Add some data access methods to Connection

backend/src/db.rs

@@ -1,14 +1,14 @@
-use crate::consts::SQL_FILENAME;
-
-use super::consts;
-
 use std::{fs::{self, File}, path::Path, io::Read};
 
+use itertools::Itertools;
 //use rusqlite::types::ToSql;
 //use rusqlite::{Connection, Result, NO_PARAMS};
 use r2d2::Pool;
 use r2d2_sqlite::SqliteConnectionManager;
 
+use crate::consts;
+use crate::model;
+
 const CURRENT_DB_VERSION: u32 = 1;
 
 #[derive(Debug)]
@@ -19,30 +19,28 @@ pub enum DBError {
     Other(String),
 }
 
-pub struct Connection {
-    //con: rusqlite::Connection
-    pool: Pool<SqliteConnectionManager>
-}
-
-pub struct Recipe {
-    pub title: String,
-    pub id: i32,
-}
-
-impl std::convert::From<rusqlite::Error> for DBError  {
+impl From<rusqlite::Error> for DBError  {
     fn from(error: rusqlite::Error) -> Self {
         DBError::SqliteError(error)
     }
 }
 
-impl std::convert::From<r2d2::Error> for DBError  {
+impl From<r2d2::Error> for DBError  {
     fn from(error: r2d2::Error) -> Self {
         DBError::R2d2Error(error)
     }
 }
 
+type Result<T> = std::result::Result<T, DBError>;
+
+#[derive(Clone)]
+pub struct Connection {
+    //con: rusqlite::Connection
+    pool: Pool<SqliteConnectionManager>
+}
+
 impl Connection {
-    pub fn new() -> Result<Connection, DBError> {
+    pub fn new() -> Result<Connection> {
 
         let data_dir = Path::new(consts::DB_DIRECTORY);
 
@@ -62,11 +60,7 @@ impl Connection {
      * Called after the connection has been established for creating or updating the database.
      * The 'Version' table tracks the current state of the database.
      */
-    fn create_or_update(self: &Self) -> Result<(), DBError> {
-        // let connection = Connection::new();
-        // let mut stmt = connection.sqlite_con.prepare("SELECT * FROM versions ORDER BY date").unwrap();
-        // let mut stmt = connection.sqlite_con.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='versions'").unwrap();
-
+    fn create_or_update(&self) -> Result<()> {
         // Check the Database version.
         let mut con = self.pool.get()?;
         let tx = con.transaction()?;
@@ -78,7 +72,7 @@ impl Connection {
                         [],
                         |row| row.get::<usize, String>(0)
                     ) {
-                Ok(_) => tx.query_row("SELECT [version] FROM [Version]", [], |row| row.get(0)).unwrap_or_default(),
+                Ok(_) => tx.query_row("SELECT [version] FROM [Version] ORDER BY [id] DESC", [], |row| row.get(0)).unwrap_or_default(),
                 Err(_) => 0
             }
         };
@@ -92,14 +86,18 @@ impl Connection {
         Ok(())
     }
 
-    fn update_to_next_version(current_version: u32, tx: &rusqlite::Transaction) -> Result<bool, DBError> {
+    fn update_to_next_version(current_version: u32, tx: &rusqlite::Transaction) -> Result<bool> {
         let next_version = current_version + 1;
 
         if next_version <= CURRENT_DB_VERSION {
             println!("Update to version {}...", next_version);
         }
 
-        fn ok(updated: bool) -> Result<bool, DBError> {
+        fn update_version(to_version: u32, tx: &rusqlite::Transaction) -> Result<()> {
+            tx.execute("INSERT INTO [Version] ([version], [datetime]) VALUES (?1, datetime('now'))", [to_version]).map(|_| ()).map_err(DBError::from)
+        }
+
+        fn ok(updated: bool) -> Result<bool> {
             if updated {
                 println!("Version updated");
             }
@@ -109,6 +107,7 @@ impl Connection {
         match next_version {
             1 => {
                 tx.execute_batch(&load_sql_file(next_version)?)?;
+                update_version(next_version, tx)?;
 
                 ok(true)
             }
@@ -122,13 +121,36 @@ impl Connection {
         }
     }
 
-    pub fn get_all_recipes() {
+    pub fn get_all_recipe_titles(&self) -> Result<Vec<(i32, String)>> {
+        let con = self.pool.get()?;
+        let mut stmt = con.prepare("SELECT [id], [title] FROM [Recipe] ORDER BY [title]")?;
+        let titles =
+            stmt.query_map([], |row| {
+                Ok((row.get(0)?, row.get(1)?))
+            })?.map(|r| r.unwrap()).collect_vec(); // TODO: remove unwrap.
+        Ok(titles)
+    }
 
+    pub fn get_all_recipes(&self) -> Result<Vec<model::Recipe>> {
+        let con = self.pool.get()?;
+        let mut stmt = con.prepare("SELECT [id], [title] FROM [Recipe] ORDER BY [title]")?;
+        let recipes =
+            stmt.query_map([], |row| {
+                Ok(model::Recipe::new(row.get(0)?, row.get(1)?))
+            })?.map(|r| r.unwrap()).collect_vec(); // TODO: remove unwrap.
+        Ok(recipes)
+    }
+
+    pub fn get_recipe(&self, id: i32) -> Result<model::Recipe> {
+        let con = self.pool.get()?;
+        con.query_row("SELECT [id], [title] FROM [Recipe] WHERE [id] = ?1", [id], |row| {
+            Ok(model::Recipe::new(row.get(0)?, row.get(1)?))
+        }).map_err(DBError::from)
     }
 }
 
-fn load_sql_file(version: u32) -> Result<String, DBError> {
-    let sql_file = SQL_FILENAME.replace("{VERSION}", &version.to_string());
+fn load_sql_file(version: u32) -> Result<String> {
+    let sql_file = consts::SQL_FILENAME.replace("{VERSION}", &version.to_string());
     let mut file = File::open(&sql_file).map_err(|err| DBError::Other(format!("Cannot open SQL file ({}): {}", &sql_file, err.to_string())))?;
     let mut sql = String::new();
     file.read_to_string(&mut sql).map_err(|err| DBError::Other(format!("Cannot read SQL file ({}) : {}", &sql_file, err.to_string())))?;