{- |
Module representing a JSON-API link object.

Specification: <http://jsonapi.org/format/#document-links>
-}
module Network.JSONApi.Link
( Links
, Rel
, Href
, toLinks
) where

import Data.Aeson (ToJSON, FromJSON)
import Data.Map (Map)
import qualified Data.Map as Map
import Data.Swagger (ToSchema)
import Data.Text (Text, pack)
import GHC.Generics (Generic)
import Network.URL (URL, exportURL)

{- |
Type representing a JSON-API link object.

Links are an abstraction around an underlying Map consisting of
relevance identifiers as keys and URIs as values.

Example JSON:
@
"links": {
  "self": "http://example.com/posts/1"
}
@

Specification: <http://jsonapi.org/format/#document-links>
-}
newtype Links = Links (Map Rel Href)
  deriving (Show, Eq, Ord, ToJSON, FromJSON, Generic)

instance ToSchema Links

type Rel = Text
type Href = Text

{- |
Constructor function for building Links
-}
toLinks :: [(Rel, URL)] -> Links
toLinks = Links . Map.fromList . map buildLink

buildLink :: (Rel, URL) -> (Rel, Href)
buildLink (key, url) = (key, pack (exportURL url))