feat: add pdf generation

frontend/elm.json

@@ -1,19 +1,21 @@
 {
     "type": "application",
-    "source-directories": ["src"],
+    "source-directories": [
+        "src"
+    ],
     "elm-version": "0.19.1",
     "dependencies": {
         "direct": {
             "elm/browser": "1.0.2",
+            "elm/bytes": "1.0.8",
             "elm/core": "1.0.5",
+            "elm/file": "1.0.5",
             "elm/html": "1.0.0",
             "elm/http": "2.0.0",
             "elm/json": "1.1.3",
             "elm/time": "1.0.0"
         },
         "indirect": {
-            "elm/bytes": "1.0.8",
-            "elm/file": "1.0.5",
             "elm/url": "1.0.0",
             "elm/virtual-dom": "1.0.3"
         }

frontend/src/Main.elm

@@ -1,7 +1,9 @@
 port module Main exposing (..)
 
 import Browser
+import Bytes exposing (Bytes)
 import Dict exposing (Dict)
+import File.Download
 import Html exposing (..)
 import Html.Attributes exposing (..)
 import Html.Events exposing (..)
@@ -430,6 +432,8 @@ type Msg
     | SchoolYearActivated (Result Http.Error ())
     | DeleteSchoolYear Int
     | SchoolYearDeleted (Result Http.Error ())
+    | DownloadYearlySummaryPDF
+    | YearlySummaryPDFReceived (Result Http.Error Bytes.Bytes)
 
 
 update : Msg -> Model -> ( Model, Cmd Msg )
@@ -1631,6 +1635,29 @@ update msg model =
         SchoolYearDeleted (Err _) ->
             ( { model | error = Just "Fehler beim Löschen" }, Cmd.none )
 
+        DownloadYearlySummaryPDF ->
+            case model.token of
+                Just token ->
+                    ( { model | isProcessing = True }, downloadYearlySummaryPDF token )
+
+                Nothing ->
+                    ( model, Cmd.none )
+
+        YearlySummaryPDFReceived (Ok pdfBytes) ->
+            let
+                filename =
+                    "Jahresuebersicht_" ++ String.fromInt model.currentYear ++ ".pdf"
+            in
+            ( { model | isProcessing = False }, File.Download.bytes filename "application/pdf" pdfBytes )
+
+        YearlySummaryPDFReceived (Err _) ->
+            ( { model
+                | error = Just "Fehler beim Herunterladen der PDF"
+                , isProcessing = False
+              }
+            , Cmd.none
+            )
+
 
 
 -- SUBSCRIPTIONS
@@ -2606,7 +2633,35 @@ viewTimeEntriesTab model =
 viewYearlyHoursSummary : Model -> Html Msg
 viewYearlyHoursSummary model =
     div [ class "box" ]
-        [ if List.isEmpty model.yearlyHoursSummary then
+        [ div [ class "level mb-4" ]
+            [ div [ class "level-left" ]
+                [ div [ class "level-item" ]
+                    [ h3 [ class "subtitle is-5 mb-0" ] [ text "Jahresübersicht" ]
+                    ]
+                ]
+            , div [ class "level-right" ]
+                [ div [ class "level-item" ]
+                    [ a
+                        [ class "button is-info"
+                        , onClick DownloadYearlySummaryPDF
+                        , disabled model.isProcessing
+                        ]
+                        [ span [ class "icon" ]
+                            [ i [ class "fas fa-file-pdf" ] [] ]
+                        , span []
+                            [ text
+                                (if model.isProcessing then
+                                    "Wird erstellt..."
+
+                                 else
+                                    "PDF exportieren"
+                                )
+                            ]
+                        ]
+                    ]
+                ]
+            ]
+        , if List.isEmpty model.yearlyHoursSummary then
             p [ class "has-text-centered" ] [ text "Keine Daten vorhanden" ]
 
           else
@@ -2950,7 +3005,7 @@ viewWeekNavigation model =
                     , style "flex-direction" "column"
                     , style "align-items" "center"
                     , style "gap" "0.5rem"
-                    , style "min-width" "250px" -- Verhindert Kompression
+                    , style "min-width" "250px"
                     ]
                     [ p
                         [ class "heading"
@@ -4225,3 +4280,34 @@ schoolYearDecoder =
         (field "start_date" string)
         (field "end_date" string)
         (field "is_active" bool)
+
+
+downloadYearlySummaryPDF : String -> Cmd Msg
+downloadYearlySummaryPDF token =
+    Http.request
+        { method = "GET"
+        , headers = [ Http.header "Authorization" ("Bearer " ++ token) ]
+        , url = "/api/admin/yearly-summary/pdf"
+        , body = Http.emptyBody
+        , expect =
+            Http.expectBytesResponse YearlySummaryPDFReceived
+                (\response ->
+                    case response of
+                        Http.GoodStatus_ _ body ->
+                            Ok body
+
+                        Http.BadUrl_ url ->
+                            Err (Http.BadUrl url)
+
+                        Http.Timeout_ ->
+                            Err Http.Timeout
+
+                        Http.NetworkError_ ->
+                            Err Http.NetworkError
+
+                        Http.BadStatus_ metadata _ ->
+                            Err (Http.BadStatus metadata.statusCode)
+                )
+        , timeout = Nothing
+        , tracker = Nothing
+        }