package ports

import (
	"context"
	"fmt"

	"galaxy/authsession/internal/domain/challenge"
	"galaxy/authsession/internal/domain/common"
)

// ChallengeStore provides source-of-truth persistence for auth confirmation
// challenges without exposing storage-specific primitives.
type ChallengeStore interface {
	// Get returns the stored challenge for challengeID. Implementations must
	// wrap ErrNotFound when challengeID does not exist.
	Get(ctx context.Context, challengeID common.ChallengeID) (challenge.Challenge, error)

	// Create persists record as a new challenge. Implementations must wrap
	// ErrConflict when record.ID already exists.
	Create(ctx context.Context, record challenge.Challenge) error

	// CompareAndSwap replaces previous with next when the currently stored
	// challenge matches previous exactly. Implementations must wrap ErrConflict
	// when the stored challenge differs from previous and wrap ErrNotFound when
	// previous.ID does not exist.
	CompareAndSwap(ctx context.Context, previous challenge.Challenge, next challenge.Challenge) error
}

// ValidateComparableChallenges reports whether previous and next are suitable
// for one ChallengeStore compare-and-swap call.
func ValidateComparableChallenges(previous challenge.Challenge, next challenge.Challenge) error {
	if err := previous.Validate(); err != nil {
		return fmt.Errorf("previous challenge: %w", err)
	}
	if err := next.Validate(); err != nil {
		return fmt.Errorf("next challenge: %w", err)
	}
	if previous.ID != next.ID {
		return fmt.Errorf("challenge compare-and-swap ids must match: %q != %q", previous.ID, next.ID)
	}

	return nil
}