add lokal backend

1 files changed, 66 insertions, 0 deletions

diff --git a/db.vala b/db.vala
new file mode 100644
index 0000000..6467e6c
--- /dev/null
+++ b/db.vala
@@ -0,0 +1,66 @@
+public class Database {
+	private Sqlite.Database db;
+	private Sqlite.Statement insert_stmt;
+	private Sqlite.Statement product_stmt;
+	uint64 user = 0;
+	private static string insert_query = "INSERT INTO purchases ('user', 'product') VALUES (?, ?)";
+	private static string product_query = "SELECT name FROM products WHERE id = ?";
+
+	public Database(string file) {
+		int rc;
+
+		rc = Sqlite.Database.open (file, out db);
+		if(rc != Sqlite.OK) {
+			error("could not open database!");
+		}
+
+		rc = this.db.prepare_v2(insert_query, -1, out insert_stmt);
+		if(rc != Sqlite.OK) {
+			error("could not prepare insert statement!");
+		}
+
+		rc = this.db.prepare_v2(product_query, -1, out product_stmt);
+		if(rc != Sqlite.OK) {
+			error("could not prepare article statement!");
+		}
+	}
+
+	public void login(uint64 id) {
+		this.user = id;
+	}
+
+	public void logout() {
+		this.user = 0;
+	}
+
+	public void buy(uint64 article) {
+		this.insert_stmt.reset();
+		this.insert_stmt.bind_text(1, "%llu".printf(user));
+		this.insert_stmt.bind_text(2, "%llu".printf(article));
+
+		int rc = this.insert_stmt.step();
+
+		if(rc != Sqlite.DONE)
+			error("[interner Fehler: %d]".printf(rc));
+	}
+
+	public string get_product_name(uint64 article) {
+		this.product_stmt.reset();
+		this.product_stmt.bind_text(1, "%llu".printf(article));
+
+		int rc = this.product_stmt.step();
+
+		switch(rc) {
+			case Sqlite.ROW:
+				return this.product_stmt.column_text(0);
+			case Sqlite.DONE:
+				return "unbekanntes Produkt: %llu".printf(article);
+			default:
+				return "[interner Fehler: %d]".printf(rc);
+		}
+	}
+
+	public bool is_logged_in() {
+		return (user != 0);
+	}
+}