// map-switch.js — 断言"章节 / 场景 / 细分场景"三个下拉框真的跳到选中的地图
//
// 这里防的是一类会静默退化的 bug：下拉框写错查询参数（早期是 `?quadrant=` 而资源包路径读
// `?level=`），于是换图失败、悄悄回到该 act 的城镇。断言方式是拦下处理函数构造出来的目标 URL
// （`location.search` 的赋值在同一个任务里），再检查参数名与取值。
//
// 同时核对三级结构本身：章节是「第一章…第五章」、场景是中文场景名、细分场景是所选场景的变体
// （罗格营地是 北/东/南/西）。
//
//   CHROME=/root/.cache/ms-playwright/chromium-1223/chrome-linux64/chrome
//   node scripts/browser/inspect-page.mjs "$CHROME" \
//     "https://www.laiseek.xyz/diablo2/?act=1" scripts/browser/checks/map-switch.js
(async () => {
  const sleep = (ms) => new Promise((r) => setTimeout(r, ms))
  const deadline = Date.now() + 120000
  while (Date.now() < deadline) {
    const s = window.__d2webAct
    if (s && (s.ready || s.error)) break
    await sleep(200)
  }
  await sleep(800)

  // 处理函数用的是 location.search 赋值，拦 URLSearchParams.toString 就能拿到目标。
  const seen = []
  const paramsToString = URLSearchParams.prototype.toString
  URLSearchParams.prototype.toString = function () { const value = paramsToString.call(this); seen.push(`?${value}`); return value }

  const texts = (id) => Array.from(document.querySelectorAll(`#${id} option`)).map((o) => o.textContent)
  const result = {
    source: window.__d2webAct.source,
    headerLinks: Array.from(document.querySelectorAll('header a')).map((a) => a.textContent),
    actOptions: texts('act'),
    sceneOptions: texts('scene'),
    variantOptions: texts('variant'),
  }

  /**
   * 选中某个下拉框的某个值并捕获它构造出的目标 URL。
   *
   * @param id - select id.
   * @param pick - chooses a value out of the options.
   * @param match - how to judge the captured `?level=`: a variant label *is* the value,
   *   while a scene navigates to its **first variant**, whose label starts with the slug.
   */
  const trySwitch = (id, pick, match = (value, level) => level === value) => {
    const select = document.querySelector(`#${id}`)
    if (select === null) return { error: 'no such select' }
    const values = Array.from(select.querySelectorAll('option')).map((o) => o.value)
    const value = pick(values) ?? values[0]
    seen.length = 0
    select.value = value
    select.dispatchEvent(new Event('change', { bubbles: true }))
    const target = seen.at(-1) ?? null
    let params = null
    try { params = target === null ? null : new URL(target, location.origin).searchParams } catch { params = null }
    return {
      picked: value,
      target,
      levelParam: params === null ? null : params.get('level'),
      actParam: params === null ? null : params.get('act'),
      switchesMap: params !== null && match(value, params.get('level') ?? '') && params.get('act') !== null,
    }
  }

  // 章节切换跳到该 act 的第一个场景的第一个细分：`?act=` 变了，`?level=` 也该跟着变。
  result.actSwitch = trySwitch('act', values => values[1] ?? values[0],
    (act, level) => act !== String(window.__d2webAct.act) && level !== '')
  result.variantSwitch = trySwitch('variant', values => values[1] ?? values[0])
  result.sceneSwitch = trySwitch('scene', values => values[1] ?? values[0],
    (slug, level) => level === slug || level.startsWith(`${slug}-`))
  URLSearchParams.prototype.toString = paramsToString

  const checks = [
    ['resource pack path', result.source === 'pack'],
    ['header 上没有多余链接', result.headerLinks.length === 0],
    ['章节是五章中文名', result.actOptions.join('') === '第一章第二章第三章第四章第五章'],
    ['场景是中文名（不是 Act N - …）', result.sceneOptions.every(text => !/^Act \d/.test(text)) && result.sceneOptions.length > 1],
    ['细分场景是方位（罗格营地 北/东/南/西）', result.variantOptions.includes('北') && result.variantOptions.includes('南')],
    ['细分场景切换写 ?level=', result.variantSwitch.switchesMap === true],
    ['场景切换跳到该场景的首个细分（?level= 以 slug 开头）且带 ?act=', result.sceneSwitch.switchesMap === true],
    ['章节切换同时改 ?act= 与 ?level=', result.actSwitch.switchesMap === true],
  ]
  return {
    ...result,
    act: window.__d2webAct.act,
    level: window.__d2webAct.level,
    pass: checks.every(([, ok]) => ok),
    checks,
  }
})()