ui: Initial Elm UI import

Merged from https://github.com/jhillyerd/inbucket-elm

Uses https://github.com/halfzebra/create-elm-app

ui/src/Route.elm

@@ -0,0 +1,84 @@
+module Route exposing (Route(..), fromLocation, href, modifyUrl, newUrl)
+
+import Html exposing (Attribute)
+import Html.Attributes as Attr
+import Navigation exposing (Location)
+import UrlParser as Url exposing ((</>), Parser, parseHash, s, string)
+
+
+type Route
+    = Unknown String
+    | Home
+    | Mailbox String
+    | Message String String
+    | Monitor
+    | Status
+
+
+matcher : Parser (Route -> a) a
+matcher =
+    Url.oneOf
+        [ Url.map Home (s "")
+        , Url.map Message (s "m" </> string </> string)
+        , Url.map Mailbox (s "m" </> string)
+        , Url.map Monitor (s "monitor")
+        , Url.map Status (s "status")
+        ]
+
+
+routeToString : Route -> String
+routeToString page =
+    let
+        pieces =
+            case page of
+                Unknown _ ->
+                    []
+
+                Home ->
+                    []
+
+                Mailbox name ->
+                    [ "m", name ]
+
+                Message mailbox id ->
+                    [ "m", mailbox, id ]
+
+                Monitor ->
+                    [ "monitor" ]
+
+                Status ->
+                    [ "status" ]
+    in
+        "/#/" ++ String.join "/" pieces
+
+
+
+-- PUBLIC HELPERS
+
+
+href : Route -> Attribute msg
+href route =
+    Attr.href (routeToString route)
+
+
+modifyUrl : Route -> Cmd msg
+modifyUrl =
+    routeToString >> Navigation.modifyUrl
+
+
+newUrl : Route -> Cmd msg
+newUrl =
+    routeToString >> Navigation.newUrl
+
+
+fromLocation : Location -> Route
+fromLocation location =
+    if String.isEmpty location.hash then
+        Home
+    else
+        case parseHash matcher location of
+            Nothing ->
+                Unknown location.hash
+
+            Just route ->
+                route