import std/[
  options,
  times
]

import
  deser,
  deser_json

proc fromTimestamp(deserializer: var auto): Time =
  fromUnix(deserialize(int64, deserializer))

proc toTimestamp(self: Time, serializer: var auto) =
  serializer.serializeInt64(self.toUnix())

type
  ChatType = enum
    Private = "private"
    Group = "group"

  Chat {.renameAll(SnakeCase).} = object
    id: int64
    username {.skipSerializeIf(isNone).}: Option[string]
    created {.serializeWith(toTimestamp), deserializeWith(fromTimestamp).}: Time

    case kind {.renamed("type").}: ChatType
    of Private:
      firstName: string
      lastName {.skipSerializeIf(isNone).}: Option[string]
      bio {.skipSerializeIf(isNone).}: Option[string]
    of Group:
      title: string

# Use public to export deserialize or serialize procedures
# false by default
makeSerializable(Chat, public=true)
makeDeserializable(Chat, public=true)

const
  json = """
  {
    "id": 123,
    "username": "gabbhack",
    "created": 1234567890,
    "type": "private",
    "first_name": "Gabben"
  }
  """
  chat = Chat(
    id: 123,
    username: some "gabbhack",
    created: fromUnix(1234567890),
    kind: Private,
    firstName: "Gabben"
  )

echo Chat.fromJson(json)
echo chat.toJson()