#import "KeychainHelper.h"

NS_ASSUME_NONNULL_BEGIN

@implementation KeychainHelper

+ (NSString *)authenticationKey {
  const char *service = [kKeychainService UTF8String];
  const char *account = [kAuthenticationKeyKeychainKey UTF8String];

  UInt32 authenticationKeyLength = 0;
  void *authenticationKeyData = NULL;

  OSStatus status = SecKeychainFindGenericPassword(
      NULL, (UInt32)strlen(service), service, (UInt32)strlen(account), account,
      &authenticationKeyLength, &authenticationKeyData, NULL);

  if (status == errSecSuccess && authenticationKeyData != NULL) {
    NSString *authenticationKey = [[NSString alloc] initWithBytes:authenticationKeyData
                                                  length:authenticationKeyLength
                                                encoding:NSUTF8StringEncoding];
    SecKeychainItemFreeContent(NULL, authenticationKeyData);
    return authenticationKey;
  }

  return nil;
}

+ (OSStatus)setAuthenticationKey:(NSString *)authenticationKey {
  const char *service = [kKeychainService UTF8String];
  const char *account = [kAuthenticationKeyKeychainKey UTF8String];
  const char *authenticationKeyCString = [authenticationKey UTF8String];

  // First try to find existing item
  SecKeychainItemRef item = NULL;
  OSStatus findStatus = SecKeychainFindGenericPassword(
      NULL, (UInt32)strlen(service), service, (UInt32)strlen(account), account,
      NULL, NULL, &item);

  OSStatus status;
  if (findStatus == errSecSuccess) {
    // Update existing item
    status = SecKeychainItemModifyAttributesAndData(
        item, NULL, (UInt32)strlen(authenticationKeyCString), authenticationKeyCString);
    CFRelease(item);
  } else {
    // Create new item
    status = SecKeychainAddGenericPassword(
        NULL, (UInt32)strlen(service), service, (UInt32)strlen(account),
        account, (UInt32)strlen(authenticationKeyCString), authenticationKeyCString, NULL);
  }

  return status;
}

+ (OSStatus) deleteAuthenticationKey {
  const char *service = [kKeychainService UTF8String];
  const char *account = [kAuthenticationKeyKeychainKey UTF8String];

  SecKeychainItemRef item = NULL;
  OSStatus findStatus = SecKeychainFindGenericPassword(
      NULL, (UInt32)strlen(service), service, (UInt32)strlen(account), account,
      NULL, NULL, &item);

  if (findStatus == errSecSuccess) {
    OSStatus deleteStatus = SecKeychainItemDelete(item);
    CFRelease(item);
    return deleteStatus;
  }

  return findStatus;
}

@end

NS_ASSUME_NONNULL_END