Common.hs

module Unclog.Common
  ( -- * commonly used types
    LogEntry (..)

    -- ** types that are lifted by template haskell
  , LogLevel (..)
  , Location (..)
  , Position (..)

    -- * channels for publish / subscribe
  , PLogChan (..)
  , SLogChan (..)
  )
where

import Chronos.Types (Time)
import Data.ByteString (StrictByteString)
import Data.Text (Text)
import GHC.Generics (Generic)
import Language.Haskell.TH.Syntax (Lift)
import UnliftIO

-- | the datatype to communicate between a log source and a logging backend
data LogEntry = MkLogEntry
  { level :: {-# UNPACK #-} !LogLevel
  -- ^ the log level
  , timestamp :: {-# UNPACK #-} !Time
  -- ^ the time at which the log entry was emitted
  , location :: {-# UNPACK #-} !Location
  , payload :: {-# UNPACK #-} !StrictByteString
  -- ^ the payload, this is the unstructure part of the log, converting from the structured to the unstructured
  -- version is the task of the logging frontend
  }
  deriving stock (Eq, Ord, Show, Generic)

-- | a loglevel
data LogLevel = Debug | Info | Warn | Fatal
  deriving stock (Eq, Ord, Show, Generic, Lift)

-- | a source code position
data Position = MkPosition
  { posLeft :: {-# UNPACK #-} !Int
  , posRight :: {-# UNPACK #-} !Int
  }
  deriving stock (Eq, Ord, Show, Generic, Lift)

-- | the code location at which the log entry was generated
data Location = MkLocation
  { locpkg :: {-# UNPACK #-} !Text
  -- ^ the package in which the log entry was generated
  , locmod :: {-# UNPACK #-} !Text
  -- ^ the module in which the log entry was generated
  , locpos :: {-# UNPACK #-} !Position
  -- ^ the position at which the log entry was generated
  }
  deriving stock (Eq, Ord, Show, Generic, Lift)

-- | a publish channel with multiple writers
newtype PLogChan = MkPLogChan {unPLogChan :: TChan LogEntry}
  deriving newtype (Eq)

-- | a read channel created from a publis
newtype SLogChan = MkSLogChan {unSLogChan :: TChan LogEntry}
  deriving newtype (Eq)