[frontend] commit all the things!!!!

frontend/.gitignore

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+node_modules/
+elm-stuff/
+bundle.js
+

frontend/Makefile

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+MAIN  = src/Main.elm
+OUTJS = bundle.js
+
+ELM      = elm
+ELM_LIVE = elm-live
+ELMFLAGS =
+
+.PHONY: default help clean clean-gitignore live
+
+default: help
+
+# -- END-USER RELEVANT -- #
+
+build: $(OUTJS)  ## Compiles the app.
+
+# -- DEV TARGETS -- #
+
+live:  ## Runs an elm-live server for development.
+	$(ELM_LIVE) $(MAIN) -- $(ELMFLAGS)
+
+# -- THE TARGETS THAT ACTUALLY DO STUFF -- #
+
+$(OUTJS): $(shell find src)
+	$(ELM) make $(ELMFLAGS) $(MAIN) --output $(OUTJS)
+
+# -- HELPERS -- #
+
+help:  # stolen from marmelab.com/blog/2016/02/29/auto-documented-makefile.html
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "%-10s %s\n", $$1, $$2}'
+
+clean:  ## Cleans generated files
+	rm -rf elm-stuff/build-artifacts/
+	rm -f $(OUTJS)
+
+clean-all: clean-gitignore  ## Cleans everything, including downloaded dependencies
+	rm -rf $$(cat ./.gitignore | grep -v '^#')

frontend/README.md

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+# front-end
+
+[![contributions welcome](https://img.shields.io/badge/contributions-welcome-brightgreen.svg?style=flat)](https://github.com/evilham/prometheus-adlermanager/issues)
+
+# Development Quick-Start
+
+Requires `elm`. See [its docs](https://guide.elm-lang.org/install.html) for installation instructions.
+
+`make run` will install dependencies and build the front-end. The result is a pile of static files.

frontend/elm.json

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+{
+    "type": "application",
+    "source-directories": [
+        "src"
+    ],
+    "elm-version": "0.19.0",
+    "dependencies": {
+        "direct": {
+            "elm/browser": "1.0.1",
+            "elm/core": "1.0.2",
+            "elm/html": "1.0.0",
+            "elm/http": "2.0.0",
+            "elm/time": "1.0.0",
+            "justinmimbs/time-extra": "1.1.0"
+        },
+        "indirect": {
+            "elm/bytes": "1.0.7",
+            "elm/file": "1.0.1",
+            "elm/json": "1.1.2",
+            "elm/parser": "1.1.0",
+            "elm/url": "1.0.0",
+            "elm/virtual-dom": "1.0.2",
+            "justinmimbs/date": "3.1.2"
+        }
+    },
+    "test-dependencies": {
+        "direct": {},
+        "indirect": {}
+    }
+}

frontend/notes.txt

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+TODO:
+
+- [ ] production build: like https://github.com/rtfeldman/elm-spa-example
+- [ ] think about server-side rendering

frontend/src/Config.elm

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+module Config exposing (..)
+
+api_url = "/api"

frontend/src/Main.elm

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+module Main exposing (main)
+
+import Browser
+
+import Model
+import Update
+import View
+import Subscriptions
+
+main = Browser.document
+    { init   = \flags -> (Model.init flags, Update.init)
+    , update = Update.update
+    , view   = View.view
+    , subscriptions = Subscriptions.subscriptions
+    }

frontend/src/Model.elm

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+module Model exposing (Model, Msg(..), init)
+
+import Http
+import Time
+
+import Utils
+
+type alias Model =
+    { loading  : Bool
+    , data     : List String
+    , now      : Time.Posix
+    , err      : Maybe Http.Error
+    }
+
+type Msg = NewData       (Result Http.Error (List String))
+         | NewNow        Time.Posix
+         | RefreshWanted
+
+-- INIT --
+
+init : () -> Model
+init flags =
+    { loading  = True
+    , data     = []
+    , now      = Utils.time_0
+    , err      = Nothing
+    }

frontend/src/Subscriptions.elm

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+module Subscriptions exposing (subscriptions)
+
+import Time
+
+import Model exposing (Model, Msg(..))
+
+subscriptions : Model -> Sub Msg
+subscriptions model = Sub.batch
+    [ Time.every (30*1000) (always RefreshWanted)
+    ]

frontend/src/Update.elm

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+module Update exposing (update, init)
+
+import Task
+import Time
+
+import Model exposing (Model, Msg(..))
+
+update : Msg -> Model -> (Model, Cmd Msg)
+update msg model =
+    case msg of
+        NewData (Ok new)  -> ({model | err = Nothing, data = new}, Cmd.none)
+        NewData (Err err) -> ({model | err = Just err},            Cmd.none)
+        NewNow  date      -> ({model | now = date},                Cmd.none)
+        RefreshWanted     -> ( model,                              refresh )
+
+-- COMMANDS --
+
+-- get_data : Cmd Msg
+-- get_data = Http.send NewData Tw.get_request
+
+get_now : Cmd Msg
+get_now = Task.perform NewNow Time.now
+
+refresh : Cmd Msg
+refresh = Cmd.batch [get_now]
+-- refresh = Cmd.batch [get_now, get_data]
+
+-- INIT --
+
+init : Cmd Msg
+init = refresh

frontend/src/Utils.elm

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+module Utils exposing (..)
+
+import Time       exposing (Month(..), utc)
+import Time.Extra as Time
+
+time_0 : Time.Posix
+time_0 = Time.Parts 1970 Jan 1 0 0 0 0 |> Time.partsToPosix utc
+
+time_inf : Time.Posix -- TODO update by 2038 ;-)
+time_inf = Time.Parts 2038 Jan 1 0 0 0 0 |> Time.partsToPosix utc
+
+just_time : Maybe Time.Posix -> Time.Posix
+just_time = Maybe.withDefault time_0

frontend/src/View.elm

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+module View exposing (view)
+
+import Browser
+import Html    exposing (text)
+
+import Model exposing (Model, Msg(..))
+
+view : Model -> Browser.Document Msg
+view model =
+    { title = "Hello World"
+    , body  = [text "hello", text "world"]
+    }