import { grid, cols, rows } from './state.js';
import { config } from './config.js';
import { createCell } from './physics.js';

const dxs = [0, 0, -1, 1];
const dys = [1, -1, 0, 0];

export function updatePlant(x, y, cell) {
    // Woodification (stalk formation under weight)
    let weight = 0;
    const requiredWeight = 5;
    for (let i = 1; i <= requiredWeight; i++) {
        if (y - i < 0) break;
        const above = grid[x][y - i];
        if (above && (above.type === 'plant' || above.type === 'wood')) {
            weight++;
        } else {
            break;
        }
    }

    if (weight >= requiredWeight && Math.random() < config.plant.woodificationChance) {
        grid[x][y] = createCell('wood');
        return;
    }

    // Roots: infects touching dirt into plant
    if (Math.random() < config.plant.growChance * 0.15) {
        const dir = Math.floor(Math.random() * 4);
        const nx = x + dxs[dir];
        const ny = y + dys[dir];
        if (nx >= 0 && nx < cols && ny >= 0 && ny < rows && grid[nx][ny] && grid[nx][ny].type === 'dirt') {
            grid[nx][ny] = createCell('plant');
            return;
        }
    }

    // Organic upward branch growth towards light
    if (Math.random() < config.plant.growChance) {
        const r = Math.random();
        const dx = r < 0.2 ? -1 : (r > 0.8 ? 1 : 0);
        const nx = x + dx;
        const ny = y - 1;
        if (nx >= 0 && nx < cols && ny >= 0 && !grid[nx][ny]) {
            grid[nx][ny] = createCell('plant');
        }
    }
}