module Example exposing (Example, preview, view, wrapMsg, wrapState)

import Category exposing (Category)
import Css exposing (..)
import Css.Global exposing (a, descendants)
import Html.Styled as Html exposing (Html)
import Html.Styled.Attributes as Attributes
import Html.Styled.Events as Events
import Html.Styled.Lazy as Lazy
import KeyboardSupport exposing (KeyboardSupport)
import Nri.Ui.ClickableText.V3 as ClickableText
import Nri.Ui.Colors.V1 as Colors exposing (..)
import Nri.Ui.Container.V2 as Container
import Nri.Ui.Fonts.V1 as Fonts
import Nri.Ui.Heading.V2 as Heading
import Nri.Ui.Html.Attributes.V2 as AttributeExtras exposing (targetBlank)


type alias Example state msg =
    { name : String
    , version : Int
    , state : state
    , update : msg -> state -> ( state, Cmd msg )
    , subscriptions : state -> Sub msg
    , preview : List (Html Never)
    , view : state -> List (Html msg)
    , categories : List Category
    , keyboardSupport : List KeyboardSupport
    }


fullName : Example state msg -> String
fullName example =
    "Nri.Ui." ++ example.name ++ ".V" ++ String.fromInt example.version


wrapMsg :
    (msg -> msg2)
    -> (msg2 -> Maybe msg)
    -> Example state msg
    -> Example state msg2
wrapMsg wrapMsg_ unwrapMsg example =
    { name = example.name
    , version = example.version
    , state = example.state
    , update =
        \msg2 state ->
            case unwrapMsg msg2 of
                Just msg ->
                    example.update msg state
                        |> Tuple.mapSecond (Cmd.map wrapMsg_)

                Nothing ->
                    ( state, Cmd.none )
    , subscriptions = \state -> Sub.map wrapMsg_ (example.subscriptions state)
    , preview = example.preview
    , view = \state -> List.map (Html.map wrapMsg_) (example.view state)
    , categories = example.categories
    , keyboardSupport = example.keyboardSupport
    }


wrapState :
    (state -> state2)
    -> (state2 -> Maybe state)
    -> Example state msg
    -> Example state2 msg
wrapState wrapState_ unwrapState example =
    { name = example.name
    , version = example.version
    , state = wrapState_ example.state
    , update =
        \msg state2 ->
            case unwrapState state2 of
                Just state ->
                    example.update msg state
                        |> Tuple.mapFirst wrapState_

                Nothing ->
                    ( state2, Cmd.none )
    , subscriptions =
        unwrapState
            >> Maybe.map example.subscriptions
            >> Maybe.withDefault Sub.none
    , preview = example.preview
    , view =
        unwrapState
            >> Maybe.map example.view
            >> Maybe.withDefault []
    , categories = example.categories
    , keyboardSupport = example.keyboardSupport
    }


preview : (String -> msg2) -> Example state msg -> Html msg2
preview navigate =
    Lazy.lazy (preview_ navigate)


preview_ : (String -> msg2) -> Example state msg -> Html msg2
preview_ navigate example =
    Container.view
        [ Container.gray
        , Container.css
            [ Css.flexBasis (Css.px 150)
            , Css.hover
                [ Css.backgroundColor Colors.glacier
                , Css.cursor Css.pointer
                ]
            ]
        , Container.custom [ Events.onClick (navigate (exampleHref example)) ]
        , Container.html
            (ClickableText.link example.name
                [ ClickableText.href (exampleHref example)
                , ClickableText.css [ Css.marginBottom (Css.px 10) ]
                ]
                :: [ Html.div
                        [ Attributes.css
                            [ Css.displayFlex
                            , Css.flexDirection Css.column
                            ]
                        ]
                        (List.map (Html.map never) example.preview)
                   ]
            )
        ]


view : Example state msg -> Html msg
view =
    Lazy.lazy view_


view_ : Example state msg -> Html msg
view_ example =
    Html.div
        [ -- this class makes the axe accessibility checking output easier to parse
          String.replace "." "-" example.name
            |> (++) "module-example__"
            |> Attributes.class
        ]
        [ Html.div
            [ Attributes.css
                [ displayFlex
                , alignItems center
                , justifyContent flexStart
                , flexWrap Css.wrap
                , Fonts.baseFont
                , descendants [ Css.Global.a [ textDecoration none ] ]
                ]
            ]
            [ exampleLink example
            , docsLink example
            , srcLink example
            ]
        , KeyboardSupport.view example.keyboardSupport
        , Html.div
            [ Attributes.css
                [ padding (px 40)
                , boxShadow5 zero (px 2) (px 4) zero (rgba 0 0 0 0.25)
                , border3 (px 1) solid gray92
                , borderRadius (px 20)
                , margin3 (px 10) zero (px 40)
                ]
            ]
            (example.view example.state)
        ]


exampleHref : Example state msg -> String
exampleHref example =
    "#/doodad/" ++ example.name


exampleLink : Example state msg -> Html msg
exampleLink example =
    Heading.h2 []
        [ ClickableText.link (fullName example)
            [ ClickableText.href (exampleHref example)
            , ClickableText.large
            , ClickableText.custom
                [ -- this data attribute is used to name the Percy screenshots
                  String.replace "." "-" example.name
                    |> Attributes.attribute "data-percy-name"
                ]
            ]
        ]


docsLink : Example state msg -> Html msg
docsLink example =
    let
        link =
            "https://package.elm-lang.org/packages/NoRedInk/noredink-ui/latest/"
                ++ String.replace "." "-" (fullName example)
    in
    ClickableText.link "Docs"
        [ ClickableText.linkExternal link
        , ClickableText.css [ Css.marginLeft (Css.px 20) ]
        ]


srcLink : Example state msg -> Html msg
srcLink example =
    let
        link =
            String.replace "." "/" (fullName example)
                ++ ".elm"
                |> (++) "https://github.com/NoRedInk/noredink-ui/blob/master/src/"
    in
    ClickableText.link "Source"
        [ ClickableText.linkExternal link
        , ClickableText.css [ Css.marginLeft (Css.px 20) ]
        ]