'use strict'

module.exports = (impl) ->
    {Item} = impl.Types

    DATA =
        shader: null
        isSvg: false
        callback: null
        image:
            source: ''
            width: 0
            height: 0
        resource: null

    onSvgImageResize = ->
        if this.sourceSize.width < this.width
            this.sourceSize.width = this.width * 1.2
        if this.sourceSize.height < this.height
            this.sourceSize.height = this.height * 1.2
        return

    useShader = (item) ->
        data = item._impl

        data.shader = impl.utils.createQmlObject """
        Item {
            id: shader;
            property variant image: null;
            property double offsetX: 0;
            property double offsetY: 0;
            property int xDir: 1;
            property int yDir: 1;
            anchors.fill: this.image;
            clip: true;

            onOffsetXChanged: {
                this.updateOffset();
            }
            onOffsetYChanged: {
                this.updateOffset();
            }
            onWidthChanged: {
                this.updateSize();
            }
            onHeightChanged: {
                this.updateSize();
            }
            onXDirChanged: {
                this.updateDir();
            }
            onYDirChanged: {
                this.updateDir();
            }

            function updateSize(){
                this.updateImages();
                this.updateOffset();
            }

            function updateDir(){
                var children = this.children,
                    c00 = children[0],
                    c10 = children[1],
                    c01 = children[2],
                    c11 = children[3];
                c10.baseX = c11.baseX = c00.width * this.xDir * -1;
                c01.baseY = c11.baseY = c00.height * this.yDir * -1;
            }

            function updateImages(){
                var children = this.children,
                    width = Math.floor(this.width / this.image.width) * this.image.width,
                    height = Math.floor(this.height / this.image.height) * this.image.height;
                if (!isFinite(width) || !isFinite(height)){
                    return;
                }

                for (var i = 0; i < 4; i++){
                    var child = children[i];
                    child.width = width;
                    child.height = height;
                }

                this.updateDir();
            }

            function updateOffset(){
                var children = this.children,
                    offsetX = this.offsetX % this.width,
                    offsetY = this.offsetY % this.height;
                if (children.length !== 5){
                    return;
                }

                for (var i = 0; i < 4; i++){
                    var child = children[i];
                    child.offsetX = offsetX;
                    child.offsetY = offsetY;
                }

                this.xDir = offsetX > 0 ? 1 : -1;
                this.yDir = offsetY > 0 ? 1 : -1;
            }

            Repeater {
                model: 4;

                Image {
                    source: shader.image ? shader.image.source : '';
                    sourceSize.width: shader.image ? shader.image.sourceSize.width : 0;
                    sourceSize.height: shader.image ? shader.image.sourceSize.height : 0;
                    fillMode: Image.Tile;
                    property double offsetX: 0;
                    property double offsetY: 0;
                    property double baseX: 0;
                    property double baseY: 0;
                    x: this.baseX + this.offsetX;
                    y: this.baseY + this.offsetY;
                }
            }
        }
        """, data.elem.parent

        # TODO: what with elem children and items order
        data.shader.image = data.elem

        return

    DATA: DATA

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

    create: (data) ->
        data.elem ?= impl.utils.createQmlObject 'Image { asynchronous: true }'

        Item.create.call @, data

    setImageSource: do ->
        onStatusChanged = ->
            data = @_impl
            {elem, callback} = data
            elem.statusChanged.disconnect @, onStatusChanged

            if elem.status is Image.Ready
                data.image.width = data.resource?.width or elem.sourceSize.width
                data.image.height = data.resource?.height or elem.sourceSize.height
                callback?.call @, null, data.image
            else if elem.status is Image.Error
                callback?.call @, true

        (val, callback) ->
            data = @_impl
            {elem} = data

            data.image.source = val
            data.callback = callback
            data.resource = null

            unless impl.utils.DATA_URI_RE.test(val)
                # if rsc = impl.Renderer.resources?.getResource(val)
                #   data.resource = rsc
                #   val = 'qrc:' + rsc.resolve(val, ImageResourceRequest)
                # else
                val = impl.utils.toUrl(val)
            elem.source = val or ''

            if ///^data:image\/svg+|\.svg$///.test(val)
                elem.fillMode = Image.PreserveAspectFit
                unless data.isSvg
                    elem.widthChanged.connect elem, onSvgImageResize
                    elem.heightChanged.connect elem, onSvgImageResize
                    elem.statusChanged.connect elem, onSvgImageResize
                    data.isSvg = true
            else
                elem.fillMode = Image.Stretch
                if data.isSvg
                    elem.widthChanged.disconnect elem, onSvgImageResize
                    elem.heightChanged.disconnect elem, onSvgImageResize
                    elem.statusChanged.disconnect elem, onSvgImageResize
                    data.isSvg = false

            switch elem.status
                when Image.Ready, Image.Error
                    onStatusChanged.call @
                else
                    elem.statusChanged.connect @, onStatusChanged
            return

    setImageSourceWidth: (val) ->
        @_impl.elem.sourceSize.width = val
        return

    setImageSourceHeight: (val) ->
        @_impl.elem.sourceSize.height = val
        return

    setImageFillMode: (val) ->
        switch val
            when 'Stretch'
                @_impl.elem.fillMode = Image.Stretch
            when 'Tile'
                @_impl.elem.fillMode = Image.Tile
        return

    setImageOffsetX: (val) ->
        # unless @_impl.shader
        #   useShader @
        # @_impl.shader.offsetX = val
        return

    setImageOffsetY: (val) ->
        # unless @_impl.shader
        #   useShader @
        # @_impl.shader.offsetY = val
        return