// SQL for the integration bridge's configuration (TEAMS.md §7.2, phase 8).
//
// One table, and almost all of its subtlety is in the schema comment rather than
// here: `team_key` is a generated `IFNULL(team_id, 0)`, so the deployment-wide
// default and the per-Team overrides live under one UNIQUE key without the
// default row needing a NULL in a primary key it cannot have.
//
// **Reads join `teams` and callers get the Team's name.** Not for display alone:
// the resolver's answer is the input to a message that names a Team, and a second
// round trip per notification to fetch a name the first query already walked past
// is the kind of thing that only shows up under a busy forum.

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

const COLUMNS = `
  c.id, c.platform, c.team_id, c.events, c.channel_ref, c.enabled,
  c.members_ack, c.members_ack_by, c.members_ack_at, c.updated_at`

/**
 * Every row for a platform — the default first, then the overrides by Team name.
 *
 * The admin panel's whole listing, in one query. `team_name` is NULL on exactly
 * one row (the default), which is also how the client tells them apart without
 * needing to reason about `team_id`.
 */
async function listForPlatform(platform) {
  return query(
    `SELECT ${COLUMNS}, t.name AS team_name, t.slug AS team_slug, t.display_name_override,
            u.username AS members_ack_username
       FROM team_integration_config c
       LEFT JOIN teams t ON t.id = c.team_id
       LEFT JOIN users u ON u.id = c.members_ack_by
      WHERE c.platform = ?
      ORDER BY c.team_id IS NOT NULL, COALESCE(t.name, '')`,
    [platform],
  )
}

/**
 * The row that governs `teamId`, or null.
 *
 * `team_key` is what makes this one query rather than two: asking for the pair
 * (0, teamId) returns the default and the override together, and `ORDER BY
 * team_key DESC LIMIT 1` puts the override first when it exists. A caller that
 * fetched the default and then looked for an override would do two round trips
 * per notification for an answer the index already holds.
 */
async function resolveFor(platform, teamId) {
  const rows = await query(
    `SELECT ${COLUMNS}, t.name AS team_name, t.display_name_override
       FROM team_integration_config c
       LEFT JOIN teams t ON t.id = c.team_id
      WHERE c.platform = ? AND c.team_key IN (0, ?)
      ORDER BY c.team_key DESC
      LIMIT 1`,
    [platform, Number(teamId)],
  )
  return rows[0] || null
}

async function getById(id) {
  const rows = await query(
    `SELECT ${COLUMNS}, t.name AS team_name FROM team_integration_config c
       LEFT JOIN teams t ON t.id = c.team_id
      WHERE c.id = ? LIMIT 1`,
    [Number(id)],
  )
  return rows[0] || null
}

async function getForTeam(platform, teamId) {
  const rows = await query(
    `SELECT ${COLUMNS} FROM team_integration_config c
      WHERE c.platform = ? AND c.team_key = ? LIMIT 1`,
    [platform, teamId === null || teamId === undefined ? 0 : Number(teamId)],
  )
  return rows[0] || null
}

/**
 * Create or replace the row for (platform, team).
 *
 * A full replace rather than a patch, and the acknowledgement columns are part of
 * what is replaced — the model decides what they should be, because "did the
 * channel change" is a comparison against the row that is about to be overwritten
 * and only the model has both halves.
 */
async function upsert({ platform, teamId, events, channelRef, enabled, membersAck, membersAckBy, membersAckAt }) {
  await query(
    `INSERT INTO team_integration_config
       (platform, team_id, events, channel_ref, enabled, members_ack, members_ack_by, members_ack_at)
     VALUES (?, ?, ?, ?, ?, ?, ?, ?)
     ON DUPLICATE KEY UPDATE
       events = VALUES(events),
       channel_ref = VALUES(channel_ref),
       enabled = VALUES(enabled),
       members_ack = VALUES(members_ack),
       members_ack_by = VALUES(members_ack_by),
       members_ack_at = VALUES(members_ack_at)`,
    [
      platform,
      teamId === null || teamId === undefined ? null : Number(teamId),
      JSON.stringify(events || []),
      channelRef || null,
      enabled ? 1 : 0,
      membersAck ? 1 : 0,
      membersAckBy || null,
      membersAckAt || null,
    ],
  )
  return getForTeam(platform, teamId)
}

async function remove(platform, teamId) {
  const res = await query('DELETE FROM team_integration_config WHERE platform = ? AND team_key = ?', [
    platform,
    teamId === null || teamId === undefined ? 0 : Number(teamId),
  ])
  return Number(res && res.affectedRows) || 0
}

module.exports = { listForPlatform, resolveFor, getById, getForTeam, upsert, remove }