#include "sandbag.h"
#include "attack.h"
#include "level.h"
#include "conf.h"
#include "tools.h"
#include "lzy.h"
#include "particle.h"

static struct Sandbag sandbag;
static void sandbag_move(struct Vec2 spd);
static struct Vec2 sandbag_update_rem();
static int sandbag_collide_pixel(int x, int y, tile_t id);
static int sandbag_collide(int x, int y, tile_t id, int h);

void
sandbag_init(void)
{
	sandbag.pos = (struct Vec2){300, 96};
	sandbag.spd = (struct FVec2){0.0f, 0.0f};
	sandbag.rem = (struct FVec2){0.0f, 0.0f};
	sandbag.dir = (struct Vec2){1, 0};
	sandbag.hitstun = 0;
	sandbag.iced = 0;
	sandbag.life = 0;
	sandbag.active = 1;
}

void
sandbag_update(int frame)
{
	const struct Vec2 level_dim = level_get_dim();
	
	if(!sandbag.active) return;
	const struct Attack *attack = attack_table_collide(sandbag.pos.x, sandbag.pos.y, 24, 24, 0);
	if(attack != NULL) {
		sandbag.spd.x = attack->dir.x * 5 * (sandbag.life > 50 ? (float)sandbag.life / 50 : 1);
		sandbag.spd.y = -attack->dir.y * 5 * (sandbag.life > 50 ? (float)sandbag.life / 100 + 0.5 : 1);
		if(!sandbag.hitstun) {
			sandbag.life += attack->dam;
			LZY_Sleep(10);
		};
		sandbag.hitstun = 5;
		if(attack->ice) {sandbag.iced = 30;}
	}

	sandbag.spd.x *= (1 - AIR_FRIC) / (sandbag.iced ? 2 : 1);
	sandbag.spd.y += GRAVITY;

	if (sandbag.spd.x) {
		sandbag.dir.x = sign(sandbag.spd.x);
	}
		
	sandbag_move(sandbag_update_rem());

	if(sandbag.hitstun > 0) {sandbag.hitstun -= 1;}
	if(sandbag.iced > 0) {sandbag.iced -= 1;}
	if(sandbag.hitstun && frame % 2 && sandbag.life > 80) {
		particle_new(sandbag.pos.x + 12, sandbag.pos.y + 12, 10 + rand() % 2, 5);
	}
	if(frame % 4 && sandbag.life > 120) {
		particle_new(sandbag.pos.x + 12, sandbag.pos.y + 12, 12 + (frame % 8) / 2 % 2, 2);
	}

	if(sandbag.pos.x > level_dim.x * TILE_S + 48 || sandbag.pos.x < -72 ||
	   sandbag.pos.y > level_dim.y * TILE_S + 48 || sandbag.pos.y < -96) {
	   sandbag_init();
	}
}

static struct Vec2
sandbag_update_rem(void)
{
	struct FVec2 spdrem = (struct FVec2){sandbag.spd.x + sandbag.rem.x,
	                                     sandbag.spd.y + sandbag.rem.y};
	struct Vec2 ispd = (struct Vec2){spdrem.x, spdrem.y};

	sandbag.rem.x = spdrem.x - (float)ispd.x;
	sandbag.rem.y = spdrem.y - (float)ispd.y;
	return ispd;
}

static void
sandbag_move(struct Vec2 spd)
{
	if (sandbag_collide(sandbag.pos.x, sandbag.pos.y, 1, 4)) {
		return;
	}

	/* OOB */
	const struct Vec2 level_dim = level_get_dim();
	
	int coll_shift = 0;

	const int sign_x = sign(spd.x);
	if (sign_x) {sandbag.dir.x = sign_x;}
	
	if (spd.x) {
		sandbag.pos.x += spd.x;

		if (sandbag_collide(sandbag.pos.x, sandbag.pos.y, 1, 1)) {
			for(float i = 0.1f; i < 4; i+= 0.1) {
				if(!sandbag_collide(sandbag.pos.x, sandbag.pos.y + i, 1, 1)) {
					sandbag.pos.y += i;
					coll_shift = 1;
					break;
				}
				if(!sandbag_collide(sandbag.pos.x, sandbag.pos.y - i, 1, 1)) {
					sandbag.pos.y -= i;
					coll_shift = 1;
					break;
				}
			}
		}

		if(sandbag_collide(sandbag.pos.x, sandbag.pos.y, 1, 1)) {
			if(abs(sandbag.spd.x) > 16) {
				sandbag.spd.x = - sandbag.spd.x / 4;
			} else {
				sandbag.spd.x = 0.0f;
			}
			sandbag.rem.x = 0.0f;
			while (sandbag_collide(sandbag.pos.x, sandbag.pos.y, 1, 1)) {
				sandbag.pos.x -= sign_x;
			}
		}
	}
	
	const int sign_y = sign(spd.y);
	if (sign_y) {sandbag.dir.y = sign_y;}

	if (spd.y && !coll_shift) {
		sandbag.pos.y += spd.y;

		if (sandbag_collide(sandbag.pos.x, sandbag.pos.y, 1, 1)) {
			for(float i = 0.1f; i < 4; i += 0.1) {
				if(!sandbag_collide(sandbag.pos.x + i, sandbag.pos.y, 1, 1)) {
					sandbag.pos.x += i;
					break;
				}
				if(!sandbag_collide(sandbag.pos.x - i, sandbag.pos.y, 1, 1)) {
					sandbag.pos.x -= i;
					break;
				}
			}
		}

		if(sandbag_collide(sandbag.pos.x, sandbag.pos.y, 1, 1)) {
			if(abs(sandbag.spd.y) > 16) {
				sandbag.spd.y = - sandbag.spd.y / 4;
			} else {
				sandbag.spd.y = 0.0f;
			}
			sandbag.rem.y = 0.0f;
			while (sandbag_collide(sandbag.pos.x, sandbag.pos.y, 1, 1)) {
				sandbag.pos.y -= sign_y;
			}
		}
	}
}

void
sandbag_draw(int frame)
{
	if(!sandbag.active) return;
	if(sandbag.hitstun)	{
		LZY_DrawTile(39, sandbag.pos.x, sandbag.pos.y);
	} else {
		LZY_DrawTile(38, sandbag.pos.x, sandbag.pos.y);
	}
	if(sandbag.iced > 0) {
		LZY_DrawTile(16, sandbag.pos.x, sandbag.pos.y);
	}
}

static int
sandbag_collide_pixel(int x, int y, tile_t id)
{
	const tile_t tile = level_get_px(x, y);

	if (!tile) {
		return 0;
	}

	if (id == 1) {
		return (tile) % TILESET_W;
	}

	return tile == id;
}

static int
sandbag_collide(int x, int y, tile_t id, int h)
{

	const struct Vec2 pos_tl = (struct Vec2){x + h, y + h};
	const struct Vec2 pos_br =
	    (struct Vec2){x + PLAYER_S - h - 1, y + PLAYER_S - h - 1};
	const struct Vec2 middle =
	    (struct Vec2){x + PLAYER_S / 2, y + PLAYER_S / 2};

	if (sandbag_collide_pixel(pos_tl.x, pos_tl.y, id) ||
	    sandbag_collide_pixel(pos_br.x, pos_br.y, id) ||
	    sandbag_collide_pixel(pos_tl.x, pos_br.y, id) ||
	    sandbag_collide_pixel(pos_br.x, pos_tl.y, id)) {
		return 1;
	}
	return 0;
}

int
sandbag_get_life(void) {
	return sandbag.life;
}