Main.elm

module Main exposing (main)

import Html exposing (Html, div, input, node, pre, text)
import Html.Events exposing (onInput)
import Html.Attributes exposing (placeholder, style)
import Http
import Regex


main : Program Never Model Msg
main =
    Html.program
        { init = Model "" Nothing [] ! [loadWordbook]
        , view = view
        , update = update
        , subscriptions = \_ -> Sub.none
        }


--------------------------------------------------------------------------------
-- MODEL --
-----------

type alias Model =
    { query : String
    , content : Maybe String
    , wordbook : List String
    }

loadWordbook : Cmd Msg
loadWordbook =
    let url = "./vortaro.text"
        request = Http.getString url
    in Http.send Load request


--------------------------------------------------------------------------------
-- UPDATE --
------------

type Msg
    = Query String
    | Load (Result Http.Error String)

type KnownErrors
    = NoWordbook
    | HttpError Http.Error

update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
    case msg of
        Query query ->
            case model.wordbook of
                [] -> { model
                      | query = query
                      , content = showErrorMessage NoWordbook |> Just
                      } ! []

                wordbook -> { model
                            | query = query
                            , content = find query wordbook
                            } ! []

        Load (Ok data) ->
            {model | wordbook = String.split "\n" data} ! []

        Load (Err err) ->
            {model | content = HttpError err |> showErrorMessage |> Just} ! []


find : String -> List String -> Maybe String
find query wordbook =
    if String.length query > 1
    then
        let rquery = Regex.regex query
            filter_ = Regex.contains rquery
            sep = Regex.regex "\\t::"
        in
            wordbook
            |> List.filter filter_
            |> String.join "\n\n"
            |> Regex.replace Regex.All sep (\_ -> "\n")
            |> Just

    else Nothing

showErrorMessage : KnownErrors -> String
showErrorMessage errorType =
    case errorType of
        HttpError (Http.BadPayload message _) -> message
        HttpError (Http.BadStatus res) -> res.status.message
        HttpError (Http.BadUrl message) -> message
        HttpError Http.NetworkError -> "rede indisponível"
        HttpError Http.Timeout -> "requisição expirou"
        NoWordbook -> "dicionário não carregado"


--------------------------------------------------------------------------------
-- VIEW --
----------

view : Model -> Html Msg
view model =
    div []
        [ input [placeholder "Serĉu", onInput Query] []
        , display model.content
        ]

display : Maybe String -> Html msg
display content =
    let preStyle =
        style
            [ ("background-color", "white")
            , ("word-break", "break-word")
            , ("word-wrap", "break-word")
            , ("white-space", "pre-wrap")
            , ("white-space", "-moz-pre-wrap")
            , ("white-space", "-o-pre-wrap")
            , ("white-space", "-pre-wrap")
            , ("overflow-x", "hidden")
            , ("overflow-y", "scroll")
            , ("border-style", "inset")
            , ("border-width", "medium")
            , ("height", "25em")
            , ("width", "128ex")
            ]
        render = pre [preStyle]

    in case content of
        Just value -> render [text value]
        Nothing    -> render [text ""]