Add support for more generic notification

This is a start to have different kinds of notifications. It is
possible to be notified via e-mail, matrix or gotify. It also extends
the current "periodic query" for due items by allowing notification
over different channels. A "generic periodic query" variant is added
as well.

modules/webapp/src/main/elm/Comp/EventSample.elm

@@ -0,0 +1,182 @@
+{-
+   Copyright 2020 Eike K. & Contributors
+
+   SPDX-License-Identifier: AGPL-3.0-or-later
+-}
+
+
+module Comp.EventSample exposing (Model, Msg, init, initWith, update, viewJson, viewMessage)
+
+import Api
+import Comp.FixedDropdown
+import Data.DropdownStyle as DS
+import Data.EventType exposing (EventType)
+import Data.Flags exposing (Flags)
+import Html exposing (..)
+import Html.Attributes exposing (..)
+import Http
+import Json.Decode as D
+import Json.Print
+import Markdown
+import Messages.Comp.EventSample exposing (Texts)
+
+
+type alias Model =
+    { eventTypeDropdown : Comp.FixedDropdown.Model EventType
+    , selectedEventType : Maybe EventType
+    , content : String
+    }
+
+
+init : Model
+init =
+    { eventTypeDropdown = Comp.FixedDropdown.init Data.EventType.all
+    , selectedEventType = Nothing
+    , content = ""
+    }
+
+
+initWith : Flags -> EventType -> ( Model, Cmd Msg )
+initWith flags evt =
+    ( { init | selectedEventType = Just evt }
+    , Api.sampleEvent flags evt SampleEvent
+    )
+
+
+type Msg
+    = EventTypeMsg (Comp.FixedDropdown.Msg EventType)
+    | SampleEvent (Result Http.Error String)
+
+
+
+--- Update
+
+
+update : Flags -> Msg -> Model -> ( Model, Cmd Msg )
+update flags msg model =
+    case msg of
+        EventTypeMsg lm ->
+            let
+                ( evm, evt ) =
+                    Comp.FixedDropdown.update lm model.eventTypeDropdown
+
+                sampleCmd =
+                    case evt of
+                        Just ev ->
+                            Api.sampleEvent flags ev SampleEvent
+
+                        Nothing ->
+                            Cmd.none
+            in
+            ( { model
+                | eventTypeDropdown = evm
+                , selectedEventType = evt
+              }
+            , sampleCmd
+            )
+
+        SampleEvent (Ok str) ->
+            ( { model | content = str }, Cmd.none )
+
+        SampleEvent (Err err) ->
+            ( model, Cmd.none )
+
+
+
+--- View
+
+
+styleBase : String
+styleBase =
+    "bg-gray-100 dark:bg-bluegray-900 text-gray-900 dark:text-gray-100 text-sm leading-5"
+
+
+stylePayload : String
+stylePayload =
+    "px-2 font-mono overflow-auto max-h-96 h-full whitespace-pre"
+
+
+styleMessage : String
+styleMessage =
+    "-my-2 "
+
+
+jsonPrettyCfg =
+    { indent = 2
+    , columns = 80
+    }
+
+
+dropdownCfg texts =
+    { display = texts.eventType >> .name
+    , icon = \_ -> Nothing
+    , selectPlaceholder = texts.selectEvent
+    , style = DS.mainStyleWith "w-48"
+    }
+
+
+viewJson : Texts -> Model -> Html Msg
+viewJson texts model =
+    let
+        json =
+            Result.withDefault ""
+                (Json.Print.prettyString jsonPrettyCfg model.content)
+    in
+    div
+        [ class "flex flex-col w-full relative"
+        ]
+        [ div [ class "flex inline-flex items-center absolute top-2 right-4" ]
+            [ Html.map EventTypeMsg
+                (Comp.FixedDropdown.viewStyled2 (dropdownCfg texts)
+                    False
+                    model.selectedEventType
+                    model.eventTypeDropdown
+                )
+            ]
+        , div
+            [ class "flex pt-5"
+            , class styleBase
+            , class stylePayload
+            , classList [ ( "hidden", json == "" ) ]
+            ]
+            [ text json
+            ]
+        ]
+
+
+viewMessage : Texts -> Model -> Html Msg
+viewMessage texts model =
+    let
+        titleDecoder =
+            D.at [ "message", "title" ] D.string
+
+        bodyDecoder =
+            D.at [ "message", "body" ] D.string
+
+        title =
+            D.decodeString titleDecoder model.content
+
+        body =
+            D.decodeString bodyDecoder model.content
+    in
+    div
+        [ class "flex flex-col w-full relative"
+        ]
+        [ div [ class "flex inline-flex items-center absolute top-2 right-4" ]
+            [ Html.map EventTypeMsg
+                (Comp.FixedDropdown.viewStyled2 (dropdownCfg texts)
+                    False
+                    model.selectedEventType
+                    model.eventTypeDropdown
+                )
+            ]
+        , div
+            [ class "flex flex-col py-5 px-2 markdown-preview"
+            , class styleBase
+            ]
+            [ Markdown.toHtml [ class styleMessage ]
+                (Result.withDefault "" title)
+            , Markdown.toHtml [ class styleMessage ]
+                (Result.withDefault "" body)
+            ]
+        ]