import Member from '../../models/member.js'
import { requireAuth } from '../../utils/auth.js'

export default defineEventHandler(async (event) => {
  const member = await requireAuth(event)
  const memberId = member._id

  const topics = member.board?.topics || []
  if (!topics.length) {
    return { suggestions: [] }
  }

  const query = getQuery(event)
  const filterTag = query.tag || null

  let myTopics = topics
  if (filterTag) {
    myTopics = myTopics.filter((t) => t.tagSlug === filterTag)
  }
  if (!myTopics.length) {
    return { suggestions: [] }
  }

  const mySlugs = myTopics.map((t) => t.tagSlug)

  const candidates = await Member.find({
    _id: { $ne: memberId },
    status: 'active',
    'board.topics.tagSlug': { $in: mySlugs },
  })
    .select('name avatar craftTags circle board privacy')
    .lean()

  if (!candidates.length) {
    return { suggestions: [] }
  }

  const myTopicMap = {}
  for (const t of myTopics) {
    myTopicMap[t.tagSlug] = t.state
  }

  const suggestions = []
  for (const candidate of candidates) {
    const theirTopics = candidate.board?.topics || []
    const matchingTags = []

    for (const theirTopic of theirTopics) {
      const myState = myTopicMap[theirTopic.tagSlug]
      if (!myState) continue

      matchingTags.push({
        tagSlug: theirTopic.tagSlug,
        yourState: myState,
        theirState: theirTopic.state,
      })
    }

    if (!matchingTags.length) continue

    // Privacy filter: only expose fields the candidate allows to other members
    const privacy = candidate.privacy || {}
    const filtered = {
      _id: candidate._id,
      name: candidate.name,
      circle: candidate.circle,
    }

    const avatarPrivacy = privacy.avatar || 'public'
    if (avatarPrivacy === 'public' || avatarPrivacy === 'members') {
      filtered.avatar = candidate.avatar
    }

    const craftTagsPrivacy = privacy.craftTags || 'members'
    if (craftTagsPrivacy === 'public' || craftTagsPrivacy === 'members') {
      filtered.craftTags = candidate.craftTags
    }

    // Expose slackHandle only when the candidate has opted into peer support.
    // Slack handle is the contact-in-place path — without it, there is no way
    // for the current member to reach out.
    if (candidate.board?.offerPeerSupport && candidate.board?.slackHandle) {
      filtered.slackHandle = candidate.board.slackHandle
    }

    suggestions.push({
      member: filtered,
      matchingTags,
      matchCount: matchingTags.length,
    })
  }

  suggestions.sort((a, b) => b.matchCount - a.matchCount)

  return { suggestions }
})