import {
  checkAdminSecret,
  setLegacyAuthCookie
} from '../../utils/access'
import { createApiError } from '../../utils/api-error'
import {
  createSession,
  isInitialized,
  rowToAuthUser,
  verifyPassword
} from '../../utils/auth'
import { findUserByUsername } from '../../utils/db'
import { getAdminSecret } from '../../utils/env'
import { verifyLoginVerification, type VerificationBody } from '../../utils/login-verification'
import { clientIp, logInfo, logWarn } from '../../utils/logger'

interface LoginBody extends VerificationBody {
  username?: string
  password?: string
  secret?: string
}

const loginAttempts = new Map<string, { count: number, resetAt: number }>()
const MAX_ATTEMPTS = 10
const WINDOW_MS = 15 * 60 * 1000

function checkRateLimit(ip: string): void {
  const now = Date.now()
  const entry = loginAttempts.get(ip)
  if (!entry || now > entry.resetAt) {
    loginAttempts.set(ip, { count: 1, resetAt: now + WINDOW_MS })
    return
  }
  entry.count += 1
  if (entry.count > MAX_ATTEMPTS) {
    throw createError({
      statusCode: 429,
      statusMessage: '登录尝试过于频繁，请稍后再试'
    })
  }
}

export default defineEventHandler(async (event) => {
  const ip = clientIp(event)
  checkRateLimit(ip)

  const body = await readBody<LoginBody>(event)
  await verifyLoginVerification(event, body ?? {})
  const initialized = isInitialized()

  if (!initialized) {
    const adminSecret = getAdminSecret(event)
    if (!adminSecret) {
      createApiError(event, 'FORBIDDEN', '请先完成系统初始化', 403)
    }

    const input = body?.secret?.trim()
    if (!input || !(await checkAdminSecret(input, adminSecret))) {
      logWarn('legacy login failed: invalid secret', { ip })
      createApiError(event, 'UNAUTHORIZED', '密钥错误', 401)
    }

    await setLegacyAuthCookie(event, adminSecret)
    logInfo('legacy login success', { ip })

    return { success: true, needsMigration: true }
  }

  const username = body?.username?.trim() ?? ''
  const password = body?.password ?? ''

  if (!username || !password) {
    createApiError(event, 'INVALID_REQUEST', '请输入用户名和密码', 400)
  }

  const user = findUserByUsername(username)
  if (!user || !verifyPassword(password, user.password_hash)) {
    logWarn('login failed: invalid credentials', { ip, username })
    createApiError(event, 'UNAUTHORIZED', '用户名或密码错误', 401)
  }

  await createSession(event, user.id)
  logInfo('login success', { ip, username: user.username })

  return {
    success: true,
    user: rowToAuthUser(user)
  }
})