[main] WIP major rework of current design, database management and other things

src/app.py

@@ -1,38 +1,60 @@
 import sys
-from PySide6 import QtWidgets, QtCore
+import os
+import logging
 
+from PySide6.QtWidgets import QMessageBox, QApplication
+
+from utils.config import UserConfig
+from utils.database import DatabaseManager
+from utils.errors.database_config_error import DatabaseConfigError
+from utils.setup_logger import setup_logger
 
 from ui.window import LibraryWindow
 
 
+class LibraryApp():
+    def __init__(self, user_config: UserConfig | None = None):
+        setup_logger()
+        self.logger = logging.getLogger(__name__)
+        self.logger.info("Starting")
+        
+        self.qt_app = QApplication([])
+        self.user_config = user_config
+        
+        try:
+            self.database_manger = DatabaseManager()
+        except DatabaseConfigError as e:
+            detail_text = f"Invalid config: {e.config_name}"
+            self.show_error(e.message, detail_text=detail_text)
+            sys.exit(1)
+        except FileNotFoundError:
+            self.show_error("Configuration not found")
+            sys.exit(1)
+
+        self.window = LibraryWindow()
+
+    def run(self) -> int:
+        self.window.show()
+        status = self.qt_app.exec()
+        self.cleanup()
+        self.logger.info("Exitting")
+        return status
+
+    def show_error(self, text: str, detail_text: str = ""):
+        error_dialog = QMessageBox()
+        error_dialog.setIcon(QMessageBox.Icon.Critical)
+        error_dialog.setWindowTitle("Error")
+        error_dialog.setText(text)
+        if detail_text:
+            error_dialog.setInformativeText(detail_text)
+        error_dialog.setStandardButtons(QMessageBox.StandardButton.Ok)
+        error_dialog.exec()
+
+    def cleanup(self) -> None:
+        self.logger.info("Cleaning up")
+        self.database_manger.cleanup()
+
+
 if __name__ == "__main__":
-    app = QtWidgets.QApplication([])
-    window = LibraryWindow()
-    window.show()
-    sys.exit(app.exec())
-
-# from sqlalchemy import create_engine
-# from sqlalchemy.orm import sessionmaker
-
-# from models.book_overview_view import BookOverviewView
-
-# # Replace with your MySQL database credentials
-# DATABASE_URI = 'mysql+mysqlconnector://username:password@localhost:3306/library'
-
-# # Create the engine
-# engine = create_engine(DATABASE_URI)
-
-# from models.base import Base
-# Base.metadata.create_all(engine)
-
-# # Create a configured session class
-# SessionLocal = sessionmaker(bind=engine)
-
-# # Create a session instance
-# session = SessionLocal()
-
-# books = session.query(BookOverviewView).all()
-# for book in books:
-#     print(book.title, book.author_name, book.categories)
-
-# session.close()
+    library_app = LibraryApp()
+    sys.exit(library_app.run())

src/models/__init__.py

@@ -7,6 +7,6 @@ from .member import Member
 from .librarian import Librarian
 from .loan import Loan
 
-from .book_overview_view import BookOverviewView
+from .book_overview import BooksOverview
 
 __all__ = ["Author", "Book", "BookCategory", "BookCategoryLink", "Member", "Librarian", "Loan", "BookOverviewView"]

src/models/book_overview.py

@@ -0,0 +1,31 @@
+from sqlalchemy import Column, String, TIMESTAMP, Integer, Text, Enum
+
+from .base import Base
+
+from models.book import BookStatusEnum
+
+class BooksOverview(Base):
+    __tablename__  = 'books_overview'
+    __table_args__ = {'extend_existing': True}
+
+
+    id             = Column(Integer, primary_key=True)
+    title          = Column(String, nullable=False)
+    author_name    = Column(String, nullable=False)
+    author_id      = Column(Integer, nullable=False)
+    categories     = Column(Text, nullable=True)
+    year_published = Column(Integer, nullable=True)
+    isbn           = Column(String, nullable=True)
+    status         = Column(Enum(BookStatusEnum), nullable=False)
+    created_at     = Column(TIMESTAMP, nullable=False)
+    borrower_name  = Column(String, nullable=True)
+    member_id      = Column(Integer, nullable=True)
+    librarian_name = Column(String, nullable=True)
+    librarian_id   = Column(Integer, nullable=True)
+
+    # This prevents accidental updates/deletes as it's a view
+    def __repr__(self):
+        return (f"<BooksOverview(id={self.id}, title={self.title}, author_name={self.author_name}, "
+                f"categories={self.categories}, year_published={self.year_published}, isbn={self.isbn}, "
+                f"status={self.status}, created_at={self.created_at}, borrower_name={self.borrower_name}, "
+                f"librarian_name={self.librarian_name})>")

src/models/book_overview_view.py

@@ -1,16 +0,0 @@
-from sqlalchemy import Column, String, TIMESTAMP, Integer
-
-from .base import Base
-
-class BookOverviewView(Base):
-    __tablename__ = 'books_overview'
-
-    id             = Column(Integer, primary_key=True, autoincrement=True)
-    title          = Column(String())
-    author_name    = Column(String())
-    categories     = Column(String())
-    year_published = Column(String())
-    isbn           = Column(String())
-    created_at     = Column(TIMESTAMP())
-    borrower_name  = Column(String())
-    librarian_name = Column(String())

src/ui/dashboard/book_card.py

@@ -0,0 +1,68 @@
+from PySide6.QtGui import QGuiApplication, QAction
+from PySide6.QtQml import QQmlApplicationEngine
+from PySide6.QtWidgets import QHBoxLayout, QVBoxLayout, QLabel, QWidget, QMenu, QSizePolicy, QLayout
+
+from models.book import BookStatusEnum
+
+from models.book_overview import BooksOverview
+
+STATUS_TO_COLOR_MAP = {
+    BookStatusEnum.available: "#3c702e",
+    BookStatusEnum.borrowed: "#702525",
+    BookStatusEnum.reserved: "#bc7613"
+}
+class BookCard(QWidget):
+    def __init__(self, book_overview: BooksOverview):
+        super().__init__()
+
+        # Create the layout for the card
+        layout = QHBoxLayout(self)
+        layout.setSizeConstraint(QLayout.SizeConstraint.SetMinimumSize)  # Ensure minimum size is respected
+        self.setSizePolicy(QSizePolicy.Policy.Preferred, QSizePolicy.Policy.Fixed)  # Avoid vertical stretching
+
+        layout.setContentsMargins(10, 10, 10, 10)  # Optional: Add margins for spacing
+        layout.setSpacing(10)
+
+        # Left-side content
+        left_side = QVBoxLayout()
+        layout.addLayout(left_side)
+        title_label = QLabel(book_overview.title)
+        author_label = QLabel("By: " + book_overview.author_name)
+        isbn_label = QLabel("ISBN: " + (book_overview.isbn or "Not Available"))
+        left_side.addWidget(title_label)
+        left_side.addWidget(author_label)
+        left_side.addWidget(isbn_label)
+
+        # Right-side content
+        right_side = QVBoxLayout()
+        layout.addLayout(right_side)
+        status_label = QLabel(str(book_overview.status))
+        status_label.setStyleSheet(f"color: {STATUS_TO_COLOR_MAP[book_overview.status]}")
+        right_side.addWidget(status_label)
+
+        if book_overview.librarian_name and book_overview.borrower_name:
+            borrower_label = QLabel("Borrowed: " + book_overview.borrower_name)
+            librarian_label = QLabel("By: " + book_overview.librarian_name)
+            right_side.addWidget(borrower_label)
+            right_side.addWidget(librarian_label)
+
+        self.setLayout(layout)
+
+
+    def contextMenuEvent(self, event):
+        """Override to create a custom right-click menu."""
+        context_menu = QMenu(self)
+
+        # Add actions to the menu
+        action_edit_book = context_menu.addAction("Edit Book")
+        action_edit_author = context_menu.addAction("Edit Author")
+        action_mark_returned = context_menu.addAction("Mark as Returned")
+
+        # Execute the menu and get the selected action
+        action = context_menu.exec_(self.mapToGlobal(event.pos()))
+        if action == action_edit_book:
+            self.label.setText("Edit Book selected")
+        elif action == action_edit_author:
+            self.label.setText("Edit Author selected")
+        elif action == action_mark_returned:
+            self.label.setText("Mark as Returned selected")

src/ui/dashboard/book_list_entry.py

@@ -1,27 +0,0 @@
-from PySide6.QtGui import QGuiApplication, QAction
-from PySide6.QtQml import QQmlApplicationEngine
-from PySide6 import QtWidgets, QtCore
-
-from models.book import BookStatusEnum
-
-STATUS_TO_COLOR_MAP = {
-    BookStatusEnum.available: "highlight",
-    BookStatusEnum.borrowed: "highlighted-text",
-    BookStatusEnum.reserved: "base"
-}
-
-class BookListEntry(QtWidgets.QWidget):
-    def __init__(self, title, status):
-        super().__init__()
-
-        layout = QtWidgets.QHBoxLayout(self)
-
-        book_label = QtWidgets.QLabel(title)
-        layout.addWidget(book_label)
-
-        status_label = QtWidgets.QLabel(status)
-        status_label.setStyleSheet(f"color: palette({STATUS_TO_COLOR_MAP[status]});")
-        layout.addWidget(status_label)
-
-
-        self.setLayout(layout)

src/ui/dashboard/dashboard.py

@@ -1,92 +1,87 @@
-from PySide6.QtGui import QGuiApplication, QAction
-from PySide6.QtQml import QQmlApplicationEngine
-from PySide6 import QtWidgets, QtCore
+from PySide6.QtGui import QAction
+from PySide6.QtWidgets import (
+    QWidget, QVBoxLayout, QHBoxLayout, QLabel, QLineEdit, QScrollArea,
+    QFrame, QPushButton, QMessageBox, QVBoxLayout, QScrollArea
+)
+from PySide6.QtCore import Qt
 
-from ui.settings import SettingsDialog
-class LibraryDashboard(QtWidgets.QWidget):
+from .book_card import BookCard
+from models.book_overview import BooksOverview
+
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+class LibraryDashboard(QWidget):
     def __init__(self):
         super().__init__()
 
         # Central widget and layout
-        main_layout = QtWidgets.QVBoxLayout(self)
+        main_layout = QVBoxLayout(self)
 
         # Title label
-        title_label = QtWidgets.QLabel("Dashboard", self)
-        title_label.setAlignment(QtCore.Qt.AlignCenter)
+        title_label = QLabel("Dashboard", self)
+        title_label.setAlignment(Qt.AlignCenter)
         title_label.setStyleSheet("font-size: 20px; font-weight: bold; color: #0078D4;")
         main_layout.addWidget(title_label)
 
-
-        # Available books list
-        available_label = QtWidgets.QLabel("Available Books")
-        available_label.setStyleSheet("font-size: 16px;")
-        main_layout.addWidget(available_label)
-
         # Search bar
-        self.search_input = QtWidgets.QLineEdit()
+        self.search_input = QLineEdit()
         self.search_input.setPlaceholderText("Type to search...")
         self.search_input.textChanged.connect(self.filter_books)
         main_layout.addWidget(self.search_input)
 
+        # Scrollable area for cards
+        self.scroll_area = QScrollArea()
+        self.scroll_area.setWidgetResizable(True)
 
-        self.available_books_list = QtWidgets.QListWidget()
-        self.books = ["Book One", "Book Two", "Book Three", "Book Four",
-                      "Book Five", "Book Six", "Book Seven", "Book Eight"]
+        # Container widget for the scroll area
+        self.scroll_widget = QWidget()
+        self.scroll_layout = QVBoxLayout(self.scroll_widget)
+        self.scroll_layout.setSpacing(5)  # Optional: Adjust spacing between cards
+        self.scroll_layout.setContentsMargins(0, 0, 0, 0)
 
-        self.available_books_list.addItems(self.books)
-        self.available_books_list.itemClicked.connect(self.edit_book)
-        self.available_books_list.setStyleSheet("""
-            QListWidget {
-                font-size: 14px;
-            }
-            QListWidget::item {
-                padding: 5px;
-            }
-            QListWidget::item:hover {
-                background-color: palette(highlight);
-                color: palette(highlighted-text);
-            }
-            """)
-        main_layout.addWidget(self.available_books_list)
+        # Example cards
+        # self.books = self.fetch_books_from_db()
+        # self.book_cards = []
 
-        # Borrowed books list
-        borrowed_label = QtWidgets.QLabel("Currently Borrowed Books")
-        borrowed_label.setStyleSheet("font-size: 16px;")
-        main_layout.addWidget(borrowed_label)
+        # for book in self.books:
+        #     card = BookCard(book)
+        #     self.scroll_layout.addWidget(card)
+        #     self.book_cards.append(card)
 
-        self.borrowed_books_list = QtWidgets.QListWidget()
-        self.borrowed_books_list.addItems(["Book Two", "Book Four"])
-        self.borrowed_books_list.itemClicked.connect(self.return_book)
-        main_layout.addWidget(self.borrowed_books_list)
+        self.scroll_widget.setLayout(self.scroll_layout)
+        self.scroll_area.setWidget(self.scroll_widget)
+        main_layout.addWidget(self.scroll_area)
 
         # Buttons for actions
-        button_layout = QtWidgets.QHBoxLayout()
-        register_member_button = QtWidgets.QPushButton("Add New Member")
+        button_layout = QHBoxLayout()
+        register_member_button = QPushButton("Add New Member")
         register_member_button.clicked.connect(self.register_member)
         button_layout.addWidget(register_member_button)
 
-        add_borrow_record_button = QtWidgets.QPushButton("Add Borrow Record")
+        add_borrow_record_button = QPushButton("Add Borrow Record")
         add_borrow_record_button.clicked.connect(self.add_borrow_record)
         button_layout.addWidget(add_borrow_record_button)
 
         main_layout.addLayout(button_layout)
 
     def filter_books(self, text):
-        """Filter the available books list based on the search input."""
-        self.available_books_list.clear()
-        filtered_books = [book for book in self.books if text.lower() in book.lower()]
-        self.available_books_list.addItems(filtered_books)
-
-    # Slots for button actions
-    def edit_book(self, item):
-        QtWidgets.QMessageBox.information(self, "Edit Book", f"Edit details for '{item.text()}'.")
-
-    def return_book(self, item):
-        QtWidgets.QMessageBox.information(self, "Return Book", f"Mark '{item.text()}' as returned.")
+        """Filter the cards based on the search input."""
+        for card, book in zip(self.book_cards, self.books):
+            card.setVisible(text.lower() in book["title"].lower() or text.lower() in book["description"].lower())
 
     def register_member(self):
-        QtWidgets.QMessageBox.information(self, "Add Member", "Open dialog to register a new member.")
+        QMessageBox.information(self, "Add Member", "Open dialog to register a new member.")
 
     def add_borrow_record(self):
-        QtWidgets.QMessageBox.information(self, "Add Borrow Record", "Open dialog to add a borrow record.")
+        QMessageBox.information(self, "Add Borrow Record", "Open dialog to add a borrow record.")
 
+    def fetch_books_from_db(self):
+        
+        """Fetch all books from the database."""
+        try:
+            session = SessionLocal()
+            books = session.query(BooksOverview).all()
+            return books
+        except Exception as e:
+            QMessageBox.critical(self, "Database Error", f"Failed to fetch books: {e}")
+            return []

src/ui/settings.py

@@ -2,12 +2,14 @@ import sys
 
 from PySide6 import QtWidgets
 
+from utils.config import UserConfig, TransactionLevel
+
 class SettingsDialog(QtWidgets.QDialog):
     def __init__(self, parent=None):
         super().__init__(parent)
 
         self.setWindowTitle("Settings")
-        self.setMinimumSize(400, 300)
+        self.setMinimumSize(400, 100)
 
         # Position the dialog relative to the parent (main window)
         if parent:
@@ -18,29 +20,24 @@ class SettingsDialog(QtWidgets.QDialog):
         # Create layout
         layout = QtWidgets.QVBoxLayout(self)
 
-        # Checkbox: Enable Notifications
-        self.notifications_checkbox = QtWidgets.QCheckBox("Enable Notifications")
-        layout.addWidget(self.notifications_checkbox)
+        data_mode_layout = QtWidgets.QHBoxLayout()
 
-        # Checkbox: Dark Mode
-        self.dark_mode_checkbox = QtWidgets.QCheckBox("Enable Dark Mode")
-        layout.addWidget(self.dark_mode_checkbox)
+        self.data_mode_label = QtWidgets.QLabel("Data mode:")
+        data_mode_layout.addWidget(self.data_mode_label)
 
-        # Dropdown: Language Selection
-        self.language_label = QtWidgets.QLabel("Language:")
-        layout.addWidget(self.language_label)
+        self.data_mode_dropdown = QtWidgets.QComboBox()
+        for tl in TransactionLevel:
+            self.data_mode_dropdown.addItem(tl.name.capitalize(), tl.value)
 
-        self.language_dropdown = QtWidgets.QComboBox()
-        self.language_dropdown.addItems(["English", "Spanish", "French", "German"])
-        layout.addWidget(self.language_dropdown)
+        data_mode_layout.addWidget(self.data_mode_dropdown)
+        layout.addLayout(data_mode_layout)
 
-        # Dropdown: Theme Selection
-        self.theme_label = QtWidgets.QLabel("Theme:")
-        layout.addWidget(self.theme_label)
-
-        self.theme_dropdown = QtWidgets.QComboBox()
-        self.theme_dropdown.addItems(["Light", "Dark", "System Default"])
-        layout.addWidget(self.theme_dropdown)
+        # Set the currently selected mode to the mode in UserConfig
+        config = UserConfig()
+        current_level = config.transaction_level
+        index = self.data_mode_dropdown.findData(current_level)
+        if index != -1:
+            self.data_mode_dropdown.setCurrentIndex(index)
 
         # Buttons
         button_layout = QtWidgets.QHBoxLayout()
@@ -56,16 +53,13 @@ class SettingsDialog(QtWidgets.QDialog):
         layout.addLayout(button_layout)
 
     def save_settings(self):
-        # Example of how to fetch settings
-        notifications = self.notifications_checkbox.isChecked()
-        dark_mode = self.dark_mode_checkbox.isChecked()
-        language = self.language_dropdown.currentText()
-        theme = self.theme_dropdown.currentText()
+        data_mode = self.data_mode_dropdown.currentData()
+
+        config = UserConfig()
+        config.transaction_level = data_mode
 
         print("Settings Saved:")
-        print(f"Notifications: {notifications}")
-        print(f"Dark Mode: {dark_mode}")
-        print(f"Language: {language}")
-        print(f"Theme: {theme}")
+        print(f"Data Mode: {config.transaction_level}")
+
 
         self.accept()

src/ui/window.py

@@ -56,11 +56,11 @@ class LibraryWindow(QtWidgets.QMainWindow):
         # File menu
         file_menu = menu_bar.addMenu("File")
 
-        import_action = QAction("Import", self)
+        import_action = QAction("Import books", self)
         import_action.triggered.connect(self.import_data)
         file_menu.addAction(import_action)
 
-        export_action = QAction("Export", self)
+        export_action = QAction("Export overview", self)
         export_action.triggered.connect(self.export_data)
         file_menu.addAction(export_action)
 
@@ -74,9 +74,10 @@ class LibraryWindow(QtWidgets.QMainWindow):
         # Edit menu
         edit_menu = menu_bar.addMenu("Edit")
 
-        preferences = QAction("Preferences", self)
-        preferences.triggered.connect(self.edit_preferences)
-        edit_menu.addAction(preferences)
+        preferences_action = QAction("Preferences", self)
+        preferences_action.setShortcut("Ctrl+,")
+        preferences_action.triggered.connect(self.edit_preferences)
+        edit_menu.addAction(preferences_action)
 
         # Help menu
         help_menu = menu_bar.addMenu("Help")
@@ -100,4 +101,4 @@ class LibraryWindow(QtWidgets.QMainWindow):
         pass
 
     def about(self):
-        QtWidgets.QMessageBox.information(self, "About", "Library Dashboard v1.0\nDeveloped by You.")
+        QtWidgets.QMessageBox.information(self, "About", "Library app demonstrating the phantom read problem")

src/utils/config.py

@@ -0,0 +1,76 @@
+import enum
+import os
+
+from utils.errors.database_config_error import DatabaseConfigError
+from dotenv import load_dotenv
+import logging
+
+
+class DatabaseConfig():
+    def __init__(self):
+        self.logger = logging.getLogger(__name__)
+        self.logger.debug("Parsing .env")
+
+        anything_set = load_dotenv()
+
+        if anything_set:
+            self.logger.debug(".env found")
+        else:
+            self.logger.error(".env not found")
+            raise FileNotFoundError(".env not found.")
+
+        host = os.getenv("DATABASE_HOST")
+        port = os.getenv("DATABASE_PORT", "3306")
+        name = os.getenv("DATABASE_NAME")
+        user = os.getenv("DATABASE_USER")
+        password = os.getenv("DATABASE_PASSWORD")
+
+        self.logger.debug("Validating fetched values from .env")
+
+        if host is None or host == "":
+            self.logger.error("DATABASE_HOST is empty")
+            raise DatabaseConfigError(
+                "Config is invalid.", "DATABASE_HOST", "(Empty)")
+        if name is None or name == "":
+            self.logger.error("DATABASE_NAME is empty")
+            raise DatabaseConfigError(
+                "Config is invalid.", "DATABASE_NAME", "(Empty)")
+        if user is None or user == "":
+            self.logger.error("DATABASE_USER is empty")
+            raise DatabaseConfigError(
+                "Config is invalid.", "DATABASE_USER", "(Empty)")
+        if password is None or password == "":
+            self.logger.error("DATABASE_PASSWORD is empty")
+            raise DatabaseConfigError(
+                "Config is invalid.", "DATABASE_PASSWORD", "(Empty)")
+
+        if not port.isdigit():
+            self.logger.error("DATABASE_PORT is invalid. Not a number")
+            raise DatabaseConfigError(
+                "Config is invalid", "DATABASE_PORT", port)
+
+        self.logger.debug("All config validated")
+
+        self.host = host
+        self.port = port
+        self.name = name
+        self.user = user
+        self.password = password
+
+
+class TransactionLevel(enum.Enum):
+    insecure = 'READ UNCOMMITED'
+    secure = 'SERIALIZABLE'
+
+
+class UserConfig():
+    _instance = None
+
+    def __new__(cls, *args, **kwargs):
+        if cls._instance is None:
+            cls._instance = super().__new__(cls)
+        return cls._instance
+
+    def __init__(self):
+        if not hasattr(self, "transaction_level"):
+            self.transaction_level = TransactionLevel.insecure

src/utils/database.py

@@ -0,0 +1,27 @@
+import logging
+
+from mysql.connector import connect, cursor
+
+from utils.config import DatabaseConfig
+from utils.errors.database_config_error import DatabaseConfigError
+
+
+class DatabaseManager():
+    def __init__(self) -> None:
+        self.logger = logging.getLogger(__name__)
+        self.logger.info("Reading database config")
+        self.database_config = DatabaseConfig()
+        self.connection = connect(
+            host=self.database_config.host,
+            port=self.database_config.port,
+            database=self.database_config.name,
+            user=self.database_config.user,
+            password=self.database_config.password
+        )
+
+    def get_cursor(self) -> cursor.MySQLCursorAbstract:
+        return self.connection.cursor(dictionary=True)
+
+    def cleanup(self) -> None:
+        self.logger.debug("Closing connection")
+        self.connection.close()

src/utils/errors/database_config_error.py

@@ -0,0 +1,7 @@
+class DatabaseConfigError(Exception):
+    def __init__(self, message: str, config_name: str, config_value: str):
+        super().__init__(message)
+        
+        self.message = message
+        self.config_name = config_name
+        self.config_value = config_value

src/utils/setup_logger.py

@@ -0,0 +1,14 @@
+import sys
+import logging
+
+def setup_logger():
+    logger = logging.getLogger()
+    logger.setLevel(logging.DEBUG)
+
+    handler = logging.StreamHandler(sys.stdout)
+    handler.setLevel(logging.DEBUG)
+
+    formatter = logging.Formatter("[%(levelname)s] - %(name)s - %(message)s")
+    handler.setFormatter(formatter)
+
+    logger.addHandler(handler)