// 关卡地图工具：让手工 ASCII 不必逐格数点
// G(w, rows) —— 每行不足宽度自动补 '.'，最后一列强制为 '#'（外墙）
export function G(w, rows) {
  return rows.map(r => {
    const s = r.length >= w ? r.slice(0, w) : r + '.'.repeat(w - r.length);
    return s.slice(0, w - 1) + '#';
  });
}

// 重复字符：rep('%', 20)
export const rep = (ch, n) => ch.repeat(Math.max(0, n | 0));

// 空格行
export const E = w => '#' + rep('.', w - 2);

// 实心跳台：plat(w, 起列, 长度) => 一行带 '#####' 的字符串
export function plat(w, x0, len, ch = '#') {
  if (x0 < 1) x0 = 1;
  return '#' + rep('.', x0 - 1) + rep(ch, len);
}

// 实体行：ent(w, [列, 字符], ...) => 一行只在指定列放实体字符
export function ent(w, ...items) {
  const a = new Array(w).fill('.');
  a[0] = '#';
  for (const [x, ch] of items) if (x > 0 && x < w - 1) a[x] = ch;
  return a.join('');
}

// 地板行：从 col1 开始按 [字符, 长度] 铺满，最后一列由 G 补 '#'
export function flr(...parts) {
  let s = '#';
  for (const [ch, n] of parts) s += rep(ch, n);
  return s;
}

// ---------------- 2D 网格构建器 ----------------
// 大地图用拼字符串极易出错（宽度对不齐 / 数错列），改用网格对象：
//   const m = new Map(120, 30); m.rect(x,y,w,h,'#'); ... m.out()
export class Grid {
  constructor(w, h, fill = '.') {
    this.w = w; this.h = h;
    this.g = Array.from({ length: h }, () => new Array(w).fill(fill));
  }
  set(x, y, ch) {
    if (x >= 0 && x < this.w && y >= 0 && y < this.h) this.g[y][x] = ch;
    return this;
  }
  rect(x, y, w, h, ch) {
    for (let iy = y; iy < y + h; iy++)
      for (let ix = x; ix < x + w; ix++) this.set(ix, iy, ch);
    return this;
  }
  hline(y, x0, x1, ch) { for (let x = x0; x <= x1; x++) this.set(x, y, ch); return this; }
  vline(x, y0, y1, ch) { for (let y = y0; y <= y1; y++) this.set(x, y, ch); return this; }
  border(ch = '#') {
    this.hline(0, 0, this.w - 1, ch);
    this.hline(this.h - 1, 0, this.w - 1, ch);
    this.vline(0, 0, this.h - 1, ch);
    this.vline(this.w - 1, 0, this.h - 1, ch);
    return this;
  }
  out() { return this.g.map(r => r.join('')); }
}

/** 落脚台序列：chain(起始列, 起始宽, [间隙...], 台宽) => [{x,w}, ...] */
export function chain(x0, w0, gaps, padW = 2) {
  const out = [{ x: x0, w: w0 }];
  let x = x0 + w0;
  for (const g of gaps) { x += g; out.push({ x, w: padW }); x += padW; }
  return out;
}