Ksenia Number Game in Elm

Main.elm

module Main exposing (..)

import Html exposing (Html, button, div, input, p, program, text)
import Html.Attributes exposing (placeholder, type_)
import Html.Events exposing (onClick, onInput)


-- MODEL


type GameState
    = Started
    | Lost
    | Won
    | InProgress


type alias Model =
    { mysteryNumber : Int
    , maxGuesses : Int
    , guessesMade : Int
    , gameState : GameState
    , inputValue : Int
    }


init : ( Model, Cmd Msg )
init =
    ( { mysteryNumber = 50
      , maxGuesses = 10
      , guessesMade = 0
      , gameState = Started
      , inputValue = 0
      }
    , Cmd.none
    )



-- MESSAGES


type Msg
    = Guess
    | Restart
    | EnterText String



-- VIEW


view : Model -> Html Msg
view model =
    div
        []
        [ messageDisplay model
        , inputField
        , guessButton model
        ]


messageDisplay model =
    p [] [ text (gameMessage model) ]


guessButton model =
    if
        model.gameState
            == Started
            || model.gameState
            == InProgress
    then
        button [ onClick Guess ] [ text "guess" ]
    else
        button [ onClick Restart ] [ text "restart" ]


inputField =
    input
        [ placeholder "Enter a number..."
        , type_ "number"
        , onInput EnterText
        ]
        []


gameMessage model =
    let
        stateMessage model =
            " Your guess: "
                ++ toString model.inputValue
                ++ ", State: "
                ++ toString model.gameState
                ++ ", Mystery Number: "
                ++ toString model.mysteryNumber
                ++ if model.gameState == Started || model.gameState == InProgress then
                    ", Guess Number: "
                        ++ toString model.guessesMade
                        ++ ", Max Guesses:  "
                        ++ toString model.maxGuesses
                   else
                    ""
    in
        case model.gameState of
            Started ->
                "I am thinking of a number between 1 and 100." ++ stateMessage model

            InProgress ->
                if model.inputValue < model.mysteryNumber then
                    "That's too low." ++ stateMessage model
                else
                    "That's too high." ++ stateMessage model

            Lost ->
                "You've run out of guesses! The mystery number was: "
                    ++ toString model.mysteryNumber
                    ++ ". "
                    ++ "Game Over!"
                    ++ stateMessage model

            Won ->
                "That's correct! It took you: "
                    ++ toString model.guessesMade
                    ++ " guesses. "
                    ++ "Game Over!"
                    ++ stateMessage model



-- UPDATE


update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        Guess ->
            let
                checkGameState : Model -> GameState
                checkGameState model =
                    if model.guessesMade >= model.maxGuesses && model.inputValue /= model.mysteryNumber then
                        Lost
                    else if model.guessesMade <= model.maxGuesses && model.inputValue == model.mysteryNumber then
                        Won
                    else
                        InProgress
            in
                ( { model | guessesMade = model.guessesMade + 1, gameState = checkGameState model }, Cmd.none )

        EnterText text ->
            let
                intValue =
                    String.toInt text
                        |> Result.toMaybe
                        |> Maybe.withDefault 0
            in
                ( { model | inputValue = intValue }, Cmd.none )

        Restart ->
            init



-- SUBSCRIPTIONS


subscriptions : Model -> Sub Msg
subscriptions model =
    Sub.none



-- MAIN


main : Program Never Model Msg
main =
    program
        { init = init
        , view = view
        , update = update
        , subscriptions = subscriptions
        }