package main

import (
	e "codeberg.org/pebbe/errors"

	"bufio"
	"os"
	"regexp"
	"strings"
)

var (
	x      = e.ExitErr
	reFile = regexp.MustCompile(`(.*)(2[0-9][0-9][0-9]\.[0-5][0-9])(.*)`)
	seen   = make(map[string]bool)
)

func main() {

	m := reFile.FindStringSubmatch(os.Args[1])
	infile := m[0]
	prefix := m[1]
	suffix := m[3] + ".t20"
	target := infile + ".t20"

	dirs, err := os.ReadDir("..")
	x(err)
	for _, dir := range dirs {
		if !dir.IsDir() {
			continue
		}
		dirname := dir.Name()
		if dirname[0] != '2' {
			continue
		}
		files, err := os.ReadDir("../" + dirname)
		x(err)
		for _, file := range files {
			name := file.Name()
			if strings.HasPrefix(name, prefix) && strings.HasSuffix(name, suffix) && name < target {
				fp, err := os.Open("../" + dirname + "/" + name)
				x(err)
				scanner := bufio.NewScanner(fp)
				for scanner.Scan() {
					seen[strings.Split(scanner.Text(), "\t")[1]] = true
				}
				x(scanner.Err())
				x(fp.Close())
			}
		}
	}

	fpin, err := os.Open(infile)
	x(err)
	fpout, err := os.Create(target)
	x(err)
	scanner := bufio.NewScanner(fpin)
	n := 0
	for scanner.Scan() && n < 20 {
		line := scanner.Text()
		w := strings.Split(line, "\t")[1]
		if seen[w] {
			continue
		}
		n++
		x(fpout.WriteString(line + "\n"))
	}
	x(scanner.Err())
	x(fpout.Close())
	x(fpin.Close())
}