module Main exposing (main)

import Browser
import Sort.Set exposing (Set)
import Html exposing (Html, div, input, label, p, section, text, h3)
import Html.Events exposing (onCheck, onClick)
import Html.Attributes exposing (class, type_, id)
import Modules exposing
  ( Module
  , all_modules
  , download_license
  , DownloadType(..)
  , module_property
  , module_desc
  , module_sorter
  )
import Html.Attributes exposing (attribute)

main: Program () Model Msg
main =
  Browser.element
    { init = init
    , update = update
    , view = view
    , subscriptions = subscriptions
    }

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

-- INIT + Model


type alias Model =
  { enabled_modules : Set Module
  }

init : () -> (Model, Cmd Msg)
init () =
  ( { enabled_modules = Sort.Set.empty module_sorter }
  , Cmd.none
  )

-- UPDATE

type Msg
  = ToggleModule Module Bool
  | Download DownloadType

add_or_remove : Bool -> (a -> Set a -> Set a)
add_or_remove active =
  if active then
    Sort.Set.insert
  else
    Sort.Set.remove

update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
  case msg of
    ToggleModule mod enabled ->
      ( { model | enabled_modules = add_or_remove enabled mod model.enabled_modules }
      , Cmd.none
      )
    Download dtype ->
      ( model , download_license dtype (Sort.Set.toList model.enabled_modules) )

-- VIEW

view_module_button : Set Module -> Module -> Html Msg
view_module_button enabled mod =
  label
    (class "module-button"
      :: (if Sort.Set.memberOf enabled mod then [class "active"] else [])
      )
    [ div []
      [ div [class "cooler-checkbox"]
        [ input
          [ type_ "checkbox"
          , onCheck (ToggleModule mod)
          ] []
        ]
      , h3 [] [ text (module_property .name mod) ]
      , p [] (module_desc mod)
      ]
    ]

view_modules : Set Module -> Html Msg
view_modules modules =
  section [id "modules"] (
      all_modules
        |> List.map (view_module_button modules)
  )

view_cooler_button : String -> msg -> Html msg
view_cooler_button name message =
  div
    [ class "cool-button"
    , onClick message
    ]
    [ div
      [ class "bevel"
      , class "tr"
      , attribute "aria-hidden" "true"
      ] []
    , div [] [ text name ]
    , div
      [ class "bevel"
      , class "bl"
      , attribute "aria-hidden" "true"
      ] []
    ]

view_download_button : (String, DownloadType) -> Html Msg
view_download_button (name, dtype) =
  view_cooler_button name (Download dtype)

downloads : Html Msg
downloads =
  section [id "downloads"]
    ( List.map view_download_button
      [ ("Markdown", Markdown)
      , ("Plaintext", Plain)
      , ("HTML", Html)
      ]
    )


view : Model -> Html Msg
view model =
  div [id "elm-area"]
    [ view_modules model.enabled_modules
    , downloads
    ]