import { grid, cols, rows } from './state.js';
import { move } from './actions.js';

export function updateDirt(x, y, cell) {
    const below = y + 1;
    if (below >= rows) return;

    const belowCell = grid[x][below];
    if (!belowCell) {
        move(x, y, x, below);
    } else if (belowCell.type === 'water' || belowCell.type === 'acid') {
        // Fall through water or acid (slower)
        if (Math.random() < 0.2) {
            grid[x][below] = cell;
            grid[x][y] = belowCell;
            cell.updated = true;
            belowCell.updated = true;
        }
    } else {
        // Try sliding left or right
        const left = x > 0 && !grid[x - 1][below];
        const right = x < cols - 1 && !grid[x + 1][below];
        
        if (left && right) move(x, y, Math.random() < 0.5 ? x - 1 : x + 1, below);
        else if (left) move(x, y, x - 1, below);
        else if (right) move(x, y, x + 1, below);
    }
}