#include "MyPongScene.h"

#include <stdlib.h> // rand

#include <charcoal/constants.h>

#include <charcoal/PhysicsTypes.h>
#include <charcoal/Collision.h>

#include <charcoal-builtin/MeshGenerator.h>

#include <charcoal-builtin/GLUtil.h>

#define LEFT_PADDLE_UP_KEY GLFW_KEY_A
#define LEFT_PADDLE_DOWN_KEY GLFW_KEY_Z

#define RIGHT_PADDLE_UP_KEY GLFW_KEY_APOSTROPHE
#define RIGHT_PADDLE_DOWN_KEY GLFW_KEY_SLASH

#define OUTLINE_THICKNESS 25.0f
#define OUTLINE_OFFSET 25.0f

#define OUTLINE_INWARDS (OUTLINE_OFFSET + OUTLINE_THICKNESS)

#define PADDLE_THICKNESS 25.0f
#define PADDLE_HEIGHT 150.0f

#define LIFE_THICKNESS 15.0f
#define LIFE_OFFSET 10.0f
#define LIFE_INWARDS (OUTLINE_INWARDS + LIFE_THICKNESS)

#define BALL_THICKNESS 25.0f

#define HALF_BALL_THICKNESS 12.5f

#define INITIAL_BALL_SPEED 250.0f
#define BALL_SPEED_INCREMENT 50.0f
#define PADDLE_SPEED 500.0f

#define STARTING_LIVES 5


MyPongScene::MyPongScene(Application& application)
	: Scene(application),

	m_outline_column(meshgenerator::gen_rect_p<basic::Vertex, basic::Index>(DRAW_TRIANGLES, m_screen_size.x - 2 * OUTLINE_THICKNESS, OUTLINE_THICKNESS), DRAW_TRIANGLES),
	m_outline_row(meshgenerator::gen_rect_p<basic::Vertex, basic::Index>(DRAW_TRIANGLES, OUTLINE_THICKNESS, m_screen_size.y - 2 * OUTLINE_THICKNESS), DRAW_TRIANGLES),
	m_ball(meshgenerator::gen_rect_p<basic::Vertex, basic::Index>(DRAW_TRIANGLES, BALL_THICKNESS, BALL_THICKNESS), DRAW_TRIANGLES),
	m_life(meshgenerator::gen_rect_p<basic::Vertex, basic::Index>(DRAW_TRIANGLES, LIFE_THICKNESS, LIFE_THICKNESS), DRAW_TRIANGLES),
	m_paddle(meshgenerator::gen_rect_p<basic::Vertex, basic::Index>(DRAW_TRIANGLES, PADDLE_THICKNESS, PADDLE_HEIGHT), DRAW_TRIANGLES),

	m_outline_column_batch(&m_outline_column, 2),
	m_outline_row_batch(&m_outline_row, 2),
	m_ball_batch(&m_ball, 1),
	m_life_batch(&m_life, STARTING_LIVES * 2),
	m_paddle_batch(&m_paddle, 2),

	m_outline_top_pose(glm::vec3(0.0f, (m_screen_size.y - OUTLINE_THICKNESS) / 2.0f - OUTLINE_OFFSET, 0.0f)),
	m_outline_bottom_pose(glm::vec3(0.0f, -((m_screen_size.y - OUTLINE_THICKNESS) / 2.0f - OUTLINE_OFFSET), 0.0f)),
	m_outline_left_pose(glm::vec3(-((m_screen_size.x - OUTLINE_THICKNESS) / 2.0f - OUTLINE_OFFSET), 0.0f, 0.0f)),
	m_outline_right_pose(glm::vec3((m_screen_size.x - OUTLINE_THICKNESS) / 2.0f - OUTLINE_OFFSET, 0.0f, 0.0f)),

	m_ball_pose(glm::vec3(0.0f, 0.0f, 0.0f)),
	m_paddle_left_pose(glm::vec3(-(m_screen_size.x / 2.0f - OUTLINE_INWARDS - 2.5f * PADDLE_THICKNESS), 0.0f, 0.0f)),
	m_paddle_right_pose(glm::vec3(m_screen_size.x / 2.0f - OUTLINE_INWARDS - 2.5f * PADDLE_THICKNESS, 0.0f, 0.0f)),

	m_camera(m_screen_size),

	m_left_lives(STARTING_LIVES),
	m_right_lives(STARTING_LIVES)
{
	m_pipeline.add_batch(&m_outline_column_batch);
	m_pipeline.add_batch(&m_outline_row_batch);
	m_pipeline.add_batch(&m_ball_batch);
	m_pipeline.add_batch(&m_life_batch);
	m_pipeline.add_batch(&m_paddle_batch);

	m_pipeline.set_camera(&m_camera);
}

void MyPongScene::init()
{
	// Batches
	m_outline_column_batch.init();
	m_outline_row_batch.init();
	m_ball_batch.init();
	m_life_batch.init();
	m_paddle_batch.init();

	// Set these once here since they will never change
	m_outline_column_batch.reset_rendered();
	m_outline_column_batch.add_rendered(m_outline_top_pose);
	m_outline_column_batch.add_rendered(m_outline_bottom_pose);

	m_outline_row_batch.reset_rendered();
	m_outline_row_batch.add_rendered(m_outline_left_pose);
	m_outline_row_batch.add_rendered(m_outline_right_pose);

	reset_ball();
}

void MyPongScene::update(float delta_time, clock_t clock)
{
	// Move Paddles

	const glm::vec3 up(0.0f, 1.0f, 0.0f);
	const glm::vec3 down(0.0f, -1.0f, 0.0f);

	if (m_left_lives > 0)
	{
		if (m_input_manager.is_key_down(LEFT_PADDLE_UP_KEY))
		{
			m_paddle_left_pose.translate(up * PADDLE_SPEED * delta_time);
		}
		if (m_input_manager.is_key_down(LEFT_PADDLE_DOWN_KEY))
		{
			m_paddle_left_pose.translate(down * PADDLE_SPEED * delta_time);
		}
	}
	
	if (m_right_lives > 0)
	{
		if (m_input_manager.is_key_down(RIGHT_PADDLE_UP_KEY))
		{
			m_paddle_right_pose.translate(up * PADDLE_SPEED * delta_time);
		}
		if (m_input_manager.is_key_down(RIGHT_PADDLE_DOWN_KEY))
		{
			m_paddle_right_pose.translate(down * PADDLE_SPEED * delta_time);
		}
	}

	// Move ball

	if (m_right_lives > 0 && m_left_lives > 0)
	{
		m_ball_pose.translate(glm::vec3(m_ball_direction * m_ball_speed * delta_time, 0.0f));
	}

	vec3 ball_position = m_ball_pose.get_position();

	// Bounce Top and Bottom

	if (ball_position.y + HALF_BALL_THICKNESS + OUTLINE_INWARDS > m_screen_size.y / 2.0f)
	{
		m_ball_direction.y = -glm::abs(m_ball_direction.y);
	}

	if (ball_position.y - HALF_BALL_THICKNESS - OUTLINE_INWARDS < -m_screen_size.y / 2.0f)
	{
		m_ball_direction.y = glm::abs(m_ball_direction.y);
	}

	// Scoring

	if (ball_position.x + HALF_BALL_THICKNESS + OUTLINE_INWARDS > m_screen_size.x / 2.0f)
	{
		m_right_lives -= 1;
		reset_ball();
	}

	if (ball_position.x - HALF_BALL_THICKNESS - OUTLINE_INWARDS < -m_screen_size.x / 2.0f)
	{
		m_left_lives -= 1;
		reset_ball();
	}

	// Bounce off Paddles

	glm::vec3 left_paddle_position = m_paddle_left_pose.get_position();
	glm::vec3 right_paddle_position = m_paddle_right_pose.get_position();

	physics::Rect ball_hitbox(glm::vec2(ball_position.x, ball_position.y), BALL_THICKNESS, BALL_THICKNESS);
	physics::Rect left_paddle_hitbox(glm::vec2(left_paddle_position.x, left_paddle_position.y), PADDLE_THICKNESS, PADDLE_HEIGHT);
	physics::Rect right_paddle_hitbox(glm::vec2(right_paddle_position.x, right_paddle_position.y), PADDLE_THICKNESS, PADDLE_HEIGHT);

	if (physics::collision::rect_in_rect(ball_hitbox, left_paddle_hitbox))
	{
		float ball_y = m_ball_direction.y * m_ball_speed;
		if (m_input_manager.is_key_down(LEFT_PADDLE_UP_KEY))
		{
			ball_y += PADDLE_SPEED;
		}
		else if (m_input_manager.is_key_down(LEFT_PADDLE_DOWN_KEY))
		{
			ball_y -= PADDLE_SPEED;
		}
		m_ball_direction = glm::normalize(glm::vec2(m_ball_speed, ball_y));
		m_ball_speed += BALL_SPEED_INCREMENT;
	}

	if (physics::collision::rect_in_rect(ball_hitbox, right_paddle_hitbox))
	{
		float ball_y = m_ball_direction.y * m_ball_speed;
		if (m_input_manager.is_key_down(RIGHT_PADDLE_UP_KEY))
		{
			ball_y += PADDLE_SPEED;
		}
		else if (m_input_manager.is_key_down(RIGHT_PADDLE_DOWN_KEY))
		{
			ball_y -= PADDLE_SPEED;
		}
		m_ball_direction = glm::normalize(glm::vec2(-m_ball_speed, ball_y));
		m_ball_speed += BALL_SPEED_INCREMENT;
	}

	// Update Render Batches

	m_ball_batch.reset_rendered();
	m_ball_batch.add_rendered(m_ball_pose);

	m_paddle_batch.reset_rendered();
	m_paddle_batch.add_rendered(m_paddle_left_pose);
	m_paddle_batch.add_rendered(m_paddle_right_pose);

	// Update Life Render Batch

	m_life_batch.reset_rendered();

	Poseable left_life_pose(glm::vec3(-m_screen_size.x / 2.0f + LIFE_INWARDS, -m_screen_size.y / 2.0f + LIFE_INWARDS, 0.0f));
	Poseable right_life_pose(glm::vec3(m_screen_size.x / 2.0f - LIFE_INWARDS, -m_screen_size.y / 2.0f + LIFE_INWARDS, 0.0f));

	for (int i = 0; i < m_left_lives; ++i)
	{
		m_life_batch.add_rendered(left_life_pose);
		left_life_pose.translate(glm::vec3(LIFE_THICKNESS + LIFE_OFFSET, 0.0f, 0.0f));
	}

	for (int i = 0; i < m_right_lives; ++i)
	{
		m_life_batch.add_rendered(right_life_pose);
		right_life_pose.translate(glm::vec3(-(LIFE_THICKNESS + LIFE_OFFSET), 0.0f, 0.0f));
	}
}

void MyPongScene::prerender()
{
	m_camera.prerender();
	m_outline_column_batch.prerender();
	m_outline_row_batch.prerender();
	m_ball_batch.prerender();
	m_life_batch.prerender();
	m_paddle_batch.prerender();
}

void MyPongScene::render()
{
	glutil::clear_screen();
	m_pipeline.render();
}

float MyPongScene::random()
{
	return rand() / (float)RAND_MAX;
}

vec2 MyPongScene::rand_dir(float radians_low, float radians_high)
{
	float radians = radians_low + random() * (radians_high - radians_low);
	return glm::vec2(glm::cos(radians), glm::sin(radians));
}

void MyPongScene::reset_ball()
{
	m_ball_speed = INITIAL_BALL_SPEED;
	m_ball_pose.update_position(vec3(0.0f, 0.0f, 0.0f));
	if (random() < 0.5)
	{
		// Toward right
		m_ball_direction = rand_dir((float)charcoal::TAU_7_8, (float)charcoal::TAU_7_8 + (float)charcoal::TAU_1_4);
	}
	else
	{
		// Toward left
		m_ball_direction = rand_dir((float)charcoal::TAU_3_8, (float)charcoal::TAU_5_8);
	}
}