Behaviour.hs

{-|
Module      : System.Console.Ask.Behaviour
Copyright   : 2025 Toma Sasaki
Licence     : MIT
Maintainer  : netst915@gmail.com
Portability : Portable

@System.Console.Ask.Behaviour@ provides 'Behaviour', its fields and 'set'.
You should import this module if you want to customise the behaviour of ConsoleAsk.
-}

{-# LANGUAGE TemplateHaskell #-}

module System.Console.Ask.Behaviour
    ( NewlineTiming (..)
    , DefaultValueStyle (..)
    , Behaviour (..)
    , defaultBehaviour
    , newlineTiming
    , defaultValueStyle
    , defaultValueViewer
    , mandatoryQuestionErrorMsg
    , invalidInputErrorMsg
    , set
    ) where

import           Control.Lens (makeLenses, set)
import           Data.Text    (Text)

-- | 'NewlineTiming' is the timing of ConsoleAsk outputs newline between questions.
--
-- 'AfterPrompt'
--
-- @
-- Question1?
-- > ABC
--
-- Question2?
-- > DEF
--
-- @
--
-- 'BeforePrompt'
--
-- @
--
--
-- Question1?
-- > ABC
--
-- Question2?
-- > DEF
-- @
--
-- 'None'
--
-- @
-- Question1?
-- > ABC
-- Question2?
-- > DEF
-- @
--
data NewlineTiming = AfterPrompt | BeforePrompt | None deriving Eq

-- | 'DefaultValueStyle' is the setting of where the default value is displayed.
--
-- 'OnQuestionLine'
--
-- @
-- Question1? (Default: \"ABC\")
-- >
-- @
--
-- 'OnNewline'
--
-- @
-- Question1?
-- Default: \"ABC\"
-- >
-- @
--
data DefaultValueStyle = OnQuestionLine | OnNewline deriving Eq

-- | 'Behaviour' specifies ConsoleAsk behaviours.
-- 'set' is useful for editing already existing 'Behaviour' definitions field-by-field.
--
-- @
-- let customBehaviour = 'set' 'System.Console.Ask.Behaviour.newlineTiming' 'BeforePrompt' 'System.Console.Ask.Behaviour.defaultBehaviour'
-- @
--
data Behaviour = Behaviour
    { -- | Please see 'NewlineTiming'.
      --
      _newlineTiming             :: NewlineTiming
      -- | Please see 'DefaultValueStyle'.
      --
    , _defaultValueStyle         :: DefaultValueStyle
      -- | '_defaultValueViewer' is the message displayed if the question has a default value.
      -- It is a function whose argument is the default value of the question.
      --
      -- Assume @'_defaultValueViewer' = ("Default Value is: " <>)@,
      --
      -- >>> askOrElse "Do you need notifications?" False :: Ask Bool
      -- Do you need notifications? (Default Value is: False)
      -- >
      --
    , _defaultValueViewer        :: Text -> Text
      -- | '_mandatoryQuestionErrorMsg' is the message displayed if the user has not answered the question even though it is mandatory.
      -- If @Nothing@, ConsoleAsk will not display the message.
      --
      -- Assume @'_mandatoryQuestionErrorMsg' = Just "PLEASE ANSWER THIS QUESTION!!!"@,
      --
      -- >>> ask "What is your name?" :: Ask Text
      -- What is your name?
      -- >
      -- PLEASE ANSWER THIS QUESTION!!!
      --
    , _mandatoryQuestionErrorMsg :: Maybe Text
      -- | '_invalidInputErrorMsg' is the message displayed if the user enters an invalid value.
      -- If @Nothing@, ConsoleAsk will not display the message.
      --
      -- Assume @'_invalidInputErrorMsg' = Just "????????"@,
      --
      -- >>> ask "How old are you?" :: Ask Int
      -- How old are you?
      -- > abc
      -- ????????
      --
    , _invalidInputErrorMsg      :: Maybe Text
    }

makeLenses ''Behaviour

-- | 'defaultBehaviour' is the default definition of ConsoleAsk behaviour.
--
-- @
-- 'defaultBehaviour' = 'Behaviour'
--     { '_newlineTiming'             = 'AfterPrompt'
--     , '_defaultValueStyle'         = 'OnQuestionLine'
--     , '_defaultValueViewer'        = (\"Default\" <>)
--     , '_mandatoryQuestionErrorMsg' = Just \"This question is mandatory.\"
--     , '_invalidInputErrorMsg'      = Just \"Invalid input.\"
--     }
-- @
--
defaultBehaviour :: Behaviour
defaultBehaviour =
    Behaviour
        { _newlineTiming             = AfterPrompt
        , _defaultValueStyle         = OnQuestionLine
        , _defaultValueViewer        = ("Default: " <>)
        , _mandatoryQuestionErrorMsg = Just "This question is mandatory."
        , _invalidInputErrorMsg      = Just "Invalid input."
        }