package main

import (
	"archive/zip"
	"bufio"
	"flag"
	"fmt"
	"io/fs"
	"log"
	"os"
	"path/filepath"
	"strings"
	"sync"
)

var inputDir = flag.String("d", "/", "Dir search")

func appendLineToFile(filename string, line string) error {
	file, err := os.OpenFile(filename, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		return err
	}
	defer file.Close()

	_, err = file.WriteString(line + "\n")
	return err
}

func getAllFiles(root string) ([]string, error) {
	var files []string

	err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if !d.IsDir() {
			files = append(files, path)
		}
		return nil
	})

	return files, err
}

func loadStrings() ([]string, error) {
	log.Println("Loading search.txt")
	var list []string

	file, err := os.Open("search.txt")
	if err != nil {
		return list, err
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := scanner.Text()
		list = append(list, strings.TrimSpace(line))
		log.Println("+", line)
	}

	if err := scanner.Err(); err != nil {
		return list, err
	}

	log.Println("Loaded search.txt")
	return list, nil
}

func checkArchive(zipPath string, list []string) error {
	r, err := zip.OpenReader(zipPath)
	if err != nil {
		return err
	}
	defer r.Close()

	for _, f := range r.File {
		if strings.Contains(f.Name, ".txt") {
			rc, err := f.Open()
			if err != nil {
				continue
			}
			defer rc.Close()

			scanner := bufio.NewScanner(rc)
			for scanner.Scan() {
				line := scanner.Text()
				for _, str := range list {
					if strings.Contains(line, str) {
						log.Println("Found:", line)
						result := fmt.Sprintf("%s;%s", line, zipPath)
						appendLineToFile("result.txt", result)
					}
				}
			}

			if err := scanner.Err(); err != nil {
				continue
			}
		}
	}

	return nil
}

func threadNew(ch chan string, list []string, wg *sync.WaitGroup) {
	for zipPath := range ch {
		log.Println("Check", zipPath)
		checkArchive(zipPath, list)
		wg.Done()
	}
}

func main() {
	var wg sync.WaitGroup

	flag.Parse()
	list, err := loadStrings()
	if err != nil {
		log.Fatalf("fail load search list: %v", err)
	}

	files, err := getAllFiles(*inputDir)
	if err != nil {
		log.Fatalf("fail load files list: %v", err)
	}

	log.Println("Files:", len(files))

	ch := make(chan string)
	for i := 0; i < 10; i++ {
		go threadNew(ch, list, &wg)
	}

	for _, zipPath := range files {
		wg.Add(1)
		ch <- zipPath
	}

	wg.Wait()
}