Draft: Servant Api Specification

This PR does 3 things:

1. Specifies a modular definition for the Skete Servant api, along with associated clients and server. The design is granular to facilitate better testing (standalone clients are easier to test when their component apis are separate from the rest of the API)

2. Restructures the project to define a toplevel RestAPI.hs module, with client/server/util definitions in an associated RestAPI/* namespace.

3. Adds the Servant-* dependencies, cleans up old code.

Addresses #21

src/Distribution/Skete/Haskell/API/Features/Core.hs

+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE TypeOperators #-}
+module Distribution.Skete.Haskell.API.Features.Core
+( -- * Core API
+  CoreApi(..)
+, coreApi
+, coreApiHandlers
+, coreApiServer
+
+  -- ** Package list endpoints
+, GetPackagesIndexApi
+, getPackagesIndexApi
+
+  -- ** Package index endpoints
+, GetIndexGzipApi
+, getIndexGzipApi
+, GetIndexTarballApi
+, getIndexTarballApi
+
+  -- ** Get package endpoints
+, GetPackagesApi
+, getPackagesApi
+, PostPackagesApi
+, postPackagesApi
+
+  -- ** Package info endpoints
+, GetPackageIdApi
+, getPackageIdApi
+, GetPackageIdGzipApi
+, getPackageIdGzipApi
+, PutPackageIdGzipApi
+, putPackageIdGzipApi
+, GetPackageIdCabalApi
+, getPackageIdCabalApi
+, PutPackageIdCabalApi
+, putPackageIdCabalApi
+, GetPackageIdRevisionsApi
+, getPackageIdRevisionsApi
+, GetPackageIdRevisionApi
+, getPackageIdRevisionApi
+) where
+
+
+import Distribution.Skete.Haskell.API.Types.Core
+
+import Servant
+import Servant.API.Generic
+import Servant.HTML.Blaze
+import Servant.Server.Generic
+
+data CoreApi route
+  = CoreApi
+  { getPackagesIndex :: route :- GetPackagesIndexApi
+  , getIndexGzip :: route :- GetIndexGzipApi
+  , getIndexTarball :: route :- GetIndexTarballApi
+  , getPackages :: route :- GetPackagesApi
+  , postPackages :: route :- PostPackagesApi
+  , getPackageId :: route :- GetPackageIdApi
+  , getPackageIdGzip :: route :- GetPackageIdGzipApi
+  , putPackageIdGzip :: route :- PutPackageIdGzipApi
+  , getPackageIdCabal :: route :- GetPackageIdCabalApi
+  , putPackageIdCabal :: route :- PutPackageIdCabalApi
+  , getPackageIdRevisions :: route :- GetPackageIdRevisionsApi
+  , getPackageIdRevision :: route :- GetPackageIdRevisionApi
+  } deriving Generic
+
+-- | Singleton instance for 'CoreApi'.
+--
+coreApi :: Proxy (ToServantApi CoreApi)
+coreApi = genericApi (Proxy :: Proxy CoreApi)
+
+-- | Core Api Handlers.
+--
+-- TODO: Stubbed in Distribution.Skete.Haskell.API.Features.Core.Server
+--
+coreApiHandlers :: CoreApi AsServer
+coreApiHandlers = CoreApi
+  { getPackagesIndex = error "TODO: handler not yet written"
+  , getIndexGzip = error "TODO: handler not yet written"
+  , getIndexTarball = error "TODO: handler not yet written"
+  , getPackages = error "TODO: handler not yet written"
+  , postPackages = error "TODO: handler not yet written"
+  , getPackageId = error "TODO: handler not yet written"
+  , getPackageIdGzip = error "TODO: handler not yet written"
+  , putPackageIdGzip = error "TODO: handler not yet written"
+  , getPackageIdCabal = error "TODO: handler not yet written"
+  , putPackageIdCabal = error "TODO: handler not yet written"
+  , getPackageIdRevisions = error "TODO: handler not yet written"
+  , getPackageIdRevision = error "TODO: handler not yet written"
+  }
+
+-- | Core API server instance
+--
+coreApiServer :: ToServant CoreApi AsServer
+coreApiServer = genericServer coreApiHandlers
+
+-- -------------------------------------------------------------------- --
+-- GET /packages/index.tar.gz
+
+type GetPackagesIndexApi
+  = Summary "Get gzip of package index."
+  :> Description "Get gzip of package descriptions from Hackage server."
+  :> "packages"
+  :> "index.tar.gz"
+  :> Get '[Gzip] Gzip
+
+getPackagesIndexApi :: Proxy GetPackagesIndexApi
+getPackagesIndexApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /packages/index.tar.gz
+
+type GetIndexGzipApi
+  = Summary "Get gzip of package index."
+  :> Description "Get gzip of the package index for Hackage server."
+  :> "01-index.tar.gz"
+  :> Get '[Gzip] Gzip
+
+getIndexGzipApi :: Proxy GetIndexGzipApi
+getIndexGzipApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /packages/index.tar
+
+type GetIndexTarballApi
+  = Summary "Get tarball of package index."
+  :> Description "Get tarball of the package index for Hackage server."
+  :> "01-index.tar"
+  :> Get '[Tarball] Tarball
+
+getIndexTarballApi :: Proxy GetIndexTarballApi
+getIndexTarballApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /packages/
+
+type GetPackagesApi
+  = Summary "Get list of all packages"
+  :> Description "Get list of all packages for Hackage server."
+  :> "packages"
+  :> Get '[JSON, HTML] [PkgInfo]
+
+getPackagesApi :: Proxy GetPackagesApi
+getPackagesApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /packages/
+
+type PostPackagesApi
+  = Summary "Upload a package"
+  :> Description "Upload a package to a Hackage server."
+  :> "packages"
+  :> ReqBody '[HTML] PkgInfo
+  :> Post '[HTML] PkgInfo
+
+postPackagesApi :: Proxy PostPackagesApi
+postPackagesApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /package/:package
+
+type GetPackageIdApi
+  = Summary "Show detailed package info."
+  :> Description "Show detailed description of a Hackage package."
+  :> "package"
+  :> Capture "package"
+  :> Get '[HTML] [PkgInfo]
+
+getPackageIdApi :: Proxy GetPackageIdApi
+getPackageIdApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /package/:package/:tarball.tar.gz
+
+type GetPackageIdGzipApi
+  = Summary "Get package tarball"
+  :> Description "Get package description tarball for a Hackage package."
+  :> "package"
+  :> Capture "package"
+  :> Capture "tarball.tar.gz"
+  :> Get '[Gzip] Gzip
+
+getPackageIdGzipApi :: Proxy GetPackageIdGzipApi
+getPackageIdGzipApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- PUT /package/:package/:tarball.tar.gz
+
+type PutPackageIdGzipApi
+  = Summary "Get package tarball"
+  :> Description "Get package description tarball for a Hackage package."
+  :> "package"
+  :> Capture "package"
+  :> Capture "tarball.tar.gz"
+  :> Put '[Gzip] Gzip
+
+putPackageIdGzipApi :: Proxy PutPackageIdGzipApi
+putPackageIdGzipApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /package/:package/:cabal.cabal
+
+type GetPackageIdCabalApi
+  = Summary "Get package .cabal file"
+  :> Description "Get package description .cabal file for a Hackage package."
+  :> "package"
+  :> Capture "package"
+  :> Capture "cabal.cabal"
+  :> Get '[OctetStream] CabalFileText
+
+getPackageIdCabalApi :: Proxy GetPackageIdCabalApi
+getPackageIdCabalApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- Put /package/:package/:cabal.cabal
+
+type PutPackageIdCabalApi
+  = Summary "Get package .cabal file"
+  :> Description "Get package description .cabal file for a Hackage package."
+  :> "package"
+  :> Capture "package"
+  :> Capture "cabal.cabal"
+  :> Put '[CabalFileText] CabalFileText
+
+putPackageIdCabalApi :: Proxy PutPackageIdCabalApi
+putPackageIdCabalApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /package/:package/revisions
+
+type GetPackageIdRevisionsApi
+  = Summary "Get package .cabal file"
+  :> Description "Get package description .cabal file for a Hackage package."
+  :> "package"
+  :> Capture "package"
+  :> "revisions"
+  :> Get '[JSON, HTML] [CabalFileText]
+
+getPackageIdRevisionsApi :: Proxy GetPackageIdRevisionsApi
+getPackageIdRevisionsApi = Proxy
+
+-- -------------------------------------------------------------------- --
+-- GET /package/:package/revisions/:revision
+
+type GetPackageIdRevisionApi
+  = Summary "Get package .cabal file"
+  :> Description "Get package description .cabal file for a Hackage package."
+  :> "package"
+  :> Capture "package"
+  :> "revisions"
+  :> Capture "revision"
+  :> Get '[CabalFileText] CabalFileText
+
+getPackageIdRevisionApi :: Proxy GetPackageIdRevisionApi
+getPackageIdRevisionApi = Proxy