import { Router } from 'express'
import bcrypt from 'bcrypt'
import { validateBody } from '../middleware/validate.js'
import { asyncHandler } from '../utils/asyncHandler.js'
import { AppError } from '../middleware/error.js'
import { getDb } from '../db/database.js'
import * as userRepo from '../repositories/userRepo.js'
import * as settingsRepo from '../repositories/settingsRepo.js'
import { setupSchema } from '../validators/setupSchemas.js'
import { signToken } from '../utils/tokens.js'

const router = Router()

const SALT_ROUNDS = 10

function getSiteTitle(): string | null {
  return settingsRepo.getSetting('site_name') ?? null
}

// GET /api/setup/status
router.get(
  '/status',
  asyncHandler(async (_req, res) => {
    const title = getSiteTitle()
    res.json({
      completed: !!title,
      siteTitle: title ?? undefined,
    })
  })
)

// POST /api/setup
router.post(
  '/',
  validateBody(setupSchema),
  asyncHandler(async (req, res) => {
    const db = getDb()

    // Atomic transaction prevents race conditions between concurrent setup requests
    const tx = db.transaction(() => {
      const title = settingsRepo.getSetting('site_name')
      if (title) {
        throw new AppError(400, 'Setup already completed')
      }

      const userCount = userRepo.countUsers()
      if (userCount > 0) {
        throw new AppError(400, 'Users already exist')
      }

      const {
        email,
        password,
        displayName,
        siteTitle,
        language,
        smtpHost,
        smtpPort,
        smtpUser,
        smtpPass,
        smtpFrom,
        smtpSecure,
        appUrl,
      } = req.body

      const passwordHash = bcrypt.hashSync(password, SALT_ROUNDS)

      const { id } = userRepo.createUser({
        email,
        passwordHash,
        displayName,
        role: 'admin',
        emailVerified: 1,
      })

      const settings: Array<[string, string]> = [
        ['site_name', siteTitle?.trim() || 'BrainWave'],
        ['site_language', language || 'en'],
        ['maintenance_mode', 'false'],
      ]

      if (smtpHost !== undefined) settings.push(['smtp_host', smtpHost])
      if (smtpPort !== undefined) settings.push(['smtp_port', smtpPort])
      if (smtpUser !== undefined) settings.push(['smtp_user', smtpUser])
      if (smtpPass !== undefined) settings.push(['smtp_pass', smtpPass])
      if (smtpFrom !== undefined) settings.push(['smtp_from', smtpFrom])
      if (smtpSecure !== undefined) settings.push(['smtp_secure', smtpSecure])
      if (appUrl !== undefined) settings.push(['app_url', appUrl])

      settingsRepo.setSettingsBatch(settings)

      return { id, email, displayName }
    })

    const { id, email, displayName } = tx()

    const token = signToken({
      userId: id,
      email,
      displayName,
      role: 'admin',
    })

    res.status(201).json({
      message: 'Setup completed successfully',
      token,
      user: {
        id,
        email,
        displayName,
        role: 'admin',
      },
    })
  })
)

export default router