'use strict'

utils = require 'src/utils'

module.exports = (impl) ->
    {now} = Date

    createElem = do ->
        QML_ANIMATORS =
            x: 'XAnimator'
            y: 'YAnimator'
            scale: 'ScaleAnimator'
            rotation: 'RotationAnimator'
            opacity: 'OpacityAnimator'

        (anim) ->
            if anim.updateProperty
                qmlType = 'NumberAnimation'
            else
                qmlType = QML_ANIMATORS[anim.property] or 'NumberAnimation'
            isAnimation = qmlType is 'NumberAnimation'

            qmlStr =
                "SequentialAnimation {" +
                    "id: main;" +
                    "property var target: null;" +
                    "property real from;" +
                    "property real to;" +
                    "property real startDelay: 0;" +
                    "property real loopDelay: 0;" +
                    "property var duration: 0;" +
                    "property string easing: 'Linear';" +
                    "property bool loop: false;" +
                    "PauseAnimation { duration: main.startDelay }" +
                    "SequentialAnimation {" +
                        "loops: main.loop ? Animation.Infinite : 1;" +
                        "#{qmlType} {" +
                            "id: animation;" +
                            "target: main.target;" +
                            (if isAnimation then "property: '#{anim._property}';" else "") +
                            "duration: main.duration;" +
                            "from: main.from;" +
                            "to: main.to;" +
                            "easing.type: Easing[main.easing];" +
                        "}" +
                        "PauseAnimation { duration: main.loopDelay }" +
                    "}" +
                "}"

            impl.utils.createQmlObject qmlStr, __stylesWindow

    reqSend = false
    pending = []
    nowTime = now()

    vsync = ->
        reqSend = false
        nowTime = now()

        i = 0; n = pending.length
        while i < n
            anim = pending[i]

            if anim._running
                updateAnimation anim
                i++
            else
                # remove element in not ordered list
                # this array may change due loop
                pending[i] = pending[n-1]
                pending[n-1] = pending[pending.length-1]
                pending.pop()
                n--

        requestAnimationFrame vsync
        return
    requestAnimationFrame? vsync

    updateAnimation = (anim) ->
        data = anim._impl

        progress = (nowTime - data.startTime) / anim._duration
        if progress < 0
            data.progress = 1
            return
        else if progress > 1
            progress = 1
        data.progress = progress
        running = progress isnt 1 or (anim._running and anim._loop && anim._when)

        target = anim._target
        if anim._updateData or not running
            val = (data.to - data.from) * progress + data.from

            if anim._updateProperty or not running
                anim._updatePending = true
                target[anim._property] = val
                anim._updatePending = false
            else
                target[data.internalPropertyName] = val

        if progress is 1
            if running
                data.startTime += anim._loopDelay + anim._duration
        return

    onStarted = ->
        @_impl.startTime = nowTime + @_startDelay
        updateAnimation @
        pending.push @
    onStopped = ->
        @running = false
        updateAnimation @

    DATA =
        type: 'number'
        accepts: false
        running: false
        startTime: 0
        from: 0
        to: 0

    DATA: DATA

    createData: impl.utils.createDataCloner 'PropertyAnimation', DATA

    create: (data) ->
        impl.Types.PropertyAnimation.create.call @, data

    startAnimation: do (_super = impl.startAnimation) -> ->
        data = @_impl
        if data.type isnt 'number' or not data.propertySetter or not @_target._impl.elem.hasOwnProperty(@property)
            data.accepts = false
            _super.call @
            return

        data.accepts = true

        if data.dirty
            data.dirty = false
            data.elem?.destroy()
            data.elem = createElem @
            data.elem.started.connect @, onStarted
            data.elem.stopped.connect @, onStopped
        {elem} = data

        elem.target = @_target._impl.elem
        elem.easing = @_impl.easingType
        elem.startDelay = @_startDelay
        elem.loopDelay = @_loopDelay
        elem.duration = @_duration
        elem.loop = @_loop
        if @_property is 'rotation'
            elem.from = impl.utils.radToDeg @_from
            elem.to = impl.utils.radToDeg @_to
        else
            elem.from = @_from
            elem.to = @_to

        impl[data.propertySetter].call @_target, elem.from

        data.startTime = nowTime + @_startDelay
        data.from = @_from
        data.to = @_to
        elem.start()

        return

    stopAnimation: do (_super = impl.stopAnimation) -> ->
        data = @_impl
        if not data.accepts or data.type isnt 'number'
            _super.call @
            return

        data.elem?.stop()
        return