// ── SQL for zone presets, and what each server said about its zone mods ──────
//
// The presets are the module's own (PLAN_REDESIGNS §3.1, D195). What a server
// has — its ZoneManager's flag list (D211), ZoneDomes and the domes helper (D194)
// — is read out of the hello each server's state row keeps whole (`raw`), so the
// preset form works while a server is off.

const core = require('../../core')

const PRESETS = 'rust_zone_presets'
const PRESET_SERVERS = 'rust_zone_preset_servers'
const SERVERS = 'rust_servers'
const STATE = 'rust_server_state'

/** The driver hands JSON_EXTRACT and TEXT back as strings. A bad value is no value. */
function json(value, fallback) {
  if (value === null || value === undefined) return fallback
  if (typeof value !== 'string') return value
  try {
    return JSON.parse(value)
  } catch {
    return fallback
  }
}

function shape(row, serverIds) {
  return {
    id: Number(row.id),
    name: row.name,
    flags: json(row.flags, []),
    settings: json(row.settings, {}),
    allServers: Boolean(row.allServers),
    servers: serverIds,
    updatedAt: row.updatedAt ? new Date(row.updatedAt).toISOString() : null,
  }
}

/** Every preset, with the servers each names, oldest first. */
async function listPresets() {
  const [rows, links] = await Promise.all([
    core.query(
      `SELECT id, name, flags, settings, all_servers AS allServers, updated_at AS updatedAt
         FROM ${PRESETS} ORDER BY name ASC, id ASC`,
    ),
    core.query(`SELECT preset_id AS presetId, server_id AS serverId FROM ${PRESET_SERVERS} ORDER BY server_id ASC`),
  ])
  const by = new Map()
  for (const l of links) {
    const id = Number(l.presetId)
    if (!by.has(id)) by.set(id, [])
    by.get(id).push(l.serverId)
  }
  return rows.map((r) => shape(r, by.get(Number(r.id)) || []))
}

async function getPreset(id) {
  const rows = await core.query(
    `SELECT id, name, flags, settings, all_servers AS allServers, updated_at AS updatedAt
       FROM ${PRESETS} WHERE id = ?`,
    [id],
  )
  if (!rows[0]) return null
  const links = await core.query(`SELECT server_id AS serverId FROM ${PRESET_SERVERS} WHERE preset_id = ? ORDER BY server_id ASC`, [id])
  return shape(rows[0], links.map((l) => l.serverId))
}

/**
 * Writes one preset and replaces its server list. The model has checked every
 * server exists first, so the inserts below have nothing left to refuse. The
 * list is written in one statement, so a preset is never left half-listed.
 */
async function savePreset({ id = null, name, flags, settings, allServers, servers }, userId = null) {
  let presetId = id
  if (presetId) {
    await core.query(
      `UPDATE ${PRESETS} SET name = ?, flags = ?, settings = ?, all_servers = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?`,
      [name, JSON.stringify(flags), JSON.stringify(settings), allServers ? 1 : 0, presetId],
    )
    await core.query(`DELETE FROM ${PRESET_SERVERS} WHERE preset_id = ?`, [presetId])
  } else {
    const res = await core.query(
      `INSERT INTO ${PRESETS} (name, flags, settings, all_servers, created_by) VALUES (?, ?, ?, ?, ?)`,
      [name, JSON.stringify(flags), JSON.stringify(settings), allServers ? 1 : 0, userId],
    )
    presetId = Number(res.insertId)
  }
  if (!allServers && servers.length > 0) {
    await core.query(
      `INSERT INTO ${PRESET_SERVERS} (preset_id, server_id) VALUES ${servers.map(() => '(?, ?)').join(', ')}`,
      servers.flatMap((serverId) => [presetId, serverId]),
    )
  }
  return presetId
}

async function deletePreset(id) {
  await core.query(`DELETE FROM ${PRESETS} WHERE id = ?`, [id])
}

/**
 * Each configured server, in the operator's order, with what its last hello said
 * about ZoneManager (`{ version, flags }`) and ZoneDomes (`{ loaded, version,
 * helper, ready }`). Either is null for a server that never said: no ZoneManager,
 * a plugin before protocol 13, or a server never reached.
 */
async function listZoneServers() {
  const rows = await core.query(
    `SELECT s.id, s.name, s.enabled,
            JSON_EXTRACT(st.raw, '$.zoneManager') AS zoneManager,
            JSON_EXTRACT(st.raw, '$.integrations.zoneDomes') AS zoneDomes
       FROM ${SERVERS} s
       LEFT JOIN ${STATE} st ON st.server_id = s.id
      ORDER BY s.sort_order ASC, s.id ASC`,
  )
  return rows.map((r) => {
    const zm = json(r.zoneManager, null)
    const zd = json(r.zoneDomes, null)
    return {
      id: r.id,
      name: r.name,
      enabled: Boolean(r.enabled),
      zoneManager:
        zm && typeof zm === 'object'
          ? {
              version: typeof zm.version === 'string' ? zm.version : null,
              flags: Array.isArray(zm.flags) ? zm.flags.filter((f) => typeof f === 'string') : null,
            }
          : null,
      zoneDomes:
        zd && typeof zd === 'object'
          ? {
              loaded: zd.loaded === true,
              version: typeof zd.version === 'string' ? zd.version : null,
              helper: zd.helper && typeof zd.helper.state === 'string' ? zd.helper : null,
              ready: zd.ready === true,
            }
          : null,
    }
  })
}

module.exports = { PRESETS, PRESET_SERVERS, listPresets, getPreset, savePreset, deletePreset, listZoneServers }