package notes

import (
	"bufio"
	"errors"
	"local/notes-server/filetree"
	"log"
	"os"
	"path"
	"path/filepath"
	"regexp"
	"strings"
)

type searcher struct {
	patterns []*regexp.Regexp
}

func newSearcher(phrase string) (*searcher, error) {
	phrases := strings.Split(phrase, " ")
	patterns := make([]*regexp.Regexp, 0)
	for _, phrase := range phrases {
		if len(phrase) == 0 {
			continue
		}
		pattern, err := regexp.Compile("(?i)" + phrase)
		if err != nil {
			return nil, err
		}
		patterns = append(patterns, pattern)
	}
	if len(patterns) < 1 {
		return nil, errors.New("no search specified")
	}
	return &searcher{
		patterns: patterns,
	}, nil
}

func (s *searcher) matches(input []byte) bool {
	for _, pattern := range s.patterns {
		if !pattern.Match(input) {
			return false
		}
	}
	return true
}

func (n *Notes) Search(phrase string) (string, error) {
	searcher, err := newSearcher(phrase)
	if err != nil {
		return "", err
	}
	files := filetree.NewFiles()
	err = filepath.Walk(n.root,
		func(walked string, info os.FileInfo, err error) error {
			if err != nil {
				return err
			}
			if info.IsDir() {
				return nil
			}
			if size := info.Size(); size < 1 || size > (5*1024*1024) {
				return nil
			}
			ok, err := grepFile(walked, searcher)
			if err != nil && err.Error() == "bufio.Scanner: token too long" {
				err = nil
			}
			if err == nil && ok {
				p := filetree.NewPathFromLocal(path.Dir(walked))
				files.Push(p, info)
			}
			if err != nil {
				log.Printf("failed to scan %v: %v", walked, err)
			}
			return err
		},
	)
	return filetree.Paths(*files).List(true), err
}

func grepFile(file string, searcher *searcher) (bool, error) {
	if d := path.Base(path.Dir(file)); strings.HasPrefix(d, ".") && strings.HasSuffix(d, ".attachments") {
		return false, nil
	}
	if strings.Contains(file, "/.git/") {
		return false, nil
	}
	f, err := os.Open(file)
	if err != nil {
		return false, err
	}
	defer f.Close()
	scanner := bufio.NewScanner(f)
	for scanner.Scan() {
		if searcher.matches(scanner.Bytes()) {
			return true, scanner.Err()
		}
	}
	return false, scanner.Err()
}