import { SignJWT } from "jose"

async function getAccessToken(saJson: string) {
  const key = JSON.parse(saJson)
  const now = Math.floor(Date.now() / 1000)
  const jwt = await new SignJWT({
    scope: "https://www.googleapis.com/auth/webmasters.readonly",
  })
    .setProtectedHeader({ alg: "RS256", typ: "JWT" })
    .setIssuer(key.client_email)
    .setAudience("https://oauth2.googleapis.com/token")
    .setIssuedAt(now)
    .setExpirationTime(now + 3600)
    .sign(await importPrivateKey(key.private_key))

  const res = await fetch("https://oauth2.googleapis.com/token", {
    method: "POST",
    body: new URLSearchParams({
      grant_type: "urn:ietf:params:oauth:grant-type:jwt-bearer",
      assertion: jwt,
    }),
  })
  const { access_token } = await res.json()
  return access_token
}

async function queryGSC(token: string, siteUrl: string) {
  const url = `https://searchconsole.googleapis.com/webmasters/v3/sites/${encodeURIComponent(siteUrl)}/searchAnalytics/query`

  const body = {
    startDate: "2026-03-25",
    endDate: "2026-04-21",
    dimensions: ["query", "page"],
    rowLimit: 1000,
  }

  const res = await fetch(url, {
    method: "POST",
    headers: { Authorization: `Bearer ${token}` },
    body: JSON.stringify(body),
  })
  return res.json()
}

// हर दिन सुबह 3 बजे चलाएँ
export default {
  async scheduled(event: ScheduledEvent, env: Env) {
    const token = await getAccessToken(env.GSC_SA_JSON)
    const data = await queryGSC(token, env.GSC_SITE_URL)

    // D1 में सहेजें
    for (const row of data.rows) {
      await env.DB.prepare(
        "INSERT INTO gsc_daily (date, query, page, clicks, impressions, ctr, position) VALUES (?, ?, ?, ?, ?, ?, ?)"
      ).bind(new Date().toISOString().slice(0, 10), row.keys[0], row.keys[1], row.clicks, row.impressions, row.ctr, row.position).run()
    }
  },
}

[triggers]
crons = ["0 18 * * *"]  # हर दिन KST 03:00

// गिरते keywords का पता लगाना
const sql = `
  SELECT query, SUM(clicks) as recent_clicks,
    (SELECT SUM(clicks) FROM gsc_daily WHERE query=g.query AND date BETWEEN DATE(?, '-14 days') AND DATE(?, '-8 days')) as prev_clicks
  FROM gsc_daily g
  WHERE date >= DATE(?, '-7 days')
  GROUP BY query
  HAVING prev_clicks > 10 AND recent_clicks < prev_clicks * 0.5
`
const dropped = await env.DB.prepare(sql).bind(today, today, today).all()

if (dropped.results.length > 0) {
  await fetch(telegramUrl, {
    method: "POST",
    body: JSON.stringify({
      chat_id: env.CHAT_ID,
      text: `गिरते keywords ${dropped.results.length} का पता चला`,
    }),
  })
}