X-Git-Url: http://git.euphorik.ch/?a=blobdiff_plain;f=backend%2Fsrc%2Fdb.rs;h=1d38a454f03091e1d1020f1a19001919494aef8b;hb=4fbc599d074180920b20ee46e80cc0d3669a4129;hp=a2066b81bc225fdf042cb0f7bcd44ac7c4211dc3;hpb=3ebbe8172b0430bae5c554925a4582c9fec545f3;p=recipes.git

diff --git a/backend/src/db.rs b/backend/src/db.rs
index a2066b8..1d38a45 100644
--- a/backend/src/db.rs
+++ b/backend/src/db.rs
@@ -1,52 +1,136 @@
-use std::path::Path;
-use std::fs;
+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
+    //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() -> Connection {
+    pub fn new() -> Result<Connection, DBError> {
 
-        // TODO: use a constant in consts module.
-        let data_dir = Path::new("data");
+        let data_dir = Path::new(consts::DB_DIRECTORY);
 
         if !data_dir.exists() {
             fs::DirBuilder::new().create(data_dir).unwrap();
         }
 
-        Connection { con: rusqlite::Connection::open(data_dir.join("recipes.sqlite")).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)
     }
 
-    pub fn create_or_update(self: &Self) -> rusqlite::Result<&str> {
-        //let connection = Connection::new();
+    /*
+     * 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 version = {
-            let stmt_version_table = self.con.prepare("SELECT name FROM sqlite_master WHERE type='table' AND name='versions'")?;
-            /*if stmt_version_table.query(rusqlite::NO_PARAMS)?.count() == 0 {
-                0
-            } else {
-                1 // let stmt_versions = self.con.prepare("SELECT number FROM [")
-            }*/
-            0
+        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
+            }
         };
 
-        self.con.query_row(
-            "SELECT name FROM sqlite_master WHERE type='table' AND name='versions'",
-            rusqlite::NO_PARAMS,
-            |row| Ok(dbg!("test"))
-        )
+        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)
 }
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