package distro

import (
	"bufio"
	"fmt"
	"net/http"
	"regexp"
	"strings"
	"sync"
)

const (
	ubuntuMirrorsBaseUrl = "http://mirrors.ubuntu.com"
)

type Ubuntu struct{}

func (d Ubuntu) GetName() string {
	return "ubuntu"
}

func (d Ubuntu) GetRepos() []string {
	return []string{DefaultRepo}
}

func (d Ubuntu) FetchMirrors(repos []string, repoMirrors chan<- RepoMirror, done *sync.WaitGroup) {
	defer done.Done()

	countryMirrorsRe := regexp.MustCompile(`>([A-Z]{2}\.txt)<`)
	re := regexp.MustCompile(`^\S*((https?|ftp)://.*)\S*$`)

	resp, err := http.Get(ubuntuMirrorsBaseUrl)
	if err != nil {
		return
	}
	defer resp.Body.Close()

	if resp.StatusCode == http.StatusOK {
		scanner := bufio.NewScanner(resp.Body)
		for scanner.Scan() {
			line := strings.TrimSpace(scanner.Text())
			m := countryMirrorsRe.FindSubmatch([]byte(line))
			if len(m) > 1 {
				url := fmt.Sprintf("%s/%s", ubuntuMirrorsBaseUrl, string(m[1]))
				done.Add(1)
				go func(u string) {
					defer done.Done()

					resp, err := http.Get(u)
					if err != nil {
						return
					}
					defer resp.Body.Close()

					if resp.StatusCode == http.StatusOK {
						scanner := bufio.NewScanner(resp.Body)
						for scanner.Scan() {
							line := strings.TrimSpace(scanner.Text())
							m := re.FindSubmatch([]byte(line))
							if len(m) > 1 {
								repoMirrors <- RepoMirror{d.GetName(), DefaultRepo, string(m[1])}
							}
						}
					}
				}(url)
			}
		}
	}
}