module Network.HTTP2.TLS.Client.Settings where

import Data.X509.CertificateStore (CertificateStore)
import Network.Socket

import Network.Control
import Network.HTTP2.Client (
    cacheLimit,
    defaultClientConfig,
 )
import Network.TLS (SessionData, SessionID, SessionManager, noSessionManager)

-- Client settings type.
data Settings = Settings
    { settingsKeyLogger :: String -> IO ()
    -- ^ Key logger (TLS and H2)
    --
    -- Applications may wish to set this depending on the SSLKEYLOGFILE environment variable.
    --
    -- Default: do nothing.
    , settingsValidateCert :: Bool
    -- ^ Should we validate TLS certificates? (TLS and H2)
    --
    -- >>> settingsValidateCert defaultSettings
    -- True
    , settingsCAStore :: CertificateStore
    -- ^ Certificate store used for validation. (TLS and H2)
    --
    -- Default: 'mempty'.
    , settingsServerNameOverride :: Maybe HostName
    -- ^ Server name override (H2)
    --
    -- By default, the server name (for TLS SNI) is set based on the
    -- 'Network.HTTP2.Client.authority', corresponding to the HTTP2
    -- @:authority@ pseudo-header. In rare circumstances these two values should
    -- be different (for example in the case of domain fronting);
    -- 'settingsServerNameOverride' can be used to give SNI a different value
    -- than @:authority@.
    , settingsAddrInfoFlags :: [AddrInfoFlag]
    -- ^ Obsoleted.
    , settingsCacheLimit :: Int
    -- ^ How many pushed responses are contained in the cache (H2 and H2c)
    --
    -- >>> settingsCacheLimits defaultSettings
    -- 64
    , settingsConcurrentStreams :: Int
    -- ^ The maximum number of incoming streams on the net (H2 and H2c)
    --
    -- >>> settingsConcurrentStreams defaultSettings
    -- 64
    , settingsStreamWindowSize :: Int
    -- ^ The window size of incoming streams (H2 and H2c)
    --
    -- >>> settingsStreamWindowSize defaultSettings
    -- 262144
    , settingsConnectionWindowSize :: Int
    -- ^ The window size of a connection (H2 and H2c)
    --
    -- >>> settingsConnectionWindowSize defaultSettings
    -- 1048575
    , settingsSessionManager :: SessionManager
    -- ^ TLS session manager (H2 and TLS)
    --
    -- Default: 'noSessionManager'
    , settingsWantSessionResume :: Maybe (SessionID, SessionData)
    -- ^ Try to resume a TLS session (H2 and TLS)
    --
    -- >>> settingsWantSessionResume defaultSettings
    -- Nothing
    , settingsUseEarlyData :: Bool
    -- ^ Try to use 0-RTT (H2 and TLS)
    --
    -- This is only supported for @tls >= 2.0@.
    --
    -- >>> settingsUseEarlyData defaultSettings
    -- False
    }

-- | Default settings.
defaultSettings :: Settings
defaultSettings =
    Settings
        { settingsKeyLogger = \_ -> return ()
        , settingsValidateCert = True
        , settingsCAStore = mempty
        , settingsServerNameOverride = Nothing
        , settingsAddrInfoFlags = []
        , settingsCacheLimit = cacheLimit defaultClientConfig
        , settingsConcurrentStreams = defaultMaxStreams
        , settingsStreamWindowSize = defaultMaxStreamData
        , settingsConnectionWindowSize = defaultMaxData
        , settingsSessionManager = noSessionManager
        , settingsWantSessionResume = Nothing
        , settingsUseEarlyData = False
        }