Update intro/part7

intro/part7/src/Page/Home.elm

@@ -3,20 +3,25 @@ module Page.Home exposing (Model, Msg, init, subscriptions, toSession, update, v
 {-| The homepage. You can get here via either the / or /#/ routes.
 -}
 
-import Article
+import Api
+import Article exposing (Article, Preview)
 import Article.Feed as Feed
 import Article.FeedSources as FeedSources exposing (FeedSources, Source(..))
 import Article.Tag as Tag exposing (Tag)
+import Browser.Dom as Dom
 import Html exposing (..)
 import Html.Attributes exposing (attribute, class, classList, href, id, placeholder)
 import Html.Events exposing (onClick)
 import Http
+import HttpBuilder
 import Loading
 import Log
 import Page
+import PaginatedList exposing (PaginatedList)
 import Session exposing (Session)
 import Task exposing (Task)
 import Time
+import Username exposing (Username)
 import Viewer.Cred as Cred exposing (Cred)
 
 
@@ -27,6 +32,8 @@ import Viewer.Cred as Cred exposing (Cred)
 type alias Model =
     { session : Session
     , timeZone : Time.Zone
+    , feedTab : FeedTab
+    , feedPage : Int
 
     -- Loaded independently from server
     , tags : Status (List Tag)
@@ -41,28 +48,35 @@ type Status a
     | Failed
 
 
+type FeedTab
+    = YourFeed Cred
+    | GlobalFeed
+    | TagFeed Tag
+
+
 init : Session -> ( Model, Cmd Msg )
 init session =
     let
-        feedSources =
+        feedTab =
             case Session.cred session of
                 Just cred ->
-                    FeedSources.fromLists (YourFeed cred) [ GlobalFeed ]
+                    YourFeed cred
 
                 Nothing ->
-                    FeedSources.fromLists GlobalFeed []
+                    GlobalFeed
 
         loadTags =
-            Tag.list
-                |> Http.toTask
+            Http.toTask Tag.list
     in
     ( { session = session
       , timeZone = Time.utc
+      , feedTab = feedTab
+      , feedPage = 1
       , tags = Loading
       , feed = Loading
       }
     , Cmd.batch
-        [ Feed.init session feedSources
+        [ fetchFeed session feedTab 1
             |> Task.attempt CompletedFeedLoad
         , Tag.list
             |> Http.send CompletedTagsLoad
@@ -87,7 +101,17 @@ view model =
                     [ div [ class "col-md-9" ] <|
                         case model.feed of
                             Loaded feed ->
-                                viewFeed model.timeZone feed
+                                [ div [ class "feed-toggle" ] <|
+                                    List.concat
+                                        [ [ viewTabs
+                                                (Session.cred model.session)
+                                                model.feedTab
+                                          ]
+                                        , Feed.viewArticles model.timeZone feed
+                                            |> List.map (Html.map GotFeedMsg)
+                                        , [ Feed.viewPagination ClickedFeedPage feed ]
+                                        ]
+                                ]
 
                             Loading ->
                                 []
@@ -130,11 +154,58 @@ viewBanner =
         ]
 
 
-viewFeed : Time.Zone -> Feed.Model -> List (Html Msg)
-viewFeed timeZone feed =
-    div [ class "feed-toggle" ]
-        [ Feed.viewFeedSources feed |> Html.map GotFeedMsg ]
-        :: (Feed.viewArticles timeZone feed |> List.map (Html.map GotFeedMsg))
+
+-- TABS
+
+
+viewTabs : Maybe Cred -> FeedTab -> Html Msg
+viewTabs maybeCred tab =
+    case tab of
+        YourFeed cred ->
+            Feed.viewTabs [] (yourFeed cred) [ globalFeed ]
+
+        GlobalFeed ->
+            let
+                otherTabs =
+                    case maybeCred of
+                        Just cred ->
+                            [ yourFeed cred ]
+
+                        Nothing ->
+                            []
+            in
+            Feed.viewTabs otherTabs globalFeed []
+
+        TagFeed tag ->
+            let
+                otherTabs =
+                    case maybeCred of
+                        Just cred ->
+                            [ yourFeed cred, globalFeed ]
+
+                        Nothing ->
+                            [ globalFeed ]
+            in
+            Feed.viewTabs otherTabs (tagFeed tag) []
+
+
+yourFeed : Cred -> ( String, Msg )
+yourFeed cred =
+    ( "Your Feed", ClickedTab (YourFeed cred) )
+
+
+globalFeed : ( String, Msg )
+globalFeed =
+    ( "Global Feed", ClickedTab GlobalFeed )
+
+
+tagFeed : Tag -> ( String, Msg )
+tagFeed tag =
+    ( "#" ++ Tag.toString tag, ClickedTab (TagFeed tag) )
+
+
+
+-- TAGS
 
 
 viewTags : List Tag -> Html Msg
@@ -160,6 +231,8 @@ viewTag tagName =
 
 type Msg
     = ClickedTag Tag
+    | ClickedTab FeedTab
+    | ClickedFeedPage Int
     | CompletedFeedLoad (Result Http.Error Feed.Model)
     | CompletedTagsLoad (Result Http.Error (List Tag))
     | GotTimeZone Time.Zone
@@ -171,12 +244,28 @@ type Msg
 update : Msg -> Model -> ( Model, Cmd Msg )
 update msg model =
     case msg of
-        ClickedTag tagName ->
+        ClickedTag tag ->
             let
-                subCmd =
-                    Feed.selectTag (Session.cred model.session) tagName
+                feedTab =
+                    TagFeed tag
             in
-            ( model, Cmd.map GotFeedMsg subCmd )
+            ( { model | feedTab = feedTab }
+            , fetchFeed model.session feedTab 1
+                |> Task.attempt CompletedFeedLoad
+            )
+
+        ClickedTab tab ->
+            ( { model | feedTab = tab }
+            , fetchFeed model.session tab 1
+                |> Task.attempt CompletedFeedLoad
+            )
+
+        ClickedFeedPage page ->
+            ( { model | feedPage = page }
+            , fetchFeed model.session model.feedTab page
+                |> Task.andThen (\feed -> Task.map (\_ -> feed) scrollToTop)
+                |> Task.attempt CompletedFeedLoad
+            )
 
         CompletedFeedLoad (Ok feed) ->
             ( { model | feed = Loaded feed }, Cmd.none )
@@ -242,6 +331,53 @@ update msg model =
 
 
 
+-- HTTP
+
+
+fetchFeed : Session -> FeedTab -> Int -> Task Http.Error Feed.Model
+fetchFeed session feedTabs page =
+    let
+        maybeCred =
+            Session.cred session
+
+        builder =
+            case feedTabs of
+                YourFeed cred ->
+                    Api.url [ "articles", "feed" ]
+                        |> HttpBuilder.get
+                        |> Cred.addHeader cred
+
+                GlobalFeed ->
+                    Api.url [ "articles" ]
+                        |> HttpBuilder.get
+                        |> Cred.addHeaderIfAvailable maybeCred
+
+                TagFeed tag ->
+                    Api.url [ "articles" ]
+                        |> HttpBuilder.get
+                        |> Cred.addHeaderIfAvailable maybeCred
+                        |> HttpBuilder.withQueryParam "tag" (Tag.toString tag)
+    in
+    builder
+        |> HttpBuilder.withExpect (Http.expectJson (Feed.decoder maybeCred articlesPerPage))
+        |> PaginatedList.fromRequestBuilder articlesPerPage page
+        |> Task.map (Feed.init session)
+
+
+articlesPerPage : Int
+articlesPerPage =
+    10
+
+
+scrollToTop : Task x ()
+scrollToTop =
+    Dom.setViewport 0 0
+        -- It's not worth showing the user anything special if scrolling fails.
+        -- If anything, we'd log this to an error recording service.
+        |> Task.onError (\_ -> Task.succeed ())
+
+
+
 -- SUBSCRIPTIONS