// ── Abuse reports: the missing half of moderation (TEAMS.md §5.6) ──────────
//
// Two rules shape everything in this file, and both are easier to break than to
// notice broken:
//
//   1. **A report is not a moderation action.** Filing one changes nothing about
//      the content — it opens a queue item. That keeps it clear of §5.3's
//      leader/staff moderation ledger, which records things that actually
//      happened. If reporting hid a post, reporting would BE moderation, and the
//      first person to work that out would have found a way to hide anything.
//
//   2. **Reports go to site staff and to nobody else.** The gap §5.6 exists to
//      close has a specific shape: leaders moderate their own Team's forum, and a
//      Team's leaders are exactly the people who will not report their own Team.
//      A leader-visible queue would route a complaint about a leader back to that
//      leader. The org lead settled this on 2026-08-18 — reports are **site
//      administration only**, with no leader-facing view at all, not even a
//      read-only one scoped to their own Team.
//
// The reporter's ACCESS is the caller's business, not this file's: the player
// route resolves the forum first, so anyone reaching `file()` is someone who can
// already see the thing they are reporting. What this file does check is that the
// target is really in the Team the caller reached it through — otherwise a
// participant in one Team could file reports carrying another Team's id, and the
// queue's per-Team filter would quietly be lying.

const reportsDb = require('./contentReports.db')
const forumDb = require('../teams/teamForum.db')

const TARGET_TYPES = ['team_forum_thread', 'team_forum_post', 'team_forum_upload']
const REASONS = ['spam', 'abuse', 'sexual', 'illegal', 'impersonation', 'other']
const STATUSES = ['open', 'reviewing', 'actioned', 'dismissed']

// A body excerpt for the queue, not a rendered post. Staff triage on what was
// written, and `body_html` is stored already sanitised — but the queue is a list,
// so it gets text and a length cap rather than markup.
const EXCERPT_CHARS = 300
const excerpt = (html) => String(html || '')
  .replace(/<[^>]*>/g, ' ')
  .replace(/\s+/g, ' ')
  .trim()
  .slice(0, EXCERPT_CHARS)

/**
 * Does this target exist, and is it in this Team?
 *
 * Returns the team id the target really belongs to, or null. The caller compares
 * it with the Team the request came through — a mismatch is a 404 for the same
 * §5.5.1 reason a foreign thread id is: confirming a target exists somewhere else
 * on the site is itself a disclosure.
 */
async function targetTeamId(targetType, targetId) {
  if (targetType === 'team_forum_thread') {
    const thread = await forumDb.threadById(targetId)
    return thread ? thread.team_id : null
  }
  if (targetType === 'team_forum_post') {
    const post = await forumDb.postById(targetId)
    if (!post) return null
    const thread = await forumDb.threadById(post.thread_id)
    return thread ? thread.team_id : null
  }
  if (targetType === 'team_forum_upload') {
    const upload = await forumDb.uploadById(targetId)
    return upload ? upload.team_id : null
  }
  return null
}

/**
 * File a report.
 *
 * A duplicate answers 409 rather than pretending to succeed. Silently accepting
 * it would be friendlier for one tap and dishonest for the second: a member who
 * reports twice because nothing seemed to happen deserves to be told the first
 * one is already in the queue.
 */
async function file({ team, actor, targetType, targetId, reason, detail }) {
  if (!TARGET_TYPES.includes(targetType)) {
    return { ok: false, status: 400, error: 'Unknown report target' }
  }
  if (!REASONS.includes(reason)) {
    return { ok: false, status: 400, error: 'Unknown report reason' }
  }

  const owner = await targetTeamId(targetType, targetId)
  if (owner == null || owner !== team.id) {
    return { ok: false, status: 404, error: 'Not found' }
  }

  const id = await reportsDb.insert({
    targetType,
    targetId,
    teamId: team.id,
    reporterUserId: actor.id,
    reporterUsername: actor.username,
    reason,
    detail,
  })
  if (id == null) {
    return { ok: false, status: 409, error: 'You have already reported this. Staff are looking at it.' }
  }
  return { ok: true, reportId: id }
}

/**
 * The staff queue, with each row's target attached.
 *
 * Enrichment is three batched reads keyed by target type, not one read per row.
 * The alternative N+1s a page of a hundred into three hundred queries, which is
 * how a queue becomes a thing staff avoid opening.
 *
 * A target that has since been hard-deleted comes back as `null`, and the report
 * still lists. That is deliberate: "somebody reported this and by the time we
 * looked it was gone" is a fact a moderator needs, and dropping the row would
 * hide the pattern of a member deleting their own content the moment it is
 * reported.
 */
async function queue({ status, teamId, limit, offset } = {}) {
  const rows = await reportsDb.list({ status, teamId, limit, offset })
  if (!rows.length) return []

  const idsOf = (type) => rows.filter((r) => r.target_type === type).map((r) => Number(r.target_id))
  const [threads, posts, uploads] = await Promise.all([
    reportsDb.threadsByIds([...new Set(idsOf('team_forum_thread'))]),
    reportsDb.postsByIds([...new Set(idsOf('team_forum_post'))]),
    reportsDb.uploadsByIds([...new Set(idsOf('team_forum_upload'))]),
  ])

  const byId = (list) => new Map(list.map((row) => [Number(row.id), row]))
  const threadMap = byId(threads)
  const postMap = byId(posts)
  const uploadMap = byId(uploads)

  return rows.map((r) => ({ ...publicReport(r), target: describeTarget(r, { threadMap, postMap, uploadMap }) }))
}

/**
 * The reported content, resolved.
 *
 * **Every miss returns `null`, never `undefined`.** They look interchangeable in
 * JavaScript and are not in JSON: `undefined` is dropped by `JSON.stringify`, so
 * a hard-deleted target would reach the client as an ABSENT `target` key rather
 * than as an explicit null, and the queue's own contract says nullable. A client
 * distinguishing "gone" from "not resolved yet" would get it wrong.
 */
function describeTarget(report, { threadMap, postMap, uploadMap }) {
  const id = Number(report.target_id)
  if (report.target_type === 'team_forum_thread') {
    const t = threadMap.get(id)
    if (!t) return null
    return {
      kind: 'thread',
      threadId: t.id,
      title: t.title,
      type: t.type,
      status: t.status,
      author: t.created_username,
    }
  }
  if (report.target_type === 'team_forum_post') {
    const p = postMap.get(id)
    if (!p) return null
    return {
      kind: 'post',
      postId: p.id,
      threadId: p.thread_id,
      threadTitle: p.thread_title,
      author: p.author_username,
      status: p.status,
      excerpt: excerpt(p.body_html),
      createdAt: p.created_at,
    }
  }
  if (report.target_type === 'team_forum_upload') {
    const u = uploadMap.get(id)
    if (!u) return null
    // §5.6's fourth rule: uploader, size and the SNIFFED type, without hunting.
    // This is the payoff for §5.5.4's attribution table being load-bearing rather
    // than bookkeeping.
    return {
      kind: 'upload',
      uploadId: u.id,
      postId: u.post_id,
      uploader: u.uploader_username,
      filename: u.filename,
      url: `/uploads/${u.filename}`,
      mimetype: u.mimetype,
      byteSize: u.byte_size,
      createdAt: u.created_at,
      deleted: u.deleted_at != null,
    }
  }
  return null
}

function publicReport(row) {
  return {
    id: row.id,
    targetType: row.target_type,
    targetId: Number(row.target_id),
    teamId: row.team_id,
    reporter: row.reporter_username || '[deleted account]',
    reporterDeleted: row.reporter_user_id == null,
    reason: row.reason,
    detail: row.detail,
    status: row.status,
    handledBy: row.handled_username,
    handledNote: row.handled_note,
    handledAt: row.handled_at,
    createdAt: row.created_at,
  }
}

/** Move a report along the queue. Staff-only by its route. */
async function handle({ id, actor, status, note }) {
  if (!STATUSES.includes(status)) {
    return { ok: false, status: 400, error: 'Unknown report status' }
  }
  const report = await reportsDb.byId(id)
  if (!report) return { ok: false, status: 404, error: 'Report not found' }

  await reportsDb.handle(id, {
    status,
    handledBy: actor.id,
    handledUsername: actor.username,
    note,
  })
  return { ok: true, report: publicReport(await reportsDb.byId(id)) }
}

module.exports = {
  TARGET_TYPES,
  REASONS,
  STATUSES,
  EXCERPT_CHARS,
  file,
  queue,
  handle,
  openCount: reportsDb.openCount,
  publicReport,
  targetTeamId,
}