package main

import (
	"fmt"
	"os"
	"strings"
	"text/tabwriter"

	"github.com/spf13/cobra"

	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/config"
	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/hook"
	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/setup"
)

func hostsCmd() *cobra.Command {
	cmd := &cobra.Command{
		Use:   "hosts",
		Short: "Manage static hosts that are not in NetBox",
		Long: `Static hosts are defined under hosts: in the config. They are found before
NetBox, work offline, and support shortcuts, rules (kind: static), aliases,
completion, sftp, scp, and tunnels like NetBox hosts.`,
		RunE: func(cmd *cobra.Command, args []string) error { return listHosts() },
	}
	cmd.AddCommand(hostsListCmd(), hostsAddCmd(), hostsRemoveCmd())
	return cmd
}

func hostsListCmd() *cobra.Command {
	return &cobra.Command{
		Use:   "list",
		Short: "List static hosts",
		RunE:  func(cmd *cobra.Command, args []string) error { return listHosts() },
	}
}

func listHosts() error {
	cfg, err := config.Load()
	if err != nil {
		return err
	}
	if len(cfg.Hosts) == 0 {
		fmt.Println("No static hosts. Add one with: netssh hosts add NAME ADDRESS")
		return nil
	}
	w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
	fmt.Fprintln(w, "NAME\tADDRESS\tUSER\tPORT\tTAGS")
	for _, host := range cfg.Hosts {
		port := ""
		if host.Port > 0 {
			port = fmt.Sprint(host.Port)
		}
		fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n", host.Name, host.Address, host.User, port, strings.Join(host.Tags, ","))
	}
	return w.Flush()
}

func hostsAddCmd() *cobra.Command {
	var host config.StaticHost
	var replace bool
	cmd := &cobra.Command{
		Use:   "add NAME ADDRESS",
		Short: "Add a static host (or replace one with --replace)",
		Example: `  netssh hosts add router 192.168.1.1 --user admin
  netssh hosts add backup backup.example.org --port 2222 --tag offsite`,
		Args: cobra.ExactArgs(2),
		RunE: func(cmd *cobra.Command, args []string) error {
			cfg, err := config.Load()
			if err != nil {
				return err
			}
			host.Name, host.Address = args[0], args[1]
			if existing := cfg.StaticHost(host.Name); existing != nil {
				if !replace {
					return fmt.Errorf("static host %q already exists; use --replace to overwrite it", existing.Name)
				}
				host.SSH = existing.SSH // keep SSH options set in the config or wizard
				*existing = host
			} else {
				cfg.Hosts = append(cfg.Hosts, host)
			}
			return saveHosts(cfg)
		},
	}
	cmd.Flags().StringVar(&host.User, "user", "", "Login user (default: ssh.default_user)")
	cmd.Flags().IntVar(&host.Port, "port", 0, "SSH port (default: ssh.default_port or 22)")
	cmd.Flags().StringSliceVar(&host.Tags, "tag", nil, "Tag for ssh.rules (repeatable)")
	cmd.Flags().BoolVar(&replace, "replace", false, "Overwrite an existing static host")
	return cmd
}

func hostsRemoveCmd() *cobra.Command {
	return &cobra.Command{
		Use:     "remove NAME",
		Aliases: []string{"rm"},
		Short:   "Remove a static host",
		Args:    cobra.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			cfg, err := config.Load()
			if err != nil {
				return err
			}
			for i, host := range cfg.Hosts {
				if strings.EqualFold(host.Name, args[0]) {
					cfg.Hosts = append(cfg.Hosts[:i], cfg.Hosts[i+1:]...)
					return saveHosts(cfg)
				}
			}
			return fmt.Errorf("no static host %q", args[0])
		},
		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]cobra.Completion, cobra.ShellCompDirective) {
			cfg, err := config.Load()
			if err != nil || len(args) > 0 {
				return nil, cobra.ShellCompDirectiveNoFileComp
			}
			var names []string
			for _, host := range cfg.Hosts {
				if strings.HasPrefix(strings.ToLower(host.Name), strings.ToLower(toComplete)) {
					names = append(names, host.Name)
				}
			}
			return names, cobra.ShellCompDirectiveNoFileComp
		},
	}
}

// saveHosts writes the config and regenerates the shell aliases.
func saveHosts(cfg *config.Config) error {
	if err := setup.Save(*cfg); err != nil {
		return err
	}
	loaded, err := config.Load()
	if err != nil {
		return err
	}
	c := newCache(loaded)
	_ = c.Load()
	if err := hook.WriteAliasFiles(hook.BuildAliasEntries(c.All(), *loaded)); err != nil {
		fmt.Fprintf(os.Stderr, "warning: could not write alias files: %v\n", err)
	}
	return nil
}