1 files changed, 48 insertions, 0 deletions
diff --git a/src/client/elm/Model/PaymentCategory.elm b/src/client/elm/Model/PaymentCategory.elm
new file mode 100644
index 0000000..87678fe
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+++ b/src/client/elm/Model/PaymentCategory.elm
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+module Model.PaymentCategory exposing
+  ( PaymentCategories
+  , paymentCategoriesDecoder
+  , search
+  , isCategoryUnused
+  , set
+  , update
+  )
+
+import Dict exposing (Dict)
+import Json.Decode as Decode exposing (Decoder)
+
+import Model.Category exposing (CategoryId, categoryIdDecoder)
+import Utils.Json as Json
+import Utils.Search as Search
+
+type alias PaymentCategories = List PaymentCategory
+
+type alias PaymentCategory =
+  { name : String
+  , category : CategoryId
+  }
+
+paymentCategoriesDecoder : Decoder PaymentCategories
+paymentCategoriesDecoder =
+  Decode.list <| Decode.map2 PaymentCategory
+    (Decode.field "name" Decode.string)
+    (Decode.field "category" categoryIdDecoder)
+
+search : String -> PaymentCategories -> Maybe CategoryId
+search paymentName paymentCategories =
+  paymentCategories
+    |> List.filter (\pc -> Search.format pc.name == Search.format paymentName)
+    |> List.head
+    |> Maybe.map .category
+
+isCategoryUnused : CategoryId -> PaymentCategories -> Bool
+isCategoryUnused category paymentCategories =
+  paymentCategories
+    |> List.filter ((==) category << .category)
+    |> List.isEmpty
+
+set : String -> CategoryId -> PaymentCategories -> PaymentCategories
+set name category paymentCategories = update name name category paymentCategories
+
+update : String -> String -> CategoryId -> PaymentCategories -> PaymentCategories
+update oldName newName category paymentCategories =
+  { name = newName, category = category } :: List.filter (\pc -> not <| Search.format pc.name == Search.format oldName) paymentCategories