package sysproxy

import (
	"os"
	"path/filepath"
	"strings"
)

// SentinelPath is written while Navis owns the OS system proxy.
// Survives crash/kill so the next launch can clear a stuck proxy.
func SentinelPath(cfgPath string) string {
	dir := filepath.Dir(strings.TrimSpace(cfgPath))
	if dir == "" || dir == "." {
		dir, _ = os.UserConfigDir()
		if dir == "" {
			dir = os.TempDir()
		}
		dir = filepath.Join(dir, "Navis")
	}
	return filepath.Join(dir, ".navis-proxy-on")
}

// WriteSentinel marks that system proxy was enabled by Navis.
func WriteSentinel(cfgPath, httpHostPort string) {
	path := SentinelPath(cfgPath)
	_ = os.MkdirAll(filepath.Dir(path), 0o755)
	_ = os.WriteFile(path, []byte(strings.TrimSpace(httpHostPort)+"\n"), 0o600)
}

// ClearSentinel removes the ownership marker after a clean Disable.
func ClearSentinel(cfgPath string) {
	_ = os.Remove(SentinelPath(cfgPath))
}

// HasSentinel reports whether a previous session left the proxy marked on.
func HasSentinel(cfgPath string) bool {
	_, err := os.Stat(SentinelPath(cfgPath))
	return err == nil
}