"""
System Settings API endpoints.
Provides key-value storage for system-wide configuration.
"""
from flask import Blueprint, jsonify, request
from server.database import Session
from models.models import SystemSetting
from server.permissions import admin_or_higher
from sqlalchemy.exc import SQLAlchemyError

system_settings_bp = Blueprint('system_settings', __name__, url_prefix='/api/system-settings')


@system_settings_bp.route('', methods=['GET'])
@admin_or_higher
def get_all_settings():
    """
    Get all system settings.
    Admin+ only.
    """
    session = Session()
    try:
        settings = session.query(SystemSetting).all()
        return jsonify({
            'settings': [s.to_dict() for s in settings]
        }), 200
    except SQLAlchemyError as e:
        return jsonify({'error': str(e)}), 500
    finally:
        session.close()


@system_settings_bp.route('/<key>', methods=['GET'])
@admin_or_higher
def get_setting(key):
    """
    Get a specific system setting by key.
    Admin+ only.
    """
    session = Session()
    try:
        setting = session.query(SystemSetting).filter_by(key=key).first()
        if not setting:
            return jsonify({'error': 'Setting not found'}), 404
        return jsonify(setting.to_dict()), 200
    except SQLAlchemyError as e:
        return jsonify({'error': str(e)}), 500
    finally:
        session.close()


@system_settings_bp.route('/<key>', methods=['POST', 'PUT'])
@admin_or_higher
def update_setting(key):
    """
    Create or update a system setting.
    Admin+ only.
    
    Request body:
    {
        "value": "string",
        "description": "string" (optional)
    }
    """
    session = Session()
    try:
        data = request.get_json()
        if not data:
            return jsonify({'error': 'No data provided'}), 400
        
        value = data.get('value')
        description = data.get('description')
        
        # Try to find existing setting
        setting = session.query(SystemSetting).filter_by(key=key).first()
        
        if setting:
            # Update existing
            setting.value = value
            if description is not None:
                setting.description = description
        else:
            # Create new
            setting = SystemSetting(
                key=key,
                value=value,
                description=description
            )
            session.add(setting)
        
        session.commit()
        return jsonify(setting.to_dict()), 200
    except SQLAlchemyError as e:
        session.rollback()
        return jsonify({'error': str(e)}), 500
    finally:
        session.close()


@system_settings_bp.route('/<key>', methods=['DELETE'])
@admin_or_higher
def delete_setting(key):
    """
    Delete a system setting.
    Admin+ only.
    """
    session = Session()
    try:
        setting = session.query(SystemSetting).filter_by(key=key).first()
        if not setting:
            return jsonify({'error': 'Setting not found'}), 404
        
        session.delete(setting)
        session.commit()
        return jsonify({'message': 'Setting deleted successfully'}), 200
    except SQLAlchemyError as e:
        session.rollback()
        return jsonify({'error': str(e)}), 500
    finally:
        session.close()


# Convenience endpoints for specific settings
@system_settings_bp.route('/supplement-table', methods=['GET'])
@admin_or_higher
def get_supplement_table_settings():
    """
    Get supplement table URL and enabled status.
    Admin+ only.
    """
    session = Session()
    try:
        url_setting = session.query(SystemSetting).filter_by(key='supplement_table_url').first()
        enabled_setting = session.query(SystemSetting).filter_by(key='supplement_table_enabled').first()
        
        return jsonify({
            'url': url_setting.value if url_setting else '',
            'enabled': enabled_setting.value == 'true' if enabled_setting else False,
        }), 200
    except SQLAlchemyError as e:
        return jsonify({'error': str(e)}), 500
    finally:
        session.close()


@system_settings_bp.route('/supplement-table', methods=['POST'])
@admin_or_higher
def update_supplement_table_settings():
    """
    Update supplement table URL and enabled status.
    Admin+ only.
    
    Request body:
    {
        "url": "https://...",
        "enabled": true/false
    }
    """
    session = Session()
    try:
        data = request.get_json()
        if not data:
            return jsonify({'error': 'No data provided'}), 400
        
        url = data.get('url', '')
        enabled = data.get('enabled', False)
        
        # Update or create URL setting
        url_setting = session.query(SystemSetting).filter_by(key='supplement_table_url').first()
        if url_setting:
            url_setting.value = url
        else:
            url_setting = SystemSetting(
                key='supplement_table_url',
                value=url,
                description='URL für Vertretungsplan / WebUntis (Stundenplan-Änderungstabelle)'
            )
            session.add(url_setting)
        
        # Update or create enabled setting
        enabled_setting = session.query(SystemSetting).filter_by(key='supplement_table_enabled').first()
        if enabled_setting:
            enabled_setting.value = 'true' if enabled else 'false'
        else:
            enabled_setting = SystemSetting(
                key='supplement_table_enabled',
                value='true' if enabled else 'false',
                description='Ob Vertretungsplan aktiviert ist'
            )
            session.add(enabled_setting)
        
        session.commit()
        
        return jsonify({
            'url': url,
            'enabled': enabled,
            'message': 'Supplement table settings updated successfully'
        }), 200
    except SQLAlchemyError as e:
        session.rollback()
        return jsonify({'error': str(e)}), 500
    finally:
        session.close()