import gleam/dynamic/decode.{type Decoder}
import gleam/json.{type Json}

pub type SurveySize {
  Small
  Moderate
  Large
}

pub fn parse(value: String) -> Result(SurveySize, Nil) {
  case value {
    "SMALL" -> Ok(Small)
    "MODERATE" -> Ok(Moderate)
    "LARGE" -> Ok(Large)
    _ -> Error(Nil)
  }
}

pub fn decoder() -> Decoder(SurveySize) {
  use value <- decode.then(decode.string)
  case parse(value) {
    Ok(survey_size) -> decode.success(survey_size)
    Error(Nil) -> decode.failure(Small, "SurveySize")
  }
}

pub fn to_string(survey_size: SurveySize) -> String {
  case survey_size {
    Small -> "SMALL"
    Moderate -> "MODERATE"
    Large -> "LARGE"
  }
}

pub fn encode(survey_size: SurveySize) -> Json {
  json.string(to_string(survey_size))
}