// Updated NextAuth configuration with dynamic session timeout from database

import NextAuth, {
  NextAuthOptions,
  Session,
  User,
  Account
} from 'next-auth'
import { JWT } from "next-auth/jwt"
import CredentialsProvider from 'next-auth/providers/credentials'
import { SAMLProvider } from './saml/provider'
import { getUserById } from '@/lib/users/repository'
import { authenticateWithSGips, verifyExternalCredentials } from '@/lib/users/auth/verifyCredentails'
import { verifyOtpTemp } from '@/lib/users/verifyOtp'
import { getSecuritySettings } from '@/lib/password-policy/service'

// 인증 방식 타입 정의
type AuthMethod = 'otp' | 'email' | 'sgips' | 'saml'

// 모듈 보강 선언 (인증 방식 추가)
declare module "next-auth" {
  interface Session {
    user: {
      id: string
      name?: string | null
      email?: string | null
      image?: string | null
      companyId?: number | null
      techCompanyId?: number | null
      domain?: string | null
      reAuthTime?: number | null
      authMethod?: AuthMethod
      sessionExpiredAt?: number | null // 세션 만료 시간 추가
    }
  }

  interface User {
    id: string
    imageUrl?: string | null
    companyId?: number | null
    techCompanyId?: number | null
    domain?: string | null
    reAuthTime?: number | null
    authMethod?: AuthMethod
  }
}

declare module "next-auth/jwt" {
  interface JWT {
    id?: string
    imageUrl?: string | null
    companyId?: number | null
    techCompanyId?: number | null
    domain?: string | null
    reAuthTime?: number | null
    authMethod?: AuthMethod
    sessionExpiredAt?: number | null // 세션 만료 시간 추가
  }
}

// 보안 설정 캐시 (성능 최적화)
let securitySettingsCache: {
  data: any | null
  lastFetch: number
  ttl: number
} = {
  data: null,
  lastFetch: 0,
  ttl: 5 * 60 * 1000 // 5분 캐시
}

// 보안 설정을 가져오는 함수 (캐시 적용)
async function getCachedSecuritySettings() {
  const now = Date.now()
  
  if (!securitySettingsCache.data || 
      (now - securitySettingsCache.lastFetch) > securitySettingsCache.ttl) {
    try {
      securitySettingsCache.data = await getSecuritySettings()
      securitySettingsCache.lastFetch = now
    } catch (error) {
      console.error('Failed to fetch security settings:', error)
      // 기본값 사용
      securitySettingsCache.data = {
        sessionTimeoutMinutes: 480 // 8시간 기본값
      }
    }
  }
  
  return securitySettingsCache.data
}

export const authOptions: NextAuthOptions = {
  providers: [
    // OTP provider
    CredentialsProvider({
      name: 'Credentials',
      credentials: {
        email: { label: 'Email', type: 'text' },
        code: { label: 'OTP code', type: 'text' },
      },
      async authorize(credentials, req) {
        const { email, code } = credentials ?? {}

        const user = await verifyOtpTemp(email ?? '')
        if (!user) {
          return null
        }

        // 보안 설정에서 세션 타임아웃 가져오기
        const securitySettings = await getCachedSecuritySettings()
        const sessionTimeoutMs = securitySettings.sessionTimeoutMinutes * 60 * 1000
        const reAuthTime = Date.now()

        return {
          id: String(user.id ?? email ?? "dts"),
          email: user.email,
          imageUrl: user.imageUrl ?? null,
          name: user.name,
          companyId: user.companyId,
          techCompanyId: user.techCompanyId as number | undefined,
          domain: user.domain,
          reAuthTime,
          authMethod: 'otp' as AuthMethod,
        }
      },
    }),
    
    // ID/패스워드 provider (S-Gips와 일반 이메일 구분)
    CredentialsProvider({
      id: 'credentials-password',
      name: 'Username Password',
      credentials: {
        username: { label: "Username", type: "text" },
        password: { label: "Password", type: "password" },
        provider: { label: "Provider", type: "text" },
      },
      async authorize(credentials, req) {
        if (!credentials?.username || !credentials?.password) {
          return null;
        }
        
        try {
          let authResult;
          const isSSgips = credentials.provider === 'sgips';
          
          if (isSSgips) {
            authResult = await authenticateWithSGips(
              credentials.username,
              credentials.password
            );
          } else {
            authResult = await verifyExternalCredentials(
              credentials.username,
              credentials.password
            );
          }
          
          if (authResult.success && authResult.user) {
            return {
              id: authResult.user.id,
              name: authResult.user.name,
              email: authResult.user.email,
              imageUrl: authResult.user.imageUrl ?? null,
              companyId: authResult.user.companyId,
              techCompanyId: authResult.user.techCompanyId,
              domain: authResult.user.domain,
              reAuthTime: Date.now(),
              authMethod: isSSgips ? 'sgips' as AuthMethod : 'email' as AuthMethod,
            };
          }

          return null;
          
        } catch (error) {
          console.error("Authentication error:", error);
          return null;
        }
      }
    }),

    // SAML Provider
    SAMLProvider({
      id: "credentials-saml",
      name: "SAML SSO",
      idp: {
        sso_login_url: process.env.SAML_IDP_SSO_URL!,
        sso_logout_url: process.env.SAML_IDP_SLO_URL || '',
        certificates: [process.env.SAML_IDP_CERT!]
      },
      sp: {
        entity_id: process.env.SAML_SP_ENTITY_ID!,
        private_key: process.env.SAML_SP_PRIVATE_KEY || '',
        certificate: process.env.SAML_SP_CERT || '',
        assert_endpoint: process.env.SAML_SP_CALLBACK_URL || `${process.env.NEXTAUTH_URL}/api/saml/callback`
      }
    })
  ],

  session: {
    strategy: 'jwt',
    // JWT 기본 maxAge는 30일로 설정하되, 실제 세션 만료는 콜백에서 처리
    maxAge: 30 * 24 * 60 * 60, // 30일
  },

  callbacks: {
    // JWT 콜백 - 세션 타임아웃 설정 (만료 체크는 session 콜백에서)
    async jwt({ token, user, account, trigger, session }) {
      // 보안 설정 가져오기
      const securitySettings = await getCachedSecuritySettings()
      const sessionTimeoutMs = securitySettings.sessionTimeoutMinutes * 60 * 1000

      // 최초 로그인 시
      if (user) {
        const reAuthTime = Date.now()
        token.id = user.id
        token.email = user.email
        token.name = user.name
        token.companyId = user.companyId
        token.techCompanyId = user.techCompanyId
        token.domain = user.domain
        token.imageUrl = user.imageUrl
        token.reAuthTime = reAuthTime
        token.authMethod = user.authMethod
        token.sessionExpiredAt = reAuthTime + sessionTimeoutMs
      }

      // 인증 방식 결정 (account 정보 기반)
      if (account && !token.authMethod) {
        const reAuthTime = Date.now()
        if (account.provider === 'credentials-saml') {
          token.authMethod = 'saml'
          token.reAuthTime = reAuthTime
          token.sessionExpiredAt = reAuthTime + sessionTimeoutMs
        } else if (account.provider === 'credentials') {
          // OTP는 이미 user.authMethod에서 설정됨
          if (!token.sessionExpiredAt) {
            token.sessionExpiredAt = (token.reAuthTime || Date.now()) + sessionTimeoutMs
          }
        } else if (account.provider === 'credentials-password') {
          // credentials-password는 이미 user.authMethod에서 설정됨
          if (!token.sessionExpiredAt) {
            token.sessionExpiredAt = (token.reAuthTime || Date.now()) + sessionTimeoutMs
          }
        }
      }

      // 세션 업데이트 시 (재인증 시간 업데이트)
      if (trigger === "update" && session) {
        if (session.reAuthTime !== undefined) {
          token.reAuthTime = session.reAuthTime
          // 재인증 시간 업데이트 시 세션 만료 시간도 연장
          token.sessionExpiredAt = session.reAuthTime + sessionTimeoutMs
        }
        
        if (session.user) {
          if (session.user.name !== undefined) token.name = session.user.name
          if (session.user.email !== undefined) token.email = session.user.email
          if (session.user.image !== undefined) token.imageUrl = session.user.image
        }
      }

      return token
    },

    // Session 콜백 - 세션 만료 체크 및 정보 포함
    async session({ session, token }: { session: Session; token: JWT }) {
      // 세션 만료 체크
      if (token.sessionExpiredAt && Date.now() > token.sessionExpiredAt) {
        console.log(`Session expired for user ${token.email}. Expired at: ${new Date(token.sessionExpiredAt)}`)
        // 만료된 세션 처리 - 빈 세션 반환하여 로그아웃 유도
        return {
          expires: new Date(0).toISOString(), // 즉시 만료
          user: null as any
        }
      }

      if (token) {
        session.user = {
          id: token.id as string,
          email: token.email as string,
          name: token.name as string,
          domain: token.domain as string,
          companyId: token.companyId as number,
          techCompanyId: token.techCompanyId as number,
          image: token.imageUrl ?? null,
          reAuthTime: token.reAuthTime as number | null,
          authMethod: token.authMethod as AuthMethod,
          sessionExpiredAt: token.sessionExpiredAt as number | null,
        }
      }
      return session
    },

    // Redirect 콜백
    async redirect({ url, baseUrl }) {
      if (url.startsWith("/")) {
        return `${baseUrl}${url}`;
      }
      else if (new URL(url).origin === baseUrl) {
        return url;
      }
      return baseUrl;
    },
  },

  pages: {
    signIn: '/auth/login',
    error: '/auth/error',
  },

  // 디버깅을 위한 이벤트 로깅
  events: {
    async signIn({ user, account, profile }) {
      const securitySettings = await getCachedSecuritySettings()
      console.log(`User ${user.email} signed in via ${account?.provider} (authMethod: ${user.authMethod}), session timeout: ${securitySettings.sessionTimeoutMinutes} minutes`);
    },
    async signOut({ session, token }) {
      console.log(`User ${session?.user?.email || token?.email} signed out`);
    }
  }
}

const handler = NextAuth(authOptions)
export { handler as GET, handler as POST }