package cmd

import (
	"fmt"
	"io"
	"regexp"
	"strings"

	"github.com/spf13/cobra"
)

var unknownCommandPattern = regexp.MustCompile(`unknown command "([^"]+)" for "([^"]+)"`)

type commandMetadata struct {
	Use     string
	Short   string
	Long    string
	Example string
	Aliases []string
}

const generatedHelpTemplate = `{{with (or .Long .Short)}}{{. | trimTrailingWhitespaces}}

{{end}}Usage:
  {{.UseLine}}{{if gt (len .Aliases) 0}}

Aliases:
  {{.NameAndAliases}}{{end}}{{if .HasAvailableSubCommands}}

Available Commands:{{range .Commands}}{{if .IsAvailableCommand}}
  {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{end}}{{if .LocalNonPersistentFlags.HasAvailableFlags}}

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

Global Flags:
{{.InheritedFlags.FlagUsages | trimTrailingWhitespaces}}{{else if .HasAvailablePersistentFlags}}

Global Flags:
{{.PersistentFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}{{if .HasExample}}

Examples:
{{.Example | trimTrailingWhitespaces}}{{end}}
`

func configureCobraCommand(command *cobra.Command, stdout io.Writer) {
	command.SilenceErrors = true
	command.SilenceUsage = true
	command.DisableSuggestions = true
	command.DisableAutoGenTag = true
	command.CompletionOptions.DisableDefaultCmd = true
	command.SetOut(stdout)
	command.SetErr(io.Discard)
	configureGeneratedHelp(command)
}

func configureGeneratedHelp(command *cobra.Command) {
	command.SetHelpTemplate(generatedHelpTemplate)
}

func newCommand(meta commandMetadata, stdout io.Writer) *cobra.Command {
	command := &cobra.Command{
		Use:     meta.Use,
		Short:   meta.Short,
		Long:    meta.Long,
		Example: meta.Example,
		Aliases: meta.Aliases,
	}
	configureCobraCommand(command, stdout)
	return command
}

func cobraNoArgs(commandName string) cobra.PositionalArgs {
	return func(_ *cobra.Command, args []string) error {
		if len(args) != 0 {
			return fmt.Errorf("%s does not accept arguments", commandName)
		}
		return nil
	}
}

func executeCobraCommand(command *cobra.Command, args []string) error {
	command.SetArgs(args)
	return command.Execute()
}

func normalizeRootCommandError(err error) error {
	unknown, target, ok := parseUnknownCommandError(err)
	if ok && target == "clinic" {
		return fmt.Errorf("unknown command: %s", unknown)
	}
	if ok && target == "clinic version" {
		return fmt.Errorf("version does not accept arguments")
	}
	if ok && strings.HasPrefix(target, "clinic ") {
		parts := strings.Fields(target)
		if len(parts) == 2 {
			switch parts[1] {
			case "auth", "profile":
				return fmt.Errorf("unknown %s subcommand: %s", parts[1], unknown)
			}
		}
	}
	return err
}

func normalizeFamilyCommandError(err error, family string) error {
	unknown, target, ok := parseUnknownCommandError(err)
	if ok && target == family {
		return fmt.Errorf("unknown %s subcommand: %s", family, unknown)
	}
	return err
}

func parseUnknownCommandError(err error) (string, string, bool) {
	if err == nil {
		return "", "", false
	}

	matches := unknownCommandPattern.FindStringSubmatch(err.Error())
	if len(matches) != 3 {
		return "", "", false
	}

	return matches[1], strings.TrimSpace(matches[2]), true
}