classDiagram
    %% Controller Package
    class AbhaRegistrationController {
        +generateSessionToken() ResponseEntity~SessionTokenResponse~
        +getPublicCertificate() ResponseEntity~PublicKeyResponse~
        +requestAadhaarOtp(AadhaarOtpRequest) ResponseEntity~OtpResponse~
        +resendAadhaarOtp(ResendOtpRequest) ResponseEntity~OtpResponse~
        +enrollAbha(AbhaEnrollmentRequest) ResponseEntity~AbhaEnrollmentResponse~
    }

    %% Service Package
    class AbhaRegistrationService {
        <<interface>>
        +generateSessionToken() SessionTokenResponse
        +getPublicCertificate() PublicKeyResponse
        +requestAadhaarOtp(AadhaarOtpRequest) OtpResponse
        +resendAadhaarOtp(ResendOtpRequest) OtpResponse
        +enrollAbha(AbhaEnrollmentRequest) AbhaEnrollmentResponse
    }

    class AbhaRegistrationServiceImpl {
        -authenticationService AuthenticationService
        -encryptionService EncryptionService
        -restTemplate RestTemplate
        -objectMapper ObjectMapper
        -applicationProperties ApplicationProperties
        +generateSessionToken() SessionTokenResponse
        +getPublicCertificate() PublicKeyResponse
        +requestAadhaarOtp(AadhaarOtpRequest) OtpResponse
        +resendAadhaarOtp(ResendOtpRequest) OtpResponse
        +enrollAbha(AbhaEnrollmentRequest) AbhaEnrollmentResponse
    }

    class AuthenticationService {
        <<interface>>
        +generateSessionToken() String
    }

    class AuthenticationServiceImpl {
        -restTemplate RestTemplate
        -objectMapper ObjectMapper
        -applicationProperties ApplicationProperties
        +generateSessionToken() String
    }

    class EncryptionService {
        <<interface>>
        +getPublicKey() String
        +encryptWithPublicKey(data String, publicKey String) String
    }

    class EncryptionServiceImpl {
        -restTemplate RestTemplate
        -objectMapper ObjectMapper
        -applicationProperties ApplicationProperties
        +getPublicKey() String
        +encryptWithPublicKey(data String, publicKey String) String
    }

    %% Model Request Package
    class AadhaarOtpRequest {
        -txnId String
        -scope List~String~
        -loginHint String
        -loginId String
        -otpSystem String
    }

    class ResendOtpRequest {
        -txnId String
        -scope List~String~
        -loginHint String
        -loginId String
        -otpSystem String
    }

    class AbhaEnrollmentRequest {
        -authData AuthData
        -consent Consent
    }

    class AuthData {
        -authMethods List~String~
        -otp OtpData
    }

    class OtpData {
        -txnId String
        -otpValue String
        -mobile String
    }

    class Consent {
        -code String
        -version String
    }

    %% Model Response Package
    class SessionTokenResponse {
        -accessToken String
        -expiresIn Long
        -refreshToken String
        -refreshExpiresIn Long
        -tokenType String
    }

    class PublicKeyResponse {
        -publicKey String
        -keyId String
    }

    class OtpResponse {
        -txnId String
        -status String
        -message String
    }

    class AbhaEnrollmentResponse {
        -abhaNumber String
        -phrAddress String
        -name String
        -gender String
        -yearOfBirth String
        -monthOfBirth String
        -dayOfBirth String
        -mobile String
        -authMethods List~String~
        -accessToken String
        -refreshToken String
    }

    %% Config Package
    class ApplicationProperties {
        -abhaBaseUrl String
        -clientId String
        -clientSecret String
        -sessionEndpoint String
        -publicKeyEndpoint String
        -otpRequestEndpoint String
        -enrollmentEndpoint String
    }

    class RestTemplateConfig {
        +restTemplate() RestTemplate
        +objectMapper() ObjectMapper
    }

    class GlobalExceptionHandler {
        +handleApiException(ApiException) ResponseEntity~ErrorResponse~
        +handleValidationException(ValidationException) ResponseEntity~ErrorResponse~
        +handleGeneralException(Exception) ResponseEntity~ErrorResponse~
    }

    %% Exception Package
    class ApiException {
        -errorCode String
        -errorMessage String
        -httpStatus HttpStatus
    }

    class ValidationException {
        -errors Map~String,String~
    }

    class ErrorResponse {
        -timestamp LocalDateTime
        -status int
        -error String
        -message String
        -path String
    }

    %% Util Package
    class HeaderUtil {
        +generateRequestId()$ String
        +getTimestamp()$ String
        +addCommonHeaders(HttpHeaders)$ HttpHeaders
    }

    class RsaEncryptionUtil {
        +encrypt(data String, publicKey String)$ String
    }

    %% Relationships
    AbhaRegistrationController --> AbhaRegistrationService
    AbhaRegistrationService <|.. AbhaRegistrationServiceImpl
    AbhaRegistrationServiceImpl --> AuthenticationService
    AbhaRegistrationServiceImpl --> EncryptionService
    AuthenticationService <|.. AuthenticationServiceImpl
    EncryptionService <|.. EncryptionServiceImpl

    AbhaRegistrationServiceImpl --> ApplicationProperties
    AuthenticationServiceImpl --> ApplicationProperties
    EncryptionServiceImpl --> ApplicationProperties
    AbhaRegistrationServiceImpl ..> HeaderUtil
    EncryptionServiceImpl ..> RsaEncryptionUtil

    AbhaRegistrationServiceImpl ..> AadhaarOtpRequest
    AbhaRegistrationServiceImpl ..> ResendOtpRequest
    AbhaRegistrationServiceImpl ..> AbhaEnrollmentRequest
    AbhaRegistrationServiceImpl ..> SessionTokenResponse
    AbhaRegistrationServiceImpl ..> PublicKeyResponse
    AbhaRegistrationServiceImpl ..> OtpResponse
    AbhaRegistrationServiceImpl ..> AbhaEnrollmentResponse

    AbhaEnrollmentRequest *-- AuthData
    AuthData *-- OtpData
    AbhaEnrollmentRequest *-- Consent

    RestTemplateConfig ..> ApplicationProperties
    GlobalExceptionHandler ..> ErrorResponse
    GlobalExceptionHandler ..> ApiException
    GlobalExceptionHandler ..> ValidationException