#!/usr/bin/env node
// 外部素材抓取：由系統排程（cron 或 systemd timer）執行，把天氣與新聞寫進快取檔；
// companion 的 hook 只讀這個檔，絕不連網。只存標題、摘要、連結、時間（at 為抓取時間，毫秒）。
//
//   node fetch-materials.mjs            # 讀 ~/.companion/user.json 的 location 與 feeds
//   COMPANION_ROOT=/path node fetch-materials.mjs
//
// 沒有 setup location= 就不做任何事（素材功能未啟用）。
import { mkdir, readFile, rename, writeFile } from 'node:fs/promises'
import { homedir } from 'node:os'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'

export const NEWS_PER_FEED = 5
export const NEWS_MAX = 20
export const SUMMARY_MAX = 120

// WMO 天氣代碼 → 標題（與 hooks/companion/rules.ts 的 WEATHER_MOOD 對應）
export function weatherTitle(code) {
  if (code === 0 || code === 1) return '晴'
  if (code === 2) return '多雲'
  if (code === 3) return '陰'
  if (code === 45 || code === 48) return '霧'
  if (code >= 51 && code <= 57) return '毛毛雨'
  if ((code >= 61 && code <= 67) || (code >= 80 && code <= 82)) return '雨'
  if ((code >= 71 && code <= 77) || code === 85 || code === 86) return '雪'
  if (code >= 95) return '雷雨'
  return '陰'
}

// 先還原跳脫的標籤再整個移除（RSS 的 description 常是跳脫過的 HTML），最後才還原 &amp;
const decode = s =>
  s
    .replace(/<!\[CDATA\[([\s\S]*?)\]\]>/g, '$1')
    .replace(/&lt;/g, '<').replace(/&gt;/g, '>')
    .replace(/<[^>]*>/g, ' ')
    .replace(/&quot;/g, '"').replace(/&#39;|&apos;/g, "'").replace(/&amp;/g, '&')
    .replace(/\s+/g, ' ')
    .trim()

const tag = (block, name) => {
  const m = new RegExp(`<${name}[^>]*>([\\s\\S]*?)</${name}>`, 'i').exec(block)
  return m ? decode(m[1]) : ''
}

/** 解析 RSS 2.0 與 Atom，只留標題、摘要、連結 */
export function parseFeed(xml, at) {
  const blocks = xml.match(/<item[\s>][\s\S]*?<\/item>|<entry[\s>][\s\S]*?<\/entry>/gi) ?? []
  const items = []
  for (const b of blocks) {
    const title = tag(b, 'title')
    const link = tag(b, 'link') || (/<link[^>]*href=["']([^"']+)["']/i.exec(b)?.[1] ?? '')
    if (!title || !/^https?:\/\//.test(link)) continue
    const summary = (tag(b, 'description') || tag(b, 'summary') || tag(b, 'content')).slice(0, SUMMARY_MAX)
    items.push({ title, summary, link, at })
  }
  return items.slice(0, NEWS_PER_FEED)
}

async function getJson(fetchFn, url) {
  const res = await fetchFn(url)
  if (!res.ok) throw new Error(`${res.status} ${url}`)
  return res.json()
}

/** location 可以是「緯度,經度」或地名（用 Open-Meteo 地理編碼查） */
export async function locate(fetchFn, location) {
  const m = /^\s*(-?\d+(?:\.\d+)?)\s*,\s*(-?\d+(?:\.\d+)?)\s*$/.exec(location)
  if (m) return { lat: Number(m[1]), lon: Number(m[2]), name: location.trim() }
  const j = await getJson(fetchFn, `https://geocoding-api.open-meteo.com/v1/search?name=${encodeURIComponent(location)}&count=1&language=zh`)
  const r = j.results?.[0]
  if (!r) throw new Error(`找不到地點：${location}`)
  return { lat: r.latitude, lon: r.longitude, name: r.name ?? location }
}

export async function fetchWeather(fetchFn, location, at) {
  const { lat, lon, name } = await locate(fetchFn, location)
  const url = `https://api.open-meteo.com/v1/forecast?latitude=${lat}&longitude=${lon}&current=temperature_2m,weather_code&timezone=auto`
  const j = await getJson(fetchFn, url)
  const cur = j.current
  if (!cur || typeof cur.weather_code !== 'number') throw new Error('天氣資料格式不符')
  return { title: weatherTitle(cur.weather_code), summary: `${name} ${cur.temperature_2m}°C`, link: url, at }
}

async function readJson(path) {
  try {
    return JSON.parse(await readFile(path, 'utf8'))
  } catch {
    return null
  }
}

/**
 * 抓取並寫入快取；任何一部分失敗就保留該部分原本的快取（過期後 hook 自然當作沒查）。
 * 回傳 { enabled, weather, news, errors }。
 */
export async function run({ root = process.env.COMPANION_ROOT || join(homedir(), '.companion'), fetch: fetchFn = globalThis.fetch, now = Date.now(), log = () => {} } = {}) {
  const user = (await readJson(join(root, 'user.json'))) ?? {}
  if (!user.location) {
    log('未設定 location，素材功能未啟用（/jsc-mod-companion:setup location=…）。')
    return { enabled: false, weather: false, news: 0, errors: [] }
  }
  const path = join(root, 'materials.json')
  const prev = (await readJson(path)) ?? {}
  const errors = []
  let weather = prev.weather ?? null
  let news = Array.isArray(prev.news) ? prev.news : []
  let gotWeather = false
  try {
    weather = await fetchWeather(fetchFn, user.location, now)
    gotWeather = true
  } catch (e) {
    errors.push(`天氣：${e.message}`)
  }
  const feeds = Array.isArray(user.feeds) ? user.feeds : []
  if (feeds.length) {
    const fresh = []
    for (const url of feeds) {
      try {
        const res = await fetchFn(url)
        if (!res.ok) throw new Error(`${res.status}`)
        fresh.push(...parseFeed(await res.text(), now))
      } catch (e) {
        errors.push(`RSS ${url}：${e.message}`)
      }
    }
    if (fresh.length) {
      const seen = new Set()
      news = fresh.filter(n => !seen.has(n.link) && seen.add(n.link)).slice(0, NEWS_MAX)
    }
  }
  await mkdir(dirname(path), { recursive: true })
  const tmp = `${path}.tmp`
  await writeFile(tmp, JSON.stringify({ weather, news }, null, 2))
  await rename(tmp, path)
  for (const e of errors) log(e)
  return { enabled: true, weather: gotWeather, news: news.length, errors }
}

if (process.argv[1] && fileURLToPath(import.meta.url) === process.argv[1]) {
  run({ log: m => console.error(m) })
    .then(r => console.log(r.enabled ? `完成：天氣${r.weather ? '已更新' : '未更新'}，新聞 ${r.news} 則` : '未啟用'))
    .catch(e => {
      console.error(e.message)
      process.exitCode = 1
    })
}