// SQL for the Team tables. Raw parameterised mariadb, no ORM, per the layered
// backend convention (router → controller → model → db).
//
// This file holds statements only. Every decision about WHETHER to write — the
// four refusal gates, the quarantine, the rename rule — lives in the models above
// it, because a gate expressed as a WHERE clause is a gate nobody can find.

const { query } = require('../../utils/db')

// ── teams ──────────────────────────────────────────────────────────────────

const TEAM_COLUMNS = `
  id, module_id, external_id, name, abbr, slug, status, meta,
  member_count, linked_count, online_count,
  hidden, hidden_reason, hidden_term, name_reviewed_at, display_name_override,
  roster_synced_at, members_empty_since,
  succeeded_by, created_at, archived_at, archived_reason`

/** Every ACTIVE team for a module — the set the reconciler diffs against. */
async function activeByModule(moduleId) {
  return query(
    `SELECT ${TEAM_COLUMNS} FROM teams WHERE module_id = ? AND status = 'active' ORDER BY id`,
    [moduleId],
  )
}

/**
 * Every ACTIVE team, whichever module owns it.
 *
 * For the READ side, which must not be keyed on a provider being registered. The
 * rows are core's and they outlive the module that filled them — a module
 * uninstalled or disabled leaves a projection that is unmaintained, not one that
 * stopped existing. Listing by provider made `/teams` empty while
 * `/teams/:slug/members` still answered in full, since the lookup goes by slug:
 * the index denied a Team that direct URLs served.
 */
async function allActive() {
  return query(`SELECT ${TEAM_COLUMNS} FROM teams WHERE status = 'active' ORDER BY id`)
}

/** The ACTIVE row for an external id, or undefined. At most one, by uq_teams_active. */
async function findActive(moduleId, externalId) {
  const rows = await query(
    `SELECT ${TEAM_COLUMNS} FROM teams WHERE module_id = ? AND external_id = ? AND status = 'active'`,
    [moduleId, externalId],
  )
  return rows[0]
}

async function findById(id) {
  const rows = await query(`SELECT ${TEAM_COLUMNS} FROM teams WHERE id = ?`, [id])
  return rows[0]
}

/** By slug, ACTIVE or ARCHIVED — an archived Team stays reachable at its old slug (§2.2). */
async function findBySlug(slug) {
  const rows = await query(
    `SELECT ${TEAM_COLUMNS} FROM teams WHERE slug = ? ORDER BY (status = 'active') DESC, id DESC LIMIT 1`,
    [slug],
  )
  return rows[0]
}

/**
 * Slugs already taken, ACTIVE OR ARCHIVED.
 *
 * The unique key only constrains active rows, and this deliberately checks more
 * than the key does: §2.2 promises an archived Team stays readable at its old
 * slug, and handing that slug to a new Team would silently break every bookmark
 * and Discord link pointing at the old one.
 */
async function slugsLike(base) {
  const rows = await query('SELECT slug FROM teams WHERE slug = ? OR slug LIKE ?', [base, `${base}-%`])
  return rows.map((r) => r.slug)
}

async function insertTeam({ moduleId, externalId, name, abbr, slug, meta, hidden, hiddenReason, hiddenTerm }) {
  const res = await query(
    `INSERT INTO teams (module_id, external_id, name, abbr, slug, meta, hidden, hidden_reason, hidden_term)
     VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
    [moduleId, externalId, name, abbr, slug, meta == null ? null : JSON.stringify(meta),
      hidden ? 1 : 0, hiddenReason || null, hiddenTerm || null],
  )
  return res.insertId
}

/** Update the mutable fields. `name` and `slug` are absent by design — §2.2 freezes both. */
async function updateTeam(id, { abbr, meta }) {
  await query('UPDATE teams SET abbr = ?, meta = ? WHERE id = ?',
    [abbr, meta == null ? null : JSON.stringify(meta), id])
}

async function archiveTeam(id, reason, succeededBy = null) {
  await query(
    `UPDATE teams SET status = 'archived', archived_at = NOW(), archived_reason = ?, succeeded_by = ?
     WHERE id = ? AND status = 'active'`,
    [reason, succeededBy, id],
  )
}

/**
 * Recompute the three denormalised counts from the projection.
 *
 * Derived in one statement rather than incremented as rows change, so a missed
 * delta can never leave a count drifting from the table it summarises — the count
 * is only ever as wrong as the projection is.
 */
async function recount(teamId) {
  await query(
    `UPDATE teams t SET
       member_count = (SELECT COUNT(*) FROM team_members m WHERE m.team_id = t.id AND m.status = 'active'),
       linked_count = (SELECT COUNT(*) FROM team_members m WHERE m.team_id = t.id AND m.status = 'active' AND m.user_id IS NOT NULL),
       online_count = (SELECT COUNT(*) FROM team_members m WHERE m.team_id = t.id AND m.status = 'active' AND m.online = 1)
     WHERE t.id = ?`,
    [teamId],
  )
}

// ── team_members ───────────────────────────────────────────────────────────

const MEMBER_COLUMNS = `
  team_id, member_key, display_name, user_id, is_leader, rank_label, online, status,
  first_seen_at, last_seen_at, departed_at`

async function membersByTeam(teamId, { includeDeparted = false } = {}) {
  return query(
    `SELECT ${MEMBER_COLUMNS} FROM team_members WHERE team_id = ?` +
      (includeDeparted ? '' : " AND status = 'active'") +
      ' ORDER BY is_leader DESC, display_name, member_key',
    [teamId],
  )
}

async function memberKeys(teamId) {
  const rows = await query("SELECT member_key FROM team_members WHERE team_id = ? AND status = 'active'", [teamId])
  return rows.map((r) => r.member_key)
}

async function findMember(teamId, memberKey) {
  const rows = await query(`SELECT ${MEMBER_COLUMNS} FROM team_members WHERE team_id = ? AND member_key = ?`,
    [teamId, memberKey])
  return rows[0]
}

/** The caller's ACTIVE membership of a team, or undefined. Path 1 of §2.5, and only path 1. */
async function activeByUser(teamId, userId) {
  const rows = await query(
    `SELECT ${MEMBER_COLUMNS} FROM team_members WHERE team_id = ? AND user_id = ? AND status = 'active'`,
    [teamId, userId],
  )
  return rows[0]
}

/** Every ACTIVE membership a user holds, with the team joined on. */
async function activeTeamsForUser(userId) {
  return query(
    `SELECT ${TEAM_COLUMNS.split(',').map((c) => `t.${c.trim()}`).join(', ')},
            m.member_key, m.is_leader, m.rank_label, m.display_name AS member_display_name
     FROM team_members m JOIN teams t ON t.id = m.team_id
     WHERE m.user_id = ? AND m.status = 'active' AND t.status = 'active'
     ORDER BY t.name`,
    [userId],
  )
}

/**
 * Insert or refresh one member row.
 *
 * `first_seen_at` is never overwritten, so a member who leaves and rejoins keeps
 * the date they first appeared; `status` returns to active on the same statement,
 * which is what makes a rejoin a revived row rather than a second one.
 *
 * **`is_leader` is set on INSERT only, and deliberately not on update.** Path 2 of
 * §2.5 is answered by `getTeamLeaders()`, not by the roster — two writers for one
 * column is how a refused leadership answer turns into a silent demotion, because
 * the roster would already have written `leader: false` before the authoritative
 * call was even made. Seeding it on insert means a Team whose leadership call is
 * failing is not leaderless from the start; after that, only setLeaders() moves it.
 */
async function upsertMember({ teamId, memberKey, displayName, userId, isLeader, rankLabel, online }) {
  await query(
    `INSERT INTO team_members (team_id, member_key, display_name, user_id, is_leader, rank_label, online)
     VALUES (?, ?, ?, ?, ?, ?, ?)
     ON DUPLICATE KEY UPDATE
       display_name = VALUES(display_name),
       user_id      = VALUES(user_id),
       rank_label   = VALUES(rank_label),
       online       = VALUES(online),
       status       = 'active',
       departed_at  = NULL,
       last_seen_at = NOW()`,
    [teamId, memberKey, displayName, userId, isLeader ? 1 : 0, rankLabel, online ? 1 : 0],
  )
}

/** Soft-depart the named members. Rows are kept so history and rejoins survive. */
async function markDeparted(teamId, memberKeys_) {
  if (!memberKeys_.length) return
  const holes = memberKeys_.map(() => '?').join(', ')
  await query(
    `UPDATE team_members SET status = 'departed', departed_at = NOW(), online = 0
     WHERE team_id = ? AND status = 'active' AND member_key IN (${holes})`,
    [teamId, ...memberKeys_],
  )
}

/** Set is_leader for a whole team in one pass — the sync's path-2 write. */
async function setLeaders(teamId, leaderKeys) {
  if (leaderKeys.length) {
    const holes = leaderKeys.map(() => '?').join(', ')
    await query(
      `UPDATE team_members SET is_leader = (member_key IN (${holes})) WHERE team_id = ?`,
      [...leaderKeys, teamId],
    )
  } else {
    await query('UPDATE team_members SET is_leader = 0 WHERE team_id = ?', [teamId])
  }
}

async function setMemberLeader(teamId, memberKey, isLeader) {
  await query('UPDATE team_members SET is_leader = ? WHERE team_id = ? AND member_key = ?',
    [isLeader ? 1 : 0, teamId, memberKey])
}

// ── team_sync_state ────────────────────────────────────────────────────────

async function syncState(moduleId) {
  const rows = await query(
    `SELECT module_id, last_attempt_at, last_success_at, consecutive_failures, last_error, pending_empty_since
     FROM team_sync_state WHERE module_id = ?`,
    [moduleId],
  )
  return rows[0]
}

async function recordAttempt(moduleId) {
  await query(
    `INSERT INTO team_sync_state (module_id, last_attempt_at) VALUES (?, NOW())
     ON DUPLICATE KEY UPDATE last_attempt_at = NOW()`,
    [moduleId],
  )
}

async function recordFailure(moduleId, error) {
  await query(
    `INSERT INTO team_sync_state (module_id, last_attempt_at, consecutive_failures, last_error)
     VALUES (?, NOW(), 1, ?)
     ON DUPLICATE KEY UPDATE
       last_attempt_at = NOW(),
       consecutive_failures = consecutive_failures + 1,
       last_error = VALUES(last_error)`,
    [moduleId, String(error || '').slice(0, 500)],
  )
}

async function recordSuccess(moduleId) {
  await query(
    `INSERT INTO team_sync_state (module_id, last_attempt_at, last_success_at, consecutive_failures, last_error)
     VALUES (?, NOW(), NOW(), 0, NULL)
     ON DUPLICATE KEY UPDATE
       last_attempt_at = NOW(), last_success_at = NOW(), consecutive_failures = 0, last_error = NULL`,
    [moduleId],
  )
}

/** Bumped only when a roster was actually APPLIED — never on a refused call. */
async function markRosterSynced(teamId) {
  await query('UPDATE teams SET roster_synced_at = NOW() WHERE id = ?', [teamId])
}

/** §2.4 gate 4's per-Team quarantine. `since = null` clears it. */
async function setMembersEmptySince(teamId, since) {
  await query('UPDATE teams SET members_empty_since = ? WHERE id = ?', [since, teamId])
}

/** The §2.4 gate-2 quarantine. `since = null` clears it. */
async function setPendingEmpty(moduleId, since) {
  await query(
    `INSERT INTO team_sync_state (module_id, pending_empty_since) VALUES (?, ?)
     ON DUPLICATE KEY UPDATE pending_empty_since = VALUES(pending_empty_since)`,
    [moduleId, since],
  )
}

module.exports = {
  activeByModule,
  allActive,
  findActive,
  findById,
  findBySlug,
  slugsLike,
  insertTeam,
  updateTeam,
  archiveTeam,
  recount,
  markRosterSynced,
  setMembersEmptySince,
  membersByTeam,
  memberKeys,
  findMember,
  activeByUser,
  activeTeamsForUser,
  upsertMember,
  markDeparted,
  setLeaders,
  setMemberLeader,
  syncState,
  recordAttempt,
  recordFailure,
  recordSuccess,
  setPendingEmpty,
}