module Model.Category exposing
  ( Categories
  , Category
  , CategoryId
  , categoriesDecoder
  , categoryIdDecoder
  , empty
  )

import Json.Decode as Decode exposing (Decoder)
import Utils.Json as Json
import Dict exposing (Dict)

type alias Categories = Dict CategoryId Category

type alias CategoryId = Int

type alias Category =
  { name : String
  , color : String
  }

categoriesDecoder : Decoder Categories
categoriesDecoder =
  Json.dictDecoder (Decode.field "id" categoryIdDecoder) <|
    Decode.map2
      Category
        (Decode.field "name" Decode.string)
        (Decode.field "color" Decode.string)

categoryIdDecoder : Decoder CategoryId
categoryIdDecoder = Decode.int

empty : Categories
empty = Dict.empty