module Rattletrap.Schema where

import qualified Data.Text as Text
import qualified Rattletrap.Utility.Json as Json

data Schema = Schema
  { name :: Text.Text,
    json :: Json.Value
  }
  deriving (Eq, Show)

named :: String -> Json.Value -> Schema
named n j = Schema {name = Text.pack n, json = j}

ref :: Schema -> Json.Value
ref s = Json.object [Json.pair "$ref" $ Text.pack "#/definitions/" <> name s]

object :: [((Json.Key, Json.Value), Bool)] -> Json.Value
object xs =
  Json.object
    [ Json.pair "type" "object",
      Json.pair "properties" . Json.object $
        fmap
          ((\(k, v) -> Json.pair (Json.keyToString k) v) . fst)
          xs,
      Json.pair "required" . fmap (fst . fst) $ filter snd xs
    ]

maybe :: Schema -> Schema
maybe s =
  Schema
    { name = Text.pack "maybe-" <> name s,
      json = oneOf [ref s, json Rattletrap.Schema.null]
    }

oneOf :: [Json.Value] -> Json.Value
oneOf xs = Json.object [Json.pair "oneOf" xs]

tuple :: [Json.Value] -> Json.Value
tuple xs =
  Json.object
    [ Json.pair "type" "array",
      Json.pair "items" xs,
      Json.pair "minItems" $ length xs,
      Json.pair "maxItems" $ length xs
    ]

array :: Schema -> Schema
array s =
  Schema
    { name = Text.pack "array-" <> name s,
      json = Json.object [Json.pair "type" "array", Json.pair "items" $ ref s]
    }

boolean :: Schema
boolean = named "boolean" $ Json.object [Json.pair "type" "boolean"]

integer :: Schema
integer = named "integer" $ Json.object [Json.pair "type" "integer"]

null :: Schema
null = named "null" $ Json.object [Json.pair "type" "null"]

number :: Schema
number = named "number" $ Json.object [Json.pair "type" "number"]

string :: Schema
string = named "string" $ Json.object [Json.pair "type" "string"]