package cli

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

	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
	"github.com/juanfont/headscale/hscontrol/util"
	"github.com/pterm/pterm"
	"github.com/samber/lo"
	"github.com/spf13/cobra"
	"google.golang.org/grpc/status"
	"google.golang.org/protobuf/types/known/timestamppb"
	"tailscale.com/types/key"
)

func init() {
	rootCmd.AddCommand(nodeCmd)
	listNodesCmd.Flags().StringP("user", "u", "", "Filter by user")

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

	nodeCmd.AddCommand(listNodesCmd)

	listNodeRoutesCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")
	nodeCmd.AddCommand(listNodeRoutesCmd)

	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.Fatal(err.Error())
	}

	registerNodeCmd.Flags().StringP("key", "k", "", "Key")

	err = registerNodeCmd.MarkFlagRequired("key")
	if err != nil {
		log.Fatal(err.Error())
	}

	nodeCmd.AddCommand(registerNodeCmd)

	expireNodeCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")
	expireNodeCmd.Flags().StringP("expiry", "e", "", "Set expire to (RFC3339 format, e.g. 2025-08-27T10:00:00Z), or leave empty to expire immediately.")
	expireNodeCmd.Flags().BoolP("disable", "d", false, "Disable key expiry (node will never expire)")

	err = expireNodeCmd.MarkFlagRequired("identifier")
	if err != nil {
		log.Fatal(err.Error())
	}

	nodeCmd.AddCommand(expireNodeCmd)

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

	err = renameNodeCmd.MarkFlagRequired("identifier")
	if err != nil {
		log.Fatal(err.Error())
	}

	nodeCmd.AddCommand(renameNodeCmd)

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

	err = deleteNodeCmd.MarkFlagRequired("identifier")
	if err != nil {
		log.Fatal(err.Error())
	}

	nodeCmd.AddCommand(deleteNodeCmd)

	tagCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")
	_ = tagCmd.MarkFlagRequired("identifier")
	tagCmd.Flags().StringSliceP("tags", "t", []string{}, "List of tags to add to the node")
	nodeCmd.AddCommand(tagCmd)

	approveRoutesCmd.Flags().Uint64P("identifier", "i", 0, "Node identifier (ID)")
	_ = approveRoutesCmd.MarkFlagRequired("identifier")
	approveRoutesCmd.Flags().StringSliceP("routes", "r", []string{}, `List of routes that will be approved (comma-separated, e.g. "10.0.0.0/8,192.168.0.0/24" or empty string to remove all approved routes)`)
	nodeCmd.AddCommand(approveRoutesCmd)

	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)
		}

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

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

		request := &v1.RegisterNodeRequest{
			Key:  registrationID,
			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,
			)
		}

		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)
		}

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

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

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

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

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

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

var listNodeRoutesCmd = &cobra.Command{
	Use:     "list-routes",
	Short:   "List routes available on nodes",
	Aliases: []string{"lsr", "routes"},
	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,
			)
		}

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

		request := &v1.ListNodesRequest{}

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

		nodes := response.GetNodes()
		if identifier != 0 {
			for _, node := range response.GetNodes() {
				if node.GetId() == identifier {
					nodes = []*v1.Node{node}
					break
				}
			}
		}

		nodes = lo.Filter(nodes, func(n *v1.Node, _ int) bool {
			return (n.GetSubnetRoutes() != nil && len(n.GetSubnetRoutes()) > 0) || (n.GetApprovedRoutes() != nil && len(n.GetApprovedRoutes()) > 0) || (n.GetAvailableRoutes() != nil && len(n.GetAvailableRoutes()) > 0)
		})

		if output != "" {
			SuccessOutput(nodes, "", output)
			return
		}

		tableData := nodeRoutesToPtables(nodes)

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

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.

Use --disable to disable key expiry (node will never expire).`,
	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
		}

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

			return
		}

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

		// Handle disable expiry - node will never expire.
		if disableExpiry {
			request := &v1.ExpireNodeRequest{
				NodeId:        identifier,
				DisableExpiry: true,
			}

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

				return
			}

			SuccessOutput(response.GetNode(), "Node expiry disabled", output)

			return
		}

		expiry, err := cmd.Flags().GetString("expiry")
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error converting expiry to string: %s", err),
				output,
			)

			return
		}

		now := time.Now()

		expiryTime := now
		if expiry != "" {
			expiryTime, err = time.Parse(time.RFC3339, expiry)
			if err != nil {
				ErrorOutput(
					err,
					fmt.Sprintf("Error converting expiry to string: %s", err),
					output,
				)

				return
			}
		}

		request := &v1.ExpireNodeRequest{
			NodeId: identifier,
			Expiry: timestamppb.New(expiryTime),
		}

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

			return
		}

		if now.Equal(expiryTime) || now.After(expiryTime) {
			SuccessOutput(response.GetNode(), "Node expired", output)
		} else {
			SuccessOutput(response.GetNode(), "Node expiration updated", 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,
			)
		}

		ctx, client, conn, cancel := newHeadscaleCLIWithConfig()
		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,
			)
		}

		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,
			)
		}

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

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

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

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

		confirm := false

		force, _ := cmd.Flags().GetBool("force")
		if !force {
			confirm = util.YesNo(fmt.Sprintf(
				"Do you want to remove the node %s?",
				getResponse.GetNode().GetName(),
			))
		}

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

				return
			}

			if err != nil {
				ErrorOutput(
					err,
					"Error deleting node: "+status.Convert(err).Message(),
					output,
				)
			}

			SuccessOutput(
				map[string]string{"Result": "Node deleted"},
				"Node deleted",
				output,
			)
		} else {
			SuccessOutput(map[string]string{"Result": "Node not deleted"}, "Node not deleted", 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) {
		output, _ := cmd.Flags().GetString("output")

		confirm := false

		force, _ := cmd.Flags().GetBool("force")
		if !force {
			confirm = util.YesNo("Are you sure that you want to assign/remove IPs to/from nodes?")
		}

		if confirm || force {
			ctx, client, conn, cancel := newHeadscaleCLIWithConfig()
			defer cancel()
			defer conn.Close()

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

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

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

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

		var (
			lastSeen     time.Time
			lastSeenTime string
		)

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

		var (
			expiry     time.Time
			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")
		}

		// TODO(kradalby): as part of CLI rework, we should add the posibility to show "unusable" tags as mentioned in
		// https://github.com/juanfont/headscale/issues/2981
		var tagsBuilder strings.Builder

		for _, tag := range node.GetTags() {
			tagsBuilder.WriteString("\n" + tag)
		}

		tags := tagsBuilder.String()

		tags = strings.TrimLeft(tags, "\n")

		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
			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,
			tags,
			strings.Join([]string{IPV4Address, IPV6Address}, ", "),
			strconv.FormatBool(ephemeral),
			lastSeenTime,
			expiryTime,
			online,
			expired,
		}
		tableData = append(
			tableData,
			nodeData,
		)
	}

	return tableData, nil
}

func nodeRoutesToPtables(
	nodes []*v1.Node,
) pterm.TableData {
	tableHeader := []string{
		"ID",
		"Hostname",
		"Approved",
		"Available",
		"Serving (Primary)",
	}
	tableData := pterm.TableData{tableHeader}

	for _, node := range nodes {
		nodeData := []string{
			strconv.FormatUint(node.GetId(), util.Base10),
			node.GetGivenName(),
			strings.Join(node.GetApprovedRoutes(), "\n"),
			strings.Join(node.GetAvailableRoutes(), "\n"),
			strings.Join(node.GetSubnetRoutes(), "\n"),
		}
		tableData = append(
			tableData,
			nodeData,
		)
	}

	return tableData
}

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 := newHeadscaleCLIWithConfig()
		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,
			)
		}

		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,
			)
		}

		// 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,
			)
		}

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

var approveRoutesCmd = &cobra.Command{
	Use:   "approve-routes",
	Short: "Manage the approved routes of a node",
	Run: func(cmd *cobra.Command, args []string) {
		output, _ := cmd.Flags().GetString("output")

		ctx, client, conn, cancel := newHeadscaleCLIWithConfig()
		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,
			)
		}

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

		// Sending routes to node
		request := &v1.SetApprovedRoutesRequest{
			NodeId: identifier,
			Routes: routes,
		}

		resp, err := client.SetApprovedRoutes(ctx, request)
		if err != nil {
			ErrorOutput(
				err,
				fmt.Sprintf("Error while sending routes to headscale: %s", err),
				output,
			)
		}

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