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 { getUserByEmail, 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'
import { verifySmsToken, verifyEmailToken } from '@/lib/users/auth/passwordUtil'
import { SessionRepository } from '@/lib/users/session/repository'
import { getUserRoles } from '@/lib/users/service'


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


// ✅ 모듈 보강 선언 - roles 배열 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
      ownerCompanyId?: number | null
      domain?: string | null
      reAuthTime?: number | null
      authMethod?: AuthMethod
      sessionExpiredAt?: number | null
      dbSessionId?: string | null
      roles?: string[]  // ✅ roles 배열 추가
    }
  }

  interface User {
    id: string
    imageUrl?: string | null
    companyId?: number | null
    techCompanyId?: number | null
    ownerCompanyId?: number | null
    domain?: string | null
    reAuthTime?: number | null
    authMethod?: AuthMethod
    dbSessionId?: string | null
    roles?: string[]  // ✅ roles 배열 추가
  }
}

declare module "next-auth/jwt" {
  interface JWT {
    id?: string
    imageUrl?: string | null
    companyId?: number | null
    techCompanyId?: number | null
    ownerCompanyId?: number | null
    domain?: string | null
    reAuthTime?: number | null
    authMethod?: AuthMethod
    sessionExpiredAt?: number | null
    dbSessionId?: string | null
    roles?: string[]  // ✅ roles 배열 추가
  }
}

// 타입 변환 헬퍼 함수들
function ensureString(value: string | number): string {
  return String(value)
}

function ensureNumber(value: string | number): number {
  return typeof value === 'string' ? parseInt(value, 10) : value
}

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

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)
      securitySettingsCache.data = {
        sessionTimeoutMinutes: 480
      }
    }
  }

  return securitySettingsCache.data
}

// 클라이언트 IP 추출 헬퍼
function getClientIP(req: any): string {
  const forwarded = req.headers['x-forwarded-for']
  const realIP = req.headers['x-real-ip']

  if (forwarded) {
    return forwarded.split(',')[0].trim()
  }

  if (realIP) {
    return realIP
  }

  return req.ip || req.connection?.remoteAddress || '127.0.0.1'
}

export const authOptions: NextAuthOptions = {
  providers: [
    // ✅ OTP 로그인 - roles 정보 추가
    CredentialsProvider({
      id: 'credentials-otp',
      name: 'OTP',
      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
        }

        // ✅ 사용자 roles 정보 조회
        const userRoles = await getUserRoles(user.id)

        const securitySettings = await getCachedSecuritySettings()
        const reAuthTime = Date.now()

        return {
          id: ensureString(user.id),
          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,
          roles: userRoles,  // ✅ roles 배열 추가
        }
      },
    }),

    // ✅ MFA 완료 후 최종 인증 - roles 정보 추가 (SMS/Email OTP 지원)
    CredentialsProvider({
      id: 'credentials-mfa',
      name: 'MFA Verification',
      credentials: {
        userId: { label: 'User ID', type: 'text' },
        smsToken: { label: 'SMS Token', type: 'text' }, // SMS 또는 Email OTP 토큰
        tempAuthKey: { label: 'Temp Auth Key', type: 'text' },
        mfaType: { label: 'MFA Type', type: 'text' }, // 'sms' 또는 'email'
      },
      async authorize(credentials, req) {
        if (!credentials?.userId || !credentials?.smsToken || !credentials?.tempAuthKey) {
          console.error('MFA credentials missing')
          return null
        }

        const numericUserId = ensureNumber(credentials.userId)
        const user = await getUserById(numericUserId)
        if (!user) {
          console.error('User not found after MFA verification')
          return null
        }

        try {
          // DB에서 임시 인증 정보 확인
          const tempAuth = await SessionRepository.getTempAuthSession(credentials.tempAuthKey)
          if (!tempAuth || ensureNumber(tempAuth.userId) !== user.id) {
            console.error('Temp auth expired or not found')
            return null
          }

          // MFA 타입에 따라 SMS 또는 Email OTP 검증
          const mfaType = credentials.mfaType || 'sms'; // 기본값은 SMS
          let verificationResult;

          if (mfaType === 'email') {
            verificationResult = await verifyEmailToken(user.id, credentials.smsToken)
            console.log(`Email OTP verification for user ${user.email}:`, verificationResult.success)
          } else {
            verificationResult = await verifySmsToken(user.id, credentials.smsToken)
            console.log(`SMS OTP verification for user ${user.email}:`, verificationResult.success)
          }

          if (!verificationResult || !verificationResult.success) {
            console.error(`${mfaType.toUpperCase()} token verification failed`)
            return null
          }

          // 임시 인증 정보를 사용됨으로 표시
          await SessionRepository.markTempAuthSessionAsUsed(credentials.tempAuthKey)

          // ✅ 사용자 roles 정보 조회
          const userRoles = await getUserRoles(user.id)

          // 보안 설정 및 세션 정보 설정
          const securitySettings = await getCachedSecuritySettings()
          const reAuthTime = Date.now()
          const sessionExpiredAt = new Date(reAuthTime + (securitySettings.sessionTimeoutMinutes * 60 * 1000))

          // DB에 로그인 세션 생성
          const ipAddress = getClientIP(req)
          const userAgent = req.headers?.['user-agent']

          const dbSession = await SessionRepository.createLoginSession({
            userId: user.id,
            ipAddress,
            userAgent,
            authMethod: tempAuth.authMethod,
            sessionExpiredAt,
          })

          console.log(`MFA completed for user ${user.email} (${tempAuth.authMethod})`)

          return {
            id: ensureString(user.id),
            email: user.email,
            imageUrl: user.imageUrl ?? null,
            name: user.name,
            companyId: user.companyId,
            techCompanyId: user.techCompanyId as number | undefined,
            domain: user.domain,
            reAuthTime,
            authMethod: tempAuth.authMethod as AuthMethod,
            dbSessionId: dbSession.id,
            roles: userRoles,  // ✅ roles 배열 추가
            epId: user.epId, // Knox 계정인 경우, epId 추가 (Knox API 사용하는 경우 필요)
          }

        } catch (error) {
          console.error('MFA authorization error:', error)
          return null
        }
      },
    }),

    // 1차 인증용 프로바이더 (기존 유지)
    CredentialsProvider({
      id: 'credentials-first-auth',
      name: 'First Factor Authentication',
      credentials: {
        username: { label: "Username", type: "text" },
        password: { label: "Password", type: "password" },
        provider: { label: "Provider", type: "text" },
      },
      async authorize(credentials, req) {
        return null
      }
    }),

    // SAML Provider (기존 유지)
    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',
    maxAge: 30 * 24 * 60 * 60,
  },

  callbacks: {
    // ✅ JWT callback에 roles 정보 추가
    // JWT callback 수정
    async jwt({ token, user, account, trigger, session }) {
      const securitySettings = await getCachedSecuritySettings()
      const sessionTimeoutMs = securitySettings.sessionTimeoutMinutes * 60 * 1000

      // 최초 로그인 시 (MFA 완료 후)
      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
        token.dbSessionId = user.dbSessionId
        token.roles = user.roles
        token.ownerCompanyId = user.ownerCompanyId
      }

      // ✅ 기존 토큰이 있고 로그인이 아닌 경우, DB에서 최신 사용자 정보 조회
      if (token.id && !user && trigger !== "update") {
        try {
          const latestUser = await getUserById(parseInt(token.id))

          if (latestUser) {
            // 도메인이 변경되었다면 토큰 업데이트
            if (token.domain !== latestUser.domain) {
              console.log(`Domain changed for user ${token.email}: ${token.domain} -> ${latestUser.domain}`)
              token.domain = latestUser.domain
            }

            // 기타 정보도 최신 상태로 업데이트
            token.name = latestUser.name
            token.companyId = latestUser.companyId
            token.techCompanyId = latestUser.techCompanyId
            token.ownerCompanyId = latestUser.ownerCompanyId

            // roles 정보도 최신으로 업데이트
            const userRoles = await getUserRoles(parseInt(token.id))
            token.roles = userRoles
          }
        } catch (error) {
          console.error('Failed to fetch latest user info in JWT callback:', error)
        }
      }

      // SAML 인증 시 DB 세션 생성 및 roles 조회
      if (account && account.provider === 'credentials-saml' && token.id) {
        const reAuthTime = Date.now()
        const sessionExpiredAt = new Date(reAuthTime + sessionTimeoutMs)

        try {
          const numericUserId = ensureNumber(token.id)

          // SAML 로그인 시에도 최신 사용자 정보 조회
          const latestUser = await getUserById(numericUserId)
          if (latestUser) {
            token.domain = latestUser.domain
            token.name = latestUser.name
            token.companyId = latestUser.companyId
            token.techCompanyId = latestUser.techCompanyId
            token.ownerCompanyId = latestUser.ownerCompanyId
            token.roles = await getUserRoles(numericUserId)
          }

          const dbSession = await SessionRepository.createLoginSession({
            userId: numericUserId,
            ipAddress: '0.0.0.0',
            authMethod: 'saml',
            sessionExpiredAt,
          })

          token.authMethod = 'saml'
          token.reAuthTime = reAuthTime
          token.sessionExpiredAt = reAuthTime + sessionTimeoutMs
          token.dbSessionId = dbSession.id
        } catch (error) {
          console.error('Failed to create SAML session:', error)
        }
      }

      // 세션 업데이트 시
      if (trigger === "update" && session) {
        if (session.reAuthTime !== undefined) {
          token.reAuthTime = session.reAuthTime
          token.sessionExpiredAt = session.reAuthTime + sessionTimeoutMs

          // DB 세션 업데이트
          if (token.dbSessionId) {
            await SessionRepository.updateLoginSession(token.dbSessionId, {
              lastActivityAt: new Date(),
              sessionExpiredAt: new Date(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

          // ✅ 세션 업데이트 시 도메인 정보도 갱신 가능
          if (session.user.domain !== undefined) token.domain = session.user.domain
        }
      }

      return token
    }
,
    // ✅ Session callback에 roles 정보 추가
    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)}`)

        // DB 세션 만료 처리
        if (token.dbSessionId) {
          await SessionRepository.logoutSession(token.dbSessionId)
        }

        return {
          expires: new Date(0).toISOString(),
          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,
          ownerCompanyId: token.ownerCompanyId as number,
          image: token.imageUrl ?? null,
          reAuthTime: token.reAuthTime as number | null,
          authMethod: token.authMethod as AuthMethod,
          sessionExpiredAt: token.sessionExpiredAt as number | null,
          dbSessionId: token.dbSessionId as string | null,
          roles: token.roles as string[] || [],  // ✅ roles 정보 추가
        }
      }
      return session
    },

    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',
  },

  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`);

      // 이미 MFA에서 DB 세션이 생성된 경우가 아니라면 여기서 생성
      if (account?.provider !== 'credentials-mfa' && user.id) {
        try {
          const numericUserId = ensureNumber(user.id)

          // 기존 활성 세션 확인
          const existingSession = await SessionRepository.getActiveSessionByUserId(numericUserId)
          if (!existingSession) {
            const sessionExpiredAt = new Date(Date.now() + (securitySettings.sessionTimeoutMinutes * 60 * 1000))

            await SessionRepository.createLoginSession({
              userId: numericUserId,
              ipAddress: '0.0.0.0',
              authMethod: user.authMethod || 'unknown',
              sessionExpiredAt,
            })
          }
        } catch (error) {
          console.error('Failed to create session in signIn event:', error)
        }
      }
    },

    async signOut({ session, token }) {
      console.log(`User ${session?.user?.email || token?.email} signed out`);

      // DB에서 세션 로그아웃 처리
      const userId = session?.user?.id || token?.id
      const dbSessionId = session?.user?.dbSessionId || token?.dbSessionId

      if (dbSessionId) {
        await SessionRepository.logoutSession(dbSessionId)
      } else if (userId) {
        // dbSessionId가 없는 경우 사용자의 모든 활성 세션 로그아웃
        const numericUserId = ensureNumber(userId)
        await SessionRepository.logoutAllUserSessions(numericUserId)
      }
    }
  }
}

const handler = NextAuth(authOptions)

export { handler as GET, handler as POST }