import type { Handler } from 'hono';
import { createUser, updateUser, getUserByEmail, getUserByUsername, USER_ROLES } from 'officerdb';
import type { UserRole } from 'officerdb';
import argon2 from 'argon2';
import * as errors from '@@/custom-errors';
import { provisionUserDirs } from '@@/data-path';
import { OS_USERS_ENABLED, ensureOsUser } from '@@/os-user';
import { validatePassword } from '../auth/validate-password';
import { validateUsername } from '../auth/validate-username';
import { toPublicUser } from './manage-users';

// The owner creating a second account. Until this existed, `createUser` had exactly one call site —
// `auth/bootstrap.ts`, gated on an empty user table — so every non-owner account on any instance had
// been inserted into Postgres by hand.
//
// ── Why the owner sets the password ──
//
// The alternative is an invite: a token emailed to the person, who then sets their own. That is the
// better shape and it needs a mail path, a token table and an expiry policy. This is the honest
// intermediate: the owner types a password and tells the person, the same way they would hand over a
// wifi key. `passwordChangedAt` stays null, so nothing pretends the person chose it.
//
// ── Status is 'Active', deliberately ──
//
// The column defaults to 'Unverified' and `signin.ts` refuses anything that is not 'Active' with a bare
// UNAUTHORIZED. So an account created at the default would be indistinguishable from a wrong password,
// which is precisely the trap the hand-INSERT route fell into. An account the owner created in the admin
// UI is verified by definition — the owner is the verification.

/** Roles this route may assign. Never 'Super Admin' — see below. */
const ASSIGNABLE_ROLES = USER_ROLES.filter((r) => r !== 'Super Admin');

export const createUserHandler: Handler = async function (ctx) {
  const body = (ctx.get('body') ?? {}) as Record<string, unknown>;

  const email = typeof body.email === 'string' ? body.email.trim().toLowerCase() : '';
  const name = typeof body.name === 'string' ? body.name.trim() : '';
  const password = typeof body.password === 'string' ? body.password : '';
  const role = typeof body.role === 'string' ? body.role : 'Member';

  if (!email || !/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email)) throw errors.BAD_REQUEST('Invalid email address');
  if (!name) throw errors.BAD_REQUEST('Name is required');

  // The same validators bootstrap uses. A member's password protects the same surface a member can
  // reach, so there is no argument for a weaker rule here — and two different rules would mean the
  // owner could create an account that could not then change its own password to something similar.
  const username = validateUsername(typeof body.username === 'string' ? body.username : undefined);
  validatePassword(password);

  // Refused rather than filtered, so the owner is told instead of quietly getting a Member.
  //
  // There is exactly one owner. The database only pins user 1's role — a row-level CHECK cannot say
  // "no OTHER row may hold this" — so a second Super Admin is storable, and `getOwnerUser()` would then
  // return whichever the query reached first. That answer decides the identity the agent sidecar runs
  // as, who reaches the vault and which origin is privileged, so it is not a thing to leave to a query
  // plan. If the owner ever needs to hand the server over, that is a deliberate transfer, not a dropdown.
  if (!(ASSIGNABLE_ROLES as readonly string[]).includes(role)) {
    throw errors.BAD_REQUEST(
      role === 'Super Admin'
        ? 'There is one server owner and it cannot be created here.'
        : `Role must be one of: ${ASSIGNABLE_ROLES.join(', ')}`,
    );
  }

  // Checked before the insert purely for the message — both columns are unique, so the database is the
  // real guard and this is a race it can lose harmlessly (the insert then throws).
  if (await getUserByEmail(email)) throw errors.CONFLICT('An account with that email already exists');
  if (await getUserByUsername(username)) throw errors.CONFLICT('That username is taken');

  const user = await createUser({
    email,
    password: await argon2.hash(password),
    name,
    username,
    status: 'Active',
    role: role as UserRole,
  });

  // After the row, and not fatal if it fails. A missing directory is repairable from a shell
  // (`bun scripts/provision-user-dirs.ts <email>`); an account that half-exists because mkdir failed
  // is not, and the owner would have to go into Postgres to clean it up — the exact thing this route
  // is here to stop being necessary.
  try {
    provisionUserDirs(email);
  } catch (ex) {
    console.warn(`[users] created ${email} but could not provision its data directories`, ex);
  }

  // The Linux account, when the host is set up for it. Same posture as the directories and for the same
  // reason: this is a side effect of creating a platform account, and a failed `useradd` must not undo an
  // account that otherwise exists and can sign in. The row simply keeps `osUser: null`, which every
  // consumer already has to handle — that is what an account made before this feature looks like.
  //
  // Reported back in the response rather than only logged, so the owner sees "created, but no OS account"
  // at the moment they click rather than discovering it when a terminal opens in the wrong home.
  let osUser: string | null = null;
  let osUserError: string | null = null;
  if (OS_USERS_ENABLED) {
    const result = await ensureOsUser({ email, username });
    if (result.ok) {
      osUser = result.osUser;
      await updateUser(user.id, { osUser: result.osUser });
    } else {
      osUserError = result.error;
      console.warn(`[users] created ${email} but could not create its Linux account: ${result.error}`);
    }
  }

  return ctx.json({ user: { ...toPublicUser(user), osUser }, osUserError }, 201);
};