Initial model + some various changes

backend/src/db.rs

@@ -1,27 +1,24 @@
-use std::path::Path;
-use std::fs;
-
-//use rusqlite::types::ToSql;
-//use rusqlite::{Connection, Result, NO_PARAMS};
-
-//extern crate r2d2;
-//extern crate r2d2_sqlite;
-//extern crate rusqlite;
-
-use r2d2_sqlite::SqliteConnectionManager;
-use r2d2::Pool;
-
-#[derive(Debug)]
-pub enum DbError {
-    SqliteError(rusqlite::Error),
-    R2d2Error(r2d2::Error),
-    UnsupportedVersion(i32),
-}
+use crate::consts::SQL_FILENAME;
 
 use super::consts;
 
+use std::{fs::{self, File}, path::Path, io::Read};
+
+//use rusqlite::types::ToSql;
+//use rusqlite::{Connection, Result, NO_PARAMS};
+use r2d2::Pool;
+use r2d2_sqlite::SqliteConnectionManager;
+
 const CURRENT_DB_VERSION: u32 = 1;
 
+#[derive(Debug)]
+pub enum DBError {
+    SqliteError(rusqlite::Error),
+    R2d2Error(r2d2::Error),
+    UnsupportedVersion(u32),
+    Other(String),
+}
+
 pub struct Connection {
     //con: rusqlite::Connection
     pool: Pool<SqliteConnectionManager>
@@ -32,20 +29,20 @@ pub struct Recipe {
     pub id: i32,
 }
 
-impl std::convert::From<rusqlite::Error> for DbError  {
+impl std::convert::From<rusqlite::Error> for DBError  {
     fn from(error: rusqlite::Error) -> Self {
-        DbError::SqliteError(error)
+        DBError::SqliteError(error)
     }
 }
 
-impl std::convert::From<r2d2::Error> for DbError  {
+impl std::convert::From<r2d2::Error> for DBError  {
     fn from(error: r2d2::Error) -> Self {
-        DbError::R2d2Error(error)
+        DBError::R2d2Error(error)
     }
 }
 
 impl Connection {
-    pub fn new() -> Result<Connection, DbError> {
+    pub fn new() -> Result<Connection, DBError> {
 
         let data_dir = Path::new(consts::DB_DIRECTORY);
 
@@ -53,7 +50,7 @@ impl Connection {
             fs::DirBuilder::new().create(data_dir).unwrap();
         }
 
-        let manager = SqliteConnectionManager::file("file.db");
+        let manager = SqliteConnectionManager::file(consts::DB_FILENAME);
         let pool = r2d2::Pool::new(manager).unwrap();
 
         let connection = Connection { pool };
@@ -65,7 +62,7 @@ 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> {
+    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();
@@ -74,13 +71,14 @@ impl Connection {
         let mut con = self.pool.get()?;
         let tx = con.transaction()?;
 
+        // Version 0 corresponds to an empty database.
         let mut version = {
             match tx.query_row(
                     "SELECT [name] FROM [sqlite_master] WHERE [type] = 'table' AND [name] = 'Version'",
-                        rusqlite::NO_PARAMS,
+                        [],
                         |row| row.get::<usize, String>(0)
                     ) {
-                Ok(_) => tx.query_row("SELECT [version] FROM [Version]", rusqlite::NO_PARAMS, |row| row.get(0)).unwrap_or_default(),
+                Ok(_) => tx.query_row("SELECT [version] FROM [Version]", [], |row| row.get(0)).unwrap_or_default(),
                 Err(_) => 0
             }
         };
@@ -94,49 +92,45 @@ impl Connection {
         Ok(())
     }
 
-    fn update_to_next_version(version: i32, tx: &rusqlite::Transaction) -> Result<bool, DbError> {
-        match version {
-            0 => {
-                println!("Update to version 1...");
+    fn update_to_next_version(current_version: u32, tx: &rusqlite::Transaction) -> Result<bool, DBError> {
+        let next_version = current_version + 1;
 
-                // Initial structure.
-                tx.execute_batch(
-                    "
-                    CREATE TABLE [Version] (
-                        [id] INTEGER PRIMARY KEY,
-                        [version] INTEGER NOT NULL UNIQUE,
-                        [datetime] INTEGER DATETIME
-                    );
+        if next_version <= CURRENT_DB_VERSION {
+            println!("Update to version {}...", next_version);
+        }
 
-                    CREATE TABLE [Recipe] (
-                        [id] INTEGER PRIMARY KEY,
-                        [title] INTEGER NOT NULL,
-                        [description] INTEGER DATETIME
-                    );
-                    "
-                )?;
+        fn ok(updated: bool) -> Result<bool, DBError> {
+            if updated {
+                println!("Version updated");
+            }
+            Ok(updated)
+        }
 
-                /*
-                tx.execute(
-                    "
-                    INSERT INTO Version
-                    ",
-                    rusqlite::NO_PARAMS
-                );*/
+        match next_version {
+            1 => {
+                tx.execute_batch(&load_sql_file(next_version)?)?;
 
-                Ok(true)
+                ok(true)
             }
 
-            // Current version.
-            1 =>
-                Ok(false),
+            // Version 1 doesn't exist yet.
+            2 =>
+                ok(false),
 
             v =>
-                Err(DbError::UnsupportedVersion(v)),
+                Err(DBError::UnsupportedVersion(v)),
         }
     }
 
     pub fn get_all_recipes() {
 
     }
+}
+
+fn load_sql_file(version: u32) -> Result<String, DBError> {
+    let sql_file = 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())))?;
+    Ok(sql)
 }