From bb10bb200c74865832648f1ff771795444a37b1f Mon Sep 17 00:00:00 2001
From: Steven <stevenlgtm@gmail.com>
Date: Sat, 30 Mar 2024 13:50:18 +0800
Subject: [PATCH] chore: implement search random memos

---
 server/route/api/v2/memo_service.go | 23 ++++++++++++++++++++---
 store/db/mysql/memo.go              |  3 +++
 store/db/postgres/memo.go           |  3 +++
 store/db/sqlite/memo.go             | 15 +++++++++------
 store/memo.go                       |  1 +
 5 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/server/route/api/v2/memo_service.go b/server/route/api/v2/memo_service.go
index c9173583..bba8a887 100644
--- a/server/route/api/v2/memo_service.go
+++ b/server/route/api/v2/memo_service.go
@@ -134,16 +134,17 @@ func (s *APIV2Service) ListMemos(ctx context.Context, request *apiv2pb.ListMemos
 }
 
 func (s *APIV2Service) SearchMemos(ctx context.Context, request *apiv2pb.SearchMemosRequest) (*apiv2pb.SearchMemosResponse, error) {
+	defaultSearchLimit := 10
 	memoFind := &store.FindMemo{
 		// Exclude comments by default.
 		ExcludeComments: true,
+		Limit:           &defaultSearchLimit,
 	}
-	if err := s.buildMemoFindWithFilter(ctx, memoFind, request.Filter); err != nil {
+	err := s.buildMemoFindWithFilter(ctx, memoFind, request.Filter)
+	if err != nil {
 		return nil, status.Errorf(codes.InvalidArgument, "failed to build find memos with filter")
 	}
 
-	defaultSearchLimit := 10
-	memoFind.Limit = &defaultSearchLimit
 	memos, err := s.Store.ListMemos(ctx, memoFind)
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "failed to search memos")
@@ -696,6 +697,12 @@ func (s *APIV2Service) buildMemoFindWithFilter(ctx context.Context, find *store.
 		if filter.RowStatus != nil {
 			find.RowStatus = filter.RowStatus
 		}
+		if filter.Random {
+			find.Random = filter.Random
+		}
+		if filter.Limit != nil {
+			find.Limit = filter.Limit
+		}
 	}
 
 	// If the user is not authenticated, only public memos are visible.
@@ -730,6 +737,8 @@ var SearchMemosFilterCELAttributes = []cel.EnvOption{
 	cel.Variable("creator", cel.StringType),
 	cel.Variable("uid", cel.StringType),
 	cel.Variable("row_status", cel.StringType),
+	cel.Variable("random", cel.BoolType),
+	cel.Variable("limit", cel.IntType),
 }
 
 type SearchMemosFilter struct {
@@ -741,6 +750,8 @@ type SearchMemosFilter struct {
 	Creator           *string
 	UID               *string
 	RowStatus         *store.RowStatus
+	Random            bool
+	Limit             *int
 }
 
 func parseSearchMemosFilter(expression string) (*SearchMemosFilter, error) {
@@ -798,6 +809,12 @@ func findSearchMemosField(callExpr *expr.Expr_Call, filter *SearchMemosFilter) {
 			} else if idExpr.Name == "row_status" {
 				rowStatus := store.RowStatus(callExpr.Args[1].GetConstExpr().GetStringValue())
 				filter.RowStatus = &rowStatus
+			} else if idExpr.Name == "random" {
+				value := callExpr.Args[1].GetConstExpr().GetBoolValue()
+				filter.Random = value
+			} else if idExpr.Name == "limit" {
+				limit := int(callExpr.Args[1].GetConstExpr().GetInt64Value())
+				filter.Limit = &limit
 			}
 			return
 		}
diff --git a/store/db/mysql/memo.go b/store/db/mysql/memo.go
index 4ed837d4..33b95b33 100644
--- a/store/db/mysql/memo.go
+++ b/store/db/mysql/memo.go
@@ -91,6 +91,9 @@ func (d *DB) ListMemos(ctx context.Context, find *store.FindMemo) ([]*store.Memo
 		orders = append(orders, "`created_ts` DESC")
 	}
 	orders = append(orders, "`id` DESC")
+	if find.Random {
+		orders = append(orders, "RAND()")
+	}
 
 	fields := []string{
 		"`memo`.`id` AS `id`",
diff --git a/store/db/postgres/memo.go b/store/db/postgres/memo.go
index bfae66eb..a4284ae5 100644
--- a/store/db/postgres/memo.go
+++ b/store/db/postgres/memo.go
@@ -82,6 +82,9 @@ func (d *DB) ListMemos(ctx context.Context, find *store.FindMemo) ([]*store.Memo
 		orders = append(orders, "created_ts DESC")
 	}
 	orders = append(orders, "id DESC")
+	if find.Random {
+		orders = append(orders, "RAND()")
+	}
 
 	fields := []string{
 		`memo.id AS id`,
diff --git a/store/db/sqlite/memo.go b/store/db/sqlite/memo.go
index 38b63318..a00b941c 100644
--- a/store/db/sqlite/memo.go
+++ b/store/db/sqlite/memo.go
@@ -71,16 +71,19 @@ func (d *DB) ListMemos(ctx context.Context, find *store.FindMemo) ([]*store.Memo
 		where = append(where, "`parent_id` IS NULL")
 	}
 
-	orders := []string{}
+	orderBy := []string{}
 	if find.OrderByPinned {
-		orders = append(orders, "`pinned` DESC")
+		orderBy = append(orderBy, "`pinned` DESC")
 	}
 	if find.OrderByUpdatedTs {
-		orders = append(orders, "`updated_ts` DESC")
+		orderBy = append(orderBy, "`updated_ts` DESC")
 	} else {
-		orders = append(orders, "`created_ts` DESC")
+		orderBy = append(orderBy, "`created_ts` DESC")
+	}
+	orderBy = append(orderBy, "`id` DESC")
+	if find.Random {
+		orderBy = []string{"RANDOM()"}
 	}
-	orders = append(orders, "`id` DESC")
 
 	fields := []string{
 		"`memo`.`id` AS `id`",
@@ -101,7 +104,7 @@ func (d *DB) ListMemos(ctx context.Context, find *store.FindMemo) ([]*store.Memo
 		"LEFT JOIN `memo_organizer` ON `memo`.`id` = `memo_organizer`.`memo_id` AND `memo`.`creator_id` = `memo_organizer`.`user_id` " +
 		"LEFT JOIN `memo_relation` ON `memo`.`id` = `memo_relation`.`memo_id` AND `memo_relation`.`type` = \"COMMENT\" " +
 		"WHERE " + strings.Join(where, " AND ") + " " +
-		"ORDER BY " + strings.Join(orders, ", ")
+		"ORDER BY " + strings.Join(orderBy, ", ")
 	if find.Limit != nil {
 		query = fmt.Sprintf("%s LIMIT %d", query, *find.Limit)
 		if find.Offset != nil {
diff --git a/store/memo.go b/store/memo.go
index 77c6985b..5de413b9 100644
--- a/store/memo.go
+++ b/store/memo.go
@@ -69,6 +69,7 @@ type FindMemo struct {
 	VisibilityList  []Visibility
 	ExcludeContent  bool
 	ExcludeComments bool
+	Random          bool
 
 	// Pagination
 	Limit            *int