perf(pr): read the pull request template with one request

Signed-off-by: bircni <bircni@icloud.com>

internal/services/pulls.go

@@ -15,6 +15,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	gitea "gitea.dev/sdk"
@@ -474,20 +475,42 @@ var pullTemplatePaths = []string{
 const maxPullTemplateBytes = 1 << 20
 
 // Template returns the first pull request template found at ref, or "" when the repository has none.
+// All paths are probed concurrently; the result is decided in priority order, so a failure is
+// reported only when every higher-priority path is missing.
 func (s Pulls) Template(ctx context.Context, ref string) (string, error) {
-	for _, path := range pullTemplatePaths {
-		file, err := repoCall(ctx, s.Client, s.Repository, func(ctx context.Context, c *gitea.Client, owner, name string) (io.ReadCloser, *gitea.Response, error) {
-			return c.Repositories.GetFileReader(ctx, owner, name, ref, path)
+	type probe struct {
+		content string
+		missing bool
+		err     error
+	}
+	probes := make([]probe, len(pullTemplatePaths))
+	var wg sync.WaitGroup
+	for i, path := range pullTemplatePaths {
+		wg.Go(func() {
+			probes[i].content, probes[i].missing, probes[i].err = s.templateAt(ctx, ref, path)
 		})
-		if err != nil {
-			if IsNotFound(err) {
-				continue
-			}
-			return "", err
+	}
+	wg.Wait()
+	for _, p := range probes {
+		if !p.missing {
+			return p.content, p.err
 		}
-		data, err := io.ReadAll(io.LimitReader(file, maxPullTemplateBytes))
-		_ = file.Close()
-		return string(data), err
 	}
 	return "", nil
 }
+
+// templateAt reads one template path; missing reports a 404.
+func (s Pulls) templateAt(ctx context.Context, ref, path string) (content string, missing bool, err error) {
+	file, err := repoCall(ctx, s.Client, s.Repository, func(ctx context.Context, c *gitea.Client, owner, name string) (io.ReadCloser, *gitea.Response, error) {
+		return c.Repositories.GetFileReader(ctx, owner, name, ref, path)
+	})
+	if err != nil {
+		if IsNotFound(err) {
+			return "", true, nil
+		}
+		return "", false, err
+	}
+	data, err := io.ReadAll(io.LimitReader(file, maxPullTemplateBytes))
+	_ = file.Close()
+	return string(data), false, err
+}