/**
 * @fileoverview TSM - A TypeScript vector and matrix math library
 * @author Matthias Ferch
 * @version 0.6
 */

/*
 * Copyright (c) 2012 Matthias Ferch
 *
 * Project homepage: https://github.com/matthiasferch/tsm
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 *    1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 *
 *    2. Altered source versions must be plainly marked as such, and must not
 *    be misrepresented as being the original software.
 *
 *    3. This notice may not be removed or altered from any source
 *    distribution.
 */


///<reference path='./common.ts' />

import {vec3} from './vec3';
import {quat} from './quat';
import {mat4} from './mat4';
import {vec2} from './vec2';

export class mat3
{
    static identity = new mat3().setIdentity();

    private values = new Float32Array(9);

    static product(m1: mat3, m2: mat3, result: mat3 | null = null): mat3
    {
        const a00 = m1.at(0), a01 = m1.at(1), a02 = m1.at(2),
            a10 = m1.at(3), a11 = m1.at(4), a12 = m1.at(5),
            a20 = m1.at(6), a21 = m1.at(7), a22 = m1.at(8);

        const b00 = m2.at(0), b01 = m2.at(1), b02 = m2.at(2),
            b10 = m2.at(3), b11 = m2.at(4), b12 = m2.at(5),
            b20 = m2.at(6), b21 = m2.at(7), b22 = m2.at(8);

        if (result)
        {
            result.init([
                b00 * a00 + b01 * a10 + b02 * a20,
                b00 * a01 + b01 * a11 + b02 * a21,
                b00 * a02 + b01 * a12 + b02 * a22,

                b10 * a00 + b11 * a10 + b12 * a20,
                b10 * a01 + b11 * a11 + b12 * a21,
                b10 * a02 + b11 * a12 + b12 * a22,

                b20 * a00 + b21 * a10 + b22 * a20,
                b20 * a01 + b21 * a11 + b22 * a21,
                b20 * a02 + b21 * a12 + b22 * a22
            ]);

            return result;
        }
        else
        {
            return new mat3([
                b00 * a00 + b01 * a10 + b02 * a20,
                b00 * a01 + b01 * a11 + b02 * a21,
                b00 * a02 + b01 * a12 + b02 * a22,

                b10 * a00 + b11 * a10 + b12 * a20,
                b10 * a01 + b11 * a11 + b12 * a21,
                b10 * a02 + b11 * a12 + b12 * a22,

                b20 * a00 + b21 * a10 + b22 * a20,
                b20 * a01 + b21 * a11 + b22 * a21,
                b20 * a02 + b21 * a12 + b22 * a22
            ]);
        }
    }

    constructor(values: number[] | null = null)
    {
        if (values)
        {
            this.init(values);
        }
    }

    at(index: number): number
    {
        return this.values[index];
    }

    init(values: number[]): mat3
    {
        for (let i = 0; i < 9; i++)
        {
            this.values[i] = values[i];
        }

        return this;
    }

    reset(): void
    {
        for (let i = 0; i < 9; i++)
        {
            this.values[i] = 0;
        }
    }

    copy(dest: mat3 | null = null): mat3
    {
        if (!dest)
        {
            dest = new mat3();
        }

        for (let i = 0; i < 9; i++)
        {
            dest.values[i] = this.values[i];
        }

        return dest;
    }

    all(): number[]
    {
        const data: number[] = [];
        for (let i = 0; i < 9; i++)
        {
            data[i] = this.values[i];
        }

        return data;
    }

    row(index: number): number[]
    {
        return [
            this.values[index * 3 + 0],
            this.values[index * 3 + 1],
            this.values[index * 3 + 2]
        ];
    }

    col(index: number): number[]
    {
        return [
            this.values[index],
            this.values[index + 3],
            this.values[index + 6]
        ];
    }

    equals(matrix: mat3, threshold = EPSILON): boolean
    {
        for (let i = 0; i < 9; i++)
        {
            if (Math.abs(this.values[i] - matrix.at(i)) > threshold)
            {
                return false;
            }
        }

        return true;
    }

    determinant(): number
    {
        const a00 = this.values[0], a01 = this.values[1], a02 = this.values[2],
            a10 = this.values[3], a11 = this.values[4], a12 = this.values[5],
            a20 = this.values[6], a21 = this.values[7], a22 = this.values[8];

        const det01 = a22 * a11 - a12 * a21,
            det11 = -a22 * a10 + a12 * a20,
            det21 = a21 * a10 - a11 * a20;

        return a00 * det01 + a01 * det11 + a02 * det21;
    }

    setIdentity(): mat3
    {
        this.values[0] = 1;
        this.values[1] = 0;
        this.values[2] = 0;
        this.values[3] = 0;
        this.values[4] = 1;
        this.values[5] = 0;
        this.values[6] = 0;
        this.values[7] = 0;
        this.values[8] = 1;

        return this;
    }

    transpose(): mat3
    {
        const temp01 = this.values[1],
            temp02 = this.values[2],
            temp12 = this.values[5];

        this.values[1] = this.values[3];
        this.values[2] = this.values[6];
        this.values[3] = temp01;
        this.values[5] = this.values[7];
        this.values[6] = temp02;
        this.values[7] = temp12;

        return this;
    }

    inverse(): mat3 | null
    {
        const a00 = this.values[0], a01 = this.values[1], a02 = this.values[2],
            a10 = this.values[3], a11 = this.values[4], a12 = this.values[5],
            a20 = this.values[6], a21 = this.values[7], a22 = this.values[8];

        const det01 = a22 * a11 - a12 * a21,
            det11 = -a22 * a10 + a12 * a20,
            det21 = a21 * a10 - a11 * a20;

        let det = a00 * det01 + a01 * det11 + a02 * det21;

        if (!det)
        {
            return null;
        }

        det = 1.0 / det;

        this.values[0] = det01 * det;
        this.values[1] = (-a22 * a01 + a02 * a21) * det;
        this.values[2] = (a12 * a01 - a02 * a11) * det;
        this.values[3] = det11 * det;
        this.values[4] = (a22 * a00 - a02 * a20) * det;
        this.values[5] = (-a12 * a00 + a02 * a10) * det;
        this.values[6] = det21 * det;
        this.values[7] = (-a21 * a00 + a01 * a20) * det;
        this.values[8] = (a11 * a00 - a01 * a10) * det;

        return this;
    }

    multiply(matrix: mat3): mat3
    {
        const a00 = this.values[0], a01 = this.values[1], a02 = this.values[2],
            a10 = this.values[3], a11 = this.values[4], a12 = this.values[5],
            a20 = this.values[6], a21 = this.values[7], a22 = this.values[8];

        const b00 = matrix.at(0), b01 = matrix.at(1), b02 = matrix.at(2),
            b10 = matrix.at(3), b11 = matrix.at(4), b12 = matrix.at(5),
            b20 = matrix.at(6), b21 = matrix.at(7), b22 = matrix.at(8);

        this.values[0] = b00 * a00 + b01 * a10 + b02 * a20;
        this.values[1] = b00 * a01 + b01 * a11 + b02 * a21;
        this.values[2] = b00 * a02 + b01 * a12 + b02 * a22;

        this.values[3] = b10 * a00 + b11 * a10 + b12 * a20;
        this.values[4] = b10 * a01 + b11 * a11 + b12 * a21;
        this.values[5] = b10 * a02 + b11 * a12 + b12 * a22;

        this.values[6] = b20 * a00 + b21 * a10 + b22 * a20;
        this.values[7] = b20 * a01 + b21 * a11 + b22 * a21;
        this.values[8] = b20 * a02 + b21 * a12 + b22 * a22;

        return this;
    }

    multiplyVec2(vector: vec2, result: vec2 | null = null): vec2
    {
        const x = vector.x,
            y = vector.y;

        if (result)
        {
            result.xy = [
                x * this.values[0] + y * this.values[3] + this.values[6],
                x * this.values[1] + y * this.values[4] + this.values[7]
            ];

            return result;
        }
        else
        {
            return new vec2([
                x * this.values[0] + y * this.values[3] + this.values[6],
                x * this.values[1] + y * this.values[4] + this.values[7]
            ]);
        }
    }

    multiplyVec3(vector: vec3, result: vec3 | null = null): vec3
    {
        const x = vector.x,
            y = vector.y,
            z = vector.z;

        if (result)
        {
            result.xyz = [
                x * this.values[0] + y * this.values[3] + z * this.values[6],
                x * this.values[1] + y * this.values[4] + z * this.values[7],
                x * this.values[2] + y * this.values[5] + z * this.values[8]
            ];

            return result;
        }
        else
        {
            return new vec3([
                x * this.values[0] + y * this.values[3] + z * this.values[6],
                x * this.values[1] + y * this.values[4] + z * this.values[7],
                x * this.values[2] + y * this.values[5] + z * this.values[8]
            ]);
        }
    }

    toMat4(result: mat4 | null = null): mat4
    {
        if (result)
        {
            result.init([
                this.values[0],
                this.values[1],
                this.values[2],
                0,

                this.values[3],
                this.values[4],
                this.values[5],
                0,

                this.values[6],
                this.values[7],
                this.values[8],
                0,

                0,
                0,
                0,
                1
            ]);

            return result;
        }
        else
        {
            return new mat4([
                this.values[0],
                this.values[1],
                this.values[2],
                0,

                this.values[3],
                this.values[4],
                this.values[5],
                0,

                this.values[6],
                this.values[7],
                this.values[8],
                0,

                0,
                0,
                0,
                1
            ]);
        }
    }

    toQuat(): quat
    {
        const m00 = this.values[0], m01 = this.values[1], m02 = this.values[2],
            m10 = this.values[3], m11 = this.values[4], m12 = this.values[5],
            m20 = this.values[6], m21 = this.values[7], m22 = this.values[8];

        const fourXSquaredMinus1 = m00 - m11 - m22;
        const fourYSquaredMinus1 = m11 - m00 - m22;
        const fourZSquaredMinus1 = m22 - m00 - m11;
        const fourWSquaredMinus1 = m00 + m11 + m22;

        let biggestIndex = 0;

        let fourBiggestSquaredMinus1 = fourWSquaredMinus1;

        if (fourXSquaredMinus1 > fourBiggestSquaredMinus1)
        {
            fourBiggestSquaredMinus1 = fourXSquaredMinus1;
            biggestIndex = 1;
        }

        if (fourYSquaredMinus1 > fourBiggestSquaredMinus1)
        {
            fourBiggestSquaredMinus1 = fourYSquaredMinus1;
            biggestIndex = 2;
        }

        if (fourZSquaredMinus1 > fourBiggestSquaredMinus1)
        {
            fourBiggestSquaredMinus1 = fourZSquaredMinus1;
            biggestIndex = 3;
        }

        const biggestVal = Math.sqrt(fourBiggestSquaredMinus1 + 1) * 0.5;
        const mult = 0.25 / biggestVal;

        const result = new quat();

        switch (biggestIndex)
        {
            case 0:

                result.w = biggestVal;
                result.x = (m12 - m21) * mult;
                result.y = (m20 - m02) * mult;
                result.z = (m01 - m10) * mult;

                break;

            case 1:

                result.w = (m12 - m21) * mult;
                result.x = biggestVal;
                result.y = (m01 + m10) * mult;
                result.z = (m20 + m02) * mult;

                break;

            case 2:

                result.w = (m20 - m02) * mult;
                result.x = (m01 + m10) * mult;
                result.y = biggestVal;
                result.z = (m12 + m21) * mult;

                break;

            case 3:

                result.w = (m01 - m10) * mult;
                result.x = (m20 + m02) * mult;
                result.y = (m12 + m21) * mult;
                result.z = biggestVal;

                break;
        }

        return result;
    }

    rotate(angle: number, axis: vec3): mat3 | null
    {
        let x = axis.x,
            y = axis.y,
            z = axis.z;

        let length = Math.sqrt(x * x + y * y + z * z);

        if (!length)
        {
            return null;
        }

        if (length !== 1)
        {
            length = 1 / length;
            x *= length;
            y *= length;
            z *= length;
        }

        const s = Math.sin(angle);
        const c = Math.cos(angle);

        const t = 1.0 - c;

        const a00 = this.values[0], a01 = this.values[1], a02 = this.values[2],
            a10 = this.values[4], a11 = this.values[5], a12 = this.values[6],
            a20 = this.values[8], a21 = this.values[9], a22 = this.values[10];

        const b00 = x * x * t + c, b01 = y * x * t + z * s, b02 = z * x * t - y * s,
            b10 = x * y * t - z * s, b11 = y * y * t + c, b12 = z * y * t + x * s,
            b20 = x * z * t + y * s, b21 = y * z * t - x * s, b22 = z * z * t + c;

        this.values[0] = a00 * b00 + a10 * b01 + a20 * b02;
        this.values[1] = a01 * b00 + a11 * b01 + a21 * b02;
        this.values[2] = a02 * b00 + a12 * b01 + a22 * b02;

        this.values[3] = a00 * b10 + a10 * b11 + a20 * b12;
        this.values[4] = a01 * b10 + a11 * b11 + a21 * b12;
        this.values[5] = a02 * b10 + a12 * b11 + a22 * b12;

        this.values[6] = a00 * b20 + a10 * b21 + a20 * b22;
        this.values[7] = a01 * b20 + a11 * b21 + a21 * b22;
        this.values[8] = a02 * b20 + a12 * b21 + a22 * b22;

        return this;
    }
}