simplex-chat/src/Simplex/Chat/Call.hs

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}
{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}

{-# HLINT ignore "Use newtype instead of data" #-}

module Simplex.Chat.Call where

import Data.Aeson (FromJSON (..), ToJSON (..))
import qualified Data.Aeson.TH as J
import qualified Data.Attoparsec.ByteString.Char8 as A
import Data.ByteString.Char8 (ByteString)
import Data.Int (Int64)
import Data.Text (Text)
import Data.Time.Clock (UTCTime)
import Database.SQLite.Simple.FromField (FromField (..))
import Database.SQLite.Simple.ToField (ToField (..))
import Simplex.Chat.Types (Contact, ContactId, User)
import Simplex.Chat.Types.Util (decodeJSON, encodeJSON)
import qualified Simplex.Messaging.Crypto as C
import Simplex.Messaging.Encoding.String
import Simplex.Messaging.Parsers (defaultJSON, dropPrefix, enumJSON, fromTextField_, fstToLower, singleFieldJSON)

data Call = Call
  { contactId :: ContactId,
    callId :: CallId,
    chatItemId :: Int64,
    callState :: CallState,
    callTs :: UTCTime
  }
  deriving (Show)

isRcvInvitation :: Call -> Bool
isRcvInvitation Call {callState} = case callState of
  CallInvitationReceived {} -> True
  _ -> False

data CallStateTag
  = CSTCallInvitationSent
  | CSTCallInvitationReceived
  | CSTCallOfferSent
  | CSTCallOfferReceived
  | CSTCallNegotiated
  deriving (Show)

callStateTag :: CallState -> CallStateTag
callStateTag = \case
  CallInvitationSent {} -> CSTCallInvitationSent
  CallInvitationReceived {} -> CSTCallInvitationReceived
  CallOfferSent {} -> CSTCallOfferSent
  CallOfferReceived {} -> CSTCallOfferReceived
  CallNegotiated {} -> CSTCallNegotiated

data CallState
  = CallInvitationSent
      { localCallType :: CallType,
        localDhPrivKey :: Maybe C.PrivateKeyX25519
      }
  | CallInvitationReceived
      { peerCallType :: CallType,
        localDhPubKey :: Maybe C.PublicKeyX25519,
        sharedKey :: Maybe C.Key
      }
  | CallOfferSent
      { localCallType :: CallType,
        peerCallType :: CallType,
        localCallSession :: WebRTCSession,
        sharedKey :: Maybe C.Key
      }
  | CallOfferReceived
      { localCallType :: CallType,
        peerCallType :: CallType,
        peerCallSession :: WebRTCSession,
        sharedKey :: Maybe C.Key
      }
  | CallNegotiated
      { localCallType :: CallType,
        peerCallType :: CallType,
        localCallSession :: WebRTCSession,
        peerCallSession :: WebRTCSession,
        sharedKey :: Maybe C.Key
      }
  deriving (Show)

newtype CallId = CallId ByteString
  deriving (Eq, Show)

instance StrEncoding CallId where
  strEncode (CallId m) = strEncode m
  strDecode s = CallId <$> strDecode s
  strP = CallId <$> strP

instance FromJSON CallId where
  parseJSON = strParseJSON "CallId"

instance ToJSON CallId where
  toJSON = strToJSON
  toEncoding = strToJEncoding

instance FromField CallId where fromField f = CallId <$> fromField f

instance ToField CallId where toField (CallId m) = toField m

data RcvCallInvitation = RcvCallInvitation
  { user :: User,
    contact :: Contact,
    callType :: CallType,
    sharedKey :: Maybe C.Key,
    callTs :: UTCTime
  }
  deriving (Show)

data CallType = CallType
  { media :: CallMedia,
    capabilities :: CallCapabilities
  }
  deriving (Eq, Show)

defaultCallType :: CallType
defaultCallType = CallType CMVideo $ CallCapabilities {encryption = True}

encryptedCall :: CallType -> Bool
encryptedCall CallType {capabilities = CallCapabilities {encryption}} = encryption

-- | * Types for chat protocol
data CallInvitation = CallInvitation
  { callType :: CallType,
    callDhPubKey :: Maybe C.PublicKeyX25519
  }
  deriving (Eq, Show)

data CallMedia = CMAudio | CMVideo
  deriving (Eq, Show)

data CallCapabilities = CallCapabilities
  { encryption :: Bool
  }
  deriving (Eq, Show)

data CallOffer = CallOffer
  { callType :: CallType,
    rtcSession :: WebRTCSession,
    callDhPubKey :: Maybe C.PublicKeyX25519
  }
  deriving (Eq, Show)

data WebRTCCallOffer = WebRTCCallOffer
  { callType :: CallType,
    rtcSession :: WebRTCSession
  }
  deriving (Eq, Show)

data CallAnswer = CallAnswer
  { rtcSession :: WebRTCSession
  }
  deriving (Eq, Show)

data CallExtraInfo = CallExtraInfo
  { rtcExtraInfo :: WebRTCExtraInfo
  }
  deriving (Eq, Show)

data WebRTCSession = WebRTCSession
  { rtcSession :: Text, -- LZW compressed JSON encoding of offer or answer
    rtcIceCandidates :: Text -- LZW compressed JSON encoding of array of ICE candidates
  }
  deriving (Eq, Show)

data WebRTCExtraInfo = WebRTCExtraInfo
  { rtcIceCandidates :: Text -- LZW compressed JSON encoding of array of ICE candidates
  }
  deriving (Eq, Show)

data WebRTCCallStatus = WCSConnecting | WCSConnected | WCSDisconnected | WCSFailed
  deriving (Show)

instance StrEncoding WebRTCCallStatus where
  strEncode = \case
    WCSConnecting -> "connecting"
    WCSConnected -> "connected"
    WCSDisconnected -> "disconnected"
    WCSFailed -> "failed"
  strP =
    A.takeTill (== ' ') >>= \case
      "connecting" -> pure WCSConnecting
      "connected" -> pure WCSConnected
      "disconnected" -> pure WCSDisconnected
      "failed" -> pure WCSFailed
      _ -> fail "bad WebRTCCallStatus"

$(J.deriveJSON (enumJSON $ dropPrefix "CSTCall") ''CallStateTag)

$(J.deriveJSON (enumJSON $ dropPrefix "CM") ''CallMedia)

$(J.deriveJSON defaultJSON ''CallCapabilities)

$(J.deriveJSON defaultJSON ''CallType)

$(J.deriveJSON defaultJSON ''CallInvitation)

$(J.deriveJSON defaultJSON ''WebRTCSession)

$(J.deriveJSON defaultJSON ''CallOffer)

$(J.deriveJSON defaultJSON ''WebRTCCallOffer)

$(J.deriveJSON defaultJSON ''CallAnswer)

$(J.deriveJSON defaultJSON ''WebRTCExtraInfo)

$(J.deriveJSON defaultJSON ''CallExtraInfo)

-- database representation
$(J.deriveJSON (singleFieldJSON fstToLower) ''CallState)

instance ToField CallState where
  toField = toField . encodeJSON

instance FromField CallState where
  fromField = fromTextField_ decodeJSON

$(J.deriveJSON defaultJSON ''RcvCallInvitation)