{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}

module Model.Frequency
  ( Frequency(..)
  ) where

import Data.Aeson
import Database.SQLite.Simple (SQLData(SQLText))
import Database.SQLite.Simple.FromField (fieldData, FromField(fromField))
import Database.SQLite.Simple.Ok (Ok(Ok, Errors))
import Database.SQLite.Simple.ToField (ToField(toField))
import GHC.Generics
import qualified Data.Text as T
import Web.Scotty (parseParam, Parsable, readEither)

data Frequency =
  Punctual
  | Monthly
  deriving (Eq, Show, Read, Generic)

instance Parsable Frequency where parseParam = readEither
instance FromJSON Frequency
instance ToJSON Frequency

instance FromField Frequency where
  fromField field = case fieldData field of
    SQLText text -> Ok (read (T.unpack text) :: Frequency)
    _ -> Errors [error "SQLText field required for frequency"]

instance ToField Frequency where
  toField frequency = SQLText . T.pack . show $ frequency