#include "2048.h"
#include <stdbool.h>
#include <stdlib.h>
#include <time.h>

void game_add_block(Game *game) {

    bool is_full = true;
    for (int i = 0; i < game->field_size_x; i++) {
        for (int j = 0; j < game->field_size_y; j++) {
            if (game->field[j][i] == 0) {
                is_full = false;
                break;
            }
        }
    }
    if (is_full) {
        game->game_over = true;
        return;
    }

    size_t x, y;
    int value;
    do {
        x = rand() % game->field_size_x;
        y = rand() % game->field_size_y;
        value = (rand() % 2) + 1;
    } while (game->field[y][x] != 0);
    game->field[y][x] = value * 2;
}

Game game_init(size_t field_size_x, size_t field_size_y) {
    Game game;
    game.game_over = false;
    game.won = false;
    game.field_size_x = field_size_x;
    game.field_size_y = field_size_y;
    game.score = 0;
    game.field = malloc(sizeof(uint16_t *) * field_size_y);
    for (size_t i = 0; i < field_size_x; i++) {
        game.field[i] = calloc(field_size_y, sizeof(uint16_t) * field_size_y);
    }

    time_t t;
    srand((unsigned)time(&t));
    game_add_block(&game);

    return game;
}

void game_destroy(Game *game) {
    for (size_t i = 0; i < game->field_size_x; i++) {
        free(game->field[i]);
    }
    free(game->field);
    game->field = NULL;
}

void game_move(Game *game, Direction direction) {
    if (game->game_over || game->won) {
        return;
    }
    // I have few chained for loops that do a lot of similar stuff so I call them in a for loop for better clarity and readability
    for (int u = 0; u < 3; u++) {
        for (int i = 0; i < game->field_size_x; i++) {
            uint16_t **field = game->field;
            // move everything on one side
            for (int j = 0; j < game->field_size_y - 1; j++) {
                // a, b is the same as i and j. It is just flipped when
                // it does not go horizontally so I can access stuff vertically
                int a = i;
                int b = j;
                if (direction == Up || direction == Down) {
                    a = j;
                    b = i;
                }

                // make it so it can work with different directions
                int directionality = b;
                if (direction == Down) {
                    directionality = a;
                }
                int movement = 1;
                if (direction == Left || direction == Up) {
                    if (direction == Left) {
                        directionality = game->field_size_x - b - 1;
                    }
                    else {
                        directionality = game->field_size_y - a - 1;
                    }
                    movement = -1;
                }
                // the similar stuff
                switch (u) {
                case 0:
                case 2:
                    if (direction == Left || direction == Right) {
                        if (field[a][directionality + movement] == 0) {
                            field[a][directionality + movement] = field[a][directionality];
                            field[a][directionality] = 0;
                        }
                    }
                    else {
                        if (field[directionality + movement][b] == 0) {
                            field[directionality + movement][b] = field[directionality][b];
                            field[directionality][b] = 0;
                        }
                    }
                    break;
                case 1:
                    // TODO: fix 444 <- 48, should be 84
                    if (direction == Left || direction == Right) {
                        if (field[a][directionality + movement] == field[a][directionality]) {
                            field[a][directionality + movement] = field[a][directionality] * 2;
                            game->score += field[a][directionality + movement];
                            if (field[a][directionality + movement] == 2048) {
                                game->won = true;
                            }
                            field[a][directionality] = 0;
                            j++;
                        }
                    }
                    else {
                        if (field[directionality + movement][b] == field[directionality][b]) {
                            field[directionality + movement][b] = field[directionality][b] * 2;
                            game->score += field[directionality + movement][b];
                            if (field[directionality + movement][b] == 2048) {
                                game->won = true;
                            }
                            field[directionality][b] = 0;
                            j++;
                        }
                    }
                    break;
                }
            }
        }
    }

    game_add_block(game);
}