module Main where

import           Control.Concurrent
import           Control.Concurrent.Async
import           Control.Concurrent.STM
import           Control.Concurrent.STM.TVar
import           Control.Exception
import           Data.Either
import           Data.IP                     (IPv6, toHostAddress6)
import           System.Environment

import           Hash2Pub.FediChord
import           Hash2Pub.FediChordTypes
import           Hash2Pub.PostService        (PostService (..))

main :: IO ()
main = do
    -- ToDo: parse and pass config
    -- probably use `tomland` for that
    (fConf, sConf) <- readConfig
    -- ToDo: load persisted caches, bootstrapping nodes …
    (fediThreads, thisNode) <- fediChordInit fConf (runService sConf :: DHT d => d -> IO (PostService d))
    -- wait for all DHT threads to terminate, this keeps the main thread running
    wait fediThreads


readConfig :: IO (FediChordConf, ServiceConf)
readConfig = do
    confDomainString : ipString : portString : servicePortString : speedupString : loadBalancingEnabled : remainingArgs <- getArgs
    -- allow starting the initial node without bootstrapping info to avoid
    -- waiting for timeout
    let
        speedup = read speedupString
        statsEvalD = 120 * 10^6 `div` speedup
        confBootstrapNodes' = case remainingArgs of
            bootstrapHost : bootstrapPortString : _ ->
                [(bootstrapHost, read bootstrapPortString)]
            _ -> []
        fConf = FediChordConf
          { confDomain = confDomainString
          , confIP = toHostAddress6 . read $ ipString
          , confDhtPort = read portString
          , confBootstrapNodes = confBootstrapNodes'
          , confStabiliseInterval = 80 * 10^6
          , confBootstrapSamplingInterval = 180 * 10^6 `div` speedup
          , confMaxLookupCacheAge = 300 / fromIntegral speedup
          , confJoinAttemptsInterval = 60 * 10^6 `div` speedup
          , confMaxNodeCacheAge = 600 / fromIntegral speedup
          , confResponsePurgeAge = 60 / fromIntegral speedup
          , confRequestTimeout = 5 * 10^6 `div` speedup
          , confRequestRetries = 3
          , confEnableKChoices = loadBalancingEnabled /= "off"
          , confKChoicesOverload = 0.9
          , confKChoicesUnderload = 0.1
          , confKChoicesMaxVS = 8
          , confKChoicesRebalanceInterval = round  (realToFrac statsEvalD * 1.1 :: Double)
          }
        sConf = ServiceConf
          { confSubscriptionExpiryTime = 24*3600 / fromIntegral speedup
          , confServicePort = read servicePortString
          , confServiceHost = confDomainString
          , confLogfilePath = "../simulationData/logs/" <> confDomainString <> ".log"
          , confSpeedupFactor = speedup
          , confStatsEvalDelay = statsEvalD
          }
    pure (fConf, sConf)