// ! adapted from https://github.com/f-23/react-native-passkey/blob/fdcf7cf297debb247ada6317337767072158629c/ios/PasskeyDelegate.swift
import Foundation
import AuthenticationServices
import ExpoModulesCore

protocol PasskeyResultHandler {
  func onSuccess(_ data: PublicKeyCredentialJSON)
  func onFailure(_ error: Error)
}


class PasskeyDelegate: NSObject, ASAuthorizationControllerDelegate, ASAuthorizationControllerPresentationContextProviding  {
    private let handler: PasskeyResultHandler 

    init(handler: PasskeyResultHandler) {
        self.handler = handler
    }

    // Perform the authorization request for a given ASAuthorizationController instance
    @available(iOS 15.0, *)
    func performAuthForController(controller: ASAuthorizationController) {
        controller.delegate = self;
        controller.presentationContextProvider = self;
        controller.performRequests();
    }

    @available(iOS 13.0, *)
    func presentationAnchor(for controller: ASAuthorizationController) -> ASPresentationAnchor {
        return UIApplication.shared.keyWindow ?? ASPresentationAnchor()
    }

    
    @available(iOS 13.0, *)
    func authorizationController(
        controller: ASAuthorizationController,
        didCompleteWithError error: Error
    ) {
        handler.onFailure(error)
    }

    @available(iOS 15.0, *)
    func authorizationController(controller: ASAuthorizationController,
                                 didCompleteWithAuthorization authorization: ASAuthorization) {

        switch (authorization.credential) {
        case let credential as ASAuthorizationPlatformPublicKeyCredentialRegistration:
            if credential.rawAttestationObject == nil {
                handler.onFailure((ASAuthorizationError(ASAuthorizationError.Code.failed)))
            }
            
            var largeBlob: AuthenticationExtensionsLargeBlobOutputsJSON?
            if #available(iOS 17.0, *) {
                largeBlob = AuthenticationExtensionsLargeBlobOutputsJSON(
                    supported: Field.init(wrappedValue: credential.largeBlob?.isSupported)
                )
            }
            
            let clientExtensionResults = AuthenticationExtensionsClientOutputsJSON(
                largeBlob: Field.init(wrappedValue: largeBlob)
            )

            let response =  AuthenticatorAttestationResponseJSON(
                clientDataJSON: Field.init(wrappedValue: credential.rawClientDataJSON.toBase64URLEncodedString()),
                attestationObject: Field.init(wrappedValue: credential.rawAttestationObject!.toBase64URLEncodedString())
            )
            
            let registrationResult =  RegistrationResponseJSON(
                id: Field.init(wrappedValue: credential.credentialID.toBase64URLEncodedString()),
                rawId: Field.init(wrappedValue: credential.credentialID.toBase64URLEncodedString()),
                response: Field.init(wrappedValue: response),
                clientExtensionResults: Field.init(wrappedValue: clientExtensionResults)
            )
            
            handler.onSuccess(Either(registrationResult))
        
        case let credential as ASAuthorizationSecurityKeyPublicKeyCredentialRegistration:
            if credential.rawAttestationObject == nil {
                handler.onFailure((ASAuthorizationError(ASAuthorizationError.Code.failed)))
            }
            
            let response =  AuthenticatorAttestationResponseJSON(
                clientDataJSON: Field.init(wrappedValue: credential.rawClientDataJSON.toBase64URLEncodedString()),
                attestationObject: Field.init(wrappedValue: credential.rawAttestationObject!.toBase64URLEncodedString())
            )
            
            let registrationResult =  RegistrationResponseJSON(
                id: Field.init(wrappedValue: credential.credentialID.toBase64URLEncodedString()),
                rawId: Field.init(wrappedValue: credential.credentialID.toBase64URLEncodedString()),
                response: Field.init(wrappedValue: response)
            )
            
            handler.onSuccess(Either(registrationResult))
            
        case let credential as ASAuthorizationPlatformPublicKeyCredentialAssertion:
            var largeBlob: AuthenticationExtensionsLargeBlobOutputsJSON? = AuthenticationExtensionsLargeBlobOutputsJSON()
            if #available(iOS 17.0, *), let result = credential.largeBlob?.result {
                switch (result) {
                case .read(data: let blobData):
                    largeBlob?.blob = blobData?.toBase64URLEncodedString()
                case .write(success: let successfullyWritten):
                    largeBlob?.written = successfullyWritten
                @unknown default: break
                }
            }
            
            let clientExtensionResults = AuthenticationExtensionsClientOutputsJSON(largeBlob: Field.init(wrappedValue: largeBlob))
        
            let response = AuthenticatorAssertionResponseJSON(
                authenticatorData: Field.init(wrappedValue: credential.rawAuthenticatorData.toBase64URLEncodedString()),
                clientDataJSON: Field.init(wrappedValue: credential.rawClientDataJSON.toBase64URLEncodedString()),
                signature: Field.init(wrappedValue: credential.signature!.toBase64URLEncodedString()),
                userHandle: Field.init(wrappedValue: credential.userID!.toBase64URLEncodedString())
            )
            
            
            let assertionResult = AuthenticationResponseJSON(
                id: Field.init(wrappedValue: credential.credentialID.toBase64URLEncodedString()),
                rawId: Field.init(wrappedValue: credential.credentialID.toBase64URLEncodedString()),
                response: Field.init(wrappedValue: response),
                clientExtensionResults:Field.init(wrappedValue: clientExtensionResults)
            )
            
            handler.onSuccess(Either(assertionResult))
            
        case let credential as ASAuthorizationSecurityKeyPublicKeyCredentialAssertion:
            let response =  AuthenticatorAssertionResponseJSON(
                authenticatorData: Field.init(wrappedValue: credential.rawAuthenticatorData.toBase64URLEncodedString()),
                clientDataJSON: Field.init(wrappedValue: credential.rawClientDataJSON.toBase64URLEncodedString()),
                signature: Field.init(wrappedValue: credential.signature!.toBase64URLEncodedString()),
                userHandle: Field.init(wrappedValue: credential.userID!.toBase64URLEncodedString())
            )
            
            let assertionResult = AuthenticationResponseJSON(
                id: Field.init(wrappedValue: credential.credentialID.toBase64URLEncodedString()),
                rawId: Field.init(wrappedValue: credential.credentialID.toBase64URLEncodedString()),
                response: Field.init(wrappedValue: response)
            )
            
            handler.onSuccess(Either(assertionResult))
        default:
            handler.onFailure((ASAuthorizationError(ASAuthorizationError.Code.failed)))
        }
    }
}