package utils

import (
  "github.com/ethereum/eth-go"
  "github.com/ethereum/eth-go/ethminer"
  "github.com/ethereum/eth-go/ethpub"
  "github.com/ethereum/eth-go/ethrpc"
  "github.com/ethereum/eth-go/ethutil"
  "github.com/ethereum/eth-go/ethlog"
  "log"
  "io"
  "path"
  "os"
  "os/signal"
  "fmt"
  "time"
  "strings"
)

var logger = ethlog.NewLogger("CLI")
var interruptCallbacks = []func(os.Signal){}

// Register interrupt handlers callbacks
func RegisterInterrupt(cb func(os.Signal)) {
  interruptCallbacks = append(interruptCallbacks, cb)
}

// go routine that call interrupt handlers in order of registering
func HandleInterrupt() {
  c := make(chan os.Signal, 1)
  go func() {
    signal.Notify(c, os.Interrupt)
    for sig := range c {
      logger.Errorf("Shutting down (%v) ... \n", sig)
      RunInterruptCallbacks(sig)
    }
  }()
}

func RunInterruptCallbacks(sig os.Signal) {
  for _, cb := range interruptCallbacks {
    cb(sig)
  }
}

func AbsolutePath(Datadir string, filename string) string {
  if path.IsAbs(filename) {
    return filename
  }
  return path.Join(Datadir, filename)
}

func openLogFile (Datadir string, filename string) *os.File {
  path := AbsolutePath(Datadir, filename)
  file, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
  if err != nil {
    panic(fmt.Sprintf("error opening log file '%s': %v", filename, err))
  }
  return file
}

func confirm (message string) bool {
  fmt.Println(message, "Are you sure? (y/n)")
  var r string
  fmt.Scanln(&r)
  for ; ; fmt.Scanln(&r) {
    if r == "n" || r == "y" {
      break
    } else {
      fmt.Printf("Yes or no?", r)
    }
  }
  return r == "y"
}

func InitDataDir(Datadir string) {
  _, err := os.Stat(Datadir)
  if err != nil {
    if os.IsNotExist(err) {
      fmt.Printf("Debug logging directory '%s' doesn't exist, creating it\n", Datadir)
      os.Mkdir(Datadir, 0777)
    }
  }
}

func InitLogging (Datadir string, LogFile string, LogLevel int, DebugFile string) {
  var writer io.Writer
  if LogFile == "" {
    writer = os.Stdout
  } else {
    writer = openLogFile(Datadir, LogFile)
  }
  ethlog.AddLogSystem(ethlog.NewStdLogSystem(writer, log.LstdFlags, ethlog.LogLevel(LogLevel)))
  if DebugFile != "" {
    writer = openLogFile(Datadir, DebugFile)
    ethlog.AddLogSystem(ethlog.NewStdLogSystem(writer, log.LstdFlags, ethlog.DebugLevel))
  }
}

func InitConfig(ConfigFile string, Datadir string, Identifier string, EnvPrefix string) {
  InitDataDir(Datadir)
  ethutil.ReadConfig(ConfigFile, Datadir, Identifier, EnvPrefix)
  ethutil.Config.Set("rpcport", "700")
}

func exit(status int) {
  ethlog.Flush()
  os.Exit(status)
}

func NewEthereum(UseUPnP bool, OutboundPort string, MaxPeer int) *eth.Ethereum {
  ethereum, err := eth.New(eth.CapDefault, UseUPnP)
  if err != nil {
    logger.Fatalln("eth start err:", err)
  }
  ethereum.Port = OutboundPort
  ethereum.MaxPeers = MaxPeer
  return ethereum
}

func StartEthereum(ethereum *eth.Ethereum, UseSeed bool) {
  logger.Infof("Starting Ethereum v%s", ethutil.Config.Ver)
  ethereum.Start(UseSeed)
  RegisterInterrupt(func(sig os.Signal) {
    ethereum.Stop()
    ethlog.Flush()
  })
}

func ShowGenesis(ethereum *eth.Ethereum) {
  logger.Infoln(ethereum.BlockChain().Genesis())
  exit(0)
}

func KeyTasks(GenAddr bool, ImportKey string, ExportKey bool, NonInteractive bool) {
  switch {
  case GenAddr:
    if NonInteractive || confirm("This action overwrites your old private key.") {
      CreateKeyPair(true)
    }
    exit(0)
  case len(ImportKey) > 0:
    if NonInteractive || confirm("This action overwrites your old private key.") {
      // import should be from file
      mnemonic := strings.Split(ImportKey, " ")
      if len(mnemonic) == 24 {
        logger.Infoln("Got mnemonic key, importing.")
        key := ethutil.MnemonicDecode(mnemonic)
        ImportPrivateKey(key)
      } else if len(mnemonic) == 1 {
        logger.Infoln("Got hex key, importing.")
        ImportPrivateKey(ImportKey)
      } else {
        logger.Errorln("Did not recognise format, exiting.")
      }
    }
    exit(0)
  case ExportKey: // this should be exporting to a filename
    keyPair := ethutil.GetKeyRing().Get(0)
    fmt.Printf(`
Generating new address and keypair.
Please keep your keys somewhere save.

++++++++++++++++ KeyRing +++++++++++++++++++
addr: %x
prvk: %x
pubk: %x
++++++++++++++++++++++++++++++++++++++++++++
save these words so you can restore your account later: %s
`, keyPair.Address(), keyPair.PrivateKey, keyPair.PublicKey)

    exit(0)
  default:
    // Creates a keypair if none exists
    CreateKeyPair(false)
  }
}

func StartRpc(ethereum *eth.Ethereum, RpcPort int) {
  var err error
  ethereum.RpcServer, err = ethrpc.NewJsonRpcServer(ethpub.NewPEthereum(ethereum), RpcPort)
  if err != nil {
    logger.Errorf("Could not start RPC interface (port %v): %v", RpcPort, err)
  } else {
    go ethereum.RpcServer.Start()
  }
}

var miner ethminer.Miner

func StartMining(ethereum *eth.Ethereum) bool {
  if !ethereum.Mining {
    ethereum.Mining = true

    if ethutil.GetKeyRing().Len() == 0 {
      logger.Errorln("No address found, can't start mining")
      ethereum.Mining = false
      return true //????
    }
    keyPair := ethutil.GetKeyRing().Get(0)
    addr := keyPair.Address()

    go func() {
      miner = ethminer.NewDefaultMiner(addr, ethereum)
      // Give it some time to connect with peers
      time.Sleep(3 * time.Second)
      logger.Infoln("Miner started")
      miner := ethminer.NewDefaultMiner(addr, ethereum)
      miner.Start()
    }()
    RegisterInterrupt(func(os.Signal) {
      StopMining(ethereum)
    })
    return true
  }
  return false
}

func StopMining(ethereum *eth.Ethereum) bool {
  if ethereum.Mining {
    miner.Stop()
    logger.Infoln("Miner stopped")
    ethereum.Mining = false
    return true
  }
  return false
}

// Replay block
func BlockDo(ethereum *eth.Ethereum, hash []byte) error {
	block := ethereum.BlockChain().GetBlock(hash)
	if block == nil {
		return fmt.Errorf("unknown block %x", hash)
	}

	parent := ethereum.BlockChain().GetBlock(block.PrevHash)

	_, err := ethereum.StateManager().ApplyDiff(parent.State(), parent, block)
	if err != nil {
		return err
	}

	return nil

}