"""
Simple JSON-based credential storage system for EBoek.info scraper.
"""

import json
import os
from pathlib import Path
import stat


class CredentialManager:
    """
    Manages storage and retrieval of user credentials in a JSON config file.

    Credentials are stored in the user's home directory in a hidden folder
    with appropriate file permissions for basic security.
    """

    def __init__(self, app_name="eboek_scraper"):
        """
        Initialize the credential manager.

        Args:
            app_name (str): Application name for config directory
        """
        self.app_name = app_name
        self.config_dir = Path.home() / f".{app_name}"
        self.config_file = self.config_dir / "config.json"
        self._ensure_config_dir()

    def _ensure_config_dir(self):
        """
        Ensure the configuration directory exists with appropriate permissions.
        """
        try:
            if not self.config_dir.exists():
                self.config_dir.mkdir(mode=0o700, exist_ok=True)  # Only user can read/write/execute

            # Ensure directory has correct permissions (user only)
            if os.name != 'nt':  # Unix-like systems (macOS, Linux)
                os.chmod(self.config_dir, stat.S_IRWXU)  # 700 permissions

        except Exception as e:
            # If we can't create the config directory, fall back to current directory
            self.config_dir = Path(".")
            self.config_file = self.config_dir / f".{self.app_name}_config.json"

    def _load_config(self):
        """
        Load the configuration file.

        Returns:
            dict: Configuration data, empty dict if file doesn't exist
        """
        try:
            if self.config_file.exists():
                with open(self.config_file, 'r', encoding='utf-8') as f:
                    return json.load(f)
        except (json.JSONDecodeError, IOError, PermissionError) as e:
            # If there's any error reading the config, return empty dict
            pass

        return {}

    def _save_config(self, config_data):
        """
        Save configuration data to file.

        Args:
            config_data (dict): Configuration data to save

        Returns:
            bool: True if saved successfully, False otherwise
        """
        try:
            with open(self.config_file, 'w', encoding='utf-8') as f:
                json.dump(config_data, f, indent=2, ensure_ascii=False)

            # Set file permissions to be readable/writable by user only
            if os.name != 'nt':  # Unix-like systems
                os.chmod(self.config_file, stat.S_IRUSR | stat.S_IWUSR)  # 600 permissions

            return True

        except (IOError, PermissionError) as e:
            return False

    def save_credentials(self, username, password, remember=True):
        """
        Save user credentials to the config file.

        Args:
            username (str): EBoek.info username
            password (str): EBoek.info password
            remember (bool): Whether to save credentials for future use

        Returns:
            bool: True if saved successfully, False otherwise
        """
        if not remember:
            # If remember is False, just clear any existing credentials
            return self.clear_credentials()

        try:
            config = self._load_config()

            config['credentials'] = {
                'username': username,
                'password': password,
                'saved_at': str(Path.home()),  # Just to know which user saved it
            }

            return self._save_config(config)

        except Exception as e:
            return False

    def load_credentials(self):
        """
        Load stored credentials.

        Returns:
            dict or None: Dictionary with 'username' and 'password' keys if found,
                         None if no credentials are stored
        """
        try:
            config = self._load_config()
            credentials = config.get('credentials')

            if credentials and 'username' in credentials and 'password' in credentials:
                return {
                    'username': credentials['username'],
                    'password': credentials['password']
                }

        except Exception as e:
            pass

        return None

    def has_saved_credentials(self):
        """
        Check if there are saved credentials available.

        Returns:
            bool: True if credentials are available, False otherwise
        """
        return self.load_credentials() is not None

    def get_saved_username(self):
        """
        Get the saved username without the password.

        Returns:
            str or None: Saved username if available, None otherwise
        """
        credentials = self.load_credentials()
        return credentials['username'] if credentials else None

    def clear_credentials(self):
        """
        Remove stored credentials from the config file.

        Returns:
            bool: True if cleared successfully, False otherwise
        """
        try:
            config = self._load_config()

            if 'credentials' in config:
                del config['credentials']
                return self._save_config(config)

            return True  # No credentials to clear is success

        except Exception as e:
            return False

    def validate_credentials(self, username, password):
        """
        Basic validation of credential format.

        Args:
            username (str): Username to validate
            password (str): Password to validate

        Returns:
            dict: Validation result with 'valid' bool and 'errors' list
        """
        errors = []

        if not username or not username.strip():
            errors.append("Username cannot be empty")
        elif len(username.strip()) < 2:
            errors.append("Username must be at least 2 characters")

        if not password or not password.strip():
            errors.append("Password cannot be empty")
        elif len(password) < 3:
            errors.append("Password must be at least 3 characters")

        return {
            'valid': len(errors) == 0,
            'errors': errors
        }

    def get_config_file_path(self):
        """
        Get the path to the configuration file.

        Returns:
            Path: Path to the config file
        """
        return self.config_file

    def save_app_settings(self, settings):
        """
        Save application settings (non-credential settings).

        Args:
            settings (dict): Application settings to save

        Returns:
            bool: True if saved successfully, False otherwise
        """
        try:
            config = self._load_config()
            config['app_settings'] = settings
            return self._save_config(config)
        except Exception as e:
            return False

    def load_app_settings(self):
        """
        Load application settings (non-credential settings).

        Returns:
            dict: Application settings, empty dict if none saved
        """
        try:
            config = self._load_config()
            return config.get('app_settings', {})
        except Exception as e:
            return {}

    def get_default_settings(self):
        """
        Get default application settings.

        Returns:
            dict: Default settings
        """
        return {
            'headless_mode': True,
            'verbose_logging': False,
            'auto_save_credentials': True,
            'download_path': str(Path.home() / "Downloads"),
            'default_start_page': 1,
            'default_end_page': 1,
            'scraping_mode': 0  # 0=All Comics, 1=Latest Comics
        }

    def export_settings(self, export_path):
        """
        Export settings (excluding credentials) to a file.

        Args:
            export_path (str or Path): Path to export settings to

        Returns:
            bool: True if exported successfully, False otherwise
        """
        try:
            config = self._load_config()
            # Remove credentials from export
            export_config = {k: v for k, v in config.items() if k != 'credentials'}

            with open(export_path, 'w', encoding='utf-8') as f:
                json.dump(export_config, f, indent=2, ensure_ascii=False)

            return True
        except Exception as e:
            return False

    def import_settings(self, import_path):
        """
        Import settings (excluding credentials) from a file.

        Args:
            import_path (str or Path): Path to import settings from

        Returns:
            bool: True if imported successfully, False otherwise
        """
        try:
            with open(import_path, 'r', encoding='utf-8') as f:
                imported_config = json.load(f)

            # Don't import credentials for security
            if 'credentials' in imported_config:
                del imported_config['credentials']

            # Merge with existing config
            config = self._load_config()
            config.update(imported_config)

            return self._save_config(config)
        except Exception as e:
            return False