/* 落日文字画 · 28 × 44 网格
   构图全部由下方数组描述；空白格自动用「天」铺满。
   修改元素只需调整数组中的坐标与尺寸，行列范围：x 0–27，y 0–43。 */

(() => {
  const COLS = 28;
  const ROWS = 44;

  /* 云：x/y 为最宽一行的左上角，三行 3/5/3；上下拉开分布 */
  const clouds = [
    { x: 10, y: 2, tone: 'pink' },
    { x: 18, y: 6, tone: 'violet' },
    { x: 1, y: 10, tone: 'orange' },
    { x: 23, y: 13, tone: 'lilac' },
    { x: 4, y: 16, tone: 'rose' },
  ];

  /* 落日：整体下移贴近楼群，形成日落；
     色调按数组顺序，顶部偏红 → 底部偏黄 */
  const sun = [
    { y: 18, x: 13, w: 2 },
    { y: 19, x: 10, w: 8 },
    { y: 20, x: 9, w: 10 },
    { y: 21, x: 8, w: 12 },
    { y: 22, x: 7, w: 14 },
    { y: 23, x: 7, w: 14 },
    { y: 24, x: 6, w: 16 },
    { y: 25, x: 6, w: 16 },
    { y: 26, x: 6, w: 16 },
    { y: 27, x: 6, w: 16 },
    { y: 28, x: 6, w: 16 },
    { y: 29, x: 7, w: 14 },
    { y: 30, x: 7, w: 14 },
    { y: 31, x: 8, w: 12 },
    { y: 32, x: 9, w: 10 },
    { y: 33, x: 10, w: 8 },
    { y: 34, x: 13, w: 2 },
  ];

  /* 飞鸟：数量减少，间距不等，仅少量成对；上下拉开分布 */
  const birds = [
    { x: 25, y: 2, kind: 'magpie' },
    { x: 1, y: 4, kind: 'sparrow' },
    { x: 3, y: 8, kind: 'crow' },
    { x: 9, y: 13, kind: 'magpie' },
    { x: 9, y: 15, kind: 'sparrow' },
    { x: 26, y: 5, kind: 'crow' },
    { x: 17, y: 9, kind: 'sparrow' },
    { x: 21, y: 12, kind: 'magpie' },
    { x: 19, y: 15, kind: 'crow' },
  ];

  /* 天线：单列「线」，从 y 向下叠 h 格；最右楼顶另加一根深色 */
  const antennas = [
    { x: 7, y: 28, h: 3 },
    { x: 22, y: 27, h: 4 },
    { x: 26, y: 34, h: 3, cls: 'ant ant-dark' },
  ];

  /* 楼群：n 对应 .bld-n，最终按 x/y/w/h 铺满「楼」（高度裁到第 44 行） */
  const buildings = [
    { n: 1, x: 0, y: 35, w: 3, h: 9 },
    { n: 2, x: 3, y: 39, w: 3, h: 5 },
    { n: 3, x: 6, y: 31, w: 4, h: 13 },
    { n: 4, x: 10, y: 36, w: 3, h: 8 },
    { n: 5, x: 13, y: 30, w: 4, h: 14 },
    { n: 6, x: 17, y: 34, w: 3, h: 10 },
    { n: 7, x: 20, y: 31, w: 4, h: 13 },
    { n: 8, x: 24, y: 37, w: 4, h: 7 },
  ];

  /* 标题区：整格扣出的居中矩形，左右各留 3 格 */
  const TITLE = {
    text: '关于「甲子」的虚构故事',
    emphasis: '甲子',
    top: 14,
    height: 5,
    side: 3,
  };

  const BIRD_WORDS = { sparrow: '麻雀', magpie: '喜鹊', crow: '乌鸦' };

  const grid = Array.from({ length: ROWS }, () =>
    Array.from({ length: COLS }, () => ({ ch: '天', cls: 'sky' }))
  );

  const put = (x, y, ch, cls) => {
    if (x < 0 || x >= COLS || y < 0 || y >= ROWS) {
      throw new Error(`元素超出网格范围：(${x}, ${y})`);
    }
    grid[y][x] = { ch, cls };
  };

  const putRow = (y, x, n, ch, cls) => {
    for (let i = 0; i < n; i++) put(x + i, y, ch, cls);
  };

  for (const { x, y, tone } of clouds) {
    const cls = `cloud cloud-${tone}`;
    putRow(y, x + 1, 3, '云', cls);
    putRow(y + 1, x, 5, '云', cls);
    putRow(y + 2, x + 1, 3, '云', cls);
  }

  sun.forEach(({ y, x, w }, i) => {
    const tone = `sun-t${i + 1}`;
    for (let dx = 0; dx < w; dx++) put(x + dx, y, '日', `sun ${tone}`);
  });

  for (const { x, y, kind } of birds) {
    const [a, b] = BIRD_WORDS[kind];
    put(x, y, a, `bird-${kind}`);
    put(x + 1, y, b, `bird-${kind}`);
  }

  for (const { x, y, h, cls = 'ant' } of antennas) {
    for (let i = 0; i < h; i++) put(x, y + i, '线', cls);
  }

  for (const { n, x, y, w, h } of buildings) {
    for (let j = 0; j < h; j++) putRow(y + j, x, w, '楼', `bld bld-${n}`);
  }

  for (let y = TITLE.top; y < TITLE.top + TITLE.height; y++) {
    for (let x = TITLE.side; x < COLS - TITLE.side; x++) {
      grid[y][x] = { ch: '　', cls: 'cut' };
    }
  }

  /* 把同 class 的连续字符合并成一个 span，减少 DOM 节点 */
  const html = grid
    .map((row) => {
      let line = '';
      for (let i = 0; i < COLS; ) {
        let j = i + 1;
        while (j < COLS && row[j].cls === row[i].cls) j++;
        const text = row.slice(i, j).map((cell) => cell.ch).join('');
        line += `<span class="${row[i].cls}">${text}</span>`;
        i = j;
      }
      return `<div class="line">${line}</div>`;
    })
    .join('');

  const scene = document.querySelector('.scene');
  scene.innerHTML = html;

  const panel = document.createElement('div');
  panel.className = 'title-panel';
  panel.style.top = `${TITLE.top}em`;
  panel.style.left = `${TITLE.side}em`;
  panel.style.width = `${COLS - TITLE.side * 2}em`;
  panel.style.height = `${TITLE.height}em`;

  const title = document.createElement('h1');
  title.className = 'title';

  const [before, after] = TITLE.text.split(TITLE.emphasis);
  if (after === undefined) {
    title.textContent = TITLE.text;
  } else {
    const em = document.createElement('span');
    em.className = 'title-em';
    em.textContent = TITLE.emphasis;
    title.append(before, em, after);
  }

  panel.append(title);
  scene.append(panel);
})();