imworkingon: Add Gerrit last-updated detection

2 files changed, 93 insertions, 2 deletions

diff --git a/cmd/generate/gerrit.go b/cmd/generate/gerrit.go
new file mode 100644
index 0000000..c8837fc
--- /dev/null
+++ b/cmd/generate/gerrit.go
@@ -0,0 +1,54 @@
+package main
+
+import (
+	"encoding"
+	"encoding/json"
+	"fmt"
+	"strings"
+	"time"
+)
+
+// httpGetGerritJSON is like [httpGetJSON], but
+// https://gerrit-review.googlesource.com/Documentation/rest-api.html#output
+func httpGetGerritJSON(u string, out any) error {
+	str, err := httpGet(u)
+	if err != nil {
+		return err
+	}
+	if _, body, ok := strings.Cut(str, "\n"); ok {
+		str = body
+	}
+	return json.Unmarshal([]byte(str), out)
+}
+
+const GerritTimeFormat = "2006-01-02 15:04:05.000000000"
+
+type GerritTime struct {
+	Val time.Time
+}
+
+var (
+	_ fmt.Stringer             = GerritTime{}
+	_ encoding.TextMarshaler   = GerritTime{}
+	_ encoding.TextUnmarshaler = (*GerritTime)(nil)
+)
+
+// String implements [fmt.Stringer].
+func (t GerritTime) String() string {
+	return t.Val.Format(GerritTimeFormat)
+}
+
+// MarshalText implements [encoding.TextMarshaler].
+func (t GerritTime) MarshalText() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+// UnmarshalText implements [encoding.TextUnmarshaler].
+func (t *GerritTime) UnmarshalText(data []byte) error {
+	val, err := time.Parse(GerritTimeFormat, string(data))
+	if err != nil {
+		return err
+	}
+	t.Val = val
+	return nil
+}
diff --git a/cmd/generate/src_contribs.go b/cmd/generate/src_contribs.go
index f22f721..eb9d9ad 100644
--- a/cmd/generate/src_contribs.go
+++ b/cmd/generate/src_contribs.go
@@ -75,7 +75,7 @@ func (c *Contribution) Fill() error {
 	}
 	for _, u := range c.URLs {
 		if m := reGoLangGerritCL.FindStringSubmatch(u); m != nil {
-			c.URLs = append(c.URLs, "https://golang.org/cl/"+m[1])
+			c.URLs = append(c.URLs, "https://golang.org/cl/"+m[2])
 		}
 	}
 	return nil
@@ -97,7 +97,7 @@ func classifyStatus(status string) (string, error) {
 }
 
 var (
-	reGoLangGerritCL = regexp.MustCompile(`https://go-review\.googlesource\.com/c/[^/?#]+/\+/([0-9]+)(?:\?[^#]*)?(?:#.*)?$`)
+	reGoLangGerritCL = regexp.MustCompile(`https://go-review\.googlesource\.com/c/([^/?#]+)/\+/([0-9]+)(?:\?[^#]*)?(?:#.*)?$`)
 	reGitHubPR       = regexp.MustCompile(`^https://github\.com/([^/?#]+)/([^/?#]+)/pull/([0-9]+)(?:\?[^#]*)?(?:#.*)?$`)
 	reGitHubCommit   = regexp.MustCompile(`^https://github\.com/([^/?#]+)/([^/?#]+)/commit/([0-9a-f]+)(?:\?[^#]*)?(?:#.*)?$`)
 	reGitLabMR       = regexp.MustCompile(`^https://([^/]+)/([^?#]+)/-/merge_requests/([0-9]+)(?:\?[^#]*)?(?:#.*)?$`)
@@ -259,6 +259,43 @@ func (c Contribution) fetchSubmittedAt() (time.Time, error) {
 }
 
 func (c Contribution) fetchLastUpdated() (time.Time, User, error) {
+	for _, u := range c.URLs {
+		if m := reGoLangGerritCL.FindStringSubmatch(u); m != nil {
+			projectID := m[1]
+			changeID := m[2]
+
+			urlStr := "https://go-review.googlesource.com/changes/" + projectID + "~" + changeID + "?o=MESSAGES&o=DETAILED_ACCOUNTS"
+
+			var obj struct {
+				Updated  GerritTime `json:"updated"`
+				Messages []struct {
+					Author struct {
+						AccountID   int    `json:"_account_id"`
+						Name        string `json:"name"`
+						DisplayName string `json:"display_name"`
+					} `json:"author"`
+					Date GerritTime `json:"date"`
+				} `json:"messages"`
+			}
+			if err := httpGetGerritJSON(urlStr, &obj); err != nil {
+				return time.Time{}, User{}, err
+			}
+			retUpdatedAt := obj.Updated.Val
+			var retUser User
+			for _, message := range obj.Messages {
+				if message.Date.Val == retUpdatedAt {
+					if message.Author.DisplayName != "" {
+						retUser.Name = message.Author.DisplayName
+					} else {
+						retUser.Name = message.Author.Name
+					}
+					retUser.URL = fmt.Sprintf("https://go-review.googlesource.com/dashboard/%d", message.Author.AccountID)
+					break
+				}
+			}
+			return retUpdatedAt, retUser, nil
+		}
+	}
 	if m := reGitHubPR.FindStringSubmatch(c.URLs[0]); m != nil {
 		user := m[1]
 		repo := m[2]