var easing = {}
//渐变曲线函数，反应加速度的变化

//currentTime:x轴当前时间（从0-到duration）, startY：起始点, duration:总时长， wholeY:路程 (即endY-startY)
//参数基本是 x, 0, 1, 1

/* 
easeOut 基本是y= m * (x-dur)^k + n， 若k为偶数，m<0, 若k为奇数，m>0;  （因为偶数的话必须开口向下才能获得斜率递减的递增的那段，而奇数是对称的，单调递增. ）
根据x=0时y=0, x=dur时y=S , 得 n = S，m = -S/(-dur)^k

*/

easing.getEaseOut = function(k) {
    // k 是>=2的整数. 越大变化率越大, 相同初始速度所需要时间越久
    let easeFun
    k = Math.round(k)

    if (k < 2) {
        k = Math.PI / 2
        easeFun = easing.easeOutSine
    } else {
        easeFun = function(currentTime, startY, wholeY, duration) {
            if (k > 2) {
                console.log(k)
            }
            return (-wholeY / Math.pow(-duration, k)) * Math.pow(currentTime - duration, k) + wholeY
        }
    }

    return {
        k,
        easeFun
    }
}
;(easing.linearTween = function(currentTime, startY, wholeY, duration) {
    return (wholeY * currentTime) / duration + startY
}),
    (easing.easeInQuad = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration), wholeY * currentTime * currentTime + startY
    }),
    (easing.easeOutQuad = function(currentTime, startY, wholeY, duration) {
        // 如套上实际的距离S和时长dur, y = - S / dur *(x^2-2x) 当s为1,dur为1时，是  y = -(x-1)^2 + 1 ， 在0-1中是斜率递减的递增函数.     导数- S / dur *(2x-2 )   可求出实时速度  故在0这一时刻，速度为 2S/dur
        return (currentTime /= duration), -wholeY * currentTime * (currentTime - 2) + startY
    }),
    (easing.easeInOutQuad = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration / 2), currentTime < 1 ? (wholeY / 2) * currentTime * currentTime + startY : (currentTime--, (-wholeY / 2) * (currentTime * (currentTime - 2) - 1) + startY)
    }),
    (easing.easeInCubic = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration), wholeY * currentTime * currentTime * currentTime + startY
    }),
    (easing.easeOutCubic = function(currentTime, startY, wholeY, duration) {
        // y = S / dur^3 *(x-dur)^3 + S，对称中心是(dur,S),从0-dur是 斜率递减的递增函数，导数为3S/dur^3 * (x-dur)^2, 0时速度为3S/dur
        return (currentTime /= duration), currentTime--, wholeY * (currentTime * currentTime * currentTime + 1) + startY
    }),
    (easing.easeInOutCubic = function(currentTime, startY, wholeY, duration) {
        return (
            (currentTime /= duration / 2),
            currentTime < 1 ? (wholeY / 2) * currentTime * currentTime * currentTime + startY : ((currentTime -= 2), (wholeY / 2) * (currentTime * currentTime * currentTime + 2) + startY)
        )
    }),
    (easing.easeInQuart = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration), wholeY * currentTime * currentTime * currentTime * currentTime + startY
    }),
    (easing.easeOutQuart = function(currentTime, startY, wholeY, duration) {
        //根据上面的计算，估计0时速度应该是4S/dur吧……
        return (currentTime /= duration), currentTime--, -wholeY * (currentTime * currentTime * currentTime * currentTime - 1) + startY
    }),
    (easing.easeInOutQuart = function(currentTime, startY, wholeY, duration) {
        return (
            (currentTime /= duration / 2),
            currentTime < 1
                ? (wholeY / 2) * currentTime * currentTime * currentTime * currentTime + startY
                : ((currentTime -= 2), (-wholeY / 2) * (currentTime * currentTime * currentTime * currentTime - 2) + startY)
        )
    }),
    (easing.easeInQuint = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration), wholeY * currentTime * currentTime * currentTime * currentTime * currentTime + startY
    }),
    (easing.easeOutQuint = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration), currentTime--, wholeY * (currentTime * currentTime * currentTime * currentTime * currentTime + 1) + startY
    }),
    (easing.easeInOutQuint = function(currentTime, startY, wholeY, duration) {
        return (
            (currentTime /= duration / 2),
            currentTime < 1
                ? (wholeY / 2) * currentTime * currentTime * currentTime * currentTime * currentTime + startY
                : ((currentTime -= 2), (wholeY / 2) * (currentTime * currentTime * currentTime * currentTime * currentTime + 2) + startY)
        )
    }),
    (easing.easeInSine = function(currentTime, startY, wholeY, duration) {
        return -wholeY * Math.cos((currentTime / duration) * (Math.PI / 2)) + wholeY + startY
    }),
    (easing.easeOutSine = function(currentTime, startY, wholeY, duration) {
        // y' = S * PI / 2 / dur * cos(PI/2/dur * x)
        console.log('easeOutSine')
        return wholeY * Math.sin((currentTime / duration) * (Math.PI / 2)) + startY
    }),
    (easing.easeInOutSine = function(currentTime, startY, wholeY, duration) {
        return (-wholeY / 2) * (Math.cos((Math.PI * currentTime) / duration) - 1) + startY
    }),
    (easing.easeInExpo = function(currentTime, startY, wholeY, duration) {
        return wholeY * Math.pow(2, 10 * (currentTime / duration - 1)) + startY
    }),
    (easing.easeOutExpo = function(currentTime, startY, wholeY, duration) {
        return wholeY * (-Math.pow(2, (-10 * currentTime) / duration) + 1) + startY
    }),
    (easing.easeInOutExpo = function(currentTime, startY, wholeY, duration) {
        return (
            (currentTime /= duration / 2),
            currentTime < 1 ? (wholeY / 2) * Math.pow(2, 10 * (currentTime - 1)) + startY : (currentTime--, (wholeY / 2) * (-Math.pow(2, -10 * currentTime) + 2) + startY)
        )
    }),
    (easing.easeInCirc = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration), -wholeY * (Math.sqrt(1 - currentTime * currentTime) - 1) + startY
    }),
    (easing.easeOutCirc = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration), currentTime--, wholeY * Math.sqrt(1 - currentTime * currentTime) + startY
    }),
    (easing.easeInOutCirc = function(currentTime, startY, wholeY, duration) {
        return (
            (currentTime /= duration / 2),
            currentTime < 1 ? (-wholeY / 2) * (Math.sqrt(1 - currentTime * currentTime) - 1) + startY : ((currentTime -= 2), (wholeY / 2) * (Math.sqrt(1 - currentTime * currentTime) + 1) + startY)
        )
    }),
    (easing.easeInElastic = function(currentTime, startY, wholeY, duration) {
        var r = 1.70158,
            o = 0,
            a = wholeY
        return 0 === currentTime
            ? startY
            : 1 === (currentTime /= duration)
            ? startY + wholeY
            : (o || (o = 0.3 * duration),
              a < Math.abs(wholeY) ? ((a = wholeY), (r = o / 4)) : (r = (o / (2 * Math.PI)) * Math.asin(wholeY / a)),
              -(a * Math.pow(2, 10 * (currentTime -= 1)) * Math.sin(((currentTime * duration - r) * (2 * Math.PI)) / o)) + startY)
    }),
    (easing.easeOutElastic = function(currentTime, startY, wholeY, duration) {
        var r = 1.70158,
            o = 0,
            a = wholeY
        return 0 === currentTime
            ? startY
            : 1 === (currentTime /= duration)
            ? startY + wholeY
            : (o || (o = 0.3 * duration),
              a < Math.abs(wholeY) ? ((a = wholeY), (r = o / 4)) : (r = (o / (2 * Math.PI)) * Math.asin(wholeY / a)),
              a * Math.pow(2, -10 * currentTime) * Math.sin(((currentTime * duration - r) * (2 * Math.PI)) / o) + wholeY + startY)
    }),
    (easing.easeInOutElastic = function(currentTime, startY, wholeY, duration) {
        var r = 1.70158,
            o = 0,
            a = wholeY
        return 0 === currentTime
            ? startY
            : 2 === (currentTime /= duration / 2)
            ? startY + wholeY
            : (o || (o = duration * (0.3 * 1.5)),
              a < Math.abs(wholeY) ? ((a = wholeY), (r = o / 4)) : (r = (o / (2 * Math.PI)) * Math.asin(wholeY / a)),
              currentTime < 1
                  ? -0.5 * (a * Math.pow(2, 10 * (currentTime -= 1)) * Math.sin(((currentTime * duration - r) * (2 * Math.PI)) / o)) + startY
                  : a * Math.pow(2, -10 * (currentTime -= 1)) * Math.sin(((currentTime * duration - r) * (2 * Math.PI)) / o) * 0.5 + wholeY + startY)
    }),
    (easing.easeInBack = function(currentTime, startY, wholeY, duration, r) {
        return void 0 === r && (r = 1.70158), wholeY * (currentTime /= duration) * currentTime * ((r + 1) * currentTime - r) + startY
    }),
    (easing.easeOutBack = function(currentTime, startY, wholeY, duration, r) {
        return void 0 === r && (r = 1.70158), wholeY * ((currentTime = currentTime / duration - 1) * currentTime * ((r + 1) * currentTime + r) + 1) + startY
    }),
    (easing.easeInOutBack = function(currentTime, startY, wholeY, duration, r) {
        return (
            void 0 === r && (r = 1.70158),
            (currentTime /= duration / 2) < 1
                ? (wholeY / 2) * (currentTime * currentTime * (((r *= 1.525) + 1) * currentTime - r)) + startY
                : (wholeY / 2) * ((currentTime -= 2) * currentTime * (((r *= 1.525) + 1) * currentTime + r) + 2) + startY
        )
    }),
    (easing.easeOutBounce = function(currentTime, startY, wholeY, duration) {
        return (currentTime /= duration) < 1 / 2.75
            ? wholeY * (7.5625 * currentTime * currentTime) + startY
            : currentTime < 2 / 2.75
            ? wholeY * (7.5625 * (currentTime -= 1.5 / 2.75) * currentTime + 0.75) + startY
            : currentTime < 2.5 / 2.75
            ? wholeY * (7.5625 * (currentTime -= 2.25 / 2.75) * currentTime + 0.9375) + startY
            : wholeY * (7.5625 * (currentTime -= 2.625 / 2.75) * currentTime + 0.984375) + startY
    }),
    (easing.easeInBounce = function(currentTime, startY, wholeY, r) {
        return wholeY - easing.easeOutBounce(r - currentTime, 0, wholeY, r) + startY
    }),
    (easing.easeInOutBounce = function(currentTime, startY, wholeY, r) {
        return currentTime < r / 2 ? 0.5 * easing.easeInBounce(2 * currentTime, 0, wholeY, r) + startY : 0.5 * easing.easeOutBounce(x, 2 * currentTime - r, 0, wholeY, r) + 0.5 * wholeY + startY
    })

var lerp = {
    /* vector: function(currentTime, startY, f) {//xzw change, add f
		var wholeY = currentTime.clone();
		return startY = startY.clone(),
		function(duration) {
			currentTime.set(wholeY.x * (1 - duration) + startY.x * duration, wholeY.y * (1 - duration) + startY.y * duration, wholeY.z * (1 - duration) + startY.z * duration)
			f && f(currentTime,duration);
		}
	},
    quaternion: function(currentTime, startY, f) {//xzw change, add f
        var wholeY = currentTime.clone();
        return function(duration) {
            currentTime.copy(wholeY).slerp(startY, duration);
			f && f(currentTime,duration);
        }
    },
    property: function(currentTime, startY, wholeY, duration) {
        var r = currentTime[startY];
        return function(o) {
            currentTime[startY] = r * (1 - o) + wholeY * o,
            duration && duration(currentTime[startY])
        }
    },
    uniform: function(currentTime, startY, wholeY) {
        var duration = currentTime.material.uniforms[startY].value;
        return function(r) {
            try{
                currentTime.material.uniforms[startY] && (currentTime.material.uniforms[startY].value = duration * (1 - r) + wholeY * r)
            }catch(currentTime){
                console.log(1)
            }
            
        }
    },
    matrix4: function(currentTime, startY) {
        var wholeY = currentTime.clone();
        return function(duration) {
            for (var r = currentTime.elements, o = wholeY.elements, a = startY.elements, s = 0; s < 16; s++)
                r[s] = o[s] * (1 - duration) + a[s] * duration
        }
    },
    allUniforms: function(currentTime, startY, wholeY) {
        var duration = currentTime.map(function(currentTime) {
            return this.uniform(currentTime, startY, wholeY)
        }
        .bind(this));
        return function(currentTime) {
            duration.forEach(function(startY) {
                startY(currentTime)
            })
        }
    } */

    vector: function(t, i, f) {
        //xzw change, add f
        var n = t.clone()
        return (
            (i = i.clone()),
            function(e) {
                t.set(n.x * (1 - e) + i.x * e, n.y * (1 - e) + i.y * e, n.z * (1 - e) + i.z * e)
                f && f(t, e)
            }
        )
    },
    quaternion: function(t, i, f) {
        //xzw change, add f
        var n = t.clone()
        return function(e) {
            t.copy(n).slerp(i, e)
            f && f(t, e)
        }
    },
    property: function(t, i, n, r) {
        var o = t[i]
        return function(e) {
            ;(t[i] = o * (1 - e) + n * e), r && r(t[i])
        }
    },
    uniform: function(t, i, n) {
        var r = t.material.uniforms[i].value
        return function(e) {
            t.material.uniforms[i] && (t.material.uniforms[i].value = r * (1 - e) + n * e)
        }
    },
    matrix4: function(o, a) {
        var s = o.clone()
        return function(e) {
            for (var t = o.elements, i = s.elements, n = a.elements, r = 0; r < 16; r++) t[r] = i[r] * (1 - e) + n[r] * e
        }
    },
    allUniforms: function(e, t, i) {
        var n = e.map(
            function(e) {
                return this.uniform(e, t, i)
            }.bind(this)
        )
        return function(t) {
            n.forEach(function(e) {
                e(t)
            })
        }
    }
}

/* 
    渐变
    

 */

var transitions = {
    globalDone: null,
    funcs: [],
    counter: 0,
    uniqueID: 0,
    start: function(func, duration, done, delay, ease, name, id, cancelFun) {
        return (
            (delay = delay || 0),
            this.funcs.push({
                func: func,
                current: -delay * Math.abs(duration), //当前时间
                duration: (1 - Math.max(delay, 0)) * Math.abs(duration), //总时长
                done: done,
                easing: ease || easing.linearTween, //渐变曲线
                cycling: duration < 0,
                running: !0,
                debug: delay < 0,
                name: name || 'T' + this.counter,
                id: void 0 === id ? this.counter : id,
                paused: !1,
                cancelFun: cancelFun //取消时执行的函数
            }),
            func(0, 16),
            (this.counter += 1),
            func
        )
    },
    trigger: function(e) {
        var t = void 0 === e.delayRatio ? 0 : e.delayRatio,
            u = e.func || function() {},
            r = void 0 === e.duration ? 0 : e.duration
        void 0 !== e.cycling && e.cycling && (r = -Math.abs(r))
        var o = e.done || null,
            a = e.easing || easing.linearTween,
            s = e.name || 'R' + this.counter,
            l = void 0 === e.id ? this.counter : e.id
        return this.start(u, r, o, t, a, s, l)
    },
    setTimeout: function(e, t, u) {
        var duration = void 0 === u ? this.counter : u
        return this.trigger({
            done: e,
            duration: void 0 === t ? 0 : t,
            name: 'O' + this.counter,
            id: duration
        })
    },
    pause: function() {
        this.paused = !0
    },
    resume: function() {
        this.paused = !1
    },
    update: function(e) {
        this.funcs.forEach(function(t) {
            if (!(t.paused || ((t.current += 1e3 * e), t.current < 0)))
                if (t.current >= t.duration && !t.cycling) {
                    var u = t.easing(1, 0, 1, 1)
                    t.func(u, 1e3 * e), t.done && t.done(), (t.running = !1)
                } else {
                    var duration = t.easing((t.current % t.duration) / t.duration, 0, 1, 1),
                        r = t.func(duration, 1e3 * e) || !1
                    r && (t.done && t.done(), (t.running = !1))
                }
        })
        var t = this.funcs.length
        this.funcs = this.funcs.filter(function(e) {
            return e.running
        })
        var u = this.funcs.length
        if (t > 0 && 0 === u && this.globalDone) {
            var duration = this.globalDone
            ;(this.globalDone = null), duration()
        }
    },
    adjustSpeed: function(e, t) {
        for (var u = this.getById(e), duration = 0; duration < u.length; duration++) {
            var r = u[duration]
            ;(r.duration /= t), (r.current /= t)
        }
    },
    getById: function(e) {
        return this.funcs.filter(function(t) {
            return e === t.id
        })
    },
    get: function(e) {
        for (var t = 0; t < this.funcs.length; t += 1) if (this.funcs[t].func === e) return this.funcs[t]
        return null
    },
    isRunning: function(e) {
        var t = this.get(e)
        return null !== t && t.running
    },
    countActive: function() {
        for (var e = 0, t = 0; t < this.funcs.length; t += 1) e += this.funcs[t].running
        return e
    },
    listActive: function() {
        for (var e = [], t = 0; t < this.funcs.length; t += 1) this.funcs[t].running && e.push(this.funcs[t].name)
        return e
    },
    done: function(e) {
        this.globalDone = e
    },
    cancelById: function(e, dealCancelFun) {
        //xzw add dealDone
        var t = void 0 === e ? 0 : e
        let cancels = []
        this.funcs = this.funcs.filter(function(e) {
            var is = e.id == t

            if (is && dealCancelFun) {
                e.cancelFun && cancels.push(e.cancelFun)
                //e.cancelFun && e.cancelFun()
            }
            return !is
        })

        cancels.forEach(e => {
            e()
        }) //先从funcs中去除后再执行
    },
    cancel: function(e) {
        this.funcs = this.funcs.filter(function(t) {
            return t.func !== e
        })
    },
    getUniqueId: function() {
        return (this.uniqueID -= 1), this.uniqueID
    }
}

export { transitions, lerp, easing }