package service

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"

	"super-frpc/database"
	"super-frpc/global"
	"super-frpc/postLog"
)

func GetConfigDir() (string, error) {
	return global.CurrentConfig.InstancePath, nil
}

func GetFrpcPath() (string, error) {
	return global.CurrentConfig.FrpcPath, nil
}

func GetInitSystem() string {
	if runtime.GOOS == "windows" {
		return "windows"
	}
	if runtime.GOOS == "linux" {
		if _, err := os.Stat("/run/systemd/system"); err == nil {
			return "systemd"
		}
		if _, err := os.Stat("/etc/init.d"); err == nil {
			return "init.d"
		}
	}
	return "unknown"
}

func CreateBootService(instanceID int) error {
	instance, err := database.DBQueryFrpcInstanceByID(instanceID)
	if err != nil {
		return fmt.Errorf("failed to query frpc instance: %w", err)
	}

	initType := GetInitSystem()

	switch initType {
	case "systemd":
		return createSystemdService(instanceID, instance.ConfigPath, instance.RunUser)
	case "init.d":
		return createInitDService(instanceID, instance.ConfigPath, instance.RunUser)
	case "windows":
		return createWindowsBootService(instanceID, instance.ConfigPath)
	default:
		return fmt.Errorf("unsupported init system: %s", initType)
	}
}

func createSystemdService(instanceID int, configPath, runUser string) error {
	frpcPath, err := GetFrpcPath()
	if err != nil {
		return err
	}

	serviceName, err := database.GetServiceNameByInstanceID(instanceID)
	if err != nil {
		return err
	}

	instance, err := database.DBQueryFrpcInstanceByID(instanceID)
	if err != nil {
		return fmt.Errorf("failed to query frpc instance: %w", err)
	}

	user, err := database.GetUserByID(instance.UserID)
	if err != nil {
		return fmt.Errorf("failed to get user info: %w", err)
	}

	serviceContent := fmt.Sprintf(`[Unit]
Description=superfrpc_%s_%s
After=network.target

[Service]
Type=simple
ExecStart=%s -c %s
User=%s
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target
`, user.Username, instance.Name, frpcPath, configPath, runUser)

	servicePath := filepath.Join("/etc/systemd/system", serviceName+".service")
	if err := os.WriteFile(servicePath, []byte(serviceContent), 0644); err != nil {
		return fmt.Errorf("failed to create systemd service file: %w", err)
	}

	cmd := exec.Command("systemctl", "enable", serviceName)
	if output, err := cmd.CombinedOutput(); err != nil {
		os.Remove(servicePath)
		return fmt.Errorf("failed to enable service: %s, output: %s", err, output)
	}

	cmd = exec.Command("systemctl", "daemon-reload")
	if output, err := cmd.CombinedOutput(); err != nil {
		return fmt.Errorf("failed to reload daemon: %s, output: %s", err, output)
	}

	return nil
}

func createInitDService(instanceID int, configPath, runUser string) error {
	frpcPath, err := GetFrpcPath()
	if err != nil {
		return err
	}

	serviceName, err := database.GetServiceNameByInstanceID(instanceID)
	if err != nil {
		return err
	}

	instance, err := database.DBQueryFrpcInstanceByID(instanceID)
	if err != nil {
		return fmt.Errorf("failed to query frpc instance: %w", err)
	}

	user, err := database.GetUserByID(instance.UserID)
	if err != nil {
		return fmt.Errorf("failed to get user info: %w", err)
	}

	var serviceContent string
	runUserArg := ""
	if runUser != "" && runUser != "root" {
		runUserArg = runUser
		serviceContent = fmt.Sprintf(`#!/bin/sh

### BEGIN INIT INFO
# Provides:          %s
# Required-Start:    $network $remote_fs $syslog
# Required-Stop:     $network $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Description:       superfrpc %s %s
### END INIT INFO

NAME="%s"
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
DAEMON=%s
DAEMON_ARGS="-c %s"
SCRIPTNAME=/etc/init.d/$NAME
USER=%s

[ -x "$DAEMON" ] || exit 0

case "$1" in
  start)
        echo -n "Starting $NAME: "
        start-stop-daemon -S -c $USER -b -m -p /var/run/$NAME.pid --start --exec $DAEMON -- $DAEMON_ARGS
        echo "$NAME."
        ;;
  stop)
        echo -n "Stopping $NAME: "
        start-stop-daemon -K -p /var/run/$NAME.pid
        rm -f /var/run/$NAME.pid
        echo "$NAME."
        ;;
  restart)
        $0 stop
        $0 start
        ;;
  status)
        if [ -f /var/run/$NAME.pid ]; then
            echo "$NAME is running (pid $(cat /var/run/$NAME.pid))"
        else
            echo "$NAME is not running"
        fi
        ;;
  *)
        echo "Usage: $SCRIPTNAME {start|stop|restart|status}"
        exit 1
        ;;
esac

exit 0
`, serviceName, user.Username, instance.Name, serviceName, frpcPath, configPath, runUserArg)
	} else {
		serviceContent = fmt.Sprintf(`#!/bin/sh

### BEGIN INIT INFO
# Provides:          %s
# Required-Start:    $network $remote_fs $syslog
# Required-Stop:     $network $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Description:       superfrpc %s %s
### END INIT INFO

NAME="%s"
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
DAEMON=%s
DAEMON_ARGS="-c %s"
SCRIPTNAME=/etc/init.d/$NAME

[ -x "$DAEMON" ] || exit 0

case "$1" in
  start)
        echo -n "Starting $NAME: "
        start-stop-daemon -S -b -m -p /var/run/$NAME.pid --start --exec $DAEMON -- $DAEMON_ARGS
        echo "$NAME."
        ;;
  stop)
        echo -n "Stopping $NAME: "
        start-stop-daemon -K -p /var/run/$NAME.pid
        rm -f /var/run/$NAME.pid
        echo "$NAME."
        ;;
  restart)
        $0 stop
        $0 start
        ;;
  status)
        if [ -f /var/run/$NAME.pid ]; then
            echo "$NAME is running (pid $(cat /var/run/$NAME.pid))"
        else
            echo "$NAME is not running"
        fi
        ;;
  *)
        echo "Usage: $SCRIPTNAME {start|stop|restart|status}"
        exit 1
        ;;
esac

exit 0
`, serviceName, user.Username, instance.Name, serviceName, frpcPath, configPath)
	}

	servicePath := filepath.Join("/etc/init.d", serviceName)
	if err := os.WriteFile(servicePath, []byte(serviceContent), 0755); err != nil {
		return fmt.Errorf("failed to create init.d service file: %w", err)
	}

	cmd := exec.Command("/etc/init.d", serviceName, "enable")
	if output, err := cmd.CombinedOutput(); err != nil {
		os.Remove(servicePath)
		return fmt.Errorf("failed to enable service: %s, output: %s", err, output)
	}

	return nil
}

func createWindowsBootService(instanceID int, configPath string) error {
	frpcPath, err := GetFrpcPath()
	if err != nil {
		return err
	}

	serviceName, err := database.GetServiceNameByInstanceID(instanceID)
	if err != nil {
		return err
	}

	command := fmt.Sprintf("\"%s\" -c \"%s\"", frpcPath, configPath)

	cmd := exec.Command("sc", "create", serviceName, "binPath=", command, "start=", "auto")
	output, err := cmd.CombinedOutput()
	postLog.Debug(fmt.Sprintf("[createWindowsBootService] Sc create output: %s", output))
	if err != nil {
		return fmt.Errorf("failed to create Windows service: %s, output: %s", err, output)
	}

	return nil
}

func SetBootAtStart(instanceID int) error {
	initType := GetInitSystem()
	serviceName, err := database.GetServiceNameByInstanceID(instanceID)
	if err != nil {
		return err
	}

	switch initType {
	case "windows":
		cmd := exec.Command("sc", "config", serviceName, "start=", "auto")
		output, err := cmd.CombinedOutput()
		if err != nil {
			return fmt.Errorf("failed to set Windows service %s to auto-start: %s, output: %s", serviceName, err, output)
		}
		return nil
	case "systemd":
		cmd := exec.Command("systemctl", "enable", serviceName)
		output, err := cmd.CombinedOutput()
		if err != nil {
			return fmt.Errorf("failed to enable systemd service %s: %s, output: %s", serviceName, err, output)
		}
		return nil
	case "init.d":
		cmd := exec.Command("update-rc.d", serviceName, "enable")
		output, err := cmd.CombinedOutput()
		if err != nil {
			return fmt.Errorf("failed to enable init.d service %s: %s, output: %s", serviceName, err, output)
		}
		return nil
	default:
		return fmt.Errorf("unsupported init system: %s", initType)
	}
}

func RemoveBootAtStart(instanceID int) error {
	initType := GetInitSystem()
	serviceName, err := database.GetServiceNameByInstanceID(instanceID)
	if err != nil {
		return err
	}

	switch initType {
	case "windows":
		cmd := exec.Command("sc", "config", serviceName, "start=", "disabled")
		output, err := cmd.CombinedOutput()
		if err != nil {
			return fmt.Errorf("failed to set Windows service %s to disabled-start: %s, output: %s", serviceName, err, output)
		}
		return nil
	case "systemd":
		cmd := exec.Command("systemctl", "disable", serviceName)
		output, err := cmd.CombinedOutput()
		if err != nil {
			return fmt.Errorf("failed to disable systemd service %s: %s, output: %s", serviceName, err, output)
		}
		return nil
	case "init.d":
		cmd := exec.Command("update-rc.d", serviceName, "disable")
		output, err := cmd.CombinedOutput()
		if err != nil {
			return fmt.Errorf("failed to disable init.d service %s: %s, output: %s", serviceName, err, output)
		}
		return nil
	default:
		return fmt.Errorf("unsupported init system: %s", initType)
	}
}

func RemoveBootService(instanceID int) error {
	initType := GetInitSystem()
	serviceName, err := database.GetServiceNameByInstanceID(instanceID)
	if err != nil {
		return err
	}

	switch initType {
	case "systemd":
		cmd := exec.Command("systemctl", "disable", serviceName)
		cmd.CombinedOutput()

		servicePath := filepath.Join("/etc/systemd/system", serviceName+".service")
		os.Remove(servicePath)

		cmd = exec.Command("systemctl", "daemon-reload")
		cmd.CombinedOutput()

	case "init.d":
		cmd := exec.Command("/etc/init.d", serviceName, "disable")
		cmd.CombinedOutput()

		servicePath := filepath.Join("/etc/init.d", serviceName)
		os.Remove(servicePath)

	case "windows":
		cmd := exec.Command("sc", "delete", serviceName)
		postLog.Debug(fmt.Sprintf("[removeBootService] Sc delete command: %s", cmd.String()))
		if output, err := cmd.CombinedOutput(); err != nil {
			postLog.Error(fmt.Sprintf("[removeBootService] Failed to delete Windows service: %s, output: %s", err, output))
		}
	default:
		postLog.Error(fmt.Sprintf("[removeBootService] Unsupported init system: %s", initType))
	}

	return nil
}

func IsInstanceRunning(instanceID int) error {
	initType := GetInitSystem()
	serviceName, err := database.GetServiceNameByInstanceID(instanceID)
	if err != nil {
		postLog.Error(fmt.Sprintf("[IsInstanceRunning] Failed to get service name: %v", err))
		return err
	}

	instance, err := database.DBQueryFrpcInstanceByID(instanceID)
	if err != nil {
		postLog.Error(fmt.Sprintf("[IsInstanceRunning] Failed to query instance: %v", err))
		return err
	}

	switch initType {
	case "windows":
		cmd := exec.Command("sc", "query", serviceName)

		output, err := cmd.CombinedOutput()
		postLog.Debug(fmt.Sprintf("[IsInstanceRunning] Sc query output: %s", output))
		outputStr := string(output)

		if err != nil {
			postLog.Error(fmt.Sprintf("[IsInstanceRunning] Failed to check Windows service status: %s, output: %s", err, output))
			return err
		}

		if strings.Contains(outputStr, "RUNNING") {
			postLog.Info(fmt.Sprintf("[IsInstanceRunning] Windows service %s is running", instance.Name))
			return nil
		} else {
			postLog.Info(fmt.Sprintf("[IsInstanceRunning] Windows service %s is stopped", instance.Name))
			return nil
		}

	case "systemd":
		cmd := exec.Command("systemctl", "status", serviceName)

		output, err := cmd.CombinedOutput()
		outputStr := string(output)

		if err != nil {
			exitError, ok := err.(*exec.ExitError)
			if ok {
				exitCode := exitError.ExitCode()
				if exitCode == 1 {
					postLog.Debug(fmt.Sprintf("[IsInstanceRunning] Systemd service status command failed with exit code 1: %s, output: %s", serviceName, outputStr))
					return fmt.Errorf("service %s is not running", serviceName)
				}
				if exitCode == 2 {
					postLog.Debug(fmt.Sprintf("[IsInstanceRunning] Systemd service status command failed with exit code 2: %s, output: %s", serviceName, outputStr))
					return fmt.Errorf("service %s is not running", serviceName)
				}
				if exitCode == 3 {
					postLog.Debug(fmt.Sprintf("[IsInstanceRunning] Systemd service %s is not running: %s", serviceName, outputStr))
					return fmt.Errorf("service %s is not running", serviceName)
				}
				if exitCode == 4 {
					postLog.Debug(fmt.Sprintf("[IsInstanceRunning] Systemd service %s does not exist: %s", serviceName, outputStr))
					return fmt.Errorf("service %s does not exist", serviceName)
				}
			}
			postLog.Error(fmt.Sprintf("[IsInstanceRunning] Failed to check systemd service status: %s", err))
			return err
		}

		if strings.Contains(outputStr, "active (running)") {
			postLog.Info(fmt.Sprintf("[IsInstanceRunning] Systemd service %s is running", serviceName))
			return nil
		} else {
			postLog.Info(fmt.Sprintf("[IsInstanceRunning] Systemd service %s is stopped", serviceName))
			return nil
		}

	case "init.d":
		servicePath := fmt.Sprintf("/etc/init.d/%s", serviceName)
		if _, err := os.Stat(servicePath); err != nil {
			postLog.Warning(fmt.Sprintf("[IsInstanceRunning] Init.d service %s not found", serviceName))
			return nil
		}

		cmd := exec.Command(servicePath, "status")

		output, err := cmd.CombinedOutput()
		outputStr := strings.TrimSpace(string(output))

		if err != nil {
			exitError, ok := err.(*exec.ExitError)
			if ok {
				exitCode := exitError.ExitCode()
				if exitCode != 0 && !strings.Contains(outputStr, "is running") {
					postLog.Info(fmt.Sprintf("[IsInstanceRunning] Init.d service %s is stopped", serviceName))
					return nil
				}
			}
			postLog.Error(fmt.Sprintf("[IsInstanceRunning] Failed to check init.d service status: %s, output: %s", err, output))
			return err
		}

		if strings.Contains(outputStr, "is running") {
			return nil
		} else {
			return nil
		}

	default:
		postLog.Error(fmt.Sprintf("[IsInstanceRunning] Unsupported init system: %s", initType))
		return nil
	}
}

func GetInstancePid(instanceID int) int {
	initType := GetInitSystem()
	serviceName, err := database.GetServiceNameByInstanceID(instanceID)
	if err != nil {
		postLog.Error(fmt.Sprintf("[GetInstancePid] Failed to get service name: %v", err))
		return 0
	}

	switch initType {
	case "windows":
		cmd := exec.Command("sc", "query", serviceName, "info")
		output, err := cmd.CombinedOutput()
		if err != nil {
			postLog.Error(fmt.Sprintf("[GetInstancePid] Failed to get Windows service info: %s, output: %s", err, output))
			return 0
		}
		outputStr := string(output)
		lines := strings.Split(outputStr, "\n")
		for _, line := range lines {
			if strings.Contains(line, "PID") {
				parts := strings.Split(line, ":")
				if len(parts) >= 2 {
					pidStr := strings.TrimSpace(parts[1])
					pid, err := strconv.Atoi(pidStr)
					if err == nil {
						return pid
					}
				}
			}
		}
		return 0
	case "systemd":
		cmd := exec.Command("systemctl", "show", serviceName, "--property", "MainPID")
		output, err := cmd.CombinedOutput()
		if err != nil {
			postLog.Error(fmt.Sprintf("[GetInstancePid] Failed to get PID from systemd: %s, output: %s", err, output))
			return 0
		}
		outputStr := strings.TrimSpace(string(output))
		parts := strings.Split(outputStr, "=")
		if len(parts) >= 2 {
			pidStr := strings.TrimSpace(parts[1])
			if pidStr != "" && pidStr != "0" {
				pid, err := strconv.Atoi(pidStr)
				if err == nil {
					return pid
				}
			}
		}
		return 0
	case "init.d":
		servicePath := fmt.Sprintf("/etc/init.d/%s", serviceName)
		if _, err := os.Stat(servicePath); err != nil {
			postLog.Error(fmt.Sprintf("[GetInstancePid] Init.d service %s not found", serviceName))
			return 0
		}
		cmd := exec.Command(servicePath, "status")
		output, err := cmd.CombinedOutput()
		if err != nil {
			postLog.Error(fmt.Sprintf("[GetInstancePid] Failed to get init.d service status: %s, output: %s", err, output))
			return 0
		}
		outputStr := strings.TrimSpace(string(output))
		if strings.Contains(outputStr, "is running") {
			if strings.Contains(outputStr, "pid") {
				parts := strings.Split(outputStr, "pid")
				if len(parts) >= 2 {
					pidStr := strings.TrimSpace(strings.Split(parts[1], ")")[0])
					pid, err := strconv.Atoi(pidStr)
					if err == nil {
						return pid
					}
				}
			}
			pidFile := fmt.Sprintf("/var/run/%s.pid", serviceName)
			if content, err := os.ReadFile(pidFile); err == nil {
				pidStr := strings.TrimSpace(string(content))
				pid, err := strconv.Atoi(pidStr)
				if err == nil {
					return pid
				}
			}
		}
		return 0
	default:
		postLog.Error(fmt.Sprintf("[GetInstancePid] Unsupported init system: %s", initType))
		return 0
	}
}

func StartWindowsService(instanceName string) error {
	cmd := exec.Command("sc", "start", instanceName)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to start Windows service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}

func StartSystemdService(instanceName string) error {
	cmd := exec.Command("systemctl", "start", instanceName)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to start systemd service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}

func StartInitDService(instanceName string) error {
	servicePath := fmt.Sprintf("/etc/init.d/%s", instanceName)
	cmd := exec.Command(servicePath, "start")
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to start init.d service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}

func StopWindowsService(instanceName string) error {
	cmd := exec.Command("sc", "stop", instanceName)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to stop Windows service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}

func StopSystemdService(instanceName string) error {
	cmd := exec.Command("systemctl", "stop", instanceName)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to stop systemd service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}

func StopInitDService(instanceName string) error {
	servicePath := fmt.Sprintf("/etc/init.d/%s", instanceName)
	cmd := exec.Command(servicePath, "stop")
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to stop init.d service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}

func RestartWindowsService(instanceName string) error {
	cmd := exec.Command("sc", "restart", instanceName)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to restart Windows service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}

func RestartSystemdService(instanceName string) error {
	cmd := exec.Command("systemctl", "restart", instanceName)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to restart systemd service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}

func RestartInitDService(instanceName string) error {
	servicePath := fmt.Sprintf("/etc/init.d/%s", instanceName)
	cmd := exec.Command(servicePath, "restart")
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("failed to restart init.d service %s: %s, output: %s", instanceName, err, output)
	}
	return nil
}