package main

import (
	"bufio"
	"errors"
	"fmt"
	"os"
	"os/user"
	"path"
	"slices"
	"strings"

	"github.com/spf13/cobra"

	"github.com/canonical/lxd/client"
	"github.com/canonical/lxd/lxc/config"
	"github.com/canonical/lxd/shared"
	"github.com/canonical/lxd/shared/api"
	cli "github.com/canonical/lxd/shared/cmd"
	"github.com/canonical/lxd/shared/logger"
	"github.com/canonical/lxd/shared/version"
)

type cmdGlobal struct {
	asker cli.Asker

	conf     *config.Config
	confPath string
	cmd      *cobra.Command
	ret      int

	flagForceLocal bool
	flagHelp       bool
	flagHelpAll    bool
	flagLogDebug   bool
	flagLogVerbose bool
	flagProject    string
	flagQuiet      bool
	flagVersion    bool
	flagSubCmds    bool
}

func usageTemplateSubCmds() string {
	return `Usage:{{if .Runnable}}
  {{.UseLine}}{{end}}{{if .HasAvailableSubCommands}}
  {{.CommandPath}} [command]{{end}}{{if gt (len .Aliases) 0}}
Aliases:
  {{.NameAndAliases}}{{end}}{{if .HasExample}}

Examples:
  {{.Example}}{{end}}{{if .HasAvailableSubCommands}}

Available Commands:{{range .Commands}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
  {{rpad .Name .NamePadding }}  {{.Short}}{{if .HasSubCommands}}{{range .Commands}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
    {{rpad .Name .NamePadding }}  {{.Short}}{{if .HasSubCommands}}{{range .Commands}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
      {{rpad .Name .NamePadding }}  {{.Short}}{{if .HasSubCommands}}{{range .Commands}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
        {{rpad .Name .NamePadding }}  {{.Short}}{{end}}{{end}}{{end}}{{end}}{{end}}{{end}}{{end}}{{end}}{{end}}{{end}}{{end}}{{end}}{{if .HasAvailableLocalFlags}}

Flags:
{{.LocalFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}{{if .HasAvailableInheritedFlags}}

Global Flags:
  {{.InheritedFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}{{if .HasHelpSubCommands}}

Additional help topics:{{range .Commands}}{{if .IsAdditionalHelpTopicCommand}}
  {{rpad .CommandPath .CommandPathPadding}} {{.Short}}{{end}}{{end}}{{end}}{{if .HasAvailableSubCommands}}

Use "{{.CommandPath}} [command] --help" for more information about a command.{{end}}
`
}

func main() {
	// Process aliases
	err := execIfAliases()
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}

	// Setup the parser
	app := &cobra.Command{}
	app.Use = "lxc"
	app.Short = "Command line client for LXD"
	app.Long = cli.FormatSection("Description", app.Short+`

All of LXD's features can be driven through the various commands below.
For help with any of those, simply call them with --help.`)
	app.SilenceUsage = true
	app.SilenceErrors = true
	app.CompletionOptions.SetDefaultShellCompDirective(cobra.ShellCompDirectiveNoFileComp)

	// Global flags
	globalCmd := cmdGlobal{cmd: app, asker: cli.NewAsker(bufio.NewReader(os.Stdin), nil)}
	app.PersistentFlags().BoolVar(&globalCmd.flagVersion, "version", false, "Print version number")
	app.PersistentFlags().BoolVarP(&globalCmd.flagHelp, "help", "h", false, "Print help")
	app.PersistentFlags().BoolVar(&globalCmd.flagForceLocal, "force-local", false, "Force using the local unix socket")
	app.PersistentFlags().StringVar(&globalCmd.flagProject, "project", "", cli.FormatStringFlagLabel("Override the source project"))
	app.PersistentFlags().BoolVar(&globalCmd.flagLogDebug, "debug", false, "Show all debug messages")
	app.PersistentFlags().BoolVarP(&globalCmd.flagLogVerbose, "verbose", "v", false, "Show all information messages")
	app.PersistentFlags().BoolVarP(&globalCmd.flagQuiet, "quiet", "q", false, "Do not show progress information")
	app.PersistentFlags().BoolVar(&globalCmd.flagSubCmds, "sub-commands", false, "Use with help or --help to view sub-commands")

	_ = app.RegisterFlagCompletionFunc("project", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
		// Default
		remote := globalCmd.conf.DefaultRemote

		// Iterate through arguments. The first argument *may* include a remote, but it might not be the remote the user
		// is interested in. E.g. for `lxc init ubuntu:jammy c1` completions should be for projects in the default
		// remote, but for `lxc init ubuntu:jammy lab:c1` completions should be for the `lab:` remote. So iterate over
		// arguments and check if a remote is specified, then only set it as a remote if it is not public.
		for _, arg := range args {
			potentialRemote, _, ok := strings.Cut(arg, ":")
			if !ok {
				continue
			}

			remoteConf, ok := globalCmd.conf.Remotes[potentialRemote]
			if !ok {
				continue
			}

			if !remoteConf.Public {
				remote = potentialRemote
				break
			}
		}

		projects, directives := globalCmd.cmpTopLevelResourceInRemote(remote, "project", toComplete)
		if projects != nil {
			return projects, directives
		}

		return nil, cobra.ShellCompDirectiveError
	})

	// Wrappers
	app.PersistentPreRunE = globalCmd.PreRun
	app.PersistentPostRunE = globalCmd.PostRun

	// Version handling
	app.SetVersionTemplate("{{.Version}}\n")
	app.Version = version.Version
	if version.IsLTSVersion {
		app.Version = version.Version + " LTS"
	}

	// alias sub-command
	aliasCmd := cmdAlias{global: &globalCmd}
	app.AddCommand(aliasCmd.command())

	// cluster sub-command
	clusterCmd := cmdCluster{global: &globalCmd}
	app.AddCommand(clusterCmd.command())

	// config sub-command
	configCmd := cmdConfig{global: &globalCmd}
	app.AddCommand(configCmd.command())

	// console sub-command
	consoleCmd := cmdConsole{global: &globalCmd}
	app.AddCommand(consoleCmd.command())

	// copy sub-command
	copyCmd := cmdCopy{global: &globalCmd}
	app.AddCommand(copyCmd.command())

	// delete sub-command
	deleteCmd := cmdDelete{global: &globalCmd}
	app.AddCommand(deleteCmd.command())

	// exec sub-command
	execCmd := cmdExec{global: &globalCmd}
	app.AddCommand(execCmd.command())

	// export sub-command
	exportCmd := cmdExport{global: &globalCmd}
	app.AddCommand(exportCmd.command())

	// file sub-command
	fileCmd := cmdFile{global: &globalCmd}
	app.AddCommand(fileCmd.command())

	// import sub-command
	importCmd := cmdImport{global: &globalCmd}
	app.AddCommand(importCmd.command())

	// info sub-command
	infoCmd := cmdInfo{global: &globalCmd}
	app.AddCommand(infoCmd.command())

	// image sub-command
	imageCmd := cmdImage{global: &globalCmd}
	app.AddCommand(imageCmd.command())

	// init sub-command
	initCmd := cmdInit{global: &globalCmd}
	app.AddCommand(initCmd.command())

	// launch sub-command
	launchCmd := cmdLaunch{global: &globalCmd, init: &initCmd}
	app.AddCommand(launchCmd.command())

	// list sub-command
	listCmd := cmdList{global: &globalCmd}
	app.AddCommand(listCmd.command())

	// manpage sub-command
	manpageCmd := cmdManpage{global: &globalCmd}
	app.AddCommand(manpageCmd.command())

	// monitor sub-command
	monitorCmd := cmdMonitor{global: &globalCmd}
	app.AddCommand(monitorCmd.command())

	// move sub-command
	moveCmd := cmdMove{global: &globalCmd}
	app.AddCommand(moveCmd.command())

	// network sub-command
	networkCmd := cmdNetwork{global: &globalCmd}
	app.AddCommand(networkCmd.command())

	// operation sub-command
	operationCmd := cmdOperation{global: &globalCmd}
	app.AddCommand(operationCmd.command())

	// pause sub-command
	pauseCmd := cmdPause{global: &globalCmd}
	app.AddCommand(pauseCmd.command())

	// publish sub-command
	publishCmd := cmdPublish{global: &globalCmd}
	app.AddCommand(publishCmd.command())

	// profile sub-command
	profileCmd := cmdProfile{global: &globalCmd}
	app.AddCommand(profileCmd.command())

	// project sub-command
	projectCmd := cmdProject{global: &globalCmd}
	app.AddCommand(projectCmd.command())

	// replicator sub-command
	replicatorCmd := cmdReplicator{global: &globalCmd}
	app.AddCommand(replicatorCmd.command())

	// query sub-command
	queryCmd := cmdQuery{global: &globalCmd}
	app.AddCommand(queryCmd.command())

	// rebuild sub-command
	rebuildCmd := cmdRebuild{global: &globalCmd}
	app.AddCommand(rebuildCmd.command())

	// rename sub-command
	renameCmd := cmdRename{global: &globalCmd}
	app.AddCommand(renameCmd.command())

	// restart sub-command
	restartCmd := cmdRestart{global: &globalCmd}
	app.AddCommand(restartCmd.command())

	// remote sub-command
	remoteCmd := cmdRemote{global: &globalCmd}
	app.AddCommand(remoteCmd.command())

	// restore sub-command
	restoreCmd := cmdRestore{global: &globalCmd}
	app.AddCommand(restoreCmd.command())

	// snapshot sub-command
	snapshotCmd := cmdSnapshot{global: &globalCmd}
	app.AddCommand(snapshotCmd.command())

	// storage sub-command
	storageCmd := cmdStorage{global: &globalCmd}
	app.AddCommand(storageCmd.command())

	// start sub-command
	startCmd := cmdStart{global: &globalCmd}
	app.AddCommand(startCmd.command())

	// stop sub-command
	stopCmd := cmdStop{global: &globalCmd}
	app.AddCommand(stopCmd.command())

	// version sub-command
	versionCmd := cmdVersion{global: &globalCmd}
	app.AddCommand(versionCmd.command())

	// warning sub-command
	warningCmd := cmdWarning{global: &globalCmd}
	app.AddCommand(warningCmd.command())

	authCmd := cmdAuth{global: &globalCmd}
	app.AddCommand(authCmd.command())

	placementGroupCmd := cmdPlacementGroup{global: &globalCmd}
	app.AddCommand(placementGroupCmd.command())

	// Get help command
	app.InitDefaultHelpCmd()
	var help *cobra.Command
	for _, cmd := range app.Commands() {
		if cmd.Name() == "help" {
			help = cmd
			break
		}
	}

	// Help flags
	app.Flags().BoolVar(&globalCmd.flagHelpAll, "all", false, "Show less common commands")
	help.Flags().BoolVar(&globalCmd.flagHelpAll, "all", false, "Show less common commands")

	// Deal with --all flag and --sub-commands flag
	err = app.ParseFlags(os.Args[1:])
	if err == nil {
		if globalCmd.flagHelpAll {
			// Show all commands
			for _, cmd := range app.Commands() {
				if cmd.Name() == "completion" {
					continue
				}

				cmd.Hidden = false
			}
		}

		if globalCmd.flagSubCmds {
			app.SetUsageTemplate(usageTemplateSubCmds())
		}
	}

	// Run the main command and handle errors
	err = app.Execute()
	if err != nil {
		// Handle non-Linux systems
		if err == config.ErrNotLinux {
			msg := `This client has not been configured to use a remote LXD server yet.
As your platform cannot run native Linux instances, you must connect to a remote LXD server.

If you already added a remote server, make it the default with "lxc remote switch NAME".
To easily setup a local LXD server in a virtual machine, consider using: https://canonical.com/multipass`
			fmt.Fprintln(os.Stderr, msg)
			os.Exit(1)
		}

		// Default error handling
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)

		// If custom exit status not set, use default error status.
		if globalCmd.ret == 0 {
			globalCmd.ret = 1
		}
	}

	if globalCmd.ret != 0 {
		os.Exit(globalCmd.ret)
	}
}

// PreRun is set as the (*cobra.Command).PersistentPreRunE for the top level lxc command. It loads configuration and
// performs additional checks if it detects that LXD has not been configured yet.
func (c *cmdGlobal) PreRun(cmd *cobra.Command, args []string) error {
	var err error

	// If calling the help, skip pre-run
	if cmd.Name() == "help" {
		return nil
	}

	// Figure out the config directory and config path
	var configDir string
	lxdConf := os.Getenv("LXD_CONF")
	if lxdConf != "" {
		configDir = lxdConf
	} else if os.Getenv("HOME") != "" {
		configDir = path.Join(os.Getenv("HOME"), ".config", "lxc")
	} else {
		user, err := user.Current()
		if err != nil {
			return err
		}

		configDir = path.Join(user.HomeDir, ".config", "lxc")
	}

	c.confPath = os.ExpandEnv(path.Join(configDir, "config.yml"))

	// Load the configuration
	if c.flagForceLocal {
		c.conf = config.NewConfig("", true)
	} else {
		c.conf, err = config.LoadConfig(c.confPath)
		if err != nil {
			if !errors.Is(err, os.ErrNotExist) {
				return err
			}

			c.conf = config.NewConfig(configDir, true)
		}
	}

	// Override the project
	if c.flagProject != "" {
		c.conf.ProjectOverride = c.flagProject
	}

	// If the user is running a command that may attempt to connect to the local daemon
	// and this is the first time the client has been run by the user, then check to see
	// if LXD has been properly configured.  Don't display the message if the var path
	// does not exist (LXD not installed), as the user may be targeting a remote daemon.
	if !c.flagForceLocal && !shared.PathExists(c.confPath) {
		// Create the config dir so that we don't get in here again for this user.
		err = os.MkdirAll(c.conf.ConfigDir, 0750)
		if err != nil {
			return err
		}

		// Handle local servers.
		if shared.PathExists(shared.VarPath("")) {
			// Attempt to connect to the local server
			runInit := true
			d, err := lxd.ConnectLXDUnix("", nil)
			if err == nil {
				// Check if server is initialized.
				info, _, err := d.GetServer()
				if err == nil && info.Environment.Storage != "" {
					runInit = false
				}

				// Detect usable project.
				names, err := d.GetProjectNames()
				if err == nil {
					if len(names) == 1 && names[0] != "default" {
						remote := c.conf.Remotes["local"]
						remote.Project = names[0]
						c.conf.Remotes["local"] = remote
					}
				}
			}

			flush := false
			if runInit {
				msg := "If this is your first time running LXD on this machine, you should also run: lxd init"
				fmt.Fprintln(os.Stderr, msg)
				flush = true
			}

			if !slices.Contains([]string{"init", "launch"}, cmd.Name()) {
				msg := `To start your first container, try: lxc launch ubuntu:24.04
Or for a virtual machine: lxc launch ubuntu:24.04 --vm`
				fmt.Fprintln(os.Stderr, msg)
				flush = true
			}

			if flush {
				fmt.Fprintf(os.Stderr, "\n")
			}
		}

		// And save the initial configuration
		err = c.conf.SaveConfig(c.confPath)
		if err != nil {
			return err
		}
	}

	// Set the user agent, indicating that we are able to store cookies.
	err = version.UserAgentFeatures([]string{api.ClientFeatureCookieJar})
	if err != nil {
		return fmt.Errorf("Failed advertising client features: %w", err)
	}

	c.conf.UserAgent = version.UserAgent

	// Setup the logger
	err = logger.InitLogger("", "", c.flagLogVerbose, c.flagLogDebug, nil)
	if err != nil {
		return err
	}

	return nil
}

// PostRun is set as the (*cobra.Command).PersistentPostRunE hook on the top level lxc command.
// It saves any configuration that must persist between runs.
func (c *cmdGlobal) PostRun(cmd *cobra.Command, args []string) error {
	if c.conf != nil && shared.PathExists(c.confPath) {
		// Save cookies and OIDC tokens on exit
		c.conf.SaveCookies()
		c.conf.SaveOIDCTokens()
	}

	return nil
}

type remoteResource struct {
	remote string
	server lxd.InstanceServer
	name   string
}

// ParseServers parses a list of remotes (`<remote>:<resource>...`) and calls (*config.Config).GetInstanceServer
// for each remote to configure a new connection.
func (c *cmdGlobal) ParseServers(remotes ...string) ([]remoteResource, error) {
	servers := map[string]lxd.InstanceServer{}
	resources := []remoteResource{}

	for _, remote := range remotes {
		// Parse the remote
		remoteName, name, err := c.conf.ParseRemote(remote)
		if err != nil {
			return nil, err
		}

		// Setup the struct
		resource := remoteResource{
			remote: remoteName,
			name:   name,
		}

		// Look at our cache
		_, ok := servers[remoteName]
		if ok {
			resource.server = servers[remoteName]
			resources = append(resources, resource)
			continue
		}

		// New connection
		d, err := c.conf.GetInstanceServer(remoteName)
		if err != nil {
			return nil, err
		}

		resource.server = d
		servers[remoteName] = d
		resources = append(resources, resource)
	}

	return resources, nil
}

// CheckArgs checks that the given list of arguments has length between minArgs and maxArgs.
func (c *cmdGlobal) CheckArgs(cmd *cobra.Command, args []string, minArgs int, maxArgs int) (bool, error) {
	if len(args) < minArgs || (maxArgs != -1 && len(args) > maxArgs) {
		_ = cmd.Help()

		if len(args) == 0 {
			return true, nil
		}

		return true, errors.New("Invalid number of arguments")
	}

	return false, nil
}