package main

// Copyright (c) 2025 Robert Strutts <bobs@NewToFaith.com>
// License: MIT
// GIT: https://git.mysnippetsofcode.com/bobs/execguard 

import (
    "execguard/core/alert"
    "execguard/core/configure"
    "execguard/core/rotating_logger"
    "execguard/core/hasher"
    "execguard/core/make_key"
    "execguard/core/monitor_running_bins"
    "execguard/core/new_file_monitor"
    "execguard/core/scanner"
    "execguard/core/sys_database"
	"database/sql"
	"flag"
	"log"
    "strings"
	"os"
    "fmt"
    "time"    
	"path/filepath"
	_ "github.com/mattn/go-sqlite3"
)

const (
	configFileDefault     = "/etc/execguard/config.yaml"
	dbFileDefault         = "/etc/execguard/system.db"
	logFileDefault        = "/var/log/execguard.log"
    mailPathDefault       = "/usr/bin/mail"
    clamscanDefault       = "/usr/bin/clamscan"
    scanIntervalDefault   = 0 // Disabled   
)

var (
    downloadsDefault []string
    downloads []string
    configFile string
    dbFile string
    logFile string
    mailPath string
    clamscanPath string
    scanIntervalFlag int
    downloadsFlag string
    configFlag string
    dbFlag string
    logFlag string
    mailFlag string
    clamscanFlag string
    initMode bool
    enforceMode bool
    initFile string
    updateFile string
    migrateMode bool
    newKey bool
    dirs []string
    scanInterval int
    config *configure.Config
)

func main() {
    var err error
    
    flag.IntVar(&scanIntervalFlag, "scanDelayMinutes", 99, "0 disables scanner")
    flag.StringVar(&downloadsFlag, "downloads", "none", "use specified Downloads folders comma-seperated list")
    flag.StringVar(&configFlag, "config", "", "use specified file for config")
    flag.StringVar(&dbFlag, "db", "", "use specified file for database")
    flag.StringVar(&logFlag, "log", "", "use specified file for Logging")
    flag.StringVar(&mailFlag, "mail", "", "use specified file for Mail sending")
    flag.StringVar(&clamscanFlag, "scanner", "", "use specified binary for Virus Scanning")
	flag.BoolVar(&initMode, "init", false, "initialize and populate allowed executable database")
	flag.BoolVar(&enforceMode, "enforce", false, "enforce policies from Database Lock-down...")
	flag.StringVar(&initFile, "initFile", "", "file containing files to add to allowed database with hash")
    flag.StringVar(&updateFile, "update", "", "add specified file to allowed database with hash")
    flag.BoolVar(&migrateMode, "migrate", false, "recompute hashes of all allowed paths using current settings")
    flag.BoolVar(&newKey, "newKey", false, "generate a new XXTEA-compatible encryption key")
	flag.Parse()

    if newKey {
        if make_key.Make_a_key() {
            return
        } else {
            os.Exit(1) // Exit with status code 1
        }
    }

	if os.Geteuid() != 0 {
		fmt.Printf("This program must be run as root")
        os.Exit(1) // Exit with status code 1
	}
    
    scanner.SetModes(initMode, initFile, updateFile, migrateMode)
    monitor_running_bins.SetModes(initMode, initFile, updateFile, migrateMode)
    sys_database.SetModes(initMode, initFile, updateFile, migrateMode)
    
    if configFlag != "" {
       configFile = configFlag
    } else {
       configFile = configFileDefault
   }    

    if logFlag != "" {
       logFile = logFlag
    } else {
       logFile = logFileDefault
    }

	config, err := configure.LoadConfig(configFile, logFile)
	if err != nil {
		fmt.Printf("Error loading config: %v", err)
        os.Exit(3) // Exit with status code 3
	}
    
    hasher.SetGlobalConfig(*config)
    alert.SetGlobalConfig(*config)
    monitor_running_bins.SetGlobalConfig(*config)
    scanner.SetGlobalConfig(*config)
    
    // Set Vars...arguemtns first, then config, then defaults
    if dbFlag != "" {
       dbFile = dbFlag
    } else if config.DbFile != "" {
       dbFile = config.DbFile
    } else {
       dbFile = dbFileDefault     
    }

    if mailFlag != "" {
       mailPath = mailFlag
    } else if config.MailProg != "" {
       mailPath = config.MailProg
    } else {        
       mailPath = mailPathDefault 
    }

    alert.SetGlobalMail(mailPath)
    
    if clamscanFlag != "" {
       clamscanPath = clamscanFlag
    } else if config.ScannerProg != "" {
       clamscanPath = config.ScannerProg
    } else {
       clamscanPath = clamscanDefault 
    }
    
    if scanIntervalFlag != 99 {
        scanInterval = scanIntervalFlag
    } else if config.ScanInterval != 99 {
        scanInterval = config.ScanInterval
    } else {    
        scanInterval = scanIntervalDefault   
    }
    
    if downloadsFlag != "none" {
        downloads = strings.Split(downloadsFlag, ",")
    }
        
	if len(downloads) > 0 {
        dirs = downloads
    } else if len(config.Downloads) > 0 {
        dirs = config.Downloads
    } else {    
		dirs = downloadsDefault
	}

	rl, err := rotating_logger.NewRotatingLogger(config.Logging)
	if err != nil {
		fmt.Printf("Failed to initialize logger: %v", err)
	}
	defer rl.Close()

	logger := log.New(rl, "", 0)
	logger.SetPrefix(fmt.Sprintf("[%s] ", time.Now().Format(config.Logging.TimestampFormat)))

	db, err := sql.Open("sqlite3", dbFile)
	if err != nil {
		logger.Fatalf("Error opening database: %v", err)
        os.Exit(2) // Exit with status code 2
	}
	defer db.Close()

	sys_database.CreateTable(db, logger)

    if initFile != "" {
		absPath, err := filepath.Abs(initFile)
		if err != nil {
			logger.Fatalf("Invalid init file path: %v", err)
            os.Exit(1) // Exit with status code 1
		}
        sys_database.RunInit(db, logger, absPath)
        return
    }

	if updateFile != "" {
		absPath, err := filepath.Abs(updateFile)
		if err != nil {
			logger.Fatalf("Invalid update file path: %v", err)
            os.Exit(1) // Exit with status code 1
		}
		sys_database.AddToAllowed(db, logger, absPath)
		logger.Printf("Added to allowed list: %s", absPath)
		return
	}
    
    if migrateMode {
		sys_database.RunMigration(db, logger)
		return
	}
    
    if scanInterval > 0 {
        go func() {
            defer func() {
                if r := recover(); r != nil {
                    logger.Printf("Recovered from scan panic: %v", r)
                }
            }()
            scanner.PeriodicScan(config.ProtectedDirs, db, logger, mailPath, scanInterval)
        }()
    }
    
    if len(dirs) > 0 {
        go new_file_monitor.Monitor_new_files(dirs, db, logger, clamscanPath)
    }

	if err := monitor_running_bins.MonitorExecutions(db, logger, mailPath); err != nil {
		logger.Fatalf("Execution monitoring failed: %v", err)
        os.Exit(4) // Exit with status code 4
	}
}