// Team notifications posted into an operator-configured channel (TEAMS.md §7.2).
//
// **The channel comes from the app, not from guild_config.** `newsAnnounce` looks
// its channel up here because there is exactly one #news; a Team's destination is
// per-Team configuration living in `team_integration_config`, and a bot that
// resolved it would need a second copy of that table and a second place for it to
// drift. The app sends the id it already decided on.
//
// **Everything this file knows about a Team it was told.** No lookups, no
// membership checks, no access decisions: whether this content may reach this
// channel was settled on the site, where the acknowledgement that gates it lives.
// The bot is the transport, exactly as it is for slash commands.
const { EmbedBuilder } = require('discord.js')

const brand = require('../brand')
const createLogger = require('../utils/logger')

const log = createLogger('team-notify')

// Discord's own limits. Truncating here rather than trusting the app is not
// distrust — an embed that exceeds them is rejected wholesale, and a message
// silently not appearing is the worst failure mode this path has.
const TITLE_MAX = 256
const DESCRIPTION_MAX = 4096

const clamp = (value, max) => {
  const text = String(value || '').trim()
  if (!text) return null
  return text.length > max ? `${text.slice(0, max - 1)}…` : text
}

// What each stream is called in a channel. The app composes the BODY; this is
// only the label above it, and it is here because it is Discord presentation —
// the same reason the embed colour is.
const HEADINGS = {
  'team.member.joined': 'New member',
  'team.leadership.changed': 'Leadership change',
  'team.forum.post': 'New forum post',
  'team.announcement': 'Announcement',
}

async function postTeamNotification(client, { channelId, stream, teamName, teamUrl, title, body, url }) {
  if (!channelId) throw new Error('No channel id supplied.')

  const channel = await client.channels.fetch(channelId).catch(() => null)
  if (!channel || !channel.isTextBased()) {
    throw new Error('Configured channel is missing, not text-based, or not visible to the bot.')
  }

  const heading = HEADINGS[stream] || 'Team update'
  const name = clamp(teamName, 120) || 'A team'

  const embed = new EmbedBuilder()
    .setColor(brand.accentInt)
    // The Team is the AUTHOR line and the event is the title, not the other way
    // round: a channel carrying one Team's events would otherwise repeat its name
    // as every heading, and a channel carrying several needs the name to be the
    // thing the eye lands on first.
    .setAuthor(teamUrl ? { name, url: teamUrl } : { name })
    .setTitle(clamp(title, TITLE_MAX) || heading)

  if (url) embed.setURL(url)

  // Both a title and a body means a forum post: the heading has to go somewhere
  // or "New forum post" and "Announcement" become indistinguishable once the
  // thread title takes the title slot.
  //
  // **Clamped AFTER the heading is prepended, not before.** Clamping the body and
  // then adding a prefix produces a description one heading longer than the limit,
  // which discord.js rejects outright — so an over-long post would not arrive at
  // all rather than arriving truncated. The prefix is part of what has to fit.
  const composed = title && body ? `**${heading}**\n${String(body)}` : body
  const description = clamp(composed, DESCRIPTION_MAX)
  if (description) embed.setDescription(description)

  await channel.send({ embeds: [embed] })
  log.info('team notification posted', { stream, channelId, team: name })
}

module.exports = { postTeamNotification, HEADINGS, clamp, TITLE_MAX, DESCRIPTION_MAX }