',
     *             }, function (v, k) {
     *                 return new Promise(function(resolve, reject) {
     *                     resolve(`k=${k},v=${v}`)
     *                 })
     *             })
     *                 .then(function(res) {
     *                     console.log('then', JSON.stringify(res))
     *                     ms.push({ res })
     *                     resolve(ms)
     *                 })
     *                 .catch(function(err) {
     *                     console.log('catch', JSON.stringify(err))
     *                     ms.push({ err })
     *                     resolve(ms)
     *                 })
     *
     *         })
     *
     *     }
     *     console.log('test4')
     *     let r4 = await test4()
     *     console.log(JSON.stringify(r4))
     *     // test4
     *     // then ["k=t1,v=1","k=t2,v=2.345","k=t3,v=abc"]
     *     // [{"res":["k=t1,v=1","k=t2,v=2.345","k=t3,v=abc"]}]
     *
     * }
     * topAsync().catch(() => {})
     *
     */
    function pmSeries(rs, fun) {

        //pm
        let pm = genPm()

        //check
        if (!isarr(rs) && !isobj(rs)) {
            pm.reject('rs is not array or object')
            return pm
        }

        //object rs to array
        let useObj = false
        if (isobj(rs)) {
            useObj = true
            let _rs = []
            each(rs, (v, k) => {
                _rs.push({ k, v })
            })
            rs = _rs
        }

        //default fun
        if (!isfun(fun)) {
            fun = function(v) {
                return v
            }
        }

        //ts
        let k = -1
        let ts = []
        rs.reduce(function(pmm, v) {
            return pmm.then(function(t) {
                ts.push(t)
                k += 1
                let uk = k
                let uv = v
                if (useObj) {
                    uk = v.k
                    uv = v.v
                }
                if (isfun(fun)) {
                    return fun(uv, uk)
                }
                else {
                    return uv
                }
            })
        }, Promise.resolve())
            .then(function(t) {
                ts.push(t)
                ts = drop(ts)
                pm.resolve(ts)
            })
            .catch(function(err) {
                pm.reject(err)
            })

        return pm
    }

    export default pmSeries