// Copyright 2026 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package credstore

// Prober is an optional interface that a Store can implement to test
// whether its backend is available.
type Prober interface {
	Probe() bool
}

// DefaultSecureStore creates a SecureStore with the given codec and sensible defaults.
// The primary backend is an EncryptedFileStore writing to filePath+".enc"
// with its master key in the OS keyring; see EncryptedFileStore for why only
// the key lives there. When the keyring is unavailable, it falls back to
// plaintext file storage at filePath.
func DefaultSecureStore[T any](serviceName, filePath string, codec Codec[T]) *SecureStore[T] {
	return NewSecureStore[T](
		NewEncryptedFileStore[T](serviceName, filePath+".enc", codec),
		NewFileStore[T](filePath, codec))
}

// SecureStore is a composite Store that uses the keyring-backed primary
// store when the keyring is available and falls back to file-based storage
// otherwise. The active backend is chosen once at construction time.
type SecureStore[T any] struct {
	active Store[T]
}

// NewSecureStore creates a SecureStore. If kr implements Prober and the probe
// succeeds, kr is used as the active store. Otherwise, file is used as the
// fallback.
func NewSecureStore[T any](kr, file Store[T]) *SecureStore[T] {
	if p, ok := kr.(Prober); ok && p.Probe() {
		return &SecureStore[T]{active: kr}
	}
	return &SecureStore[T]{active: file}
}

// Load loads data from the active store.
func (s *SecureStore[T]) Load(clientID string) (T, error) {
	return s.active.Load(clientID)
}

// Save saves data to the active store.
func (s *SecureStore[T]) Save(clientID string, data T) error {
	return s.active.Save(clientID, data)
}

// Delete removes data from the active store.
func (s *SecureStore[T]) Delete(clientID string) error {
	return s.active.Delete(clientID)
}

// String returns a description of the active store.
func (s *SecureStore[T]) String() string {
	return s.active.String()
}