From 4ed83bdb017d7d078d7d56863f35b95940988e5b Mon Sep 17 00:00:00 2001
From: Přemysl Eric Janouch <p@janouch.name>
Date: Tue, 12 Dec 2023 06:03:51 +0100
Subject: Rearrange tag importer code

---
 main.go | 33 ++++++++++++++++++++-------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/main.go b/main.go
index 61f089a..ca54ac0 100644
--- a/main.go
+++ b/main.go
@@ -574,7 +574,22 @@ func cmdTag(args []string) error {
 		return err
 	}
 
-	// TODO: Prepare statements for tag/assignment updates.
+	// XXX: It might make sense to pre-erase all tag assignments within
+	// the given space for that image, the first time we see it:
+	//
+	//   DELETE FROM tag_assignment
+	//   WHERE sha1 = ? AND tag IN (SELECT id FROM tag WHERE space = ?)
+	//
+	// or even just clear the tag space completely:
+	//
+	//   DELETE FROM tag_assignment
+	//   WHERE tag IN (SELECT id FROM tag WHERE space = ?)
+	stmt, err := tx.Prepare(`INSERT INTO tag_assignment(sha1, tag, weight)
+		VALUES (?, (SELECT id FROM tag WHERE space = ? AND name = ?), ?)
+		ON CONFLICT DO UPDATE SET weight = ?`)
+	if err != nil {
+		return err
+	}
 
 	scanner := bufio.NewScanner(os.Stdin)
 	for scanner.Scan() {
@@ -589,20 +604,12 @@ func cmdTag(args []string) error {
 			return err
 		}
 
-		if _, err := tx.Exec(`INSERT OR IGNORE INTO tag(space, name)
-			VALUES (?, ?);`, spaceID, tag); err != nil {
+		if _, err := tx.Exec(
+			`INSERT OR IGNORE INTO tag(space, name) VALUES (?, ?);`,
+			spaceID, tag); err != nil {
 			return nil
 		}
-
-		var tagID int64
-		if err := tx.QueryRow(`SELECT id FROM tag WHERE space = ? AND name = ?`,
-			spaceID, tag).Scan(&tagID); err != nil {
-			return err
-		}
-
-		if _, err := tx.Exec(`INSERT INTO tag_assignment(sha1, tag, weight)
-			VALUES (?, ?, ?) ON CONFLICT DO UPDATE SET weight = ?`,
-			sha1, tagID, weight, weight); err != nil {
+		if _, err := stmt.Exec(sha1, spaceID, tag, weight, weight); err != nil {
 			return err
 		}
 	}
-- 
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