{-# LANGUAGE DeriveGeneric, DeriveAnyClass #-}

module Thermoprint.Server.Queue
       ( Queue(..), QueueEntry(..)
       ) where

import           Thermoprint.API (PrintingError(..), Printout)
import qualified Thermoprint.API as API (JobStatus(..))

import           Thermoprint.Server.Database

import           Data.Sequence (Seq)
import qualified Data.Sequence as Seq

import Data.Time

import           Control.DeepSeq (NFData)
import           Data.Typeable (Typeable)
import           GHC.Generics (Generic)

import           Data.Default.Class

-- | Zipper for 'Seq QueueEntry'
data Queue = Queue
  { pending :: Seq QueueEntry -- ^ Pending jobs, closest last
  , current :: Maybe QueueEntry
  , history :: Seq (QueueEntry, Maybe PrintingError) -- ^ Completed jobs, closest first
  }
  deriving (Typeable, Generic, NFData)

instance Default Queue where
  def = Queue
    { pending = Seq.empty
    , current = Nothing
    , history = Seq.empty
    }

data QueueEntry = QueueEntry
  { jobId :: JobId
  , created :: UTCTime
  }
  deriving (Typeable, Generic, NFData)