package main

import (
	"fmt"
	"os"
	"sort"

	"github.com/charmbracelet/huh"
	"github.com/spf13/cobra"
)

func newSwitchCmd() *cobra.Command {
	return &cobra.Command{
		Use:   "switch [registry]",
		Short: "Switch the active account for a registry",
		Long:  "Switch the active account used for Docker operations.\nDefault registry: atcr.io",
		Args:  cobra.MaximumNArgs(1),
		RunE:  runSwitch,
	}
}

func runSwitch(cmd *cobra.Command, args []string) error {
	serverURL := "atcr.io"
	if len(args) > 0 {
		serverURL = args[0]
	}

	appViewURL := buildAppViewURL(serverURL)

	cfg, err := loadConfig()
	if err != nil {
		return fmt.Errorf("loading config: %w", err)
	}

	reg := cfg.findRegistry(appViewURL)
	if reg == nil || len(reg.Accounts) == 0 {
		fmt.Fprintf(os.Stderr, "No accounts configured for %s.\n", serverURL)
		fmt.Fprintf(os.Stderr, "Run: docker-credential-atcr login\n")
		return nil
	}

	if len(reg.Accounts) == 1 {
		for h := range reg.Accounts {
			fmt.Fprintf(os.Stderr, "Only one account (%s) — nothing to switch.\n", h)
		}
		return nil
	}

	// For exactly 2 accounts, just toggle
	if len(reg.Accounts) == 2 {
		for h := range reg.Accounts {
			if h != reg.Active {
				reg.Active = h
				if err := cfg.save(); err != nil {
					return fmt.Errorf("saving config: %w", err)
				}
				fmt.Printf("Switched to %s on %s\n", h, serverURL)
				return nil
			}
		}
	}

	// 3+ accounts: interactive select
	var handles []string
	for h := range reg.Accounts {
		handles = append(handles, h)
	}
	sort.Strings(handles)

	var options []huh.Option[string]
	for _, h := range handles {
		label := h
		if h == reg.Active {
			label += " (current)"
		}
		options = append(options, huh.NewOption(label, h))
	}

	var selected string
	err = huh.NewSelect[string]().
		Title("Select account for " + serverURL).
		Options(options...).
		Value(&selected).
		Run()
	if err != nil {
		return err
	}

	reg.Active = selected
	if err := cfg.save(); err != nil {
		return fmt.Errorf("saving config: %w", err)
	}

	fmt.Printf("Switched to %s on %s\n", selected, serverURL)
	return nil
}