package cmd

import (
	"fmt"
	"log/slog"

	"github.com/portainer/kubesolo-os/update/pkg/state"
)

// Rollback forces an immediate switch to the other partition.
// Use this to manually revert to the previous version.
//
// State transition: any → RolledBack with LastError="manual rollback".
func Rollback(args []string) error {
	opts := parseOpts(args)
	env := opts.NewBootEnv()

	st, err := state.Load(opts.StatePath)
	if err != nil {
		slog.Warn("state file unreadable, starting fresh", "error", err)
		st = state.New()
	}

	activeSlot, err := env.ActiveSlot()
	if err != nil {
		return fmt.Errorf("reading active slot: %w", err)
	}

	passiveSlot, err := env.PassiveSlot()
	if err != nil {
		return fmt.Errorf("reading passive slot: %w", err)
	}

	slog.Info("forcing rollback", "from", activeSlot, "to", passiveSlot)

	if err := env.ForceRollback(); err != nil {
		_ = st.RecordError(opts.StatePath, fmt.Errorf("rollback failed: %w", err))
		return fmt.Errorf("rollback failed: %w", err)
	}

	if err := st.Transition(opts.StatePath, state.PhaseRolledBack, "", "manual rollback"); err != nil {
		slog.Warn("state transition failed", "phase", state.PhaseRolledBack, "error", err)
	}

	fmt.Printf("Rolled back: %s → %s\n", activeSlot, passiveSlot)
	fmt.Println("Reboot to complete rollback.")

	return nil
}