X-Git-Url: http://git.euphorik.ch/?a=blobdiff_plain;f=backend%2Fsrc%2Fdb.rs;h=1d38a454f03091e1d1020f1a19001919494aef8b;hb=4fbc599d074180920b20ee46e80cc0d3669a4129;hp=0002b41ecb7fd5167e3fef305cf4b604a1d92dd9;hpb=c012be04a9185ab5924cb314e0378c0cf6655b26;p=recipes.git

diff --git a/backend/src/db.rs b/backend/src/db.rs
index 0002b41..1d38a45 100644
--- a/backend/src/db.rs
+++ b/backend/src/db.rs
@@ -1,6 +1,136 @@
+use crate::consts::SQL_FILENAME;
 
+use super::consts;
 
+use std::{fs::{self, File}, path::Path, io::Read};
 
-fn create_or_update() {
+//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>
+}
+
+pub struct Recipe {
+    pub title: String,
+    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() -> Result<Connection, DBError> {
+
+        let data_dir = Path::new(consts::DB_DIRECTORY);
+
+        if !data_dir.exists() {
+            fs::DirBuilder::new().create(data_dir).unwrap();
+        }
+
+        let manager = SqliteConnectionManager::file(consts::DB_FILENAME);
+        let pool = r2d2::Pool::new(manager).unwrap();
+
+        let connection = Connection { pool };
+        connection.create_or_update()?;
+        Ok(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();
+
+        // Check the Database version.
+        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'",
+                        [],
+                        |row| row.get::<usize, String>(0)
+                    ) {
+                Ok(_) => tx.query_row("SELECT [version] FROM [Version]", [], |row| row.get(0)).unwrap_or_default(),
+                Err(_) => 0
+            }
+        };
+
+        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 =>
+                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