// server/utils/checkSlackJoins.js
import Member from '../models/member.js'
import { connectDB } from './mongoose.js'
import { WebClient } from '@slack/web-api'

const BATCH_SIZE = 15
const BATCH_DELAY_MS = 1000

/**
 * Check members with pending Slack invites to see if they've joined the workspace.
 * Processes in batches of 15 with 1-second delays (Slack Tier 2 rate limit).
 */
export async function checkSlackJoins(slackBotToken) {
  await connectDB()

  const client = new WebClient(slackBotToken)

  const members = await Member.find({
    slackInviteStatus: { $in: ['sent', 'accepted'] }
  }).select('_id email slackInviteStatus')

  if (members.length === 0) return { checked: 0, joined: 0 }

  let joined = 0

  for (let i = 0; i < members.length; i += BATCH_SIZE) {
    const batch = members.slice(i, i + BATCH_SIZE)

    for (const member of batch) {
      try {
        const response = await client.users.lookupByEmail({ email: member.email })
        const userId = response.user?.id

        if (userId) {
          await Member.findByIdAndUpdate(member._id, {
            slackInviteStatus: 'joined',
            slackUserId: userId
          })
          joined++
          console.log(`[check-slack-joins] ${member.email} joined Slack (${userId})`)
        }
      } catch (err) {
        // users_not_found is expected for members who haven't joined yet
        if (err.data?.error === 'users_not_found') continue

        console.error(`[check-slack-joins] Error checking ${member.email}:`, err.message || err)
        // Continue processing remaining members
      }
    }

    // Delay between batches (skip after last batch)
    if (i + BATCH_SIZE < members.length) {
      await new Promise((resolve) => setTimeout(resolve, BATCH_DELAY_MS))
    }
  }

  console.log(`[check-slack-joins] Done: ${joined}/${members.length} members joined`)
  return { checked: members.length, joined }
}