#pragma once
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>

#define MAX(x, y) (((x) > (y)) ? (x) : (y))
#define MIN(x, y) (((x) < (y)) ? (x) : (y))
#define ABS(x) (x < 0 ? -x : x)

struct Vector2 {
    float x = 0;
    float y = 0;

    Vector2 operator+(Vector2 other) {
        return { x + other.x, y + other.y };
    }

    Vector2& operator+=(Vector2 other) {
        x += other.x;
        y += other.y;
        return *this;
    }

    Vector2 operator-(Vector2 other) {
        return { x - other.x, y - other.y };
    }

    Vector2 operator*(float s) {
        return { x * s, y * s };
    }

    Vector2 operator/(float s) {
        return { x / s, y / s };
    }

    float dot(Vector2 other) {
        return x * other.x + y * other.y;
    }

    float length() {
        return sqrtf(x * x + y * y);
    }

    Vector2 normalize() {
        float len = length();
        float inverseLength = len == 0 ? 1.0 : 1.0 / len;

        return { x * inverseLength, y * inverseLength };
    }

    Vector2 negate() {
        return { -x, -y };
    }

    Vector2 getPerp() {
        return { -y, x };
    }

    void printDebug(const char* name) {
        printf("%s=Vector2(%f, %f)\n", name, x, y);
    }

    float determinant(Vector2 other) {
        //
        // [ a b ]
        // [ c d ]
        //
        // [ x other.x ]
        // [ y other.y ]
        //
        // det = a * d - b * c
        // det = x * other.y - other.x * y
        //
        return x * other.y - other.x * y;
    }
};

struct Vector3 {
    float x = 0.f;
    float y = 0.f;
    float z = 0.f;
};

struct Vector4 {
    float x = 0.f;
    float y = 0.f;
    float z = 0.f;
    float w = 0.f;

    float length() {
        return sqrtf(x * x + y * y + z * z + w * w);
    }

    Vector4 normalize() {
        float len = length();
        float inverseLength = len == 0 ? 1.0 : 1.0 / len;

        return { x * inverseLength, y * inverseLength, z * inverseLength, w * inverseLength };
    }

    Vector4 fromColor(float r, float g, float b, float a) {
        float scale = 1.f / 255.f;
        return { r * scale, g * scale, b * scale, a * scale };
    }
};

struct Mat4x4 {
    float m[16] = {
        1, 0, 0, 0,
        0, 1, 0, 0,
        0, 0, 1, 0,
        0, 0, 0, 1
    };

    Mat4x4 copy() {
        Mat4x4 result;
        memcpy(result.m, m, sizeof(float) * 16);
        return result;
    }

    Mat4x4 scale(Vector3 v) {
        Mat4x4 result = copy();
        result.m[0] = result.m[0] * v.x;
        result.m[5] = result.m[5] *v.y;
        result.m[10] = result.m[10] * v.z;
        return result;
    }

    Mat4x4 translate(Vector3 v) {
        Mat4x4 result = copy();
        result.m[12] += v.x;
        result.m[13] += v.y;
        result.m[14] += v.z;
        return result;
    }

	Mat4x4 translateByVec2(Vector2 v) {
        Mat4x4 result = copy();
        result.m[12] += v.x;
        result.m[13] += v.y;
        return result;
    }

    Mat4x4 rotate2D(float angle) {
        Mat4x4 result = copy();
        result.m[0] = cos(angle);
        result.m[1] = -sin(angle);
        result.m[4] = sin(angle);
        result.m[5] = cos(angle);
        return result;
    }

    Vector2 multByVec2(Vector2 v) {
        Vector4 vec4 = { v.x, v.y, 0.0, 1.0 };
        return {
            vec4.x * m[0] + vec4.y * m[4] + vec4.z * m[8] + vec4.w * m[12],
            vec4.x * m[1] + vec4.y * m[5] + vec4.z * m[9] + vec4.w * m[13]
        };
    }

    Mat4x4 getOrthographicMatrix(float left, float right, float bottom, float top) {
        Mat4x4 result;
        result.m[0] = 2.0 / (right - left);
        result.m[5] = 2.0 / (top - bottom);
        result.m[10] = 1.0;
        result.m[12] = -(right + left) / (right - left);
        result.m[13] = -(top + bottom) / (top - bottom);
        return result;
    }

	void print() {
		printf("[ ");
		for (int idx = 0; idx < 16; idx++) {
			printf("%f, ", m[idx]);
		}
		printf(" ]\n");
	}
};