content: -- This file is part of the Wire Server implementation.
  --
  -- Copyright (C) 2022 Wire Swiss GmbH <opensource@wire.com>
  --
  -- This program is free software: you can redistribute it and/or modify it under
  -- the terms of the GNU Affero General Public License as published by the Free
  -- Software Foundation, either version 3 of the License, or (at your option) any
  -- later version.
  --
  -- This program is distributed in the hope that it will be useful, but WITHOUT
  -- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  -- FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
  -- details.
  --
  -- You should have received a copy of the GNU Affero General Public License along
  -- with this program. If not, see <https://www.gnu.org/licenses/>.
  
  module Wire.API.SwaggerHelper where
  
  import Control.Lens
  import Data.Containers.ListUtils (nubOrd)
  import Data.HashMap.Strict.InsOrd
  import Data.OpenApi hiding (Contact, Header, Schema, ToSchema)
  import Data.OpenApi qualified as S
  import Data.Text qualified as T
  import Imports hiding (head)
  
  cleanupSwagger :: OpenApi -> OpenApi
  cleanupSwagger =
    (S.security %~ nub)
      -- sanitise definitions
      . (S.components . S.schemas . traverse %~ sanitise)
      -- strip the default errors
      . ( S.allOperations
            . S.responses
            . S.responses
            %~ foldrWithKey stripDefaultErrors mempty
        )
      -- sanitise general responses
      . (S.components . S.responses . traverse . S.content . traverse . S.schema . _Just . S._Inline %~ sanitise)
      -- sanitise all responses of all paths
      . ( S.allOperations
            . S.responses
            . S.responses
            . traverse
            . S._Inline
            . S.content
            . traverse
            . S.schema
            . _Just
            . S._Inline
            %~ sanitise
        )
    where
      sanitise :: S.Schema -> S.Schema
      sanitise =
        (S.properties . traverse . S._Inline %~ sanitise)
          . (S.required %~ nubOrd)
          . (S.enum_ . _Just %~ nub)
      -- servant-openapi and servant-swagger both insert default responses with codes 404 and 400.
      -- They have a simple structure that we can match against, and remove from the final structure.
      stripDefaultErrors :: HttpStatusCode -> Referenced Response -> Responses' -> Responses'
      stripDefaultErrors code resp resps =
        case code of
          400 -> case resp ^? _Inline . S.description of
            (Just desc) ->
              if "Invalid "
                `T.isPrefixOf` desc
                && resp
                  ^? _Inline
                    . links
                  == pure mempty
                && resp
                  ^? _Inline
                    . content
                  == pure mempty
                && resp
                  ^? _Inline
                    . headers
                  == pure mempty
                then resps
                else insert code resp resps
            Nothing -> insert code resp resps
          404 -> case resp ^? _Inline . S.description of
            (Just desc) ->
              if " not found"
                `T.isSuffixOf` desc
                && resp
                  ^? _Inline
                    . links
                  == pure mempty
                && resp
                  ^? _Inline
                    . content
                  == pure mempty
                && resp
                  ^? _Inline
                    . headers
                  == pure mempty
                then resps
                else insert code resp resps
            Nothing -> insert code resp resps
          _ -> insert code resp resps
  
  type Responses' = InsOrdHashMap HttpStatusCode (Referenced Response)
  