(function() {
    "use strict";

    var root = this,
        Chart = root.Chart,
        helpers = Chart.helpers;

    var defaultConfig = {

        ///Boolean - Whether grid lines are shown across the chart
        scaleShowGridLines: true,
        //String - Colour of the grid lines
        scaleGridLineColor: "rgba(0,0,0,.05)",
        //Number - Width of the grid lines
        scaleGridLineWidth: 1,
        //Boolean - Whether to show horizontal lines (except X axis)
        scaleShowHorizontalLines: true,
        //Boolean - Whether to show vertical lines (except Y axis)
        scaleShowVerticalLines: true,
        //Boolean - Whether to horizontally center the label and point dot inside the grid
        offsetGridLines: false,



        //Boolean - Whether to stack the lines essentially creating a stacked area chart.
        stacked: false,


        //Number - Tension of the bezier curve between points
        tension: 0.4,


        //Number - Radius of each point dot in pixels
        pointRadius: 3,
        //Number - Pixel width of point dot border
        pointBorderWidth: 1,
        //Number - Pixel width of point on hover
        pointHoverRadius: 5,
        //Number - Pixel width of point dot border on hover
        pointHoverBorderWidth: 2,
        pointBackgroundColor: Chart.defaults.global.defaultColor,
        pointBorderColor: Chart.defaults.global.defaultColor,

        //Number - amount extra to add to the radius to cater for hit detection outside the drawn point
        pointHitRadius: 6,

        //Number - Pixel width of dataset border
        borderWidth: 2,
        //Number - Pixel width of dataset border on hover
        hoverBorderWidth: 2,

        //String - A legend template
        legendTemplate: "<ul class=\"<%=name.toLowerCase()%>-legend\"><% for (var i=0; i<datasets.length; i++){%><li><span style=\"background-color:<%=datasets[i].borderColor%>\"></span><%if(datasets[i].label){%><%=datasets[i].label%><%}%></li><%}%></ul>",



    };


    Chart.Type.extend({
        name: "Line",
        defaults: defaultConfig,
        initialize: function() {

            // Events
            helpers.bindEvents(this, this.options.events, this.events);

            var _this = this;

            // Build Scale
            this.ScaleClass = Chart.Scale.extend({
                calculatePointY: function(index, datasetIndex) {

                    var value = _this.data.datasets[datasetIndex].data[index];

                    if (_this.options.stacked) {
                        var offsetPos = 0;
                        var offsetNeg = 0;
                        for (var i = 0; i < datasetIndex; i++) {
                            if (_this.data.datasets[i].data[index] < 0) {
                                offsetNeg += _this.data.datasets[i].data[index];
                            } else {
                                offsetPos += _this.data.datasets[i].data[index];
                            }
                        }
                        if (value < 0) {
                            return this.calculateY(offsetNeg + value);
                        } else {
                            return this.calculateY(offsetPos + value);
                        }
                    }

                    return this.calculateY(value);
                }
            });
            this.buildScale(this.data.labels);


            //Create a new line and its points for each dataset and piece of data
            helpers.each(this.data.datasets, function(dataset, datasetIndex) {
                dataset.metaDataset = new Chart.Line();
                dataset.metaData = [];
                helpers.each(dataset.data, function(dataPoint, index) {
                    dataset.metaData.push(new Chart.Point());
                }, this);
            }, this);

            // Set defaults for lines
            this.eachDataset(function(dataset, datasetIndex) {
                helpers.extend(dataset.metaDataset, {
                    _points: dataset.metaData,
                    _datasetIndex: datasetIndex,
                    _chart: this.chart,
                });
                // Fill in dataset defaults from options
                helpers.extend(dataset, helpers.merge(this.options, dataset));
                // Copy to view modele
                dataset.metaDataset.save();
            }, this);

            // Set defaults for points
            this.eachElement(function(point, index, dataset, datasetIndex) {
                helpers.extend(point, {
                    x: this.scale.calculateX(index),
                    y: this.scale.calculateY(0),
                    _datasetIndex: datasetIndex,
                    _index: index,
                    _chart: this.chart
                });

                // Default bezier control points
                helpers.extend(point, {
                    controlPointPreviousX: this.previousPoint(dataset, index).x,
                    controlPointPreviousY: this.nextPoint(dataset, index).y,
                    controlPointNextX: this.previousPoint(dataset, index).x,
                    controlPointNextY: this.nextPoint(dataset, index).y,
                });
                // Copy to view model
                point.save();
            }, this);

            // Create tooltip instance exclusively for this chart with some defaults.
            this.tooltip = new Chart.Tooltip({
                _chart: this.chart,
                _data: this.data,
                _options: this.options,
            }, this);

            this.update();
        },
        nextPoint: function(collection, index) {
            return collection[index - 1] || collection[index];
        },
        previousPoint: function(collection, index) {
            return collection[index + 1] || collection[index];
        },
        update: function() {

            // Update the scale
            this.scale.update();

            // Update the lines
            this.eachDataset(function(dataset, datasetIndex) {
                helpers.extend(dataset.metaDataset, {
                    // Utility
                    _datasetIndex: datasetIndex,
                    // Data
                    _points: dataset.metaData,
                    // Geometry
                    scaleTop: this.scale.startPoint,
                    scaleBottom: this.scale.endPoint,
                    scaleZero: this.scale.calculateY(0),
                    // Appearance
                    tension: dataset.tension || this.options.tension,
                    backgroundColor: dataset.backgroundColor || this.options.backgroundColor,
                    borderWidth: dataset.borderWidth || this.options.borderWidth,
                    borderColor: dataset.borderColor || this.options.borderColor,
                });
                dataset.metaDataset.pivot();
            });

            // Update the points
            this.eachElement(function(point, index, dataset, datasetIndex) {
                helpers.extend(point, {
                    // Utility
                    _chart: this.chart,
                    _datasetIndex: datasetIndex,
                    _index: index,
                    // Data
                    label: this.data.labels[index],
                    value: this.data.datasets[datasetIndex].data[index],
                    datasetLabel: this.data.datasets[datasetIndex].label,
                    // Geometry
                    offsetGridLines: this.options.offsetGridLines,
                    x: this.scale.calculateX(index),
                    y: this.scale.calculatePointY(index, datasetIndex),
                    tension: this.data.datasets[datasetIndex].metaDataset.tension,
                    // Appearnce
                    radius: this.data.datasets[datasetIndex].pointRadius || this.options.pointRadius,
                    backgroundColor: this.data.datasets[datasetIndex].pointBackgroundColor || this.options.pointBackgroundColor,
                    borderWidth: this.data.datasets[datasetIndex].pointBorderWidth || this.options.pointBorderWidth,
                    // Tooltip
                    hoverRadius: this.data.datasets[datasetIndex].pointHitRadius || this.options.pointHitRadius,
                });
            }, this);

            // Update control points for the bezier curve
            this.eachElement(function(point, index, dataset, datasetIndex) {
                var controlPoints = helpers.splineCurve(
                    this.previousPoint(dataset, index),
                    point,
                    this.nextPoint(dataset, index),
                    point.tension
                );

                point.controlPointPreviousX = controlPoints.previous.x;
                point.controlPointNextX = controlPoints.next.x;

                // Prevent the bezier going outside of the bounds of the graph
                // Cap puter bezier handles to the upper/lower scale bounds
                if (controlPoints.next.y > this.scale.endPoint) {
                    point.controlPointNextY = this.scale.endPoint;
                } else if (controlPoints.next.y < this.scale.startPoint) {
                    point.controlPointNextY = this.scale.startPoint;
                } else {
                    point.controlPointNextY = controlPoints.next.y;
                }

                // Cap inner bezier handles to the upper/lower scale bounds
                if (controlPoints.previous.y > this.scale.endPoint) {
                    point.controlPointPreviousY = this.scale.endPoint;
                } else if (controlPoints.previous.y < this.scale.startPoint) {
                    point.controlPointPreviousY = this.scale.startPoint;
                } else {
                    point.controlPointPreviousY = controlPoints.previous.y;
                }
                // Now pivot the point for animation
                point.pivot();
            }, this);

            this.render();
        },
        buildScale: function(labels) {
            var self = this;

            var dataTotal = function() {
                var values = [];
                var negativeValues = [];

                if (self.options.stacked) {
                    self.eachValue(function(value, index) {
                        values[index] = values[index] || 0;
                        negativeValues[index] = negativeValues[index] || 0;
                        if (self.options.relativePoints) {
                            values[index] = 100;
                        } else {
                            if (value < 0) {
                                negativeValues[index] += value;
                            } else {
                                values[index] += value;
                            }
                        }
                    });
                    return values.concat(negativeValues);
                }

                self.eachValue(function(value, index) {
                    values.push(value);
                });

                return values;

            };

            var scaleOptions = {
                templateString: this.options.scaleLabel,
                height: this.chart.height,
                width: this.chart.width,
                ctx: this.chart.ctx,
                textColor: this.options.scaleFontColor,
                offsetGridLines: this.options.offsetGridLines,
                fontSize: this.options.scaleFontSize,
                fontStyle: this.options.scaleFontStyle,
                fontFamily: this.options.scaleFontFamily,
                valuesCount: labels.length,
                beginAtZero: this.options.scaleBeginAtZero,
                integersOnly: this.options.scaleIntegersOnly,
                calculateYRange: function(currentHeight) {
                    var updatedRanges = helpers.calculateScaleRange(
                        dataTotal(),
                        currentHeight,
                        this.fontSize,
                        this.beginAtZero,
                        this.integersOnly
                    );
                    helpers.extend(this, updatedRanges);
                },
                xLabels: this.data.labels,
                font: helpers.fontString(this.options.scaleFontSize, this.options.scaleFontStyle, this.options.scaleFontFamily),
                lineWidth: this.options.scaleLineWidth,
                lineColor: this.options.scaleLineColor,
                showHorizontalLines: this.options.scaleShowHorizontalLines,
                showVerticalLines: this.options.scaleShowVerticalLines,
                gridLineWidth: (this.options.scaleShowGridLines) ? this.options.scaleGridLineWidth : 0,
                gridLineColor: (this.options.scaleShowGridLines) ? this.options.scaleGridLineColor : "rgba(0,0,0,0)",
                padding: (this.options.showScale) ? 0 : this.options.pointRadius + this.options.pointBorderWidth,
                showLabels: this.options.scaleShowLabels,
                display: this.options.showScale
            };

            if (this.options.scaleOverride) {
                helpers.extend(scaleOptions, {
                    calculateYRange: helpers.noop,
                    steps: this.options.scaleSteps,
                    stepValue: this.options.scaleStepWidth,
                    min: this.options.scaleStartValue,
                    max: this.options.scaleStartValue + (this.options.scaleSteps * this.options.scaleStepWidth)
                });
            }

            this.scale = new this.ScaleClass(scaleOptions);
        },
        redraw: function() {

        },
        draw: function(ease) {

            var easingDecimal = ease || 1;
            this.clear();

            this.scale.draw(easingDecimal);

            // reverse for-loop for proper stacking
            for (var i = this.data.datasets.length - 1; i >= 0; i--) {

                var dataset = this.data.datasets[i];
                var datasetIndex = i;

                // Transition Point Locations
                helpers.each(dataset.metaData, function(point, index) {
                    point.transition(easingDecimal);
                }, this);

                // Transition and Draw the line
                dataset.metaDataset.transition(easingDecimal).draw();

                // Draw the points
                helpers.each(dataset.metaData, function(point) {
                    point.draw();
                });
            }

            // Finally draw the tooltip
            this.tooltip.transition(easingDecimal).draw();
        },
        events: function(e) {

            // If exiting chart
            if (e.type == 'mouseout') {
                return this;
            }

            this.lastActive = this.lastActive || [];

            // Find Active Elements
            this.active = function() {
                switch (this.options.hoverMode) {
                    case 'single':
                        return this.getElementAtEvent(e);
                    case 'label':
                        return this.getElementsAtEvent(e);
                    case 'dataset':
                        return this.getDatasetAtEvent(e);
                    default:
                        return e;
                }
            }.call(this);

            // On Hover hook
            if (this.options.onHover) {
                this.options.onHover.call(this, this.active);
            }

            if (e.type == 'mouseup' || e.type == 'click') {
                if (this.options.onClick) {
                    this.options.onClick.call(this, e, this.active);
                }
            }

            var dataset;
            // Remove styling for last active (even if it may still be active)
            if (this.lastActive.length) {
                switch (this.options.hoverMode) {
                    case 'single':
                        dataset = this.data.datasets[this.lastActive[0]._datasetIndex];

                        this.lastActive[0].radius = dataset.pointRadius;
                        this.lastActive[0].backgroundColor = dataset.pointBackgroundColor;
                        this.lastActive[0].borderColor = dataset.pointBorderColor;
                        this.lastActive[0].borderWidth = dataset.pointBorderWidth;
                        break;
                    case 'label':
                        for (var i = 0; i < this.lastActive.length; i++) {
                            dataset = this.data.datasets[this.lastActive[i]._datasetIndex];

                            this.lastActive[i].radius = dataset.pointRadius;
                            this.lastActive[i].backgroundColor = dataset.pointBackgroundColor;
                            this.lastActive[i].borderColor = dataset.pointBorderColor;
                            this.lastActive[i].borderWidth = dataset.pointBorderWidth;
                        }
                        break;
                    case 'dataset':
                        break;
                    default:
                        // Don't change anything
                }
            }

            // Built in hover styling
            if (this.active.length && this.options.hoverMode) {
                switch (this.options.hoverMode) {
                    case 'single':
                        dataset = this.data.datasets[this.active[0]._datasetIndex];

                        this.active[0].radius = dataset.pointHoverRadius || dataset.pointRadius + 2;
                        this.active[0].backgroundColor = dataset.pointHoverBackgroundColor || helpers.color(dataset.pointBackgroundColor).saturate(0.5).darken(0.35).rgbString();
                        this.active[0].borderColor = dataset.pointHoverBorderColor || helpers.color(dataset.pointBorderColor).saturate(0.5).darken(0.35).rgbString();
                        this.active[0].borderWidth = dataset.pointHoverBorderWidth || dataset.pointBorderWidth + 2;
                        break;
                    case 'label':
                        for (var i = 0; i < this.active.length; i++) {
                            dataset = this.data.datasets[this.active[i]._datasetIndex];

                            this.active[i].radius = dataset.pointHoverRadius || dataset.pointRadius + 2;
                            this.active[i].backgroundColor = dataset.pointHoverBackgroundColor || helpers.color(dataset.pointBackgroundColor).saturate(0.5).darken(0.35).rgbString();
                            this.active[i].borderColor = dataset.pointHoverBorderColor || helpers.color(dataset.pointBorderColor).saturate(0.5).darken(0.35).rgbString();
                            this.active[i].borderWidth = dataset.pointHoverBorderWidth || dataset.pointBorderWidth + 2;
                        }
                        break;
                    case 'dataset':
                        break;
                    default:
                        // Don't change anything
                }
            }


            // Built in Tooltips
            if (this.options.showTooltips) {

                // The usual updates
                this.tooltip.initialize();

                // Active
                if (this.active.length) {
                    helpers.extend(this.tooltip, {
                        opacity: 1,
                        _active: this.active,
                    });

                    this.tooltip.update();
                } else {
                    // Inactive
                    helpers.extend(this.tooltip, {
                        opacity: 0,
                    });
                }
            }


            // Hover animations
            this.tooltip.pivot();

            if (!this.animating) {
                var changed;

                helpers.each(this.active, function(element, index) {
                    if (element !== this.lastActive[index]) {
                        changed = true;
                    }
                }, this);

                // If entering, leaving, or changing elements, animate the change via pivot
                if ((!this.lastActive.length && this.active.length) ||
                    (this.lastActive.length && !this.active.length) ||
                    (this.lastActive.length && this.active.length && changed)) {

                    this.stop();
                    this.render(this.options.hoverAnimationDuration);
                }
            }

            // Remember Last Active
            this.lastActive = this.active;
            return this;
        },
    });


}).call(this);