package keyring

import (
	"fmt"
	"runtime"
)

// CheckDependencies checks whether the native credential service answered a
// bounded read. It never writes a probe value or starts an unlock prompt at
// application startup; callers should invoke it only for keyring UI actions.
func CheckDependencies() error {
	status := DetectStatus()
	if status.ActiveBackend != BackendNone {
		return nil
	}
	if runtime.GOOS == "linux" {
		return fmt.Errorf("%w: %s\n\nSetup: %s", ErrDaemonNotRunning, status.Error, status.InstallHint)
	}
	return fmt.Errorf("%w: %s", ErrNoBackend, status.Error)
}

// NeedsInstallPrompt reports whether explicit keyring setup is needed. It is
// retained for API compatibility; the application no longer calls it during
// startup or package update discovery.
func NeedsInstallPrompt() bool {
	return DetectStatus().ActiveBackend == BackendNone
}

// CanUseKeyring reports whether the native credential store responds.
func CanUseKeyring() bool {
	return CheckDependencies() == nil
}

// GetSetupInstructions returns setup guidance when the native store cannot be
// reached. Linux uses the freedesktop Secret Service protocol for both GNOME
// Keyring and current KDE Wallet implementations.
func GetSetupInstructions() string {
	status := DetectStatus()
	if status.ActiveBackend != BackendNone {
		return ""
	}
	if runtime.GOOS != "linux" {
		return "The operating system credential store is unavailable: " + status.Error
	}
	return fmt.Sprintf(
		"The desktop Secret Service is unavailable or locked.\n\n%s\n\nLog in to a desktop session, unlock its keyring, and try again.",
		status.InstallHint,
	)
}

// ValidateSetup returns a read-only, bounded diagnostic. It deliberately does
// not create and delete a test credential.
func ValidateSetup() (bool, string) {
	status := DetectStatus()
	if status.ActiveBackend == BackendNone {
		return false, fmt.Sprintf("Native keyring unavailable: %s. %s", status.Error, status.InstallHint)
	}
	return true, fmt.Sprintf(
		"Native keyring is responding. Active backend: %s, Desktop: %s, Distro: %s",
		status.ActiveBackend,
		status.DesktopEnv,
		status.Distro,
	)
}