import NextAuth, { NextAuthOptions } from "next-auth";
import { JWT } from "next-auth/jwt";
import KeycloakProvider from "next-auth/providers/keycloak";
import { jwtDecode } from "jwt-decode";
import { DEFAULT_AUTH_COOKIE_OPTIONS } from "@/lib/cookies";

interface KeycloakProfile {
  sub: string;
  email?: string;
  name?: string;
  roles?: string[];
  preferred_username?: string;
  given_name?: string;
  family_name?: string;
  realm_access?: {
    roles: string[];
  };
}

interface DecodedToken {
  realm_access?: {
    roles: string[];
  };
  [key: string]: any;
}

declare module "next-auth" {
  interface Session {
    user: {
      id: string;
      name?: string | null;
      email?: string | null;
      image?: string | null;
      username: string;
      first_name: string;
      last_name: string;
      role: string[];
      nextcloudInitialized?: boolean;
    };
    accessToken?: string;
  }

  interface JWT {
    sub?: string;
    accessToken?: string;
    refreshToken?: string;
    accessTokenExpires?: number;
    role?: string[];
    username?: string;
    first_name?: string;
    last_name?: string;
    error?: string;
    email?: string | null;
    name?: string | null;
  }
}

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

async function refreshAccessToken(token: JWT) {
  try {
    console.log('Refreshing access token...');
    
    const response = await fetch(`${process.env.KEYCLOAK_ISSUER}/protocol/openid-connect/token`, {
      method: "POST",
      headers: { 
        "Content-Type": "application/x-www-form-urlencoded" 
      },
      body: new URLSearchParams({
        client_id: process.env.KEYCLOAK_CLIENT_ID!,
        client_secret: process.env.KEYCLOAK_CLIENT_SECRET!,
        grant_type: "refresh_token",
        refresh_token: token.refreshToken!,
      }),
    });

    const refreshedTokens = await response.json();

    if (!response.ok) {
      console.error('Token refresh failed:', refreshedTokens);
      throw refreshedTokens;
    }

    console.log('Token refreshed successfully');
    
    return {
      ...token,
      accessToken: refreshedTokens.access_token,
      refreshToken: refreshedTokens.refresh_token ?? token.refreshToken,
      accessTokenExpires: Date.now() + refreshedTokens.expires_in * 1000,
    };
  } catch (error) {
    console.error("Error refreshing access token:", error);
    return {
      ...token,
      error: "RefreshAccessTokenError",
    };
  }
}

export const authOptions: NextAuthOptions = {
  providers: [
    KeycloakProvider({
      clientId: getRequiredEnvVar("KEYCLOAK_CLIENT_ID"),
      clientSecret: getRequiredEnvVar("KEYCLOAK_CLIENT_SECRET"),
      issuer: getRequiredEnvVar("KEYCLOAK_ISSUER"),
      authorization: {
        params: {
          scope: "openid profile email roles"
        }
      },
      profile(profile) {
        console.log('Keycloak profile callback:', {
          email: profile.email,
          name: profile.name,
          sub: profile.sub,
          roles: profile.realm_access?.roles || []
        });

        // Get roles from realm_access
        const roles = profile.realm_access?.roles || [];

        // Clean up roles by removing ROLE_ prefix and converting to lowercase
        const cleanRoles = roles.map((role: string) => 
          role.replace(/^ROLE_/, '').toLowerCase()
        );

        return {
          id: profile.sub,
          name: profile.name ?? profile.preferred_username,
          email: profile.email,
          first_name: profile.given_name ?? '',
          last_name: profile.family_name ?? '',
          username: profile.preferred_username ?? profile.email?.split('@')[0] ?? '',
          role: cleanRoles,
        }
      },
    }),
  ],
  session: {
    strategy: "jwt",
    maxAge: 30 * 24 * 60 * 60, // 30 days
  },
  cookies: {
    sessionToken: {
      name: `next-auth.session-token`,
      options: {
        ...DEFAULT_AUTH_COOKIE_OPTIONS,
        httpOnly: true
      }
    },
    callbackUrl: {
      name: `next-auth.callback-url`,
      options: DEFAULT_AUTH_COOKIE_OPTIONS
    },
    csrfToken: {
      name: `next-auth.csrf-token`,
      options: {
        ...DEFAULT_AUTH_COOKIE_OPTIONS,
        httpOnly: true
      }
    }
  },
  callbacks: {
    async jwt({ token, account, profile }) {
      // Initial sign in
      if (account && profile) {
        const keycloakProfile = profile as KeycloakProfile;
        const roles = keycloakProfile.realm_access?.roles || [];
        const cleanRoles = roles.map((role: string) => 
          role.replace(/^ROLE_/, '').toLowerCase()
        );

        return {
          ...token,
          accessToken: account.access_token,
          refreshToken: account.refresh_token,
          accessTokenExpires: account.expires_at ? account.expires_at * 1000 : 0,
          sub: keycloakProfile.sub,
          role: cleanRoles,
          username: keycloakProfile.preferred_username ?? '',
          first_name: keycloakProfile.given_name ?? '',
          last_name: keycloakProfile.family_name ?? '',
        };
      }

      // Return the previous token if the access token has not expired
      if (token.accessTokenExpires && Date.now() < token.accessTokenExpires) {
        return token;
      }

      // Access token has expired, try to refresh it
      return refreshAccessToken(token);
    },
    async session({ session, token }) {
      if (token.error) {
        throw new Error(token.error);
      }

      const userRoles = Array.isArray(token.role) ? token.role : [];
      session.user = {
        id: token.sub ?? '',
        email: token.email ?? null,
        name: token.name ?? null,
        image: null,
        username: token.username ?? '',
        first_name: token.first_name ?? '',
        last_name: token.last_name ?? '',
        role: userRoles,
        nextcloudInitialized: false,
      };
      session.accessToken = token.accessToken;

      return session;
    }
  },
  pages: {
    signIn: '/signin',
    error: '/signin',
  },
  debug: process.env.NODE_ENV === 'development',
  logger: {
    error(code, metadata) {
      console.error(`Auth error: ${code}`, metadata);
    },
    warn(code) {
      console.warn(`Auth warning: ${code}`);
    },
    debug(code, metadata) {
      if (process.env.NODE_ENV === 'development') {
        console.debug(`Auth debug: ${code}`, metadata);
      }
    }
  }
};

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