import 'reflect-metadata';

import { Writable } from 'node:stream';
import { createInterface } from 'node:readline/promises';
import { DataSource } from 'typeorm';
import { PasswordService } from '../auth/services/password.service';
import {
  AuditAction,
  AuditEvent,
  AuditSource,
  PHASE_A_ENTITIES,
  Role,
  User,
  UserRole,
  UserStatus,
} from '../database/entities';

function requiredEnvironmentVariable(key: string): string {
  const value = process.env[key];
  if (!value) throw new Error(`Missing required environment variable: ${key}`);
  return value;
}

function databasePort(): number {
  const port = Number(process.env.DB_PORT ?? 5432);
  if (!Number.isInteger(port) || port < 1 || port > 65535) {
    throw new Error('DB_PORT must be a valid TCP port');
  }
  return port;
}

function createRuntimeDataSource(): DataSource {
  return new DataSource({
    type: 'postgres',
    host: requiredEnvironmentVariable('DB_HOST'),
    port: databasePort(),
    database: requiredEnvironmentVariable('DB_NAME'),
    username: requiredEnvironmentVariable('DB_APP_USER'),
    password: requiredEnvironmentVariable('DB_APP_PASSWORD'),
    entities: PHASE_A_ENTITIES,
    synchronize: false,
    migrationsRun: false,
    logging: false,
    applicationName: 'dhv2-bootstrap-admin',
    connectTimeoutMS: 5000,
  });
}

class MutedOutput extends Writable {
  muted = false;

  override _write(
    chunk: Buffer | string,
    _encoding: BufferEncoding,
    callback: (error?: Error | null) => void,
  ): void {
    if (!this.muted) process.stdout.write(chunk);
    callback();
  }
}

function validatedText(
  label: string,
  value: string,
  maximumLength: number,
): string {
  const trimmed = value.trim();
  if (!trimmed) throw new Error(`${label} is required`);
  if (trimmed.length > maximumLength) {
    throw new Error(`${label} is too long`);
  }
  return trimmed;
}

async function main(): Promise<void> {
  if (!process.stdin.isTTY || !process.stdout.isTTY) {
    throw new Error('Bootstrap admin must run in an interactive terminal');
  }

  const dataSource = createRuntimeDataSource();
  await dataSource.initialize();

  try {
    const existing = (await dataSource.query(`
      SELECT COUNT(*)::integer AS count
      FROM user_roles user_role
      INNER JOIN roles role ON role.id = user_role.role_id
      WHERE role.code = 'admin'
    `)) as Array<{ count: number }>;
    if (Number(existing[0]?.count ?? 0) > 0) {
      throw new Error('An administrator already exists; bootstrap was cancelled');
    }

    const output = new MutedOutput();
    const prompt = createInterface({
      input: process.stdin,
      output,
      terminal: true,
    });

    let username = '';
    let email = '';
    let firstName = '';
    let lastName = '';
    let password = '';
    let passwordConfirmation = '';
    let mustChangeAnswer = '';

    try {
      username = validatedText(
        'Username',
        await prompt.question('Username: '),
        80,
      ).toLowerCase();
      if (!/^[a-z0-9._-]{3,80}$/.test(username)) {
        throw new Error(
          'Username must contain 3-80 letters, numbers, dots, underscores or hyphens',
        );
      }

      email = (await prompt.question('Email (optional): ')).trim().toLowerCase();
      if (
        email &&
        (email.length > 320 || !/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email))
      ) {
        throw new Error('Email is invalid');
      }
      firstName = validatedText(
        'First name',
        await prompt.question('Nombre: '),
        120,
      );
      lastName = validatedText(
        'Last name',
        await prompt.question('Apellido: '),
        120,
      );

      const askSecret = async (label: string): Promise<string> => {
        output.muted = false;
        const pending = prompt.question(label);
        output.muted = true;
        const answer = await pending;
        output.muted = false;
        process.stdout.write('\n');
        return answer;
      };

      password = await askSecret('Contraseña (mínimo 12 caracteres): ');
      passwordConfirmation = await askSecret('Repetir contraseña: ');
      mustChangeAnswer = (
        await prompt.question('¿Forzar cambio en el primer ingreso? [S/n]: ')
      )
        .trim()
        .toLowerCase();
    } finally {
      prompt.close();
    }

    if (password.length < 12 || password.length > 128) {
      throw new Error('Password must contain between 12 and 128 characters');
    }
    if (password !== passwordConfirmation) {
      throw new Error('Password confirmation does not match');
    }
    const mustChangePassword = !['n', 'no'].includes(mustChangeAnswer);
    const passwordHash = await new PasswordService().hash(password);

    await dataSource.transaction(async (manager) => {
      await manager.query(
        "SELECT pg_advisory_xact_lock(hashtext('dhv2-bootstrap-admin'))",
      );

      const adminCount = (await manager.query(`
        SELECT COUNT(*)::integer AS count
        FROM user_roles user_role
        INNER JOIN roles role ON role.id = user_role.role_id
        WHERE role.code = 'admin'
      `)) as Array<{ count: number }>;
      if (Number(adminCount[0]?.count ?? 0) > 0) {
        throw new Error('An administrator already exists; bootstrap was cancelled');
      }

      const duplicate = (await manager.query(
        `
          SELECT 1
          FROM users
          WHERE LOWER(username) = $1
             OR ($2::text IS NOT NULL AND LOWER(email) = $2)
          LIMIT 1
        `,
        [username, email || null],
      )) as unknown[];
      if (duplicate.length > 0) {
        throw new Error('Username or email already exists');
      }

      const adminRole = await manager.getRepository(Role).findOne({
        where: { code: 'admin' },
      });
      if (!adminRole) throw new Error('Admin role seed is missing');

      const user = manager.getRepository(User).create({
        username,
        email: email || null,
        passwordHash,
        firstName,
        lastName,
        status: UserStatus.ACTIVE,
        mustChangePassword,
        failedLoginAttempts: 0,
        lockedUntil: null,
        lastLoginAt: null,
        passwordChangedAt: new Date(),
        createdBy: null,
        updatedBy: null,
      });
      await manager.getRepository(User).save(user);
      await manager.getRepository(UserRole).save(
        manager.getRepository(UserRole).create({
          userId: user.id,
          roleId: adminRole.id,
          assignedAt: new Date(),
          assignedBy: user.id,
        }),
      );
      await manager.getRepository(AuditEvent).save(
        manager.getRepository(AuditEvent).create({
          actorUserId: user.id,
          actorUsername: user.username,
          action: AuditAction.SYSTEM_BOOTSTRAP_ADMIN_CREATED,
          entityType: 'user',
          entityId: user.id,
          requestId: null,
          source: AuditSource.SYSTEM,
          ip: null,
          userAgent: null,
          beforeData: null,
          afterData: {
            username: user.username,
            email: user.email,
            firstName: user.firstName,
            lastName: user.lastName,
            status: user.status,
            mustChangePassword: user.mustChangePassword,
            roles: ['admin'],
          },
          metadata: { bootstrap: true },
        }),
      );

      process.stdout.write(`Administrador creado: ${user.username}\n`);
    });
  } finally {
    await dataSource.destroy();
  }
}

main().catch((error: unknown) => {
  const message = error instanceof Error ? error.message : 'Unknown bootstrap error';
  process.stderr.write(`Bootstrap cancelado: ${message}\n`);
  process.exitCode = 1;
});