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

pub opaque type Constellation {
  Constellation(String)
}

pub const min_length: Int = 1

pub fn parse(value: String) -> Result(Constellation, Nil) {
  case string.length(value) >= min_length {
    True -> Ok(Constellation(value))
    False -> Error(Nil)
  }
}

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

pub fn to_string(constellation: Constellation) -> String {
  let Constellation(value) = constellation
  value
}

pub fn encode(constellation: Constellation) -> Json {
  json.string(to_string(constellation))
}