// package main provides a tool named sigsum-debug.
//
// Build as follows:
//
//     $ go build -ldflags="-X 'main.someVersion=git commit $(git rev-list -1 HEAD)'"
//     $ mv sigsum-debug $GOPATH/bin/
//
// Usage:
//
//     $ sigsum-debug help
//
package main

import (
	"flag"
	"fmt"
	"log"
	"os"

	"git.sigsum.org/sigsum-tools-go/cmd/sigsum-debug/cosign"
	"git.sigsum.org/sigsum-tools-go/cmd/sigsum-debug/genkey"
	"git.sigsum.org/sigsum-tools-go/cmd/sigsum-debug/hashkey"
	"git.sigsum.org/sigsum-tools-go/cmd/sigsum-debug/hashleaf"
	"git.sigsum.org/sigsum-tools-go/cmd/sigsum-debug/pubkey"
	"git.sigsum.org/sigsum-tools-go/cmd/sigsum-debug/sign"
	"git.sigsum.org/sigsum-tools-go/internal/options"
)

const usage = `sigsum-debug version %s

Usage:
    sigsum-debug help
        Outputs a usage message.

    sigsum-debug genkey
        Outputs a new private key.

    sigsum-debug pubkey
        Reads a private key from stdin and output its public key.

    sigsum-debug hashkey
        Reads a public key from stdin and output its key hash.

    sigsum-debug hashleaf -k PRIVATE_KEY [-s SHARD_HINT]
        Reads data from STDIN and outputs a leaf hash.
        -k, --private-key    Private key to sign with
        -s, --shard-hint     Shard hint to use (Default: 0)

    sigsum-debug sign -k PRIVATE_KEY [-s SHARD_HINT]
        Reads data from STDIN and outputs a signature.
        -k, --private-key    Private key to sign with
        -s, --shard-hint     Shard hint to use (Default: 0)

    sigsum-debug cosign -w WIT_PRIV -l LOG_PUB
        Reads an ASCII signed tree head from STDIN and outputs a cosignature.
        -w, --witness-priv   Witness private key to sign with
        -l, --log-pub        Log public key to verify signed tree head
`

var (
	optPriv      string
	optPub       string
	optShardHint uint64

	someVersion = "devel"
)

func main() {
	log.SetFlags(0)

	var err error
	cmd := options.Parse(printUsage, setOptions)
	switch cmd.Name() {
	case "help":
		cmd.Usage()
	case "genkey":
		err = genkey.Main(cmd.Args())
	case "pubkey":
		err = pubkey.Main(cmd.Args())
	case "hashkey":
		err = hashkey.Main(cmd.Args())
	case "hashleaf":
		err = hashleaf.Main(cmd.Args(), optPriv, optShardHint)
	case "sign":
		err = sign.Main(cmd.Args(), optPriv, optShardHint)
	case "cosign":
		err = cosign.Main(cmd.Args(), optPriv, optPub)
	default:
		err = fmt.Errorf("invalid command %q, try %q", cmd.Name(), "sigsum help")
	}

	if err != nil {
		log.Printf("%s", err)
		os.Exit(1)
	}
}

func printUsage() {
	log.Printf(usage, someVersion)
}

func setOptions(fs *flag.FlagSet) {
	switch cmd := fs.Name(); cmd {
	case "hashleaf":
		options.AddString(fs, &optPriv, "k", "key", "")
		options.AddUint64(fs, &optShardHint, "s", "shard-hint", 0)
	case "sign":
		options.AddString(fs, &optPriv, "k", "key", "")
		options.AddUint64(fs, &optShardHint, "s", "shard-hint", 0)
	case "cosign":
		options.AddString(fs, &optPriv, "w", "witness-priv", "")
		options.AddString(fs, &optPub, "l", "log-pub", "")
	}
}