#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>

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

    void reset() {
        force = { 0, 0 };
        velocity = { 0, 0 };
        rotationalVelocity = 0.f;
        rotation = 0.f;
    }

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

    void applyGravity(float32 deltaTimeSeconds) {
        velocity += (Vector2 { 0.f, -96.f } * deltaTimeSeconds);
    }

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

        rotation += (rotationalVelocity * deltaTimeSeconds);
    }

    void setMomentOfInertia(float32 moi) {
        momentOfInertia = moi;
    }
};

struct Rectangle {
	OrthographicShape shape;
	Rigidbody body;
	Vector4 color;
	float32 width = 0.f;
	float32 height = 0.f;

	void load(OrthographicRenderer* renderer, Vector4 inColor, float32 inWidth, float32 inHeight) {
		color = inColor;
		width = inWidth;;
		height = inHeight;

		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);
	}

	void update(float32 dtSeconds) {
		body.update(dtSeconds);
		shape.model = Mat4x4().translateByVec2(body.position).rotate2D(body.rotation);
	}

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

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

struct LineSegment {
    OrthographicShape shape;
    Rigidbody body;
    Vector2 start;
    Vector2 end;
    float32 length;
    Vector2 normal;
    OrthographicVertex vertices[2];

    void load(OrthographicRenderer* renderer, Vector4 color, Vector2 inStart, Vector2 inEnd) {
        start = inStart;
        end = inEnd;
        length = (start - end).length();
        vertices[0].position = start;
        vertices[0].color = color;
        vertices[1].position = end;
        vertices[1].color = color;
        normal = (end - start).getPerp().normalize();
        shape.load(vertices, 2, renderer);

        body.reset();
        body.mass = 1000000000.f;
        body.cofOfRestition = 1.f;
        body.rotationalVelocity = 0;
        body.velocity = Vector2();
        body.momentOfInertia = body.mass * (length / 2.f);
    }

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

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

    Vector2 getPointOnLine(float32 t) {
        return {
            start.x + (end.x - start.x) * t,
            start.y + (end.y - start.y) * t,
        };
    }

    Vector2 getNormal() {
        return (end - start).getPerp().normalize();
    }
};

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;
LineSegment segmentList[4];
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);

	segmentList[0].load(&renderer, Vector4().fromColor(191, 251, 146, 255.f), Vector2 { 50.f, 0.f }, Vector2 { 50.f, static_cast<float>(context.height) });
    segmentList[1].load(&renderer, Vector4().fromColor(159, 224, 210, 255.f), Vector2 { context.width - 50.f, 0.f }, Vector2 { context.width - 50.f, static_cast<float>(context.height) });
    segmentList[2].load(&renderer, Vector4().fromColor(248, 255, 156, 255.f), Vector2 { 50.f, 50.f }, Vector2 { context.width - 50.f, 150.f });
    segmentList[3].load(&renderer, Vector4().fromColor(205, 178, 214, 255.f), Vector2 { 50.f, 150.f }, Vector2 { context.width - 50.f, 50.f });

	rectangle.load(&renderer, Vector4 { 230.f, 182.f, 35.f, 255.f }, 64.f, 32.f);
	rectangle.body.position = Vector2 { context.width / 2.f, context.height / 2.f };

    mainLoop.run(update);
}


void update(float32 deltaTimeSeconds, void* userData) {
	// Update
	rectangle.update(deltaTimeSeconds);
	
	// Renderer
	renderer.render();
	rectangle.render(&renderer);
	for (int32 segmentIndex = 0; segmentIndex < 4; segmentIndex++) {
        segmentList[segmentIndex].render(&renderer);
    }
}

void unload() {
    mainLoop.stop();
    renderer.unload();
	for (int32 segmentIndex = 0; segmentIndex < 4; segmentIndex++) {
        segmentList[segmentIndex].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;
}