#include "../../../shared_cpp/OrthographicRenderer.h"
#include "../../../shared_cpp/types.h"
#include "../../../shared_cpp/WebglContext.h"
#include "../../../shared_cpp/mathlib.h"
#include "../../../shared_cpp/MainLoop.h"
#include <cstdio>
#include <cmath>
#include <emscripten/html5.h>
#include <unistd.h>
#include <pthread.h>
#include <cmath>
#include <cfloat>

struct Rigidbody {
    Vector2 force = { 0, 0 };
    Vector2 velocity = { 0, 0 };
    Vector2 position = { 0, 0 };
    float32 mass = 1.f;

    void reset() {
        force = { 0, 0 };
        velocity = { 0, 0 };
    }

    void applyForce(Vector2 f) {
        force += f;
    }

    void applyGravity(float32 deltaTimeSeconds) {
        velocity += (Vector2 { 0.f, -50.f } * deltaTimeSeconds);
    }

    void update(float32 deltaTimeSeconds) {
        applyGravity(deltaTimeSeconds);
        
        Vector2 acceleration = force / mass;
        velocity += (acceleration * deltaTimeSeconds);
        position += (velocity * deltaTimeSeconds);
        force = Vector2 { 0.f, 0.f };
    }
};

struct Rectangle {
	OrthographicShape shape;
    Rigidbody body;

	void load(OrthographicRenderer* renderer, Vector4 color, float32 width, float32 height) {
        color = color.toNormalizedColor();

		float32 halfWidth = width / 2.f;
		float32 halfHeight = height / 2.f;

	    OrthographicVertex vertices[6];
		vertices[0].position = Vector2 { -halfWidth, -halfHeight };
		vertices[1].position = Vector2 { -halfWidth, halfHeight };
		vertices[2].position = Vector2 { halfWidth, halfHeight };
		vertices[3].position = Vector2 { -halfWidth, -halfHeight };
		vertices[4].position = Vector2 { halfWidth, -halfHeight };
		vertices[5].position = Vector2 { halfWidth, halfHeight };
		
		for (int32 i = 0; i < 6; i++) {
			vertices[i].color = color;
		}

		shape.load(vertices, 6, renderer);
		body.reset();
	}

	void update(float32 dtSeconds) {
		body.update(dtSeconds);
		shape.model = Mat4x4().translateByVec2(body.position);
	}

	void render(OrthographicRenderer* renderer) {
		shape.render(renderer);
	}

	void unload() {
		shape.unload();
	}
};

EM_BOOL onPlayClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData);
EM_BOOL onStopClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData);

void load();
void update(float32 time, void* userData);
void unload();

WebglContext context;
OrthographicRenderer renderer;
MainLoop mainLoop;
Rectangle rectangle;

int main() {
	context.init("#gl_canvas");
    emscripten_set_click_callback("#gl_canvas_play", NULL, false, onPlayClicked);
    emscripten_set_click_callback("#gl_canvas_stop", NULL, false, onStopClicked);
    return 0;
}

void load() {
    renderer.load(&context);

	rectangle.load(&renderer, Vector4 { 55.f, 235.f, 35.f, 255.f }, 32.f, 32.f);
	rectangle.body.position = Vector2 { context.width / 3.f, context.height / 3.f };
	rectangle.body.velocity = Vector2 { 100.f, 250.f };

    mainLoop.run(update);
}

void update(float32 deltaTimeSeconds, void* userData) {
    rectangle.update(deltaTimeSeconds);

    // Check collisions with walls so we don't go out of the scene. Simply reflect here.
    if (rectangle.body.position.x <= 0.f) {
        rectangle.body.position.x = 0.f;
        rectangle.body.velocity = rectangle.body.velocity - Vector2 { 1.f, 0.f } * (2 * (rectangle.body.velocity.dot(Vector2 { 1.f, 0.f })));
    }
    if (rectangle.body.position.y <= 0.f) {
        rectangle.body.position.y = 0.f;
        rectangle.body.velocity = rectangle.body.velocity - Vector2 { 0.f, 1.f } * (2 * (rectangle.body.velocity.dot(Vector2 { 0.f, 1.f })));
    } 
    if (rectangle.body.position.x >= 640.f) {
        rectangle.body.position.x = 640.f;
        rectangle.body.velocity = rectangle.body.velocity - Vector2 { -1.f, 0.f } * (2 * (rectangle.body.velocity.dot(Vector2{ -1.f, 0.f })));
    }
    if (rectangle.body.position.y >= 480.f) {
        rectangle.body.position.y = 480.f;
        rectangle.body.velocity = rectangle.body.velocity - Vector2 { 0.f, -1.f } * (2 * (rectangle.body.velocity.dot(Vector2 { 0.f, -1.f }))) ;
    }
	
	// Renderer
	renderer.render();
    rectangle.render(&renderer);
}

void unload() {
    mainLoop.stop();
    renderer.unload();
    rectangle.unload();
}

//
// Interactions with DOM handled below
//
EM_BOOL onPlayClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData) {
    printf("Play clicked\n");
    
    load();
    return true;
}

EM_BOOL onStopClicked(int eventType, const EmscriptenMouseEvent* mouseEvent, void* userData) {
    printf("Stop clicked\n");
    unload();
    return true;
}