#include "grid.h"
#include "puzzle_input.h"
#include "string.h"

static grid_ret_t index_in_range(const grid_t * grid, int ii, int jj) {
    return (ii >= grid->height) || (ii < 0) || (jj >= grid->width) || (jj < 0);
}

static void * get_index_ptr(const grid_t * grid, int ii, int jj) {
    return grid->data + (jj * grid->elem_size) + (ii * grid->width * grid->elem_size);
}



grid_ret_t grid_init(grid_t * grid, size_t max_height, size_t max_width, size_t elem_size, void * data_store) {
    grid->max_height = max_height;
    grid->max_width = max_width;
    grid->elem_size = elem_size;
    grid->data = data_store;
    grid->height = max_height;
    grid->width = max_width;

    return GRID_OK;
}

grid_ret_t grid_get_data(const grid_t * grid, int ii, int jj, void * ret) {
    if (index_in_range(grid, ii, jj)) {
        return GRID_INDEX_OUT_OF_RANGE;
    }
    else {
        void * index = get_index_ptr(grid, ii, jj);

        if (ret != NULL) {
            memcpy(ret, index, grid->elem_size);
        }
        else {
            return GRID_INVALID_RET_PTR;
        }
    }

    return GRID_OK;
}

grid_ret_t grid_set_data(const grid_t * grid, int ii, int jj, void * val) {
    if (index_in_range(grid, ii, jj)) {
        return GRID_INDEX_OUT_OF_RANGE;
    }
    else {
        void * index = get_index_ptr(grid, ii, jj);

        if (val != NULL) {
            memcpy(index, val, grid->elem_size);
        }
        else {
            return GRID_INVALID_RET_PTR;
        }
    }

    return GRID_OK;

}