#include "world.h"
#include <stdlib.h>
#include <curses.h>
#include <stdlib.h>
#include <string.h>
#include "snake.h"
// This file contains functions for drawing the the game and changing the state

// Start is called one in the beginning
void* init_game(){
    // Allocate memory for the state
    struct state* st = calloc(1,(sizeof(struct state)));
    return st;
}

// The first event
// Initialize game state
// - borders
// - snake position
// - food position
void init_snake(struct event* world, struct state* st){
    st->width = world->width;
    st->height = world->height;

    int cx = st->width / 2;
    int cy = st->height / 2;
    st->snake = NULL;
    // Place snake horizontally, centered, away from borders
    int start_x = cx - 2;
    int y = cy;
    for (int i = 0; i < 5; i++) {
        st->snake = add_snake(st->snake, start_x + i, y);
    }

    int placed = 0;
    while (placed < FOOD_COUNT) {
        int fx = rand() % (st->width - 2) + 1;  // avoid border
        int fy = rand() % (st->height - 2) + 1; // avoid border
        if (!is_snake(st->snake, fx, fy)) {
            st->foodx[placed] = fx;
            st->foody[placed] = fy;
            placed++;
        }
    }

    // Initial game vector: right
    st->sx = 1;
    st->sy = 0;
}

// Step is called in a loop once in interval.
// It should modify the state and draw it.
int world_event(struct event* w,void* game){
    static int game_over = 0;
    struct state* st = game;
    if (w->type == EVENT_START){
        game_over = 0;
        init_snake(w,st);
    }
    if (game_over) {
        // Ignore all events except EVENT_START and EVENT_ESC
        if (w->type != EVENT_ESC && w->type != EVENT_START) {
            return 0;
        }
    }
    // Called on key press
    else if (w->type == EVENT_KEY){
        int key = w->key;
        // Modifies vector of snake movement
        if (key == KEY_RIGHT){
            if (!(st->sx == -1 && st->sy == 0)) { // Prevent reverse
                st->sx = 1;
                st->sy = 0;
            }
        }
        else if (key == KEY_LEFT){
            if (!(st->sx == 1 && st->sy == 0)) { // Prevent reverse
                st->sx = -1;
                st->sy = 0;
            }
        }
        else if (key == KEY_DOWN){
            if (!(st->sx == 0 && st->sy == -1)) { // Prevent reverse
                st->sx = 0;
                st->sy = 1;
            }
        }
        else if (key == KEY_UP){
            if (!(st->sx == 0 && st->sy == 1)) { // Prevent reverse
                st->sx = 0;
                st->sy = -1;
            }
        }
    }
    // Called on esc key
    else if (w->type == EVENT_ESC){
            // Non zero means finish the loop and stop the game.
            return 1;
    }
    // Called on interval timeout
    else if (w->type == EVENT_TIMEOUT){
        clear_screen();
        // Copy screen size
        st->width = w->width;
        st->height = w->height;
        // Change game state
        int r = step_state(st);
        // Draw snake
        struct snake* sn = st->snake;
        while (sn != NULL){
            set_cell('x',sn->x,sn->y);
            sn = sn->next;
        }
        // Draw food
        for (int i = 0 ; i < FOOD_COUNT; i++){
            if (st->foodx[i] >= 0 && st->foody[i] >= 0){
                set_cell('*',st->foodx[i],st->foody[i]);
            }
        }
        // Stop the game
        if (r){
            char message[] = "Koniec";
            set_message(message,10,10);
            game_over = 1;
        }
    }
    return 0;
}


int main(int argc, char** argv){
    start_world(init_game,world_event,free);
    return 0;
}