package commands

import (
	"context"
	"errors"
	"fmt"
	"os"
	"os/signal"
	"sync"
	"syscall"
	"time"

	"git.nevets.tech/Keys/CertManager/client"
	"git.nevets.tech/Keys/CertManager/internal"
	"git.nevets.tech/Keys/CertManager/server"
)

var (
	ctx    context.Context
	cancel context.CancelFunc
	wg     sync.WaitGroup
)

func RunDaemonCmd() error {
	err := internal.CreateOrUpdatePIDFile("/var/run/certman.pid")
	if err != nil {
		if errors.Is(err, internal.ErrorPIDInUse) {
			return fmt.Errorf("daemon process is already running")
		}
		return fmt.Errorf("error creating pidfile: %v", err)
	}

	ctx, cancel = context.WithCancel(context.Background())

	// Check if main config exists
	if _, err := os.Stat("/etc/certman/certman.conf"); os.IsNotExist(err) {
		return fmt.Errorf("main config file not found, please run 'certman --install', then properly configure /etc/certman/certman.conf")
	} else if err != nil {
		return fmt.Errorf("error opening /etc/certman/certman.conf: %v", err)
	}
	err = internal.LoadConfig()
	if err != nil {
		return fmt.Errorf("error loading configuration: %v", err)
	}

	// Setup SIGINT and SIGTERM listeners
	sigChannel := make(chan os.Signal, 1)
	signal.Notify(sigChannel, syscall.SIGINT, syscall.SIGTERM)
	defer signal.Stop(sigChannel)

	reloadSigChan := make(chan os.Signal, 1)
	signal.Notify(reloadSigChan, syscall.SIGHUP)
	defer signal.Stop(reloadSigChan)

	tickSigChan := make(chan os.Signal, 1)
	signal.Notify(tickSigChan, syscall.SIGUSR1)
	defer signal.Stop(tickSigChan)

	tickRate := internal.Config().GetInt("App.tick_rate")
	ticker := time.NewTicker(time.Duration(tickRate) * time.Hour)
	defer ticker.Stop()

	wg.Add(1)
	if internal.Config().GetString("App.mode") == "server" {
		fmt.Println("Starting CertManager in server mode...")
		// Server Task loop
		go func() {
			server.Init()
			defer wg.Done()
			for {
				select {
				case <-ctx.Done():
					server.Stop()
					return
				case <-reloadSigChan:
					server.Reload()
				case <-ticker.C:
					server.Tick()
				case <-tickSigChan:
					server.Tick()
				}
			}
		}()
	} else if internal.Config().GetString("App.mode") == "client" {
		fmt.Println("Starting CertManager in client mode...")
		// Client Task loop
		go func() {
			client.Init()
			defer wg.Done()
			for {
				select {
				case <-ctx.Done():
					client.Stop()
					return
				case <-reloadSigChan:
					client.Reload()
				case <-ticker.C:
					client.Tick()
				case <-tickSigChan:
					client.Tick()
				}
			}
		}()
	} else {
		return fmt.Errorf("invalid operating mode \"" + internal.Config().GetString("App.mode") + "\"")
	}

	// Cleanup on stop
	sig := <-sigChannel
	fmt.Printf("Program terminated with %v\n", sig.String())

	stop()
	wg.Wait()
	return nil
}

func stop() {
	cancel()
	internal.ClearPIDFile()
}

func StopDaemonCmd() error {
	proc, err := internal.DaemonProcess()
	if err != nil {
		return fmt.Errorf("error getting daemon process: %v", err)
	}

	err = proc.Signal(syscall.SIGTERM)
	if err != nil {
		return fmt.Errorf("error sending SIGTERM to daemon PID: %v", err)
	}
	return nil
}

func ReloadDaemonCmd() error {
	proc, err := internal.DaemonProcess()
	if err != nil {
		return fmt.Errorf("error getting daemon process: %v", err)
	}

	err = proc.Signal(syscall.SIGHUP)
	if err != nil {
		return fmt.Errorf("error sending SIGHUP to daemon PID: %v", err)
	}
	return nil
}

func TickDaemonCmd() error {
	proc, err := internal.DaemonProcess()
	if err != nil {
		return fmt.Errorf("error getting daemon process: %v", err)
	}

	err = proc.Signal(syscall.SIGUSR1)
	if err != nil {
		return fmt.Errorf("error sending SIGUSR1 to daemon PID: %v", err)
	}
	return nil
}

func DaemonStatusCmd() error {
	fmt.Println("Not implemented :/")
	return nil
}