#include <gint/keyboard.h>
#include <gint/timer.h>
#include <gint/clock.h>
#include "draw.h"
#include "collide.h"
#include "levels.h"
#include "player.h"

#define MAX_HSPD 2.5
#define ACCELERATION 1
#define DECELERATION 0.5
#define MIN_VSPD -12.0
#define MAX_VSPD 12
#define JUMP_SPD -3.99
#define GRAV 0.4
#define JUMP_SCALE 12
#define JUMP_REDUCTION -0.41
#define UG_CAN_JUMP upgrades[0]
char coins[256];
#define DRAW_LEVEL() draw_level(level, upgrades, coins[coin_id])

void dupdate(); //gint function
//test if jump pressed
int sgn(int number); //return the sign of input double

int callback(volatile void *arg)
{
	volatile int *has_ticked = arg;
	*has_ticked = 1;
	return 0;
}

int main(void)
{
	volatile int has_ticked = 1; //fps cap
	char level[477];
	int level_id = 5050;
	//START UPGRADES
	char upgrades[] = {
		0 //jump
	};
	//END	 UPGRADES
	unsigned int coin_id = 0;
	unsigned int coin_count = 0;
	char jump_pressed = 1; //avoid holding jump
	char jump_buffer = 0; //jump buffer, last 3 frames
	unsigned int jump_hold = 0; //number of consecutive frames jump has been held
	double vspd = 0.0; //player vertical speed
	double hspd = 0; //player horizontal speed
	int move = 0;
	int direction = 0;
	int on_ground = 6; //remember if player is on solid
	int player_x = 0;
	int player_y = 0;
	int start_x = 18*16 + 2;
	int start_y = 9*16 + 4;
	int old_x, old_y;
	char spawn_buffer = 0;
	unsigned int step = 0;
	set_level(level_id, level, &coin_id);
	DRAW_LEVEL();
	draw_level_anims(level, upgrades, step);
	player_x = start_x;
	player_y = start_y;
	old_x = player_x + 1; //offset to draw it on first cycle
	old_y = player_y;
	//fps cap timer
	timer_setup(0, timer_delay(0, 16667), 0, callback, &has_ticked);
	timer_start(0);
	while (1) {
		while(!has_ticked) sleep();
		has_ticked = 0;
		//START DRAW
		step++;
		draw_level_anims(level, upgrades, step);
		draw_player(old_x, old_y, player_x, player_y);
		draw_timer(step);
		dupdate();
		old_y = player_y;
		old_x = player_x;
		//END	 DRAW
		clearevents();
		//horizontal movement & collision
		{
			move = 0;
			double friction = 1;
			int trunc_hspd;
			//ice
			if (collide(player_x, player_y + 1, level, '~')) friction = 0.2;
			move = keydown(KEY_RIGHT) + 0 - keydown(KEY_LEFT);
			if (move) {
				if (hspd < MAX_HSPD)
				{
					hspd += ACCELERATION * friction;
					if (hspd > MAX_HSPD) hspd = MAX_HSPD;
				}
				direction = move;
			}
			else if (hspd > 0)
			{
				if (friction != 0.2) hspd -= DECELERATION * friction;
				else hspd -= DECELERATION / 4 * friction;
				if (hspd < 0) hspd = 0;
			}
			trunc_hspd = hspd * direction;
			if (!collide(player_x, player_y + 1, level, '#'))
			{
				if (!collide_solid(player_x + trunc_hspd, player_y, level))
				{
					player_x += trunc_hspd;
				}
				else
				{
					int sign_hspd = sgn(trunc_hspd);
					while (!collide_solid(player_x + sign_hspd, player_y, level))
					{
						player_x += sign_hspd;
					}
					hspd = 0;
				}
			}
		}
		//ground detection
		if (vspd >= 0 && collide_solid(player_x, player_y + 1, level))
		{
			on_ground = 6;
			vspd = 0;
			if (spawn_buffer)
			{
				spawn_buffer = 0;
				set_start_pos(&start_x, &start_y, player_x, player_y);
			}
		}
		else
		{
			if (on_ground != 6 && vspd < MAX_VSPD) vspd += GRAV;
			if (on_ground) on_ground--;
		}
		//vertical movement
		if (UG_CAN_JUMP) jump_test(&jump_pressed, &jump_buffer, &jump_hold);
		//jump
		if (jump_buffer && on_ground) {
			vspd = JUMP_SPD;
			on_ground = 0;
			jump_hold = JUMP_SCALE;
		}
		else if (jump_hold && keydown(KEY_SHIFT))
		{
			jump_hold--;
			vspd += JUMP_REDUCTION;
		}
		else jump_hold = 0;
		//elevator collision and raise
		if ((collide(player_x - 1, player_y, level, '^') ||
		collide(player_x + 1, player_y, level, '^')) && vspd > MIN_VSPD)
		{
			if (vspd > -2)
			{
				vspd -= GRAV;
			}
			vspd -= GRAV;
		}
		//vertical collision
		{
			int trunc_vspd = vspd; //truncate vspd
			if (trunc_vspd)
			{
				if (!collide_solid(player_x, player_y + trunc_vspd, level))
				{
					player_y += trunc_vspd;
				}
				else
				{
					int sign_vspd = sgn(trunc_vspd);
					while (!collide_solid(player_x, player_y + sign_vspd, level))
					{
						player_y += sign_vspd;
					}
					vspd = 0;
					jump_hold = 0;
				}
			}
		}
		//spike collision and death
		if (collide(player_x, player_y, level, 'v'))
		{
			player_x = start_x;
			player_y = start_y;
			vspd = 0;
		}
		//borders collision
		if (player_x <= 22)
		{
			level_id -= 1;
			player_x = 414 + (move * (int) hspd);
			set_start_pos(&start_x, &start_y, player_x, player_y);
			set_level(level_id, level, &coin_id);
			DRAW_LEVEL();
			reset_old_pos(&old_x, &old_y);
		}
		else if (player_x >= 416)
		{
			level_id += 1;
			player_x = 24 + (move * (int) hspd);
			set_start_pos(&start_x, &start_y, player_x, player_y);
			set_level(level_id, level, &coin_id);
			DRAW_LEVEL();
			reset_old_pos(&old_x, &old_y);
		}
		else if (player_y <= 8)
		{
			level_id -= 100;
			player_y = 246;
			spawn_buffer = 1;
			set_start_pos(&start_x, &start_y, player_x, player_y);
			set_level(level_id, level, &coin_id);
			DRAW_LEVEL();
			reset_old_pos(&old_x, &old_y);
		}
		else if (player_y >= 248)
		{
			level_id += 100;
			player_y = 10;
			set_start_pos(&start_x, &start_y, player_x, player_y);
			set_level(level_id, level, &coin_id);
			DRAW_LEVEL();
			reset_old_pos(&old_x, &old_y);
		}
		//item get
		if (collide(player_x, player_y, level, 'j'))
		{
			UG_CAN_JUMP = 1;
			collide_and_erase(player_x, player_y, level, 'j');
			draw_upgrade_message('j');
		}
		//coin get
		if (collide(player_x, player_y, level, 'c'))
		{
			coins[coin_id] = 1;
			coin_count++;
			collide_and_erase(player_x, player_y, level, 'c');
		}
		//secret way/hidden passage
		collide_and_erase(player_x, player_y, level, 's');
		//exit
		if (keydown(KEY_EXIT)) return 0;
	}
}

int sgn(int number)
{
	if (number < 0) return -1;
	else return 1;
}