halogen-websocket-ipc-playzone/src/App/PermissionLevel.purs

module App.PermissionLevel where

import Prelude

import Data.Codec.Argonaut as CA
import Data.Codec.Argonaut.Variant as CAV
import Data.Variant as V
import Data.Profunctor (dimap)
import Data.Either (Either(..))
import Type.Proxy (Proxy(..))

data PermissionLevel
  = None
  | Read
  | Edit
  | Admin

codec ∷ CA.JsonCodec PermissionLevel
codec =
  dimap toVariant fromVariant $ CAV.variantMatch { permission: Right CA.string }
  where
    toVariant = case _ of
      None  →  V.inj (Proxy ∷ _ "permission") "none"
      Read  →  V.inj (Proxy ∷ _ "permission") "read"
      Edit  →  V.inj (Proxy ∷ _ "permission") "edit"
      Admin →  V.inj (Proxy ∷ _ "permission") "admin"

    fromVariant = V.match
      { permission:
          \s -> case s of
            "none"  -> None
            "read"  -> Read
            "edit"  -> Edit
            "admin" -> Admin
            _       -> None
      }