some thoughts about exceptions

exceptions.cpp

@@ -0,0 +1,105 @@
+// Squawk messenger.
+// Copyright (C) 2019  Yury Gubich <blue@macaw.me>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "exceptions.h"
+
+Core::DataBase::Directory::Directory(const std::string& p_path):
+    Exception(),
+    path(p_path) {}
+
+std::string Core::DataBase::Directory::getMessage() const {
+    return "Can't create directory for database at " + path;}
+
+Core::DataBase::Closed::Closed(
+    const std::string& p_operation,
+    const std::string& p_dbName,
+    const std::string& p_tableName
+):
+    Exception(),
+    operation(p_operation),
+    dbName(p_dbName),
+    tableName(p_tableName) {}
+
+std::string Core::DataBase::Closed::getMessage() const {
+    return "An attempt to perform operation " + operation
+            + " on closed database " + dbName
+            + " on table " + tableName;
+}
+
+Core::DataBase::Opened::Opened(const std::string& p_dbName, const std::string& p_tableName):
+    Exception(),
+    dbName(p_dbName),
+    tableName(p_tableName) {}
+
+
+std::string Core::DataBase::Opened::getMessage() const {
+    return "An attempt to add table " + tableName
+            + " to the database " + dbName
+            + " but it's can't be done because the DataBase is already opened."
+            + " Please add all tables before opening DataBase.";
+}
+
+Core::DataBase::NotFound::NotFound(
+    const std::string& p_key,
+    const std::string& p_dbName,
+    const std::string& p_tableName
+):
+    Exception(),
+    key(p_key),
+    dbName(p_dbName),
+    tableName(p_tableName) {}
+
+std::string Core::DataBase::NotFound::getMessage() const {
+    return "Element for id " + key + " wasn't found "
+            + " in database " + dbName
+            + " in table " + tableName;}
+
+Core::DataBase::Exist::Exist(
+    const std::string& p_key,
+    const std::string& p_dbName,
+    const std::string& p_tableName
+):
+    Exception(),
+    key(p_key),
+    dbName(p_dbName),
+    tableName(p_tableName) {}
+
+std::string Core::DataBase::Exist::getMessage() const {
+    return "An attempt to insert element with key " + key
+            + " to database " + dbName
+            + " to table " + tableName
+            + " but it already has an element with given id";
+}
+
+Core::DataBase::Unknown::Unknown(
+    const std::string& p_dbName,
+    const std::string& message,
+    const std::optional<std::string>& p_tableName
+):
+    Exception(),
+    dbName(p_dbName),
+    tableName(p_tableName),
+    msg(message) {}
+
+std::string Core::DataBase::Unknown::getMessage() const
+{
+    std::string result = "Unknown error in database " + dbName;
+    if (tableName.has_value()) {
+        result += " in table " + tableName.value();
+    }
+    result += ": " + msg;
+    return result;
+}