package main

import (
	"path/filepath"
	"os"
	"database/sql"
	"flag"
	"bufio"
	"fmt"
	"log"
	"strings"
	"strconv"

	_ "github.com/mattn/go-sqlite3"
)

var version = "0.0.1"

func containsSymbol(input string, symbols []string) bool {
	for _, symbol := range symbols {
		if strings.Contains(input, symbol) {
			return true
		}
	}
	return false
}

func main() {
	// Define a command-line flags
	help := flag.Bool("help", false, "print a short usage message")	
	dbPtr := flag.String("db", "./english_words.db", "SQLite3 DB file to use")
	filenamePtr := flag.String("file", "results.txt", "Name of the file to read results from")
	pwdPtr := flag.String("pwd", "", "Enter a password")
	flag.Parse()
	
	if *help {
		usage()
		return
	}
	
	// Open the SQLite3 database file
	db, err := sql.Open("sqlite3", *dbPtr)
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()
	
	// Open the file
	file, err := os.Open(*filenamePtr)
	if err != nil {
		fmt.Println("Error opening file:", err)
		return
	}
	defer file.Close()

	symbols := []string{
		".", ",", "!", ";", "?", "(", ")", "'", "\"", "...", ":", "*", "$", "@", "#", "%",
	}

	// Create a scanner to read the file line by line
	scanner := bufio.NewScanner(file)

	// Loop through each line in the file
	for scanner.Scan() {
		line := scanner.Text()

		// Split the line by spaces
		parts := strings.Fields(line)
		last := ""
		input := ""
		// Process the parsed values (assuming each line has a specific structure)
		for _, part := range parts {
			if strings.Contains(part, "_") {
				result := strings.Replace(part, "_", "", -1)
				if (*pwdPtr != "") {
					input = decompressRLE(xorStringWithPassword(result, *pwdPtr))
				} else {
					input = decompressRLE(xorBy13(result))
				}
				if containsSymbol(input, symbols) {
					last = strings.TrimRight(last, " ") + fmt.Sprintf("%s ", input)
				} else {
					last = last + fmt.Sprintf("%s ", input)
				}
			} else {
				query := "SELECT word FROM words WHERE id = ?"
				rows, err := db.Query(query, part)
				if err != nil {
					log.Fatal(err)
				}
				defer rows.Close()
				if rows.Next() {	
					var word string
					err = rows.Scan(&word)
					if err != nil {
						log.Fatal(err)
					}
					if containsSymbol(word, symbols) {
						last = strings.TrimRight(last, " ") + fmt.Sprintf("%s ", word)
					} else {
						last = last + fmt.Sprintf("%s ", word)
					}
				}		
			}
		}
		fmt.Println(last)
	}

	// Check for errors during scanning
	if err := scanner.Err(); err != nil {
		fmt.Println("Error reading file:", err)
	}	
}

// decompressRLE decompresses a string that has been Run-Length Encoded
func decompressRLE(compressed string) string {
	result := ""

	for i := 0; i < len(compressed); i += 2 {
		char := compressed[i]
		count, err := strconv.Atoi(string(compressed[i+1]))
		if err != nil {
			// Handle error if conversion fails
			fmt.Println("Error converting count to integer:", err)
			return ""
		}

		// Repeat the character count times in the result
		for j := 0; j < count; j++ {
			result += string(char)
		}
	}

	return result
}

func xorStringWithPassword(input string, password string) string {
	inputBytes := []byte(input)
	passwordBytes := []byte(password)

	for i := 0; i < len(inputBytes); i++ {
		inputBytes[i] ^= passwordBytes[i%len(passwordBytes)]
	}

	return string(inputBytes)
}

func xorBy13(input string) string {
	var result strings.Builder

	for _, char := range input {
		xored := char ^ 13
		result.WriteRune(xored)
	}

	return result.String()
}

func usage() {
	progName := filepath.Base(os.Args[0])
	fmt.Printf(`%s version %s, (c) 2024 Bob

Usage:
%s [-help] [-db english_words.db] [-file results.txt] [-pwd MyPassword]

	-db 	SQLite3 DB file to use
	-file	Name of the file to read results from
	-pwd	Enter a password

`, progName, version, progName)
}