'use strict'

const { COLLECTIONS } = require('pearcord-shared')

const INVITE_GOSSIP_WINDOW = 4096

const invitesDiscoveryMixin = {
  _inviteGossipKeys: null,
  _invitesHealWatermark: null,
  _discoveryHealWatermark: null,

  _inviteGossipKey (payload) {
    if (!payload?.code) return ''
    return `invite:${payload.guildId}:${payload.code}:${payload.expiresAt || 0}:${payload.uses || 0}`
  },

  _shouldGossipInvite (payload) {
    const hash = this._inviteGossipKey(payload)
    if (!hash) return true
    if (!this._inviteGossipKeys) this._inviteGossipKeys = new Set()
    if (this._inviteGossipKeys.has(hash)) return false
    this._inviteGossipKeys.add(hash)
    if (this._inviteGossipKeys.size > INVITE_GOSSIP_WINDOW) {
      const first = this._inviteGossipKeys.values().next().value
      if (first) this._inviteGossipKeys.delete(first)
    }
    return true
  },

  async listGuildInvites (guildId) {
    const gid = guildId || this.guild?.guild?.id || null
    if (!gid) return []
    const rows = await this.db.find(COLLECTIONS.INVITES, { guildId: gid })
    rows.sort((a, b) => (Number(b.expiresAt) || 0) - (Number(a.expiresAt) || 0))
    return rows
  },

  async _healInvitesOnPartition (guildId) {
    const gid = guildId || this.guild?.guild?.id || null
    const span = this.log.time('invite.heal', { spanKind: 'invite.heal', guildId: gid })
    try {
      if (!gid) {
        span.end({ relisted: 0, skipped: true })
        return { relisted: 0, skipped: true }
      }
      const rows = await this.db.find(COLLECTIONS.INVITES, { guildId: gid })
      const now = Date.now()
      let pruned = 0
      for (const row of rows) {
        if (row.expiresAt && row.expiresAt < now - 7 * 24 * 60 * 60 * 1000) {
          await this.db.delete(COLLECTIONS.INVITES, { code: row.code }).catch(() => {})
          pruned += 1
        }
      }
      const relisted = rows.length - pruned
      const watermark = Date.now()
      this._invitesHealWatermark = watermark
      span.end({ relisted, pruned, watermark, inviteCount: relisted })
      return { relisted, pruned, watermark }
    } catch (err) {
      this.log.error('invite.heal error', { guildId: gid, error: err?.message || String(err) })
      span.fail(err)
      return { relisted: 0, error: err?.message || String(err) }
    }
  },

  async _healDiscoveryListingsOnPartition (guildId) {
    const span = this.log.time('discovery.heal', {
      spanKind: 'discovery.heal',
      guildId: guildId || null
    })
    try {
      if (!this.discovery) {
        span.end({ relisted: 0, skipped: true })
        return { relisted: 0, skipped: true }
      }
      const rows = await this.discovery.listPublicListings({ prune: true })
      const watermark = Date.now()
      this._discoveryHealWatermark = watermark
      span.end({ relisted: rows.length, watermark, discoveryListingCount: rows.length })
      return { relisted: rows.length, watermark }
    } catch (err) {
      this.log.error('discovery.heal error', {
        guildId,
        error: err?.message || String(err)
      })
      span.fail(err)
      return { relisted: 0, error: err?.message || String(err) }
    }
  }
}

module.exports = {
  invitesDiscoveryMixin,
  INVITE_GOSSIP_WINDOW
}