export default class {
    constructor(xx, yx, xy, yy, x, y){
        if (xx && typeof xx == 'object'){
            yx = xx.yx; yy = xx.yy; y = xx.y;
            xy = xx.xy; x = xx.x; xx = xx.xx;
        }
        this.xx = xx == null ? 1 : xx;
        this.yx = yx || 0;
        this.xy = xy || 0;
        this.yy = yy == null ? 1 : yy;
        this.x = (x == null ? this.x : x) || 0;
        this.y = (y == null ? this.y : y) || 0;
        return this;
    }

    xx = 1;
    yx = 0;
    x = 0;
    xy = 0;
    yy = 1;
    y = 0;

    transform = (xx, yx, xy, yy, x, y) => {
        var m = this;
        if (xx && typeof xx == 'object'){
            yx = xx.yx; yy = xx.yy; y = xx.y;
            xy = xx.xy; x = xx.x; xx = xx.xx;
        }
        if (!x) x = 0;
        if (!y) y = 0;
        return this.transformTo(
            m.xx * xx + m.xy * yx,
            m.yx * xx + m.yy * yx,
            m.xx * xy + m.xy * yy,
            m.yx * xy + m.yy * yy,
            m.xx * x + m.xy * y + m.x,
            m.yx * x + m.yy * y + m.y
        );
    };

    transformTo = this.constructor;

    translate = (x, y) => {
        return this.transform(1, 0, 0, 1, x, y);
    };

    move = (x, y) => {
        this.x += x || 0;
        this.y += y || 0;
        return this;
    };

    scale = (x, y) => {
        if (y == null) {
            y = x;
        }
        return this.transform(x, 0, 0, y, 0, 0);
    };

    rotate = (deg, x, y) => {
        if (x == null || y == null){
            x = (this.left || 0) + (this.width || 0) / 2;
            y = (this.top || 0) + (this.height || 0) / 2;
        }

        var rad = deg * Math.PI / 180, sin = Math.sin(rad), cos = Math.cos(rad);

        this.transform(1, 0, 0, 1, x, y);
        var m = this;

        return this.transformTo(
            cos * m.xx - sin * m.yx,
            sin * m.xx + cos * m.yx,
            cos * m.xy - sin * m.yy,
            sin * m.xy + cos * m.yy,
            m.x,
            m.y
        ).transform(1, 0, 0, 1, -x, -y);
    };

    moveTo = (x, y) => {
        var m = this;
        return this.transformTo(m.xx, m.yx, m.xy, m.yy, x, y);
    };

    rotateTo = (deg, x, y) => {
        var m = this;
        var flip = m.yx / m.xx > m.yy / m.xy ? -1 : 1;
        if (m.xx < 0 ? m.xy >= 0 : m.xy < 0) flip = -flip;
        return this.rotate(deg - Math.atan2(flip * m.yx, flip * m.xx) * 180 / Math.PI, x, y);
    };

    scaleTo = (x, y) => {
        // Normalize
        var m = this;

        var h = Math.sqrt(m.xx * m.xx + m.yx * m.yx);
        m.xx /= h; m.yx /= h;

        h = Math.sqrt(m.yy * m.yy + m.xy * m.xy);
        m.yy /= h; m.xy /= h;

        return this.scale(x, y);
    };

    resizeTo = (width, height) => {
        var w = this.width, h = this.height;
        if (!w || !h) return this;
        return this.scaleTo(width / w, height / h);
    };

    inversePoint = (x, y) => {
        var a = this.xx, b = this.yx,
            c = this.xy, d = this.yy,
            e = this.x, f = this.y;
        var det = b * c - a * d;
        if (det == 0) return null;
        return {
            x: (d * (e - x) + c * (y - f)) / det,
            y: (a * (f - y) + b * (x - e)) / det
        };
    };

    point = (x, y) => {
        var m = this;
        return {
            x: m.xx * x + m.xy * y + m.x,
            y: m.yx * x + m.yy * y + m.y
        };
    };
}