Refactor authors dropdown (send get request from frontend to avoid long wait time) (#23890)

Right now the authors search dropdown might take a long time to load if
amount of authors is huge.
Example: (In the video below, there are about 10000 authors, and it
takes about 10 seconds to open the author dropdown)

https://user-images.githubusercontent.com/17645053/229422229-98aa9656-3439-4f8c-9f4e-83bd8e2a2557.mov

Possible improvements can be made, which will take 2 steps (Thanks to
@wolfogre for advice):

Step 1：
Backend: Add a new api, which returns a limit of 30 posters with matched
prefix.
Frontend: Change the search behavior from frontend search(fomantic
search) to backend search(when input is changed, send a request to get
authors matching the current search prefix)

Step 2：
Backend: Optimize the api in step 1 using indexer to support fuzzy
search.

This PR is implements the first step. The main changes:
1. Added api: `GET /{type:issues|pulls}/posters` , which return a limit
of 30 users with matched prefix (prefix sent as query). If
`DEFAULT_SHOW_FULL_NAME` in `custom/conf/app.ini` is set to true, will
also include fullnames fuzzy search.
2. Added a tooltip saying "Shows a maximum of 30 users" to the author
search dropdown
3. Change the search behavior from frontend search to backend search

After:

https://user-images.githubusercontent.com/17645053/229430960-f88fafd8-fd5d-4f84-9df2-2677539d5d08.mov

Fixes: https://github.com/go-gitea/gitea/issues/22586

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>

1 files changed, 17 insertions, 6 deletions

diff --git a/models/repo/user_repo.go b/models/repo/user_repo.go
index cdb266e014..dd2ef62201 100644
--- a/models/repo/user_repo.go
+++ b/models/repo/user_repo.go
@@ -155,14 +155,25 @@ func GetReviewers(ctx context.Context, repo *Repository, doerID, posterID int64)
 	return users, db.GetEngine(ctx).Where(cond).OrderBy(user_model.GetOrderByName()).Find(&users)
 }
 
-// GetIssuePosters returns all users that have authored an issue/pull request for the given repository
-func GetIssuePosters(ctx context.Context, repo *Repository, isPull bool) ([]*user_model.User, error) {
-	users := make([]*user_model.User, 0, 8)
+// GetIssuePostersWithSearch returns users with limit of 30 whose username started with prefix that have authored an issue/pull request for the given repository
+// If isShowFullName is set to true, also include full name prefix search
+func GetIssuePostersWithSearch(ctx context.Context, repo *Repository, isPull bool, search string, isShowFullName bool) ([]*user_model.User, error) {
+	users := make([]*user_model.User, 0, 30)
+	var prefixCond builder.Cond = builder.Like{"name", search + "%"}
+	if isShowFullName {
+		prefixCond = prefixCond.Or(builder.Like{"full_name", "%" + search + "%"})
+	}
+
 	cond := builder.In("`user`.id",
 		builder.Select("poster_id").From("issue").Where(
 			builder.Eq{"repo_id": repo.ID}.
 				And(builder.Eq{"is_pull": isPull}),
-		).GroupBy("poster_id"),
-	)
-	return users, db.GetEngine(ctx).Where(cond).OrderBy(user_model.GetOrderByName()).Find(&users)
+		).GroupBy("poster_id")).And(prefixCond)
+
+	return users, db.GetEngine(ctx).
+		Where(cond).
+		Cols("id", "name", "full_name", "avatar", "avatar_email", "use_custom_avatar").
+		OrderBy("name").
+		Limit(30).
+		Find(&users)
 }