{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}

module Network.OAuth.OAuth2.AuthorizationRequest where

import Data.Aeson
import qualified Data.Text.Encoding as T
import GHC.Generics
import Lens.Micro
import Network.OAuth.OAuth2.Internal
import URI.ByteString

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-- * Errors

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instance FromJSON Errors where
  parseJSON = genericParseJSON defaultOptions {constructorTagModifier = camelTo2 '_', allNullaryToStringTag = True}

instance ToJSON Errors where
  toEncoding = genericToEncoding defaultOptions {constructorTagModifier = camelTo2 '_', allNullaryToStringTag = True}

-- | Authorization Code Grant Error Responses https://tools.ietf.org/html/rfc6749#section-4.1.2.1
-- Implicit Grant Error Responses https://tools.ietf.org/html/rfc6749#section-4.2.2.1
data Errors
  = InvalidRequest
  | UnauthorizedClient
  | AccessDenied
  | UnsupportedResponseType
  | InvalidScope
  | ServerError
  | TemporarilyUnavailable
  deriving (Show, Eq, Generic)

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-- * URLs

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-- | Prepare the authorization URL.  Redirect to this URL
-- asking for user interactive authentication.
authorizationUrl :: OAuth2 -> URI
authorizationUrl oa = over (queryL . queryPairsL) (++ queryParts) (oauth2AuthorizeEndpoint oa)
  where
    queryParts =
      [ ("client_id", T.encodeUtf8 $ oauth2ClientId oa),
        ("response_type", "code"),
        ("redirect_uri", serializeURIRef' $ oauth2RedirectUri oa)
      ]