/**
 * A sprite that represents a line.
 *
 *     @example
 *     Ext.create({
 *        xtype: 'draw',
 *        renderTo: document.body,
 *        width: 600,
 *        height: 400,
 *        sprites: [{
 *            type: 'line',
 *            fromX: 20,
 *            fromY: 20,
 *            toX: 120,
 *            toY: 120,
 *            strokeStyle: '#1F6D91',
 *            lineWidth: 3
 *        }]
 *     });
 */
Ext.define('Ext.draw.sprite.Line', {
    extend: 'Ext.draw.sprite.Sprite',
    alias: 'sprite.line',
    type: 'line',

    inheritableStatics: {
        def: {
            processors: {
                fromX: 'number',
                fromY: 'number',
                toX: 'number',
                toY: 'number',
                crisp: 'bool'
            },

            defaults: {
                fromX: 0,
                fromY: 0,
                toX: 1,
                toY: 1,
                crisp: false,
                strokeStyle: 'black'
            },

            aliases: {
                x1: 'fromX',
                y1: 'fromY',
                x2: 'toX',
                y2: 'toY'
            },

            triggers: {
                crisp: 'bbox'
            }
        }
    },

    updateLineBBox: function(bbox, isTransform, x1, y1, x2, y2) {
        var attr = this.attr,
            matrix = attr.matrix,
            halfLineWidth = attr.lineWidth / 2,
            fromX, fromY, toX, toY,
            p, angle, sin, cos, dx, dy;

        if (attr.crisp) {
            x1 = this.align(x1);
            x2 = this.align(x2);
            y1 = this.align(y1);
            y2 = this.align(y2);
        }

        if (isTransform) {
            p = matrix.transformPoint([x1, y1]);
            x1 = p[0];
            y1 = p[1];

            p = matrix.transformPoint([x2, y2]);
            x2 = p[0];
            y2 = p[1];
        }

        fromX = Math.min(x1, x2);
        toX = Math.max(x1, x2);

        fromY = Math.min(y1, y2);
        toY = Math.max(y1, y2);

        angle = Math.atan2(toX - fromX, toY - fromY);
        sin = Math.sin(angle);
        cos = Math.cos(angle);
        dx = halfLineWidth * cos;
        dy = halfLineWidth * sin;

        // Offset start and end points of the line by half its thickness,
        // while accounting for line's angle.
        fromX -= dx;
        fromY -= dy;
        toX += dx;
        toY += dy;

        bbox.x = fromX;
        bbox.y = fromY;
        bbox.width = toX - fromX;
        bbox.height = toY - fromY;
    },

    updatePlainBBox: function(plain) {
        var attr = this.attr;

        this.updateLineBBox(plain, false, attr.fromX, attr.fromY, attr.toX, attr.toY);
    },

    updateTransformedBBox: function(transform, plain) {
        var attr = this.attr;

        this.updateLineBBox(transform, true, attr.fromX, attr.fromY, attr.toX, attr.toY);
    },

    align: function(x) {
        return Math.round(x) - 0.5;
    },

    render: function(surface, ctx) {
        var me = this,
            attr = me.attr,
            matrix = attr.matrix;

        matrix.toContext(ctx);

        ctx.beginPath();

        if (attr.crisp) {
            ctx.moveTo(me.align(attr.fromX), me.align(attr.fromY));
            ctx.lineTo(me.align(attr.toX), me.align(attr.toY));
        }
        else {
            ctx.moveTo(attr.fromX, attr.fromY);
            ctx.lineTo(attr.toX, attr.toY);
        }

        ctx.stroke();

        //<debug>
        // eslint-disable-next-line vars-on-top
        var debug = attr.debug || this.statics().debug || Ext.draw.sprite.Sprite.debug;

        if (debug) {
            // This assumes no part of the sprite is rendered after this call.
            // If it is, we need to re-apply transformations.
            // But the bounding box should always be rendered as is, untransformed.
            this.attr.inverseMatrix.toContext(ctx);

            if (debug.bbox) {
                this.renderBBox(surface, ctx);
            }
        }
        //</debug>
    }
});