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

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

	"git.sigsum.org/sigsum-tools-go/cmd/sigsum/bundle"
	"git.sigsum.org/sigsum-tools-go/cmd/sigsum/format"
	"git.sigsum.org/sigsum-tools-go/cmd/sigsum/namespace"
	"git.sigsum.org/sigsum-tools-go/cmd/sigsum/verify"

	"git.sigsum.org/sigsum-tools-go/internal/options"
	"git.sigsum.org/sigsum-tools-go/pkg/policy"
)

const usage = `sigsum version %s

Usage:
    sigsum help
        Output usage message.

    sigsum verify -t TYPE -k PUBLIC_KEY FILE
        Verify that a file's signed checksum is public and valid.
        -t, --type         Signature format (Available options: signify, minisign, ssh)
        -k, --key          Path to a public key.

    sigsum bundle -t TYPE -k PUBLIC_KEY -d DOMAIN_HINT FILE...
        Perform logging request(s) and write inclusion proof bundle(s).
        -t, --type         Signature format (Available options: signify, minisign, ssh)
        -k, --key          Path to a public key.
        -d, --domain-hint  Domain name that is aware of the public key.

    sigsum format FILE
        Output bytes to be Ed25519-signed.

    sigsum namespace
        Output namespace to be used in SSH signing context.

Transparency log proofs and signatures must be located at $FILE.sigsum.v0.
Signatures must be located at $FILE.{sig,minisig}, depending on -t TYPE.

`

var (
	optType       string
	optDomainHint string
	optPublicKey  string

	someVersion = "devel"
)

func main() {
	log.SetFlags(0)

	var err error
	var defaultPolicy policy.DefaultPolicy
	switch cmd := options.Parse(printUsage, setOptions); cmd.Name() {
	case "help":
		cmd.Usage()
	case "verify":
		err = verify.Main(cmd.Args(), &defaultPolicy, optType, optPublicKey)
	case "bundle":
		err = bundle.Main(cmd.Args(), &defaultPolicy, optType, optPublicKey, optDomainHint)
	case "format":
		err = format.Main(cmd.Args(), &defaultPolicy)
	case "namespace":
		err = namespace.Main(cmd.Args(), &defaultPolicy)
	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 "verify":
		options.AddString(fs, &optType, "t", "type", "")
		options.AddString(fs, &optPublicKey, "k", "key", "")
	case "bundle":
		options.AddString(fs, &optType, "t", "type", "")
		options.AddString(fs, &optPublicKey, "k", "key", "")
		options.AddString(fs, &optDomainHint, "d", "domain-hint", "")
	}
}