module EloTracker exposing (main)

import Api.Elo as Elo
import Element exposing (Element)
import Http
import Json.Decode as D
import Program
import Time
import Widget.Icon
import Layout
import Theme
import Screen.Leaderboard
import Element.Font
import Pixels
import Element.Background


main =
    Program.document
        { flagsDecoder = D.field "baseUrl" D.string
        , headers = headers
        , init = init
        , subscriptions = subscriptions
        , title = title
        , update = update
        , view = view
        }



-- MODEL


type alias Model =
    { baseUrl : String
    , leaderboard : Result Int Elo.Leaderboard
    , matches : Result Int (List Elo.Match)
    }


type Msg
    = OnLeaderboard (Result Http.Error Elo.Leaderboard)
    | OnMatches (Result Http.Error (List Elo.Match))
    | RefreshLeaderboard
    | RefreshMatches


init : Result D.Error String -> ( Model, Cmd Msg )
init flag =
    let
        baseUrl =
            case flag of
                Err _ ->
                    "http://localhost:5000"

                Ok v ->
                    v

        model =
            { baseUrl = baseUrl
            , leaderboard = Err 0
            , matches = Err 0
            }
    in
    ( model
    , Cmd.batch
        [ getLeaderboard model
        , getMatches model
        ]
    )



-- UPDATE


update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        OnLeaderboard (Err _) ->
            case model.leaderboard of
                Err n ->
                    ( { model | leaderboard = Err (n + 1) }, Cmd.none )

                Ok _ ->
                    ( model, Cmd.none )

        OnLeaderboard (Ok v) ->
            ( { model | leaderboard = Ok v }, Cmd.none )

        OnMatches (Err _) ->
            case model.matches of
                Err n ->
                    ( { model | matches = Err (n + 1) }, Cmd.none )

                Ok _ ->
                    ( model, Cmd.none )

        OnMatches (Ok v) ->
            ( { model | matches = Ok v }, Cmd.none )
        
        RefreshLeaderboard ->
            ( model, getLeaderboard model )
        
        RefreshMatches ->
            ( model, getMatches model )


getLeaderboard : Model -> Cmd Msg
getLeaderboard model =
    Elo.getLeaderboard { baseUrl = model.baseUrl, toMsg = OnLeaderboard }


getMatches : Model -> Cmd Msg
getMatches model =
    Elo.getMatches { baseUrl = model.baseUrl, toMsg = OnMatches }



-- SUBSCRIPTIONS


subscriptions : Model -> Sub Msg
subscriptions _ =
    Sub.batch
        [ Time.every (5 * 1000) (always RefreshLeaderboard)
        , Time.every (1 * 60 * 1000) (always RefreshMatches)
        ]



-- VIEW


headers : Model -> List { icon : Widget.Icon.Icon msg, onPress : msg }
headers _ =
    []


title : Model -> String
title model =
    case model.leaderboard of
        Err _ ->
            "EloTracker | Loading..."
        
        Ok _ ->
            "EloTracker | Leaderboard"


view : Program.ViewBox Model -> Element Msg
view data =
    case data.model.leaderboard of
        Err 0 ->
            Element.column
                [ Element.width <| Element.px <| Pixels.inPixels data.size.width
                , Element.height <| Element.px <| Pixels.inPixels data.size.height
                ]
                [ Element.column
                    [ Element.centerX
                    , Element.centerY
                    , Element.Background.color (Theme.mantleUI data.flavor)
                    , Element.padding 15
                    , Element.spacing 10
                    ]
                    [ Element.text "Loading leaderboard..."
                    , Layout.loadingIndicator { color = Theme.lavender data.flavor }
                        |> Element.el [ Element.centerX ]
                    ]
                ]
        
        Err n ->
            Element.column
                [ Element.width <| Element.px <| Pixels.inPixels data.size.width
                , Element.height <| Element.px <| Pixels.inPixels data.size.height
                ]
                [ Element.column
                    [ Element.centerX
                    , Element.centerY
                    , Element.Background.color (Theme.mantleUI data.flavor)
                    , Element.padding 15
                    , Element.spacing 10
                    ]
                    [ Element.text "Loading leaderboard..."
                    , Element.el [ Element.centerX, Element.Font.color (Theme.redUI data.flavor) ] (Element.text ("Failed " ++ (String.fromInt n) ++ " times"))
                    , Layout.loadingIndicator { color = Theme.lavender data.flavor }
                        |> Element.el [ Element.centerX ]
                    ]
                ]
        
        Ok leaderboard ->
            Screen.Leaderboard.view
                { flavor = data.flavor, model = leaderboard, size = data.size }