// Copyright 2015 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package command

import (
	"fmt"
	"os"
	"strings"

	"github.com/urfave/cli"
)

func NewMemberCommand() cli.Command {
	return cli.Command{
		Name:  "member",
		Usage: "member add, remove and list subcommands",
		Subcommands: []cli.Command{
			{
				Name:      "list",
				Usage:     "enumerate existing cluster members",
				ArgsUsage: " ",
				Action:    actionMemberList,
			},
			{
				Name:      "add",
				Usage:     "add a new member to the etcd cluster",
				ArgsUsage: "<name> <peerURL>",
				Action:    actionMemberAdd,
			},
			{
				Name:      "remove",
				Usage:     "remove an existing member from the etcd cluster",
				ArgsUsage: "<memberID>",
				Action:    actionMemberRemove,
			},
			{
				Name:      "update",
				Usage:     "update an existing member in the etcd cluster",
				ArgsUsage: "<memberID> <peerURLs>",
				Action:    actionMemberUpdate,
			},
		},
	}
}

func actionMemberList(c *cli.Context) error {
	if len(c.Args()) != 0 {
		fmt.Fprintln(os.Stderr, "No arguments accepted")
		os.Exit(1)
	}
	mAPI := mustNewMembersAPI(c)
	ctx, cancel := contextWithTotalTimeout(c)
	defer cancel()

	members, err := mAPI.List(ctx)
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}
	leader, err := mAPI.Leader(ctx)
	if err != nil {
		fmt.Fprintln(os.Stderr, "Failed to get leader: ", err)
		os.Exit(1)
	}

	for _, m := range members {
		isLeader := false
		if m.ID == leader.ID {
			isLeader = true
		}
		if len(m.Name) == 0 {
			fmt.Printf("%s[unstarted]: peerURLs=%s\n", m.ID, strings.Join(m.PeerURLs, ","))
		} else {
			fmt.Printf("%s: name=%s peerURLs=%s clientURLs=%s isLeader=%v\n", m.ID, m.Name, strings.Join(m.PeerURLs, ","), strings.Join(m.ClientURLs, ","), isLeader)
		}
	}

	return nil
}

func actionMemberAdd(c *cli.Context) error {
	args := c.Args()
	if len(args) != 2 {
		fmt.Fprintln(os.Stderr, "Provide a name and a single member peerURL")
		os.Exit(1)
	}

	mAPI := mustNewMembersAPI(c)

	url := args[1]
	ctx, cancel := contextWithTotalTimeout(c)
	defer cancel()

	m, err := mAPI.Add(ctx, url)
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}

	newID := m.ID
	newName := args[0]
	fmt.Printf("Added member named %s with ID %s to cluster\n", newName, newID)

	members, err := mAPI.List(ctx)
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}

	conf := []string{}
	for _, memb := range members {
		for _, u := range memb.PeerURLs {
			n := memb.Name
			if memb.ID == newID {
				n = newName
			}
			conf = append(conf, fmt.Sprintf("%s=%s", n, u))
		}
	}

	fmt.Print("\n")
	fmt.Printf("ETCD_NAME=%q\n", newName)
	fmt.Printf("ETCD_INITIAL_CLUSTER=%q\n", strings.Join(conf, ","))
	fmt.Printf("ETCD_INITIAL_CLUSTER_STATE=\"existing\"\n")
	return nil
}

func actionMemberRemove(c *cli.Context) error {
	args := c.Args()
	if len(args) != 1 {
		fmt.Fprintln(os.Stderr, "Provide a single member ID")
		os.Exit(1)
	}
	removalID := args[0]

	mAPI := mustNewMembersAPI(c)

	ctx, cancel := contextWithTotalTimeout(c)
	defer cancel()
	// Get the list of members.
	members, err := mAPI.List(ctx)
	if err != nil {
		fmt.Fprintln(os.Stderr, "Error while verifying ID against known members:", err.Error())
		os.Exit(1)
	}
	// Sanity check the input.
	foundID := false
	for _, m := range members {
		if m.ID == removalID {
			foundID = true
		}
		if m.Name == removalID {
			// Note that, so long as it's not ambiguous, we *could* do the right thing by name here.
			fmt.Fprintf(os.Stderr, "Found a member named %s; if this is correct, please use its ID, eg:\n\tetcdctl member remove %s\n", m.Name, m.ID)
			fmt.Fprintf(os.Stderr, "For more details, read the documentation at https://github.com/etcd-io/etcd/blob/main/Documentation/runtime-configuration.md#remove-a-member\n\n")
		}
	}
	if !foundID {
		fmt.Fprintf(os.Stderr, "Couldn't find a member in the cluster with an ID of %s.\n", removalID)
		os.Exit(1)
	}

	// Actually attempt to remove the member.
	err = mAPI.Remove(ctx, removalID)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Received an error trying to remove member %s: %s", removalID, err.Error())
		os.Exit(1)
	}

	fmt.Printf("Removed member %s from cluster\n", removalID)
	return nil
}

func actionMemberUpdate(c *cli.Context) error {
	args := c.Args()
	if len(args) != 2 {
		fmt.Fprintln(os.Stderr, "Provide an ID and a list of comma separated peerURL (0xabcd http://example.com,http://example1.com)")
		os.Exit(1)
	}

	mAPI := mustNewMembersAPI(c)

	mid := args[0]
	urls := args[1]
	ctx, cancel := contextWithTotalTimeout(c)
	err := mAPI.Update(ctx, mid, strings.Split(urls, ","))
	cancel()
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}

	fmt.Printf("Updated member with ID %s in cluster\n", mid)
	return nil
}