// Copyright 2016 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.

package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"

	"github.com/ethereum/ethash"
	"github.com/ethereum/go-ethereum/cmd/utils"
	"github.com/ethereum/go-ethereum/eth"
	"github.com/ethereum/go-ethereum/params"
	"gopkg.in/urfave/cli.v1"
)

var (
	makedagCommand = cli.Command{
		Action:    makedag,
		Name:      "makedag",
		Usage:     "Generate ethash DAG (for testing)",
		ArgsUsage: "<blockNum> <outputDir>",
		Category:  "MISCELLANEOUS COMMANDS",
		Description: `
The makedag command generates an ethash DAG in /tmp/dag.

This command exists to support the system testing project.
Regular users do not need to execute it.
`,
	}
	versionCommand = cli.Command{
		Action:    version,
		Name:      "version",
		Usage:     "Print version numbers",
		ArgsUsage: " ",
		Category:  "MISCELLANEOUS COMMANDS",
		Description: `
The output of this command is supposed to be machine-readable.
`,
	}
	licenseCommand = cli.Command{
		Action:    license,
		Name:      "license",
		Usage:     "Display license information",
		ArgsUsage: " ",
		Category:  "MISCELLANEOUS COMMANDS",
	}
)

func makedag(ctx *cli.Context) error {
	args := ctx.Args()
	wrongArgs := func() {
		utils.Fatalf(`Usage: geth makedag <block number> <outputdir>`)
	}
	switch {
	case len(args) == 2:
		blockNum, err := strconv.ParseUint(args[0], 0, 64)
		dir := args[1]
		if err != nil {
			wrongArgs()
		} else {
			dir = filepath.Clean(dir)
			// seems to require a trailing slash
			if !strings.HasSuffix(dir, "/") {
				dir = dir + "/"
			}
			_, err = ioutil.ReadDir(dir)
			if err != nil {
				utils.Fatalf("Can't find dir")
			}
			fmt.Println("making DAG, this could take awhile...")
			ethash.MakeDAG(blockNum, dir)
		}
	default:
		wrongArgs()
	}
	return nil
}

func version(ctx *cli.Context) error {
	fmt.Println(strings.Title(clientIdentifier))
	fmt.Println("Version:", params.Version)
	if gitCommit != "" {
		fmt.Println("Git Commit:", gitCommit)
	}
	fmt.Println("Protocol Versions:", eth.ProtocolVersions)
	fmt.Println("Network Id:", ctx.GlobalInt(utils.NetworkIdFlag.Name))
	fmt.Println("Go Version:", runtime.Version())
	fmt.Println("OS:", runtime.GOOS)
	fmt.Printf("GOPATH=%s\n", os.Getenv("GOPATH"))
	fmt.Printf("GOROOT=%s\n", runtime.GOROOT())
	return nil
}

func license(_ *cli.Context) error {
	fmt.Println(`Geth is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Geth is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with geth. If not, see <http://www.gnu.org/licenses/>.
`)
	return nil
}