tools: Add snippets tool

Gathers information about changes merged and reviewed for team weekly reports.

Change-Id: I53e3acc45679b4822c506d16980393fbaf337b3b
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/59022
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: James Price <jrprice@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

tools/src/cmd/snippets/main.go

@@ -0,0 +1,112 @@
+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// snippets gathers information about changes merged for weekly reports (snippets).
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+	"time"
+
+	"dawn.googlesource.com/tint/tools/src/gerrit"
+)
+
+const yyyymmdd = "2006-01-02"
+
+var (
+	// See https://dawn-review.googlesource.com/new-password for obtaining
+	// username and password for gerrit.
+	gerritUser = flag.String("gerrit-user", "", "gerrit authentication username")
+	gerritPass = flag.String("gerrit-pass", "", "gerrit authentication password")
+	userFlag   = flag.String("user", "", "user name / email")
+	afterFlag  = flag.String("after", "", "start date")
+	beforeFlag = flag.String("before", "", "end date")
+	daysFlag   = flag.Int("days", 7, "interval in days (used if --after is not specified)")
+)
+
+func main() {
+	flag.Parse()
+	if err := run(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func run() error {
+	var after, before time.Time
+	var err error
+	user := *userFlag
+	if user == "" {
+		return fmt.Errorf("Missing required 'user' flag")
+	}
+	if *beforeFlag != "" {
+		before, err = time.Parse(yyyymmdd, *beforeFlag)
+		if err != nil {
+			return fmt.Errorf("Couldn't parse before date: %w", err)
+		}
+	} else {
+		before = time.Now()
+	}
+	if *afterFlag != "" {
+		after, err = time.Parse(yyyymmdd, *afterFlag)
+		if err != nil {
+			return fmt.Errorf("Couldn't parse after date: %w", err)
+		}
+	} else {
+		after = before.Add(-time.Hour * time.Duration(24**daysFlag))
+	}
+
+	g, err := gerrit.New(gerrit.Config{Username: *gerritUser, Password: *gerritPass})
+	if err != nil {
+		return err
+	}
+
+	submitted, _, err := g.QueryChanges(
+		"status:merged",
+		"owner:"+user,
+		"after:"+date(after),
+		"before:"+date(before))
+	if err != nil {
+		return fmt.Errorf("Query failed: %w", err)
+	}
+
+	changesByProject := map[string][]string{}
+	for _, change := range submitted {
+		str := fmt.Sprintf(`* [%s](%sc/%s/+/%d)`, change.Subject, gerrit.URL, change.Project, change.Number)
+		changesByProject[change.Project] = append(changesByProject[change.Project], str)
+	}
+
+	for _, project := range []string{"tint", "dawn"} {
+		if changes := changesByProject[project]; len(changes) > 0 {
+			fmt.Println("##", strings.Title(project))
+			for _, change := range changes {
+				fmt.Println(change)
+			}
+			fmt.Println()
+		}
+	}
+
+	return nil
+}
+
+func today() time.Time {
+	return time.Now()
+}
+
+func date(t time.Time) string {
+	return t.Format(yyyymmdd)
+}