X-Git-Url: http://git.euphorik.ch/?a=blobdiff_plain;f=backend%2Fsrc%2Fdb.rs;h=1d38a454f03091e1d1020f1a19001919494aef8b;hb=108476e3554ea3a25dca5b5ab260f38c1e734221;hp=a4a0d9700492903a448af54acafb013d28b6cac5;hpb=e2e54b8f43015738af860b005825dc809f5275ab;p=recipes.git

diff --git a/backend/src/db.rs b/backend/src/db.rs
index a4a0d97..1d38a45 100644
--- a/backend/src/db.rs
+++ b/backend/src/db.rs
@@ -1,21 +1,24 @@
-use std::path::Path;
-use std::fs;
+use crate::consts::SQL_FILENAME;
 
-//use rusqlite::types::ToSql;
-//use rusqlite::{Connection, Result, NO_PARAMS};
+use super::consts;
 
-//extern crate r2d2;
-//extern crate r2d2_sqlite;
-//extern crate rusqlite;
+use std::{fs::{self, File}, path::Path, io::Read};
 
-use r2d2_sqlite::SqliteConnectionManager;
+//use rusqlite::types::ToSql;
+//use rusqlite::{Connection, Result, NO_PARAMS};
 use r2d2::Pool;
-
-
-use super::consts;
+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>
@@ -26,8 +29,20 @@ pub struct Recipe {
     pub id: i32,
 }
 
+impl std::convert::From<rusqlite::Error> for DBError  {
+    fn from(error: rusqlite::Error) -> Self {
+        DBError::SqliteError(error)
+    }
+}
+
+impl std::convert::From<r2d2::Error> for DBError  {
+    fn from(error: r2d2::Error) -> Self {
+        DBError::R2d2Error(error)
+    }
+}
+
 impl Connection {
-    pub fn new() -> Connection {
+    pub fn new() -> Result<Connection, DBError> {
 
         let data_dir = Path::new(consts::DB_DIRECTORY);
 
@@ -35,66 +50,87 @@ 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 };
-        connection.create_or_update();
-        connection
+        connection.create_or_update()?;
+        Ok(connection)
     }
 
-    fn create_or_update(self: &Self) {
+    /*
+     * 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();
+        // let mut stmt = connection.sqlite_con.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='versions'").unwrap();
 
         // Check the Database version.
-        let con = self.pool.get().unwrap();
+        let mut con = self.pool.get()?;
+        let tx = con.transaction()?;
 
-        let version = {
-            match
-                con.query_row(
+        // 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(_) => con.query_row("SELECT [version] FROM [Version]", rusqlite::NO_PARAMS, |row| row.get(0)).unwrap_or_default(),
+                        [],
+                        |row| row.get::<usize, String>(0)
+                    ) {
+                Ok(_) => tx.query_row("SELECT [version] FROM [Version]", [], |row| row.get(0)).unwrap_or_default(),
                 Err(_) => 0
             }
         };
 
-        match version {
-            0 => {
-                println!("Update to version 1...");
-                con.execute(
-                    "
-                    CREATE TABLE [Version] (
-                        [id] INTEGER PRIMARY KEY,
-                        [version] INTEGER NOT NULL,
-                        [datetime] INTEGER DATETIME
-                    )
-                    ",
-                    rusqlite::NO_PARAMS
-                );
-                con.execute(
-                    "
-                    CREATE TABLE [Recipe] (
-                        [id] INTEGER PRIMARY KEY,
-                        [title] INTEGER NOT NULL,
-                        [description] INTEGER DATETIME
-                    )
-                    ",
-                    rusqlite::NO_PARAMS
-                );
-                ()
+        while Connection::update_to_next_version(version, &tx)? {
+            version += 1;
+        }
+
+        tx.commit()?;
+
+        Ok(())
+    }
+
+    fn update_to_next_version(current_version: u32, tx: &rusqlite::Transaction) -> Result<bool, DBError> {
+        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> {
+            if updated {
+                println!("Version updated");
+            }
+            Ok(updated)
+        }
+
+        match next_version {
+            1 => {
+                tx.execute_batch(&load_sql_file(next_version)?)?;
+
+                ok(true)
             }
+
+            // Version 1 doesn't exist yet.
+            2 =>
+                ok(false),
+
             v =>
-                panic!("Unsupported database version: {}", 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)
 }
\ No newline at end of file