GenerateOrderCode generates a random code of the given length using the provided character set.

GenerateOTP generates a random OTP of the given length using numeric characters.

GetJSONFieldMap uses reflection to map struct fields to their JSON tags.

StringToIntEnv retrieves an environment variable as an integer, returning a default value if the conversion fails.

UnmarshalBool is a reusable function that unmarshals both boolean and string representations.

ValidateAndCollectErrors validates the input struct and returns any custom and validation errors found.

WriteJSONEValidation dynamically gets JSON tag fields and writes a validation error response.

WriteJSONError writes a JSON error response with the specified status code and message.

WriteJSONResponse writes a JSON response with the specified status code.

Response represents a standardized JSON response format.