Add full-text search for recipe titles

backend/sql/version_1.sql

@@ -42,7 +42,7 @@ CREATE TABLE [User] (
     )
 ) STRICT;
 
-CREATE INDEX [validation_token_index] ON [User]([validation_token]);
+CREATE INDEX [User_validation_token_index] ON [User]([validation_token]);
 CREATE UNIQUE INDEX [User_email_index] ON [User]([email]);
 
 CREATE TABLE [UserLoginToken] (
@@ -93,6 +93,29 @@ CREATE TABLE [Recipe] (
     FOREIGN KEY([user_id]) REFERENCES [User]([id]) ON DELETE SET NULL
 ) STRICT;
 
+CREATE VIRTUAL TABLE [RecipeTitle] USING FTS5(
+    [title],
+    CONTENT = [Recipe],
+    CONTENT_ROWID = [id]
+);
+
+CREATE TRIGGER [Recipe_trigger_insert] AFTER INSERT ON [Recipe] BEGIN
+    INSERT INTO [RecipeTitle]([rowid], [title])
+    VALUES (NEW.[id], NEW.[title]);
+END;
+
+CREATE TRIGGER [Recipe_trigger_delete] AFTER DELETE ON [Recipe] BEGIN
+    INSERT INTO [RecipeTitle]([RecipeTitle], [rowid], [title])
+    VALUES ('delete', OLD.[id], OLD.[title]);
+END;
+
+CREATE TRIGGER [Recipe_trigger_update] AFTER UPDATE ON [Recipe] BEGIN
+    INSERT INTO [RecipeTitle]([RecipeTitle], [rowid], [title])
+    VALUES ('delete', OLD.[id], OLD.[title]);
+
+    INSERT INTO [RecipeTitle]([rowid], [title]) VALUES (NEW.[id], NEW.[title]);
+END;
+
 CREATE TABLE [Image] (
     [id] INTEGER PRIMARY KEY,
     [recipe_id] INTEGER NOT NULL,

backend/src/data/db/recipe.rs

@@ -263,7 +263,8 @@ WHERE [id] = $1 AND ([user_id] = $2 OR (SELECT [is_admin] FROM [User] WHERE [id]
             r#"
 SELECT
     [id], [user_id], [title], [lang],
-    [estimated_time], [description], [difficulty], [servings], [is_public]
+    [estimated_time], [description], [difficulty], [servings],
+    [is_public]
 FROM [Recipe] WHERE [id] = $1
             "#,
         )
@@ -280,6 +281,29 @@ FROM [Recipe] WHERE [id] = $1
         }
     }
 
+    /// Search for recipes matching the given term in the recipe title.
+    /// The search term follows the syntax described here: <https://sqlite.org/fts5.html>.
+    pub async fn search_recipes(
+        &self,
+        lang: &str,
+        term: &str,
+    ) -> Result<Vec<model::RecipeSearchResult>> {
+        sqlx::query_as(
+            r#"
+SELECT [id], [recipe].[title], highlight([RecipeTitle], 0, '<em>', '</em>') [title_highlighted]
+FROM [RecipeTitle]
+INNER JOIN [Recipe] ON [Recipe].[id] = [RecipeTitle].[rowid]
+WHERE [Recipe].[lang] = $1 AND [RecipeTitle] MATCH $2
+ORDER BY RANK, [Recipe].[title]
+            "#,
+        )
+        .bind(lang)
+        .bind(term)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(DBError::from)
+    }
+
     pub async fn create_recipe(&self, user_id: i64) -> Result<i64> {
         let mut tx = self.tx().await?;
 
@@ -970,6 +994,72 @@ mod tests {
         Ok(())
     }
 
+    #[tokio::test]
+    async fn create_some_recipes_then_search_them_by_title() -> Result<()> {
+        let connection = Connection::new_in_memory().await?;
+
+        let user_id = create_a_user(&connection).await?;
+
+        async fn add_recipe(connection: &Connection, user_id: i64, title: &str) -> Result<i64> {
+            let recipe_id = connection.create_recipe(user_id).await?;
+            connection.set_recipe_title(recipe_id, title).await?;
+            Ok(recipe_id)
+        }
+
+        let id1 = add_recipe(&connection, user_id, "AAA yyy CCC").await?;
+        let id2 = add_recipe(&connection, user_id, "XXX yyy ZZZ").await?;
+        let id3 = add_recipe(&connection, user_id, "AAA ZZZ").await?;
+
+        {
+            let recipes = connection.search_recipes("en", "yyy").await?;
+
+            assert_eq!(recipes.len(), 2);
+
+            assert_eq!(recipes[0].id, id1);
+            assert_eq!(recipes[0].title, "AAA yyy CCC".to_string());
+            assert_eq!(
+                recipes[0].title_highlighted,
+                "AAA <em>yyy</em> CCC".to_string()
+            );
+
+            assert_eq!(recipes[1].id, id2);
+            assert_eq!(recipes[1].title, "XXX yyy ZZZ".to_string());
+            assert_eq!(
+                recipes[1].title_highlighted,
+                "XXX <em>yyy</em> ZZZ".to_string()
+            );
+        }
+
+        {
+            let recipes = connection.search_recipes("en", "aaa OR zzz").await?;
+
+            assert_eq!(recipes.len(), 3);
+
+            assert_eq!(recipes[0].id, id3);
+            assert_eq!(recipes[0].title, "AAA ZZZ".to_string());
+            assert_eq!(
+                recipes[0].title_highlighted,
+                "<em>AAA</em> <em>ZZZ</em>".to_string()
+            );
+
+            assert_eq!(recipes[1].id, id1);
+            assert_eq!(recipes[1].title, "AAA yyy CCC".to_string());
+            assert_eq!(
+                recipes[1].title_highlighted,
+                "<em>AAA</em> yyy CCC".to_string()
+            );
+
+            assert_eq!(recipes[2].id, id2);
+            assert_eq!(recipes[2].title, "XXX yyy ZZZ".to_string());
+            assert_eq!(
+                recipes[2].title_highlighted,
+                "XXX yyy <em>ZZZ</em>".to_string()
+            );
+        }
+
+        Ok(())
+    }
+
     #[tokio::test]
     async fn setters() -> Result<()> {
         let connection = Connection::new_in_memory().await?;

backend/src/data/model.rs

@@ -51,6 +51,13 @@ pub struct Recipe {
     pub groups: Vec<Group>,
 }
 
+#[derive(Debug, FromRow)]
+pub struct RecipeSearchResult {
+    pub id: i64,
+    pub title: String,
+    pub title_highlighted: String,
+}
+
 #[derive(Debug, FromRow)]
 pub struct Group {
     pub id: i64,