#include "grid.h"

#include <stdlib.h>
#include <string.h>

void grid_init(grid_t *g, int cols, int rows) {
    if (!g) return;
    if (cols < 1) cols = 1;
    if (rows < 1) rows = 1;
    g->cols = cols;
    g->rows = rows;
    g->cells = calloc((size_t)cols * (size_t)rows, 1);
    g->show_lines = 1;
}

void grid_free(grid_t *g) {
    if (!g) return;
    free(g->cells);
    g->cells = NULL;
    g->cols = 0;
    g->rows = 0;
}

void grid_resize(grid_t *g, int new_cols, int new_rows) {
    if (!g) return;
    if (new_cols < 1) new_cols = 1;
    if (new_rows < 1) new_rows = 1;
    unsigned char *ncells = calloc((size_t)new_cols * (size_t)new_rows, 1);
    if (!ncells) return;
    int copy_cols = g->cols < new_cols ? g->cols : new_cols;
    int copy_rows = g->rows < new_rows ? g->rows : new_rows;
    for (int r = 0; r < copy_rows; r++) {
        memcpy(ncells + (size_t)r * new_cols,
               g->cells + (size_t)r * g->cols,
               (size_t)copy_cols);
    }
    free(g->cells);
    g->cells = ncells;
    g->cols = new_cols;
    g->rows = new_rows;
}

void grid_clear(grid_t *g) {
    if (!g || !g->cells) return;
    memset(g->cells, 0, (size_t)g->cols * (size_t)g->rows);
}

void grid_copy(grid_t *dst, const grid_t *src) {
    if (!dst || !src || !src->cells) return;
    if (dst->cols != src->cols || dst->rows != src->rows) {
        grid_resize(dst, src->cols, src->rows);
    }
    if (dst->cols == src->cols && dst->rows == src->rows && dst->cells) {
        memcpy(dst->cells, src->cells, (size_t)src->cols * (size_t)src->rows);
    }
}

int grid_get(const grid_t *g, int c, int r) {
    if (!g || !g->cells) return 0;
    if (c < 0 || r < 0 || c >= g->cols || r >= g->rows) return 0;
    return g->cells[(size_t)r * g->cols + c];
}

void grid_set(grid_t *g, int c, int r, int val) {
    if (!g || !g->cells) return;
    if (c < 0 || r < 0 || c >= g->cols || r >= g->rows) return;
    g->cells[(size_t)r * g->cols + c] = val ? 1 : 0;
}