// Self-service account security for the logged-in user (any role). Mounted under
// the admin router (so isLoggedIn has already run and req.user is the fresh DB
// row), but NOT behind the admin-only gate — editors manage their own 2FA too.

const users = require('../../../model/users/users.model')
const activity = require('../../../model/activity/activity.model')
const userIdentities = require('../../../model/userIdentities/userIdentities.model')
const mobileSessions = require('../../../model/mobileSessions/mobileSessions.model')
const trustedDevices = require('../../../model/trustedDevices/trustedDevices.model')
const recoveryCodes = require('../../../model/recoveryCodes/recoveryCodes.model')
const sessionService = require('../../../auth/session.service')
const { establishTrust } = require('../auth/trustDevice.helper')
const { setAuthCookie, setTrustCookie, clearTrustCookie } = require('../../../auth/token')
const usernamePolicy = require('../../../auth/usernamePolicy')
const loginProtection = require('../../../middleware/loginProtection')
const botScore = require('../../../middleware/botScore')
const totp = require('../../../utils/totp')

const log = require('../../../utils/logger')('account')

// Current user's security status (does not expose the secret). has_password lets
// the player portal tell an SSO-only account (must *set* a password, no current
// one required) apart from one that already has a usable password. req.user is the
// sanitized row (password_hash stripped), so read the raw row for that one flag.
async function getAccount(req, res) {
  try {
    const raw = await users.getRawById(req.user.id)
    return res.json({
      id: req.user.id,
      username: req.user.username,
      role: req.user.role,
      email: req.user.email || null,
      status: req.user.status || 'active',
      totp_enabled: Boolean(req.user.totp_enabled),
      has_password: Boolean(raw && raw.password_hash),
    })
  } catch (err) {
    log.error('getAccount', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Re-mint this caller's session and refresh their cookie so a self-service change
// (username/password) doesn't log them out. Returns the new Session object.
function reissueSession(req, res, user) {
  const { token: sessionToken, session } = sessionService.createSession(user, req.authMethod || 'local')
  setAuthCookie(req, res, sessionToken)
  return session
}

// PATCH /account/username — change the caller's own username. The DB UNIQUE index
// is the source of truth for collisions (case-insensitive via the column's _ci
// collation): attempt the write and translate a duplicate-key error into 409.
async function changeUsername(req, res) {
  const check = usernamePolicy.validateUsername(req.body.username)
  if (!check.ok) return res.status(400).json({ message: check.message })
  try {
    if (check.name === req.user.username) {
      return res.status(400).json({ message: 'That is already your username.' })
    }
    let updated
    try {
      updated = await users.update(req.user.id, { username: check.name })
    } catch (err) {
      if (users.isDuplicateUsername(err)) {
        return res.status(409).json({ message: 'That username is already taken.' })
      }
      throw err
    }
    // The JWT embeds username; authz always uses the fresh DB row, but re-issue
    // the cookie so nothing downstream renders a stale name. No global revocation
    // — a username isn't a secret.
    reissueSession(req, res, updated)
    await activity.log({ req, action: 'account.username.change', detail: { username: updated.username } })
    log.info('account username changed', { id: req.user.id, username: updated.username })
    return res.json({ username: updated.username })
  } catch (err) {
    log.error('changeUsername', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// PATCH /account/password — change (or set) the caller's own password.
//   • Account already has a password: require currentPassword and verify it.
//   • SSO-provisioned account with a null hash: allow setting an initial password
//     with no current password required.
// users.update rotates the hash and revokes existing sessions; we then re-issue
// this caller's session so their own change doesn't log them out.
async function changePassword(req, res) {
  try {
    const raw = await users.getRawById(req.user.id)
    if (!raw) return res.status(401).json({ message: 'Unauthorized' })

    if (raw.password_hash) {
      const ok = await users.validatePassword(raw, req.body.currentPassword || '')
      if (!ok) {
        // A wrong current password is credential-guessing — trip the same
        // backoff + bot scoring as a failed login.
        loginProtection.recordFailure(req.ip)
        botScore.recordLoginFailure(req.ip)
        log.warn('changePassword wrong current password', { id: req.user.id, ip: req.ip })
        return res.status(400).json({ message: 'Your current password is incorrect.' })
      }
    }

    // Rotate the hash + revoke every existing session (users.update bumps the cutoff).
    const updated = await users.update(req.user.id, { password: req.body.newPassword })
    // Re-issue this caller's session, then rewind the cutoff just below the new
    // token's issued-at so the inclusive cutoff test doesn't catch it (see users.db).
    const session = reissueSession(req, res, updated)
    if (session && session.createdAt) {
      await users.setSessionCutoff(req.user.id, new Date(session.createdAt - 1000))
    }
    // A password change is a security event: drop every trusted device and every
    // recovery code so a compromised-then-changed account can't be re-entered with
    // a stale second-factor bypass. Clear this browser's trust cookie too.
    await trustedDevices.revokeAllForUser(req.user.id)
    await recoveryCodes.clearForUser(req.user.id)
    clearTrustCookie(req, res)
    await activity.log({ req, action: 'account.password.change' })
    log.info('account password changed', { id: req.user.id })
    return res.json({ ok: true })
  } catch (err) {
    log.error('changePassword', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Step 1: generate a fresh secret (stored but not yet enabled) and return the
// otpauth URL + a QR data URL for the user to scan. Overwrites any pending,
// not-yet-confirmed secret. Refuses if TOTP is already enabled.
async function totpSetup(req, res) {
  try {
    if (req.user.totp_enabled) {
      return res.status(409).json({ message: 'Two-factor is already enabled. Disable it first to re-enroll.' })
    }
    const { base32, otpauthUrl } = totp.generateSecret(req.user.username)
    await users.setTotpSecret(req.user.id, base32)
    const qr = await totp.qrDataUrl(otpauthUrl)
    log.info('totp setup started', { id: req.user.id, username: req.user.username })
    return res.json({ otpauthUrl, qr })
  } catch (err) {
    log.error('totpSetup', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Step 2: confirm one code against the pending secret, then flip totp_enabled on.
async function totpEnable(req, res) {
  try {
    const user = await users.getRawById(req.user.id)
    if (!user || !user.totp_secret) {
      return res.status(400).json({ message: 'Start setup before enabling two-factor.' })
    }
    if (user.totp_enabled) {
      return res.status(409).json({ message: 'Two-factor is already enabled.' })
    }
    if (!totp.verifyCode(user.totp_secret, req.body.code)) {
      return res.status(400).json({ message: 'That code is not valid. Try again.' })
    }
    await users.enableTotp(user.id)
    // Issue the initial batch of single-use recovery codes, shown to the user ONCE
    // right here (the only time they leave the server in the clear). Generation
    // replaces any prior set, so re-enrolling always starts clean.
    const codes = await recoveryCodes.generateForUser(user.id)
    await activity.log({ req, action: 'account.totp.enable' })
    await activity.log({ req, action: 'account.recovery_codes.generate', detail: { count: codes.length } })
    log.info('totp enabled', { id: user.id, username: user.username })
    return res.json({ totp_enabled: true, recoveryCodes: codes })
  } catch (err) {
    log.error('totpEnable', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Turn TOTP off. Require a current code to prove the requester still controls the
// authenticator (so a walk-up on an open session can't quietly remove 2FA).
async function totpDisable(req, res) {
  try {
    const user = await users.getRawById(req.user.id)
    if (!user || !user.totp_enabled) {
      return res.status(400).json({ message: 'Two-factor is not enabled.' })
    }
    if (!totp.verifyCode(user.totp_secret, req.body.code)) {
      return res.status(400).json({ message: 'That code is not valid. Try again.' })
    }
    await users.disableTotp(user.id)
    // With 2FA off, both the trusted-device bypass and recovery codes are moot and
    // must not linger — drop them so re-enabling later starts from a clean slate.
    await trustedDevices.revokeAllForUser(user.id)
    await recoveryCodes.clearForUser(user.id)
    clearTrustCookie(req, res)
    await activity.log({ req, action: 'account.totp.disable' })
    log.info('totp disabled', { id: user.id, username: user.username })
    return res.json({ totp_enabled: false })
  } catch (err) {
    log.error('totpDisable', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// ── Linked SSO identities (self-service) ──────────────────────────────────
// List the external accounts (Google/Discord/…) linked to the current user.
// Linking itself happens via the SSO redirect flow (/auth/sso/:provider/link).
async function listIdentities(req, res) {
  try {
    const rows = await userIdentities.listForUser(req.user.id)
    return res.json(rows.map((r) => ({ provider: r.provider, email: r.email, linked_at: r.created_at })))
  } catch (err) {
    log.error('listIdentities', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Remove a linked SSO identity from the current user's account.
async function unlinkIdentity(req, res) {
  const { provider } = req.params
  try {
    const removed = await userIdentities.unlink(req.user.id, provider)
    if (!removed) return res.status(404).json({ message: 'No linked account for that provider.' })
    await activity.log({ req, action: 'auth.sso.unlink', detail: { provider } })
    log.info('sso identity unlinked', { provider, id: req.user.id })
    return res.json({ unlinked: true })
  } catch (err) {
    log.error('unlinkIdentity', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// List the current user's active mobile device sessions (the "Active Devices"
// surface). Never exposes the token hash — only labels + timestamps.
async function listSessions(req, res) {
  try {
    const rows = await mobileSessions.listActiveForUser(req.user.id)
    return res.json(
      rows.map((r) => ({
        id: r.id,
        deviceName: r.device_name || null,
        userAgent: r.user_agent || null,
        createdAt: r.created_at,
        lastUsedAt: r.last_used_at || r.created_at,
        expiresAt: r.expires_at,
      })),
    )
  } catch (err) {
    log.error('listSessions', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Revoke one of the current user's mobile device sessions by id (ownership-scoped
// in the query so a user can only revoke their own). Idempotent.
async function revokeSession(req, res) {
  const id = Number(req.params.id)
  try {
    const n = await mobileSessions.revokeByIdForUser(id, req.user.id)
    if (n) {
      await activity.log({ req, action: 'auth.mobile.session.revoke', detail: { sessionRowId: id } })
      log.info('mobile session revoked (self)', { id, userId: req.user.id })
    }
    return res.json({ revoked: n > 0 })
  } catch (err) {
    log.error('revokeSession', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// ── Trusted devices (self-service) ─────────────────────────────────────────
// Shape a trusted_devices row for the client (never the token hash).
function toTrustedDevice(r) {
  return {
    id: r.id,
    platform: r.platform,
    deviceName: r.device_name || null,
    userAgent: r.user_agent || null,
    createdAt: r.created_at,
    lastUsedAt: r.last_used_at || r.created_at,
    expiresAt: r.expires_at,
  }
}

// List the current user's active trusted devices (Trusted Devices screen).
async function listTrustedDevices(req, res) {
  try {
    const rows = await trustedDevices.listActiveForUser(req.user.id)
    return res.json(rows.map(toTrustedDevice))
  } catch (err) {
    log.error('listTrustedDevices', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Trust the CURRENT device/browser from an authenticated session. This is the
// "revoke one, then retry" completion after a cap-reached prompt, and a general
// self-service way to trust the device you're on. Web receives the token as the
// httpOnly rg_trust cookie; native (bearer) sessions get it in the JSON body.
async function trustThisDevice(req, res) {
  try {
    const isMobile = (req.session?.authMethod || req.authMethod) === 'mobile'
    const result = await establishTrust(req, req.user, {
      platform: isMobile ? 'mobile' : 'web',
      deviceName: req.body.deviceName || null,
    })
    if (!result.ok && result.capReached) {
      return res.status(409).json({ error: 'trusted_device_limit', devices: result.devices.map(toTrustedDevice) })
    }
    if (!isMobile) {
      setTrustCookie(req, res, result.trustToken)
      return res.json({ trusted: true })
    }
    return res.json({ trusted: true, trustToken: result.trustToken })
  } catch (err) {
    log.error('trustThisDevice', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Revoke one of the current user's trusted devices by id (ownership-scoped).
async function revokeTrustedDevice(req, res) {
  const id = Number(req.params.id)
  try {
    const n = await trustedDevices.revokeByIdForUser(id, req.user.id)
    if (n) {
      await activity.log({ req, action: 'account.trusted_device.revoke', detail: { deviceId: id } })
      log.info('trusted device revoked (self)', { id, userId: req.user.id })
    }
    return res.json({ revoked: n > 0 })
  } catch (err) {
    log.error('revokeTrustedDevice', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Revoke ALL of the current user's trusted devices ("untrust everywhere"), and
// clear this browser's trust cookie.
async function revokeAllTrustedDevices(req, res) {
  try {
    const n = await trustedDevices.revokeAllForUser(req.user.id)
    clearTrustCookie(req, res)
    await activity.log({ req, action: 'account.trusted_device.revoke_all', detail: { count: n } })
    log.info('all trusted devices revoked (self)', { userId: req.user.id, count: n })
    return res.json({ revoked: n })
  } catch (err) {
    log.error('revokeAllTrustedDevices', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// ── Recovery codes (self-service) ──────────────────────────────────────────
// Remaining (unused) code count — never the codes themselves.
async function recoveryCodesStatus(req, res) {
  try {
    const remaining = await recoveryCodes.remainingForUser(req.user.id)
    return res.json({ remaining })
  } catch (err) {
    log.error('recoveryCodesStatus', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

// Regenerate the recovery-code set, returning the new codes ONCE. Password
// step-up: an account that has a password must supply and match currentPassword
// (SSO-only accounts with no password may proceed while authenticated, mirroring
// changePassword). Refuses when 2FA is off (codes only exist alongside TOTP).
async function generateRecoveryCodes(req, res) {
  try {
    const raw = await users.getRawById(req.user.id)
    if (!raw) return res.status(401).json({ message: 'Unauthorized' })
    if (!raw.totp_enabled) {
      return res.status(400).json({ message: 'Enable two-factor before generating recovery codes.' })
    }
    if (raw.password_hash) {
      const ok = await users.validatePassword(raw, req.body.currentPassword || '')
      if (!ok) {
        loginProtection.recordFailure(req.ip)
        botScore.recordLoginFailure(req.ip)
        log.warn('generateRecoveryCodes wrong current password', { id: req.user.id, ip: req.ip })
        return res.status(400).json({ message: 'Your current password is incorrect.' })
      }
    }
    const codes = await recoveryCodes.generateForUser(req.user.id)
    await activity.log({ req, action: 'account.recovery_codes.generate', detail: { count: codes.length } })
    log.info('recovery codes regenerated', { id: req.user.id })
    return res.json({ recoveryCodes: codes })
  } catch (err) {
    log.error('generateRecoveryCodes', err)
    return res.status(500).json({ message: 'Internal Server Error' })
  }
}

module.exports = {
  getAccount,
  changeUsername,
  changePassword,
  totpSetup,
  totpEnable,
  totpDisable,
  listIdentities,
  unlinkIdentity,
  listSessions,
  revokeSession,
  listTrustedDevices,
  trustThisDevice,
  revokeTrustedDevice,
  revokeAllTrustedDevices,
  recoveryCodesStatus,
  generateRecoveryCodes,
}