-- This is taken from wai-logger and customised for our use

module Hasura.Server.Logging
  ( StartupLog(..)
  , PGLog(..)
  , mkInconsMetadataLog
  , mkHttpAccessLogContext
  , mkHttpErrorLogContext
  , mkHttpLog
  , HttpInfoLog(..)
  , OperationLog(..)
  , HttpLogContext(..)
  , WebHookLog(..)
  , HttpException
  , HttpLog (..)
  ) where

import           Hasura.Prelude

import qualified Data.ByteString.Lazy          as BL
import qualified Language.GraphQL.Draft.Syntax as G
import qualified Network.HTTP.Types            as HTTP
import qualified Network.Wai.Extended          as Wai

import           Data.Aeson
import           Data.Aeson.TH
import           Data.Int                      (Int64)

import           Hasura.GraphQL.Parser.Schema  (Variable)
import           Hasura.HTTP
import           Hasura.Logging
import           Hasura.Metadata.Class
import           Hasura.RQL.Types
import           Hasura.Server.Compression
import           Hasura.Server.Types
import           Hasura.Session
import           Hasura.Tracing                (TraceT)


data StartupLog
  = StartupLog
  { slLogLevel :: !LogLevel
  , slKind     :: !Text
  , slInfo     :: !Value
  } deriving (Show, Eq)

instance ToJSON StartupLog where
  toJSON (StartupLog _ k info) =
    object [ "kind" .= k
           , "info" .= info
           ]

instance ToEngineLog StartupLog Hasura where
  toEngineLog startupLog =
    (slLogLevel startupLog, ELTStartup, toJSON startupLog)

data PGLog
  = PGLog
  { plLogLevel :: !LogLevel
  , plMessage  :: !Text
  } deriving (Show, Eq)

instance ToJSON PGLog where
  toJSON (PGLog _ msg) =
    object ["message" .= msg]

instance ToEngineLog PGLog Hasura where
  toEngineLog pgLog =
    (plLogLevel pgLog, ELTInternal ILTPgClient, toJSON pgLog)

data MetadataLog
  = MetadataLog
  { mlLogLevel :: !LogLevel
  , mlMessage  :: !Text
  , mlInfo     :: !Value
  } deriving (Show, Eq)

instance ToJSON MetadataLog where
  toJSON (MetadataLog _ msg infoVal) =
    object [ "message" .= msg
           , "info" .= infoVal
           ]

instance ToEngineLog MetadataLog Hasura where
  toEngineLog ml =
    (mlLogLevel ml, ELTInternal ILTMetadata, toJSON ml)

mkInconsMetadataLog :: [InconsistentMetadata] -> MetadataLog
mkInconsMetadataLog objs =
  MetadataLog LevelWarn "Inconsistent Metadata!" $
    object [ "objects" .= objs]

data WebHookLog
  = WebHookLog
  { whlLogLevel   :: !LogLevel
  , whlStatusCode :: !(Maybe HTTP.Status)
  , whlUrl        :: !Text
  , whlMethod     :: !HTTP.StdMethod
  , whlError      :: !(Maybe HttpException)
  , whlResponse   :: !(Maybe Text)
  , whlMessage    :: !(Maybe Text)
  } deriving (Show)

instance ToEngineLog WebHookLog Hasura where
  toEngineLog webHookLog =
    (whlLogLevel webHookLog, ELTWebhookLog, toJSON webHookLog)

instance ToJSON WebHookLog where
  toJSON whl =
    object [ "status_code" .= (HTTP.statusCode <$> whlStatusCode whl)
           , "url" .= whlUrl whl
           , "method" .= show (whlMethod whl)
           , "http_error" .= whlError whl
           , "response" .= whlResponse whl
           , "message" .= whlMessage whl
           ]

class (Monad m, Monoid (HTTPLoggingMetadata m)) => HttpLog m where

  type HTTPLoggingMetadata m

  buildHTTPLoggingMetadata :: [(G.SelectionSet G.NoFragments Variable)] -> HTTPLoggingMetadata m

  logHttpError
    :: Logger Hasura
    -- ^ the logger
    -> Maybe UserInfo
    -- ^ user info may or may not be present (error can happen during user resolution)
    -> RequestId
    -- ^ request id of the request
    -> Wai.Request
    -- ^ the Wai.Request object
    -> (BL.ByteString, Maybe Value)
    -- ^ the request body and parsed request
    -> QErr
    -- ^ the error
    -> [HTTP.Header]
    -- ^ list of request headers
    -> m ()

  logHttpSuccess
    :: Logger Hasura
    -- ^ the logger
    -> Maybe UserInfo
    -- ^ user info may or may not be present (error can happen during user resolution)
    -> RequestId
    -- ^ request id of the request
    -> Wai.Request
    -- ^ the Wai.Request object
    -> (BL.ByteString, Maybe Value)
    -- ^ the request body and parsed request
    -> BL.ByteString
    -- ^ the response bytes
    -> BL.ByteString
    -- ^ the compressed response bytes
    -- ^ TODO (from master): make the above two type represented
    -> Maybe (DiffTime, DiffTime)
    -- ^ IO/network wait time and service time (respectively) for this request, if available.
    -> Maybe CompressionType
    -- ^ possible compression type
    -> [HTTP.Header]
    -- ^ list of request headers
    -> HTTPLoggingMetadata m
    -> m ()

instance HttpLog m => HttpLog (TraceT m) where

  type HTTPLoggingMetadata (TraceT m) = HTTPLoggingMetadata m

  buildHTTPLoggingMetadata a = buildHTTPLoggingMetadata @m a

  logHttpError a b c d e f g = lift $ logHttpError a b c d e f g

  logHttpSuccess a b c d e f g h i j k = lift $ logHttpSuccess a b c d e f g h i j k

instance HttpLog m => HttpLog (ReaderT r m) where

  type HTTPLoggingMetadata (ReaderT r m) = HTTPLoggingMetadata m

  buildHTTPLoggingMetadata a = buildHTTPLoggingMetadata @m a

  logHttpError a b c d e f g = lift $ logHttpError a b c d e f g

  logHttpSuccess a b c d e f g h i j k = lift $ logHttpSuccess a b c d e f g h i j k

instance HttpLog m => HttpLog (MetadataStorageT m) where

  type HTTPLoggingMetadata (MetadataStorageT m) = HTTPLoggingMetadata m

  buildHTTPLoggingMetadata a = buildHTTPLoggingMetadata @m a

  logHttpError a b c d e f g = lift $ logHttpError a b c d e f g

  logHttpSuccess a b c d e f g h i j k = lift $ logHttpSuccess a b c d e f g h i j k

-- | Log information about the HTTP request
data HttpInfoLog
  = HttpInfoLog
  { hlStatus      :: !HTTP.Status
  , hlMethod      :: !Text
  , hlSource      :: !Wai.IpAddress
  , hlPath        :: !Text
  , hlHttpVersion :: !HTTP.HttpVersion
  , hlCompression :: !(Maybe CompressionType)
  , hlHeaders     :: ![HTTP.Header]
  -- ^ all the request headers
  } deriving (Show, Eq)

instance ToJSON HttpInfoLog where
  toJSON (HttpInfoLog st met src path hv compressTypeM _) =
    object [ "status" .= HTTP.statusCode st
           , "method" .= met
           , "ip" .= Wai.showIPAddress src
           , "url" .= path
           , "http_version" .= show hv
           , "content_encoding" .= (compressionTypeToTxt <$> compressTypeM)
           ]

-- | Information about a GraphQL/Hasura metadata operation over HTTP
data OperationLog
  = OperationLog
  { olRequestId          :: !RequestId
  , olUserVars           :: !(Maybe SessionVariables)
  , olResponseSize       :: !(Maybe Int64)
  , olRequestReadTime    :: !(Maybe Seconds)
  -- ^ Request IO wait time, i.e. time spent reading the full request from the socket.
  , olQueryExecutionTime :: !(Maybe Seconds)
  -- ^ Service time, not including request IO wait time.
  , olQuery              :: !(Maybe Value)
  , olRawQuery           :: !(Maybe Text)
  , olError              :: !(Maybe QErr)
  } deriving (Show, Eq)

$(deriveToJSON hasuraJSON{omitNothingFields = True} ''OperationLog)

data HttpLogContext
  = HttpLogContext
  { hlcHttpInfo  :: !HttpInfoLog
  , hlcOperation :: !OperationLog
  , hlcRequestId :: !RequestId
  } deriving (Show, Eq)
$(deriveToJSON hasuraJSON ''HttpLogContext)

mkHttpAccessLogContext
  :: Maybe UserInfo
  -- ^ Maybe because it may not have been resolved
  -> RequestId
  -> Wai.Request
  -> BL.ByteString
  -> Maybe (DiffTime, DiffTime)
  -> Maybe CompressionType
  -> [HTTP.Header]
  -> HttpLogContext
mkHttpAccessLogContext userInfoM reqId req res mTiming compressTypeM headers =
  let http = HttpInfoLog
             { hlStatus      = status
             , hlMethod      = bsToTxt $ Wai.requestMethod req
             , hlSource      = Wai.getSourceFromFallback req
             , hlPath        = bsToTxt $ Wai.rawPathInfo req
             , hlHttpVersion = Wai.httpVersion req
             , hlCompression  = compressTypeM
             , hlHeaders     = headers
             }
      op = OperationLog
           { olRequestId    = reqId
           , olUserVars     = _uiSession <$> userInfoM
           , olResponseSize = respSize
           , olRequestReadTime    = Seconds . fst <$> mTiming
           , olQueryExecutionTime = Seconds . snd <$> mTiming
           , olQuery = Nothing
           , olRawQuery = Nothing
           , olError = Nothing
           }
  in HttpLogContext http op reqId
  where
    status = HTTP.status200
    respSize = Just $ BL.length res

mkHttpErrorLogContext
  :: Maybe UserInfo
  -- ^ Maybe because it may not have been resolved
  -> RequestId
  -> Wai.Request
  -> (BL.ByteString, Maybe Value)
  -> QErr
  -> Maybe (DiffTime, DiffTime)
  -> Maybe CompressionType
  -> [HTTP.Header]
  -> HttpLogContext
mkHttpErrorLogContext userInfoM reqId waiReq (reqBody, parsedReq) err mTiming compressTypeM headers =
  let http = HttpInfoLog
             { hlStatus      = qeStatus err
             , hlMethod      = bsToTxt $ Wai.requestMethod waiReq
             , hlSource      = Wai.getSourceFromFallback waiReq
             , hlPath        = bsToTxt $ Wai.rawPathInfo waiReq
             , hlHttpVersion = Wai.httpVersion waiReq
             , hlCompression = compressTypeM
             , hlHeaders     = headers
             }
      op = OperationLog
           { olRequestId          = reqId
           , olUserVars           = _uiSession <$> userInfoM
           , olResponseSize       = Just $ BL.length $ encode err
           , olRequestReadTime    = Seconds . fst <$> mTiming
           , olQueryExecutionTime = Seconds . snd <$> mTiming
           , olQuery              = parsedReq
           , olRawQuery           = maybe (Just $ bsToTxt $ BL.toStrict reqBody) (const Nothing) parsedReq
           , olError              = Just err
           }
  in HttpLogContext http op reqId

data HttpLogLine
  = HttpLogLine
  { _hlLogLevel :: !LogLevel
  , _hlLogLine  :: !HttpLogContext
  }

instance ToEngineLog HttpLogLine Hasura where
  toEngineLog (HttpLogLine logLevel logLine) =
    (logLevel, ELTHttpLog, toJSON logLine)

mkHttpLog :: HttpLogContext -> HttpLogLine
mkHttpLog httpLogCtx =
  let isError = isJust $ olError $ hlcOperation httpLogCtx
      logLevel = bool LevelInfo LevelError isError
  in HttpLogLine logLevel httpLogCtx