#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 WALK_SPD 1
#define MIN_VSPD -8.0
#define JUMP_SPD -3.4
#define GRAV 0.2
#define UG_CAN_JUMP upgrades[0]

void jump_test(char *jump_pressed, char *jump_buffer, unsigned int *jump_hold); //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 = 1;
  //start upgrades (mostly bools)
  char upgrades[] = {
    0 //can jump
  };
  //end   upgrades
	char jump_pressed = 0; //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; //player vertical speed
	char hspd = 0; //player horizontal speed
	int on_ground = 6; //remember if player is on solid
	int player_x = 0;
	int player_y = 0;
  int start_x = 18*8 + 1;
  int start_y = 9*8 + 2;
	int old_x, old_y;
	set_level(level_id, level);
	draw_level(level);
  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;
		draw_player(old_x, old_y, player_x, player_y);
		dupdate();
		old_x = player_x;
		old_y = player_y;
		clearevents();
		//horizontal movement
		hspd = 0;
		if (keydown(KEY_LEFT)) hspd -= WALK_SPD;
		if (keydown(KEY_RIGHT)) hspd += WALK_SPD;
		if (!collide(player_x + hspd, player_y, level, '0'))
		{
      player_x += hspd;
		}
		//ground detection
		if (collide(player_x, player_y + 1, level, '0')) on_ground = 6;
		else
		{
			if (vspd > MIN_VSPD) vspd += GRAV;
      if (jump_hold)
			if (on_ground) on_ground--;
		}
		//vertical movement
		if (UG_CAN_JUMP) jump_test(&jump_pressed, &jump_buffer, &jump_hold);
		//if jump is pressed and on ground
		if (jump_buffer && on_ground) {
			vspd = JUMP_SPD;
			on_ground = 0;
      jump_hold = 10;
		}
    else if (jump_hold && keydown(KEY_SHIFT))
    {
      jump_hold--;
      vspd -= GRAV / 2;
    }
    else jump_hold = 0;
		//vertical collision
		{
			int trunc_vspd = vspd; //truncate vspd
			if (!collide(player_x, player_y + trunc_vspd, level, '0'))
			{
				player_y += trunc_vspd;
			}
			else
			{
				int sign_vspd = sgn(trunc_vspd);
				while (!collide(player_x, player_y + sign_vspd, level, '0'))
				{
					player_y += sign_vspd;
				}
				vspd = 0;
			}
		}
    //spike collision and death
    if (collide(player_x, player_y, level, 'v'))
    {
      player_x = start_x;
      player_y = start_y;
    }
    //borders collision
    if (player_x <= 8)
    {
      level_id -= 1;
      player_x = 201;
      set_start_pos(&start_x, &start_y, player_x, player_y);
      set_level(level_id, level);
      draw_level(level);
      reset_old_pos(&old_x, &old_y);
    }
    else if (player_x >= 208)
    {
      level_id += 1;
      player_x = 9;
      set_start_pos(&start_x, &start_y, player_x, player_y);
      set_level(level_id, level);
      draw_level(level);
      reset_old_pos(&old_x, &old_y);
    }
		//exit
		if (keydown(KEY_EXIT)) return 0;
	}
}

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