package main

import (
	"context"
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"github.com/tendermint/tendermint/crypto/ed25519"
	"github.com/tendermint/tendermint/libs/log"
	"github.com/tendermint/tendermint/privval"
	"github.com/tendermint/tendermint/tools/tm-signer-harness/internal"
	"github.com/tendermint/tendermint/version"
)

const (
	defaultAcceptRetries    = 100
	defaultBindAddr         = "tcp://127.0.0.1:0"
	defaultAcceptDeadline   = 1
	defaultConnDeadline     = 3
	defaultExtractKeyOutput = "./signing.key"
)

var defaultTMHome string

var logger = log.MustNewDefaultLogger(log.LogFormatPlain, log.LogLevelInfo, false)

// Command line flags
var (
	flagAcceptRetries int
	flagBindAddr      string
	flagTMHome        string
	flagKeyOutputPath string
)

// Command line commands
var (
	rootCmd       *flag.FlagSet
	runCmd        *flag.FlagSet
	extractKeyCmd *flag.FlagSet
	versionCmd    *flag.FlagSet
)

func init() {
	rootCmd = flag.NewFlagSet("root", flag.ExitOnError)
	rootCmd.Usage = func() {
		fmt.Println(`Remote signer test harness for Tendermint.

Usage:
  tm-signer-harness <command> [flags]

Available Commands:
  extract_key        Extracts a signing key from a local Tendermint instance
  help               Help on the available commands
  run                Runs the test harness
  version            Display version information and exit

Use "tm-signer-harness help <command>" for more information about that command.`)
		fmt.Println("")
	}

	hd, err := os.UserHomeDir()
	if err != nil {
		fmt.Println("The UserHomeDir is not defined, setting the default TM Home PATH to \"~/.tendermint\"")
		defaultTMHome = "~/.tendermint"
	} else {
		defaultTMHome = fmt.Sprintf("%s/.tendermint", hd)
	}

	runCmd = flag.NewFlagSet("run", flag.ExitOnError)
	runCmd.IntVar(&flagAcceptRetries,
		"accept-retries",
		defaultAcceptRetries,
		"The number of attempts to listen for incoming connections")
	runCmd.StringVar(&flagBindAddr, "addr", defaultBindAddr, "Bind to this address for the testing")
	runCmd.StringVar(&flagTMHome, "tmhome", defaultTMHome, "Path to the Tendermint home directory")
	runCmd.Usage = func() {
		fmt.Println(`Runs the remote signer test harness for Tendermint.

Usage:
  tm-signer-harness run [flags]

Flags:`)
		runCmd.PrintDefaults()
		fmt.Println("")
	}

	extractKeyCmd = flag.NewFlagSet("extract_key", flag.ExitOnError)
	extractKeyCmd.StringVar(&flagKeyOutputPath,
		"output",
		defaultExtractKeyOutput,
		"Path to which signing key should be written")
	extractKeyCmd.StringVar(&flagTMHome, "tmhome", defaultTMHome, "Path to the Tendermint home directory")
	extractKeyCmd.Usage = func() {
		fmt.Println(`Extracts a signing key from a local Tendermint instance for use in the remote
signer under test.

Usage:
  tm-signer-harness extract_key [flags]

Flags:`)
		extractKeyCmd.PrintDefaults()
		fmt.Println("")
	}

	versionCmd = flag.NewFlagSet("version", flag.ExitOnError)
	versionCmd.Usage = func() {
		fmt.Println(`
Prints the Tendermint version for which this remote signer harness was built.

Usage:
  tm-signer-harness version`)
		fmt.Println("")
	}
}

func runTestHarness(ctx context.Context, acceptRetries int, bindAddr, tmhome string) {
	tmhome = internal.ExpandPath(tmhome)
	cfg := internal.TestHarnessConfig{
		BindAddr:         bindAddr,
		KeyFile:          filepath.Join(tmhome, "config", "priv_validator_key.json"),
		StateFile:        filepath.Join(tmhome, "data", "priv_validator_state.json"),
		GenesisFile:      filepath.Join(tmhome, "config", "genesis.json"),
		AcceptDeadline:   time.Duration(defaultAcceptDeadline) * time.Second,
		AcceptRetries:    acceptRetries,
		ConnDeadline:     time.Duration(defaultConnDeadline) * time.Second,
		SecretConnKey:    ed25519.GenPrivKey(),
		ExitWhenComplete: true,
	}
	harness, err := internal.NewTestHarness(ctx, logger, cfg)
	if err != nil {
		logger.Error(err.Error())
		if therr, ok := err.(*internal.TestHarnessError); ok {
			os.Exit(therr.Code)
		}
		os.Exit(internal.ErrOther)
	}
	harness.Run()
}

func extractKey(tmhome, outputPath string) {
	keyFile := filepath.Join(internal.ExpandPath(tmhome), "config", "priv_validator_key.json")
	stateFile := filepath.Join(internal.ExpandPath(tmhome), "data", "priv_validator_state.json")
	fpv, err := privval.LoadFilePV(keyFile, stateFile)
	if err != nil {
		logger.Error("Can't load file pv", "err", err)
		os.Exit(1)
	}
	pkb := []byte(fpv.Key.PrivKey.(ed25519.PrivKey))
	if err := os.WriteFile(internal.ExpandPath(outputPath), pkb[:32], 0600); err != nil {
		logger.Info("Failed to write private key", "output", outputPath, "err", err)
		os.Exit(1)
	}
	logger.Info("Successfully wrote private key", "output", outputPath)
}

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	if err := rootCmd.Parse(os.Args[1:]); err != nil {
		fmt.Printf("Error parsing flags: %v\n", err)
		os.Exit(1)
	}
	if rootCmd.NArg() == 0 || (rootCmd.NArg() == 1 && rootCmd.Arg(0) == "help") {
		rootCmd.Usage()
		os.Exit(0)
	}

	switch rootCmd.Arg(0) {
	case "help":
		switch rootCmd.Arg(1) {
		case "run":
			runCmd.Usage()
		case "extract_key":
			extractKeyCmd.Usage()
		case "version":
			versionCmd.Usage()
		default:
			fmt.Printf("Unrecognized command: %s\n", rootCmd.Arg(1))
			os.Exit(1)
		}
	case "run":
		if err := runCmd.Parse(os.Args[2:]); err != nil {
			fmt.Printf("Error parsing flags: %v\n", err)
			os.Exit(1)
		}
		runTestHarness(ctx, flagAcceptRetries, flagBindAddr, flagTMHome)
	case "extract_key":
		if err := extractKeyCmd.Parse(os.Args[2:]); err != nil {
			fmt.Printf("Error parsing flags: %v\n", err)
			os.Exit(1)
		}
		extractKey(flagTMHome, flagKeyOutputPath)
	case "version":
		fmt.Println(version.TMVersion)
	default:
		fmt.Printf("Unrecognized command: %s\n", flag.Arg(0))
		os.Exit(1)
	}
}