package cli

import (
	"fmt"
	"log"
	"net/netip"
	"slices"
	"strconv"
	"strings"
	"time"

	survey "github.com/AlecAivazis/survey/v2"
	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
	"github.com/juanfont/headscale/hscontrol/util"
	"github.com/pterm/pterm"
	"github.com/spf13/cobra"
	"google.golang.org/grpc/status"
	"tailscale.com/types/key"
)

func init() {
	rootCmd.AddCommand(nodeCmd)
	listNodesCmd.Flags().StringP("user", "u", "", "Filter by user")
	listNodesCmd.Flags().BoolP("tags", "t", false, "Show tags")

	listNodesCmd.Flags().StringP("namespace", "n", "", "User")
	listNodesNamespaceFlag := listNodesCmd.Flags().Lookup("namespace")
	listNodesNamespaceFlag.Deprecated = deprecateNamespaceMessage
	listNodesNamespaceFlag.Hidden = true

	nodeCmd.AddCommand(listNodesCmd)

	registerNodeCmd.Flags().StringP("user", "u", "", "User")

	registerNodeCmd.Flags().StringP("namespace", "n", "", "User")
	registerNodeNamespaceFlag := registerNodeCmd.Flags().Lookup("namespace")
	registerNodeNamespaceFlag.Deprecated = deprecateNamespaceMessage
	registerNodeNamespaceFlag.Hidden = true

	err := registerNodeCmd.MarkFlagRequired("user")
	if err != nil {
		log.Fatalf(err.Error())
	}
	registerNodeCmd.Flags().StringP("key", "k", "", "Key")
	err = registerNodeCmd.MarkFlagRequired("key")
	if err != nil {
		log.Fatalf(err.Error())
	}
	nodeCmd.AddCommand(registerNodeCmd)

	expireNodeCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")
	err = expireNodeCmd.MarkFlagRequired("identifier")
	if err != nil {
		log.Fatalf(err.Error())
	}
	nodeCmd.AddCommand(expireNodeCmd)

	renameNodeCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")
	err = renameNodeCmd.MarkFlagRequired("identifier")
	if err != nil {
		log.Fatalf(err.Error())
	}
	nodeCmd.AddCommand(renameNodeCmd)

	deleteNodeCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")
	err = deleteNodeCmd.MarkFlagRequired("identifier")
	if err != nil {
		log.Fatalf(err.Error())
	}
	nodeCmd.AddCommand(deleteNodeCmd)

	moveNodeCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")

	err = moveNodeCmd.MarkFlagRequired("identifier")
	if err != nil {
		log.Fatalf(err.Error())
	}

	moveNodeCmd.Flags().StringP("user", "u", "", "New user")

	moveNodeCmd.Flags().StringP("namespace", "n", "", "User")
	moveNodeNamespaceFlag := moveNodeCmd.Flags().Lookup("namespace")
	moveNodeNamespaceFlag.Deprecated = deprecateNamespaceMessage
	moveNodeNamespaceFlag.Hidden = true

	err = moveNodeCmd.MarkFlagRequired("user")
	if err != nil {
		log.Fatalf(err.Error())
	}
	nodeCmd.AddCommand(moveNodeCmd)

	tagCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")

	err = tagCmd.MarkFlagRequired("identifier")
	if err != nil {
		log.Fatalf(err.Error())
	}
	tagCmd.Flags().
		StringSliceP("tags", "t", []string{}, "List of tags to add to the node")
	nodeCmd.AddCommand(tagCmd)

	nodeCmd.AddCommand(backfillNodeIPsCmd)
}

var nodeCmd = &cobra.Command{
	Use:     "nodes",
	Short:   "Manage the nodes of Headscale",
	Aliases: []string{"node", "machine", "machines"},
}

var registerNodeCmd = &cobra.Command{
	Use:   "register",
	Short: "Registers a node to your network",
	Run: func(cmd *cobra.Command, args []string) {
		output, _ := cmd.Flags().GetString("output")
		user, err := cmd.Flags().GetString("user")
		if err != nil {
			ErrorOutput(err, fmt.Sprintf("Error getting user: %s", err), output)

			return
		}

		ctx, client, conn, cancel := getHeadscaleCLIClient()
		defer cancel()
		defer conn.Close()

		machineKey, err := cmd.Flags().GetString("key")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error getting node key from flag: %s", err),
				output,
			)

			return
		}

		request := &v1.RegisterNodeRequest{
			Key:  machineKey,
			User: user,
		}

		response, err := client.RegisterNode(ctx, request)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf(
					"Cannot register node: %s\n",
					status.Convert(err).Message(),
				),
				output,
			)

			return
		}

		SuccessOutput(
			response.GetNode(),
			fmt.Sprintf("Node %s registered", response.GetNode().GetGivenName()), output)
	},
}

var listNodesCmd = &cobra.Command{
	Use:     "list",
	Short:   "List nodes",
	Aliases: []string{"ls", "show"},
	Run: func(cmd *cobra.Command, args []string) {
		output, _ := cmd.Flags().GetString("output")
		user, err := cmd.Flags().GetString("user")
		if err != nil {
			ErrorOutput(err, fmt.Sprintf("Error getting user: %s", err), output)

			return
		}
		showTags, err := cmd.Flags().GetBool("tags")
		if err != nil {
			ErrorOutput(err, fmt.Sprintf("Error getting tags flag: %s", err), output)

			return
		}

		ctx, client, conn, cancel := getHeadscaleCLIClient()
		defer cancel()
		defer conn.Close()

		request := &v1.ListNodesRequest{
			User: user,
		}

		response, err := client.ListNodes(ctx, request)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Cannot get nodes: %s", status.Convert(err).Message()),
				output,
			)

			return
		}

		if output != "" {
			SuccessOutput(response.GetNodes(), "", output)

			return
		}

		tableData, err := nodesToPtables(user, showTags, response.GetNodes())
		if err != nil {
			ErrorOutput(err, fmt.Sprintf("Error converting to table: %s", err), output)

			return
		}

		err = pterm.DefaultTable.WithHasHeader().WithData(tableData).Render()
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Failed to render pterm table: %s", err),
				output,
			)

			return
		}
	},
}

var expireNodeCmd = &cobra.Command{
	Use:     "expire",
	Short:   "Expire (log out) a node in your network",
	Long:    "Expiring a node will keep the node in the database and force it to reauthenticate.",
	Aliases: []string{"logout", "exp", "e"},
	Run: func(cmd *cobra.Command, args []string) {
		output, _ := cmd.Flags().GetString("output")

		identifier, err := cmd.Flags().GetUint64("identifier")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error converting ID to integer: %s", err),
				output,
			)

			return
		}

		ctx, client, conn, cancel := getHeadscaleCLIClient()
		defer cancel()
		defer conn.Close()

		request := &v1.ExpireNodeRequest{
			NodeId: identifier,
		}

		response, err := client.ExpireNode(ctx, request)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf(
					"Cannot expire node: %s\n",
					status.Convert(err).Message(),
				),
				output,
			)

			return
		}

		SuccessOutput(response.GetNode(), "Node expired", output)
	},
}

var renameNodeCmd = &cobra.Command{
	Use:   "rename NEW_NAME",
	Short: "Renames a node in your network",
	Run: func(cmd *cobra.Command, args []string) {
		output, _ := cmd.Flags().GetString("output")

		identifier, err := cmd.Flags().GetUint64("identifier")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error converting ID to integer: %s", err),
				output,
			)

			return
		}

		ctx, client, conn, cancel := getHeadscaleCLIClient()
		defer cancel()
		defer conn.Close()

		newName := ""
		if len(args) > 0 {
			newName = args[0]
		}
		request := &v1.RenameNodeRequest{
			NodeId:  identifier,
			NewName: newName,
		}

		response, err := client.RenameNode(ctx, request)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf(
					"Cannot rename node: %s\n",
					status.Convert(err).Message(),
				),
				output,
			)

			return
		}

		SuccessOutput(response.GetNode(), "Node renamed", output)
	},
}

var deleteNodeCmd = &cobra.Command{
	Use:     "delete",
	Short:   "Delete a node",
	Aliases: []string{"del"},
	Run: func(cmd *cobra.Command, args []string) {
		output, _ := cmd.Flags().GetString("output")

		identifier, err := cmd.Flags().GetUint64("identifier")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error converting ID to integer: %s", err),
				output,
			)

			return
		}

		ctx, client, conn, cancel := getHeadscaleCLIClient()
		defer cancel()
		defer conn.Close()

		getRequest := &v1.GetNodeRequest{
			NodeId: identifier,
		}

		getResponse, err := client.GetNode(ctx, getRequest)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf(
					"Error getting node node: %s",
					status.Convert(err).Message(),
				),
				output,
			)

			return
		}

		deleteRequest := &v1.DeleteNodeRequest{
			NodeId: identifier,
		}

		confirm := false
		force, _ := cmd.Flags().GetBool("force")
		if !force {
			prompt := &survey.Confirm{
				Message: fmt.Sprintf(
					"Do you want to remove the node %s?",
					getResponse.GetNode().GetName(),
				),
			}
			err = survey.AskOne(prompt, &confirm)
			if err != nil {
				return
			}
		}

		if confirm || force {
			response, err := client.DeleteNode(ctx, deleteRequest)
			if output != "" {
				SuccessOutput(response, "", output)

				return
			}
			if err != nil {
				ErrorOutput(
					err,
					fmt.Sprintf(
						"Error deleting node: %s",
						status.Convert(err).Message(),
					),
					output,
				)

				return
			}
			SuccessOutput(
				map[string]string{"Result": "Node deleted"},
				"Node deleted",
				output,
			)
		} else {
			SuccessOutput(map[string]string{"Result": "Node not deleted"}, "Node not deleted", output)
		}
	},
}

var moveNodeCmd = &cobra.Command{
	Use:     "move",
	Short:   "Move node to another user",
	Aliases: []string{"mv"},
	Run: func(cmd *cobra.Command, args []string) {
		output, _ := cmd.Flags().GetString("output")

		identifier, err := cmd.Flags().GetUint64("identifier")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error converting ID to integer: %s", err),
				output,
			)

			return
		}

		user, err := cmd.Flags().GetString("user")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error getting user: %s", err),
				output,
			)

			return
		}

		ctx, client, conn, cancel := getHeadscaleCLIClient()
		defer cancel()
		defer conn.Close()

		getRequest := &v1.GetNodeRequest{
			NodeId: identifier,
		}

		_, err = client.GetNode(ctx, getRequest)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf(
					"Error getting node: %s",
					status.Convert(err).Message(),
				),
				output,
			)

			return
		}

		moveRequest := &v1.MoveNodeRequest{
			NodeId: identifier,
			User:   user,
		}

		moveResponse, err := client.MoveNode(ctx, moveRequest)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf(
					"Error moving node: %s",
					status.Convert(err).Message(),
				),
				output,
			)

			return
		}

		SuccessOutput(moveResponse.GetNode(), "Node moved to another user", output)
	},
}

var backfillNodeIPsCmd = &cobra.Command{
	Use:   "backfillips",
	Short: "Backfill IPs missing from nodes",
	Long: `
Backfill IPs can be used to add/remove IPs from nodes
based on the current configuration of Headscale.

If there are nodes that does not have IPv4 or IPv6
even if prefixes for both are configured in the config,
this command can be used to assign IPs of the sort to
all nodes that are missing.

If you remove IPv4 or IPv6 prefixes from the config,
it can be run to remove the IPs that should no longer
be assigned to nodes.`,
	Run: func(cmd *cobra.Command, args []string) {
		var err error
		output, _ := cmd.Flags().GetString("output")

		confirm := false
		prompt := &survey.Confirm{
			Message: "Are you sure that you want to assign/remove IPs to/from nodes?",
		}
		err = survey.AskOne(prompt, &confirm)
		if err != nil {
			return
		}
		if confirm {
			ctx, client, conn, cancel := getHeadscaleCLIClient()
			defer cancel()
			defer conn.Close()

			changes, err := client.BackfillNodeIPs(ctx, &v1.BackfillNodeIPsRequest{Confirmed: confirm})
			if err != nil {
				ErrorOutput(
					err,
					fmt.Sprintf(
						"Error backfilling IPs: %s",
						status.Convert(err).Message(),
					),
					output,
				)

				return
			}

			SuccessOutput(changes, "Node IPs backfilled successfully", output)
		}
	},
}

func nodesToPtables(
	currentUser string,
	showTags bool,
	nodes []*v1.Node,
) (pterm.TableData, error) {
	tableHeader := []string{
		"ID",
		"Hostname",
		"Name",
		"MachineKey",
		"NodeKey",
		"User",
		"IP addresses",
		"Ephemeral",
		"Last seen",
		"Expiration",
		"Connected",
		"Expired",
	}
	if showTags {
		tableHeader = append(tableHeader, []string{
			"ForcedTags",
			"InvalidTags",
			"ValidTags",
		}...)
	}
	tableData := pterm.TableData{tableHeader}

	for _, node := range nodes {
		var ephemeral bool
		if node.GetPreAuthKey() != nil && node.GetPreAuthKey().GetEphemeral() {
			ephemeral = true
		}

		var lastSeen time.Time
		var lastSeenTime string
		if node.GetLastSeen() != nil {
			lastSeen = node.GetLastSeen().AsTime()
			lastSeenTime = lastSeen.Format("2006-01-02 15:04:05")
		}

		var expiry time.Time
		var expiryTime string
		if node.GetExpiry() != nil {
			expiry = node.GetExpiry().AsTime()
			expiryTime = expiry.Format("2006-01-02 15:04:05")
		} else {
			expiryTime = "N/A"
		}

		var machineKey key.MachinePublic
		err := machineKey.UnmarshalText(
			[]byte(node.GetMachineKey()),
		)
		if err != nil {
			machineKey = key.MachinePublic{}
		}

		var nodeKey key.NodePublic
		err = nodeKey.UnmarshalText(
			[]byte(node.GetNodeKey()),
		)
		if err != nil {
			return nil, err
		}

		var online string
		if node.GetOnline() {
			online = pterm.LightGreen("online")
		} else {
			online = pterm.LightRed("offline")
		}

		var expired string
		if expiry.IsZero() || expiry.After(time.Now()) {
			expired = pterm.LightGreen("no")
		} else {
			expired = pterm.LightRed("yes")
		}

		var forcedTags string
		for _, tag := range node.GetForcedTags() {
			forcedTags += "," + tag
		}
		forcedTags = strings.TrimLeft(forcedTags, ",")
		var invalidTags string
		for _, tag := range node.GetInvalidTags() {
			if !slices.Contains(node.GetForcedTags(), tag) {
				invalidTags += "," + pterm.LightRed(tag)
			}
		}
		invalidTags = strings.TrimLeft(invalidTags, ",")
		var validTags string
		for _, tag := range node.GetValidTags() {
			if !slices.Contains(node.GetForcedTags(), tag) {
				validTags += "," + pterm.LightGreen(tag)
			}
		}
		validTags = strings.TrimLeft(validTags, ",")

		var user string
		if currentUser == "" || (currentUser == node.GetUser().GetName()) {
			user = pterm.LightMagenta(node.GetUser().GetName())
		} else {
			// Shared into this user
			user = pterm.LightYellow(node.GetUser().GetName())
		}

		var IPV4Address string
		var IPV6Address string
		for _, addr := range node.GetIpAddresses() {
			if netip.MustParseAddr(addr).Is4() {
				IPV4Address = addr
			} else {
				IPV6Address = addr
			}
		}

		nodeData := []string{
			strconv.FormatUint(node.GetId(), util.Base10),
			node.GetName(),
			node.GetGivenName(),
			machineKey.ShortString(),
			nodeKey.ShortString(),
			user,
			strings.Join([]string{IPV4Address, IPV6Address}, ", "),
			strconv.FormatBool(ephemeral),
			lastSeenTime,
			expiryTime,
			online,
			expired,
		}
		if showTags {
			nodeData = append(nodeData, []string{forcedTags, invalidTags, validTags}...)
		}
		tableData = append(
			tableData,
			nodeData,
		)
	}

	return tableData, nil
}

var tagCmd = &cobra.Command{
	Use:     "tag",
	Short:   "Manage the tags of a node",
	Aliases: []string{"tags", "t"},
	Run: func(cmd *cobra.Command, args []string) {
		output, _ := cmd.Flags().GetString("output")
		ctx, client, conn, cancel := getHeadscaleCLIClient()
		defer cancel()
		defer conn.Close()

		// retrieve flags from CLI
		identifier, err := cmd.Flags().GetUint64("identifier")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error converting ID to integer: %s", err),
				output,
			)

			return
		}
		tagsToSet, err := cmd.Flags().GetStringSlice("tags")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error retrieving list of tags to add to node, %v", err),
				output,
			)

			return
		}

		// Sending tags to node
		request := &v1.SetTagsRequest{
			NodeId: identifier,
			Tags:   tagsToSet,
		}
		resp, err := client.SetTags(ctx, request)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error while sending tags to headscale: %s", err),
				output,
			)

			return
		}

		if resp != nil {
			SuccessOutput(
				resp.GetNode(),
				"Node updated",
				output,
			)
		}
	},
}