feat: Add installation scripts for Windows and Unix-based systems

- Created `install_and_run.bat` for Windows installation and setup.
- Created `install_and_run.sh` for Unix-based systems installation and setup.
- Removed `main.py` as it is no longer needed.
- Updated `requirements.txt` to specify package versions and added PyQt5.
- Deleted `start.bat` as it is redundant.
- Added unit tests for core functionality and scraping modes.
- Implemented input validation utilities in `utils/validators.py`.
- Added support for dual scraping modes in the scraper.

gui/login_dialog.py

@@ -0,0 +1,317 @@
+"""
+Login dialog for EBoek.info credential input.
+"""
+
+from PyQt5.QtWidgets import (
+    QDialog, QVBoxLayout, QHBoxLayout, QGridLayout,
+    QPushButton, QLabel, QLineEdit, QCheckBox, QMessageBox, QProgressBar
+)
+from PyQt5.QtCore import Qt, QTimer, QThread, pyqtSignal
+from PyQt5.QtGui import QFont
+
+from pathlib import Path
+import sys
+
+# Add the project root directory to Python path
+project_root = Path(__file__).parent.parent
+sys.path.insert(0, str(project_root))
+
+from utils.validators import validate_username, validate_password, format_error_message
+
+
+class LoginTestThread(QThread):
+    """Thread for testing login credentials without blocking the UI."""
+
+    login_result = pyqtSignal(bool, str)  # success, message
+
+    def __init__(self, username, password):
+        super().__init__()
+        self.username = username
+        self.password = password
+
+    def run(self):
+        """Test the login credentials."""
+        try:
+            # Import here to avoid circular imports and ensure GUI responsiveness
+            from core.scraper import Scraper
+
+            # Create a scraper instance for testing
+            scraper = Scraper(headless=True)
+
+            # Attempt login
+            success = scraper.login(self.username, self.password)
+
+            # Clean up
+            scraper.close()
+
+            if success:
+                self.login_result.emit(True, "Login successful!")
+            else:
+                self.login_result.emit(False, "Login failed. Please check your credentials.")
+
+        except Exception as e:
+            self.login_result.emit(False, f"Error testing login: {str(e)}")
+
+
+class LoginDialog(QDialog):
+    """
+    Dialog for entering EBoek.info login credentials.
+
+    Provides fields for username and password input, with options to save
+    credentials and test them before saving.
+    """
+
+    def __init__(self, parent=None, credential_manager=None):
+        super().__init__(parent)
+        self.credential_manager = credential_manager
+        self.test_thread = None
+
+        self.init_ui()
+        self.load_existing_credentials()
+
+    def init_ui(self):
+        """Initialize the user interface."""
+        self.setWindowTitle("EBoek.info Login")
+        self.setModal(True)
+        self.setFixedSize(400, 300)
+
+        layout = QVBoxLayout(self)
+
+        # Title
+        title_label = QLabel("EBoek.info Credentials")
+        title_font = QFont()
+        title_font.setPointSize(14)
+        title_font.setBold(True)
+        title_label.setFont(title_font)
+        title_label.setAlignment(Qt.AlignCenter)
+        layout.addWidget(title_label)
+
+        layout.addSpacing(10)
+
+        # Credentials form
+        form_layout = QGridLayout()
+
+        form_layout.addWidget(QLabel("Username:"), 0, 0)
+        self.username_input = QLineEdit()
+        self.username_input.setPlaceholderText("Enter your EBoek.info username")
+        form_layout.addWidget(self.username_input, 0, 1)
+
+        form_layout.addWidget(QLabel("Password:"), 1, 0)
+        self.password_input = QLineEdit()
+        self.password_input.setEchoMode(QLineEdit.Password)
+        self.password_input.setPlaceholderText("Enter your password")
+        form_layout.addWidget(self.password_input, 1, 1)
+
+        layout.addLayout(form_layout)
+
+        layout.addSpacing(10)
+
+        # Options
+        self.remember_checkbox = QCheckBox("Save credentials for future use")
+        self.remember_checkbox.setChecked(True)
+        layout.addWidget(self.remember_checkbox)
+
+        layout.addSpacing(5)
+
+        # Info text
+        info_label = QLabel(
+            "Note: Credentials are stored securely on your computer "
+            "for convenience. You can clear them anytime from the Settings menu."
+        )
+        info_label.setWordWrap(True)
+        info_label.setStyleSheet("color: #666; font-size: 10px;")
+        layout.addWidget(info_label)
+
+        layout.addSpacing(15)
+
+        # Test progress (hidden initially)
+        self.test_progress = QProgressBar()
+        self.test_progress.setVisible(False)
+        layout.addWidget(self.test_progress)
+
+        self.test_status_label = QLabel("")
+        self.test_status_label.setVisible(False)
+        layout.addWidget(self.test_status_label)
+
+        # Buttons
+        button_layout = QHBoxLayout()
+
+        self.test_btn = QPushButton("Test Login")
+        self.test_btn.clicked.connect(self.test_login)
+        button_layout.addWidget(self.test_btn)
+
+        button_layout.addStretch()
+
+        self.ok_btn = QPushButton("OK")
+        self.ok_btn.clicked.connect(self.accept_credentials)
+        self.ok_btn.setDefault(True)
+        button_layout.addWidget(self.ok_btn)
+
+        self.cancel_btn = QPushButton("Cancel")
+        self.cancel_btn.clicked.connect(self.reject)
+        button_layout.addWidget(self.cancel_btn)
+
+        layout.addLayout(button_layout)
+
+        # Connect Enter key to OK button
+        self.username_input.returnPressed.connect(self.password_input.setFocus)
+        self.password_input.returnPressed.connect(self.accept_credentials)
+
+    def load_existing_credentials(self):
+        """Load existing credentials if available."""
+        if self.credential_manager:
+            username = self.credential_manager.get_saved_username()
+            if username:
+                self.username_input.setText(username)
+                # Focus password field if username is pre-filled
+                self.password_input.setFocus()
+            else:
+                self.username_input.setFocus()
+
+    def validate_input(self):
+        """
+        Validate the entered credentials.
+
+        Returns:
+            tuple: (is_valid, errors_list)
+        """
+        username = self.username_input.text().strip()
+        password = self.password_input.text()
+
+        username_validation = validate_username(username)
+        password_validation = validate_password(password)
+
+        all_errors = []
+        all_errors.extend(username_validation.get('errors', []))
+        all_errors.extend(password_validation.get('errors', []))
+
+        return len(all_errors) == 0, all_errors
+
+    def test_login(self):
+        """Test the login credentials."""
+        # First validate input
+        is_valid, errors = self.validate_input()
+        if not is_valid:
+            QMessageBox.warning(self, "Invalid Input", format_error_message(errors))
+            return
+
+        # Disable UI elements during test
+        self.test_btn.setEnabled(False)
+        self.ok_btn.setEnabled(False)
+        self.username_input.setEnabled(False)
+        self.password_input.setEnabled(False)
+
+        # Show progress
+        self.test_progress.setVisible(True)
+        self.test_progress.setRange(0, 0)  # Indeterminate progress
+        self.test_status_label.setText("Testing login credentials...")
+        self.test_status_label.setVisible(True)
+
+        # Start test thread
+        username = self.username_input.text().strip()
+        password = self.password_input.text()
+
+        self.test_thread = LoginTestThread(username, password)
+        self.test_thread.login_result.connect(self.on_test_completed)
+        self.test_thread.start()
+
+    def on_test_completed(self, success, message):
+        """Handle test completion."""
+        # Re-enable UI elements
+        self.test_btn.setEnabled(True)
+        self.ok_btn.setEnabled(True)
+        self.username_input.setEnabled(True)
+        self.password_input.setEnabled(True)
+
+        # Hide progress
+        self.test_progress.setVisible(False)
+
+        # Show result
+        if success:
+            self.test_status_label.setText("✓ " + message)
+            self.test_status_label.setStyleSheet("color: #2E8B57; font-weight: bold;")
+        else:
+            self.test_status_label.setText("✗ " + message)
+            self.test_status_label.setStyleSheet("color: #f44336; font-weight: bold;")
+
+        # Auto-hide status after 5 seconds
+        QTimer.singleShot(5000, lambda: self.test_status_label.setVisible(False))
+
+        # Clean up thread
+        self.test_thread = None
+
+    def accept_credentials(self):
+        """Accept and save the credentials."""
+        # Validate input
+        is_valid, errors = self.validate_input()
+        if not is_valid:
+            QMessageBox.warning(self, "Invalid Input", format_error_message(errors))
+            return
+
+        username = self.username_input.text().strip()
+        password = self.password_input.text()
+        remember = self.remember_checkbox.isChecked()
+
+        # Save credentials if manager is available
+        if self.credential_manager:
+            if remember:
+                success = self.credential_manager.save_credentials(username, password, remember=True)
+                if not success:
+                    QMessageBox.warning(
+                        self, "Save Error",
+                        "Could not save credentials. They will be used for this session only."
+                    )
+            else:
+                # Clear any existing saved credentials if user unchecked remember
+                self.credential_manager.clear_credentials()
+
+        # Accept the dialog
+        self.accept()
+
+    def get_credentials(self):
+        """
+        Get the entered credentials.
+
+        Returns:
+            dict: Dictionary with 'username', 'password', and 'remember' keys
+        """
+        return {
+            'username': self.username_input.text().strip(),
+            'password': self.password_input.text(),
+            'remember': self.remember_checkbox.isChecked()
+        }
+
+    def closeEvent(self, event):
+        """Handle dialog close event."""
+        # Make sure test thread is stopped
+        if self.test_thread and self.test_thread.isRunning():
+            self.test_thread.quit()
+            self.test_thread.wait(1000)  # Wait up to 1 second
+
+        event.accept()
+
+    def reject(self):
+        """Handle dialog rejection (Cancel button)."""
+        # Stop test thread if running
+        if self.test_thread and self.test_thread.isRunning():
+            self.test_thread.quit()
+            self.test_thread.wait(1000)
+
+        super().reject()
+
+
+def show_login_dialog(parent=None, credential_manager=None):
+    """
+    Convenience function to show login dialog and get credentials.
+
+    Args:
+        parent: Parent widget
+        credential_manager: CredentialManager instance
+
+    Returns:
+        dict or None: Credentials if dialog accepted, None if cancelled
+    """
+    dialog = LoginDialog(parent, credential_manager)
+    if dialog.exec_() == QDialog.Accepted:
+        return dialog.get_credentials()
+    return None