package processing

import (
	"fmt"
	"io/fs"
	"path/filepath"

	models "gitea.likemath.ru/alex/gogrep/internal/models"
)

// ChannelBuffering is the size of file processing results queue
const ChannelBuffering = 10

func printGrepResults(processedChannel chan models.FileMatchData, expectedItems int) error {
	for ; expectedItems > 0; expectedItems-- {
		curProcessed := <-processedChannel
		if len(curProcessed.Lines) == 0 {
			continue
		}
		fmt.Printf("%s:\n", curProcessed.Path)
		for i := 0; i < len(curProcessed.Lines); i++ {
			fmt.Printf("%d:%s\n", curProcessed.LineIndexes[i], curProcessed.Lines[i])
		}
		fmt.Print("\n")
	}
	return nil
}

// DoGrepMain performs full grep accorgind to config and root
func DoGrepMain(config *models.GrepConfigInternal, root string) error {
	processedChannel := make(chan models.FileMatchData, ChannelBuffering)
	totalFiles := 0
	err := filepath.Walk(root, func(path string, info fs.FileInfo, err error) error {
		if err != nil {
			fmt.Printf("prevent panic by handling failure accessing a path %q: %v\n", path, err)
			return err
		}
		if config.PathPattern.FindString(path) == "" {
			return nil
		}
		if info.IsDir() {
			return nil
		}
		go ProcessSingleFile(config.TextPattern, path, processedChannel)
		totalFiles++

		return nil
	})
	if err != nil {
		return err
	}
	err = printGrepResults(processedChannel, totalFiles)
	if err != nil {
		return err
	}
	return err
}