package command

import (
	"flag"
	"fmt"
	"strings"

	"github.com/mitchellh/cli"
)

// KeysCommand is a Command implementation that handles querying, installing,
// and removing gossip encryption keys from a keyring.
type KeysCommand struct {
	Ui cli.Ui
}

func (c *KeysCommand) Run(args []string) int {
	var installKey, useKey, removeKey string
	var listKeys bool

	cmdFlags := flag.NewFlagSet("keys", flag.ContinueOnError)
	cmdFlags.Usage = func() { c.Ui.Output(c.Help()) }

	cmdFlags.StringVar(&installKey, "install", "", "install key")
	cmdFlags.StringVar(&useKey, "use", "", "use key")
	cmdFlags.StringVar(&removeKey, "remove", "", "remove key")
	cmdFlags.BoolVar(&listKeys, "list", false, "list keys")

	rpcAddr := RPCAddrFlag(cmdFlags)
	if err := cmdFlags.Parse(args); err != nil {
		return 1
	}

	client, err := RPCClient(*rpcAddr)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err))
		return 1
	}
	defer client.Close()

	// Only accept a single argument
	found := listKeys
	for _, arg := range []string{installKey, useKey, removeKey} {
		if found && len(arg) > 0 {
			c.Ui.Error("Only one of -list, -install, -use, or -remove allowed")
			return 1
		}
		found = found || len(arg) > 0
	}

	if listKeys {
		km := client.KeyManager()
		fmt.Println(km.ListKeys())
		return 0
	}

	if installKey != "" {
		return 0
	}

	if useKey != "" {
		return 0
	}

	if removeKey != "" {
		return 0
	}

	return 0
}

func (c *KeysCommand) Help() string {
	helpText := `
Usage: consul keys [options]

  Manages encryption keys used for gossip messages. Gossip encryption is
  optional. When enabled, this command may be used to examine active encryption
  keys in the cluster, add new keys, and remove old ones. When combined, this
  functionality provides the ability to perform key rotation cluster-wide,
  without disrupting the cluster.

Options:

  -install=<key>            Install a new encryption key. This will broadcast
                            the new key to all members in the cluster.
  -use=<key>                Change the primary encryption key, which is used to
                            encrypt messages. The key must already be installed
                            before this operation can succeed.
  -remove=<key>             Remove the given key from the cluster. This
                            operation may only be performed on keys which are
                            not currently the primary key.
  -list                     List all keys currently in use within the cluster.
  -rpc-addr=127.0.0.1:8400  RPC address of the Consul agent.
`
	return strings.TrimSpace(helpText)
}

func (c *KeysCommand) Synopsis() string {
	return "Manages gossip layer encryption keys"
}