1 files changed, 168 insertions, 0 deletions
diff --git a/app/class/database.class.php b/app/class/database.class.php
new file mode 100644
index 0000000..a2cab42
--- /dev/null
+++ b/app/class/database.class.php
@@ -0,0 +1,168 @@
+<?php
+
+/*
+ * SCROTT IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * For more information, please refer to UNLICENSE
+ */
+
+/* Include database configuration file if it exists */
+define("DATABASE_CONFIG_FILE", "dbconfig.php");
+is_file(DATABASE_CONFIG_FILE) && require_once DATABASE_CONFIG_FILE;
+
+require_once "class/globals.php";
+require_once "class/mysql.class.php";
+
+/*
+ * This class provides a common interface to various database drivers.
+ * Scrott provides facilities for interacting with any DBMS that we can
+ * use in PHP.  To provide support for a new DBMS, extend this class and
+ * implement the abstract functions.  Additionally, update the getInstance()
+ * function in this class so that the new implementation is used under
+ * appropriate configuration.
+ */
+abstract class database
+{
+    private static $instance = NULL;
+
+    /*
+     * Call this object's close function while being destructed
+     */
+    public function __destruct()
+    {
+        $this->_close();
+    }
+
+    /*
+     * Return the database instance object, creating it if this is the
+     * first call to this function.  This function will need maintained
+     * as new DBMSs are supported.  This function will throw if the
+     * database is not configured.
+     */
+    private static function getInstance() : database
+    {
+        global $_SCROTT;
+
+        if (self::$instance)
+            return self::$instance;
+
+        if (!isset($_SCROTT['conf']))
+            throw new Exception("Scrott database configuration is missing.");
+
+        switch ($_SCROTT['dbEngine'])
+        {
+            case "mysql":
+                $host   = $_SCROTT['dbHost'];
+                $uname  = $_SCROTT['dbUname'];
+                $passwd = $_SCROTT['dbPasswd'];
+                $dbname = $_SCROTT['dbName'];
+                self::$instance = new mysql($host, $uname, $passwd, $dbname);
+                break;
+
+            default:
+                throw new Exception("Problem with Scrott database configuration.  Invalid " .
+                    "database engine specified.");
+                break;
+        }
+
+        return self::$instance;
+    }
+
+    /*
+     * These functions are to be implemented by DBMS extensions,
+     * providing a uniform interface to database engines.
+     */
+    protected abstract function _close() : void;
+    protected abstract function _query(string $query) : array;
+    protected abstract function _esc(string $str) : string;
+
+    /*
+     * Perform a database query and return the results as an array
+     * of arrays.
+     */
+    public static function query(string $query) : array
+    {
+        return self::getInstance()->_query($query);
+    }
+
+    /*
+     * Escape a given string for use in a database query
+     */
+    public static function esc(string $str) : string
+    {
+        return self::getInstance()->_esc($str);
+    }
+
+    /*
+     * Check whether Scrott's database config is loaded
+     */
+    public static function checkConfig() : bool
+    {
+        global $_SCROTT;
+
+        if (!isset($_SCROTT['conf']))
+            return false;
+
+        $db = self::getInstance();
+        return true;
+    }
+
+    /*
+     * Test and set new database configuration parameters.
+     * If the given params fail, error's are set and this
+     * function returns false.  On success, parameters are
+     * written to 'dbconfig.php' and true is returned.
+     */
+    public static function setConfig(string $engine, string $host,
+        string $uname, string $passwd, string $name) : bool
+    {
+        global $_SCROTT;
+
+        /* test configuration */
+        $_SCROTT['conf'] = "conf";
+        $_SCROTT['dbEngine'] = $engine;
+        $_SCROTT['dbHost'] = $host;
+        $_SCROTT['dbUname'] = $uname;
+        $_SCROTT['dbPasswd'] = $passwd;
+        $_SCROTT['dbName'] = $name;
+
+        try
+        {
+            $db = self::getInstance();
+        }
+        catch (Exception $e)
+        {
+            logError(ERROR, $e->getMessage());
+            return false;
+        }
+
+        /* write file */
+        $f = fopen(DATABASE_CONFIG_FILE, "w");
+
+        if (!$f)
+        {
+            logError(ERROR, "Can not create configuration file");
+            return false;
+        }
+
+        fwrite($f, "<?php\n");
+        fwrite($f, "\$_SCROTT['conf'] = 'conf';\n");
+        fwrite($f, "\$_SCROTT['dbEngine'] = '" . $engine . "';\n");
+        fwrite($f, "\$_SCROTT['dbHost'] = '" . $host . "';\n");
+        fwrite($f, "\$_SCROTT['dbUname'] = '" . $uname . "';\n");
+        fwrite($f, "\$_SCROTT['dbPasswd'] = '" . $passwd . "';\n");
+        fwrite($f, "\$_SCROTT['dbName'] = '" . $name . "';\n");
+        fwrite($f, "?>\n");
+
+        fclose($f);
+        return true;
+    }
+}
+
+?>