1 files changed, 192 insertions, 0 deletions
diff --git a/cmd/generate/forge_part_pipermail.go b/cmd/generate/forge_part_pipermail.go
new file mode 100644
index 0000000..af6a009
--- /dev/null
+++ b/cmd/generate/forge_part_pipermail.go
@@ -0,0 +1,192 @@
+package main
+
+import (
+	"compress/gzip"
+	"errors"
+	"fmt"
+	"net/mail"
+	"net/url"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"git.lukeshu.com/www/cmd/generate/mailstuff"
+)
+
+var (
+	rePiperMailMessage = regexp.MustCompile(`^(https?://.*/pipermail/.*/)([0-4]{4}-(?:January|February|March|April|May|June|July|August|September|October|November|December))/([0-9]+)\.html$`)
+	rePiperMailDate    = regexp.MustCompile(`^\s*<I>([^<]+)</I>\s*$`)
+	rePiperMailReply   = regexp.MustCompile(`^\s*<LINK REL="made" HREF="(.*)">\s*$`)
+)
+
+type PartPiperMail struct{}
+
+var _ Forge = PartPiperMail{}
+
+func (PartPiperMail) FetchStatus(urls []string) (string, error) {
+	return "", nil
+}
+
+func (PartPiperMail) FetchSubmittedAt(urls []string) (time.Time, error) {
+	for _, u := range urls {
+		if !rePiperMailMessage.MatchString(u) {
+			continue
+		}
+		htmlStr, err := httpGet(u, nil)
+		if err != nil {
+			return time.Time{}, err
+		}
+		for _, line := range strings.Split(htmlStr, "\n") {
+			if m := rePiperMailDate.FindStringSubmatch(line); m != nil {
+				return time.Parse(time.UnixDate, m[1])
+			}
+		}
+	}
+	return time.Time{}, nil
+}
+
+func (PartPiperMail) nextMonth(ym string) string {
+	yStr, mStr, ok := strings.Cut(ym, "-")
+	if !ok {
+		panic(fmt.Errorf("invalid year-month: %q", ym))
+	}
+	switch mStr {
+	case "January":
+		return yStr + "-February"
+	case "February":
+		return yStr + "-March"
+	case "March":
+		return yStr + "-April"
+	case "April":
+		return yStr + "-May"
+	case "May":
+		return yStr + "-June"
+	case "June":
+		return yStr + "-July"
+	case "July":
+		return yStr + "-August"
+	case "August":
+		return yStr + "-September"
+	case "September":
+		return yStr + "-October"
+	case "October":
+		return yStr + "-November"
+	case "November":
+		return yStr + "-December"
+	case "December":
+		y, _ := strconv.Atoi(yStr)
+		return fmt.Sprintf("%d-January", y+1)
+	default:
+		panic(fmt.Errorf("invalid year-month: %q", ym))
+	}
+}
+
+func (p PartPiperMail) threadLen(thread *mailstuff.ThreadedMessage) int {
+	if thread == nil {
+		return 0
+	}
+
+	ret := 0
+	if thread.Message != nil {
+		ret++
+	}
+	for child := range thread.Children {
+		ret += p.threadLen(child)
+	}
+	return ret
+}
+
+func (p PartPiperMail) FetchLastUpdated(urls []string) (time.Time, User, error) {
+	for _, u := range urls {
+		m := rePiperMailMessage.FindStringSubmatch(u)
+		if m == nil {
+			continue
+		}
+		uBase := m[1]
+		uYM := m[2]
+		//uInt := m[3]
+
+		htmlStr, err := httpGet(u, nil)
+		if err != nil {
+			return time.Time{}, User{}, fmt.Errorf("could not fetch message: %w", err)
+		}
+		var msgid mailstuff.MessageID
+		for _, line := range strings.Split(htmlStr, "\n") {
+			if m := rePiperMailReply.FindStringSubmatch(line); m != nil {
+				ru, err := url.Parse(m[1])
+				if err != nil {
+					continue
+				}
+				if msgid = mailstuff.MessageID(ru.Query().Get("In-Reply-To")); msgid != "" {
+					break
+				}
+			}
+		}
+		if msgid == "" {
+			continue
+		}
+
+		var thread *mailstuff.ThreadedMessage
+		for ym, mbox := uYM, []*mail.Message(nil); true; ym = p.nextMonth(ym) {
+			lenBefore := p.threadLen(thread)
+
+			mboxGzStr, err := httpGet(uBase+ym+".txt.gz", nil)
+			if err != nil {
+				if ym == uYM || !errors.Is(err, os.ErrNotExist) {
+					return time.Time{}, User{}, fmt.Errorf("could not fetch mbox for %s: %w", ym, err)
+				}
+				break
+			}
+			gzReader, err := gzip.NewReader(strings.NewReader(mboxGzStr))
+			if err != nil {
+				return time.Time{}, User{}, fmt.Errorf("could not read mbox gz: %w", err)
+			}
+			_mbox, err := mailstuff.ReadMBox(gzReader)
+			if err != nil {
+				gzReader.Close()
+				return time.Time{}, User{}, fmt.Errorf("could not parse mbox: %w", err)
+			}
+			if err := gzReader.Close(); err != nil {
+				return time.Time{}, User{}, fmt.Errorf("close gz: %w", err)
+			}
+			mbox = append(mbox, _mbox...)
+			_, messages := mailstuff.ThreadMessages(mbox)
+			thread = messages[msgid]
+
+			if p.threadLen(thread) == lenBefore {
+				break
+			}
+		}
+		if thread == nil {
+			continue
+		}
+
+		var retTime time.Time
+		var retUser User
+
+		var walk func(*mailstuff.ThreadedMessage)
+		walk = func(msg *mailstuff.ThreadedMessage) {
+			date, dateErr := msg.Header.Date()
+			froms, fromErr := msg.Header.AddressList("From")
+			if dateErr == nil && fromErr == nil && len(froms) > 0 && (retTime.IsZero() || date.After(retTime)) {
+				retTime = date
+				retUser.Name = froms[0].Name
+				if retUser.Name == "" {
+					retUser.Name = froms[0].Address
+				}
+				retUser.URL = "mailto:" + froms[0].Address
+			}
+			for child := range msg.Children {
+				walk(child)
+			}
+		}
+		walk(thread)
+
+		if !retTime.IsZero() {
+			return retTime, retUser, nil
+		}
+	}
+	return time.Time{}, User{}, nil
+}