"""
Migrate notifications from legacy database.

This script migrates notification data from the VBScript database
to the new notifications plugin schema.

Usage:
    python -m scripts.migration.migrate_notifications --source <connection_string>
"""

import argparse
import logging
from datetime import datetime
from sqlalchemy import create_engine, text
from sqlalchemy.orm import sessionmaker

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)


def get_notification_type_mapping(target_session):
    """Get mapping of type names to IDs in target database."""
    result = target_session.execute(text(
        "SELECT notificationtypeid, typename FROM notificationtypes"
    ))
    return {row.typename.lower(): row.notificationtypeid for row in result}


def run_migration(source_conn_str, target_conn_str, dry_run=False):
    """
    Run notification migration.

    Args:
        source_conn_str: Source database connection string
        target_conn_str: Target database connection string
        dry_run: If True, don't commit changes
    """
    source_engine = create_engine(source_conn_str)
    target_engine = create_engine(target_conn_str)

    SourceSession = sessionmaker(bind=source_engine)
    TargetSession = sessionmaker(bind=target_engine)

    source_session = SourceSession()
    target_session = TargetSession()

    try:
        # Get type mappings
        type_mapping = get_notification_type_mapping(target_session)

        # Default type if not found
        default_type_id = type_mapping.get('general', 1)

        # Fetch notifications from source
        # Adjust column names based on actual legacy schema
        notifications = source_session.execute(text("""
            SELECT n.*, nt.typename
            FROM notifications n
            LEFT JOIN notificationtypes nt ON n.notificationtypeid = nt.notificationtypeid
        """))

        migrated = 0
        errors = 0

        for notif in notifications:
            notif_dict = dict(notif._mapping)

            try:
                # Map notification type
                type_name = (notif_dict.get('typename') or 'general').lower()
                type_id = type_mapping.get(type_name, default_type_id)

                # Insert into target
                target_session.execute(text("""
                    INSERT INTO notifications (
                        title, message, notificationtypeid,
                        startdate, enddate, ispinned, showbanner, allday,
                        linkurl, affectedsystems, isactive, createddate
                    ) VALUES (
                        :title, :message, :notificationtypeid,
                        :startdate, :enddate, :ispinned, :showbanner, :allday,
                        :linkurl, :affectedsystems, :isactive, :createddate
                    )
                """), {
                    'title': notif_dict.get('title', 'Untitled'),
                    'message': notif_dict.get('message', ''),
                    'notificationtypeid': type_id,
                    'startdate': notif_dict.get('startdate', datetime.utcnow()),
                    'enddate': notif_dict.get('enddate'),
                    'ispinned': notif_dict.get('ispinned', False),
                    'showbanner': notif_dict.get('showbanner', True),
                    'allday': notif_dict.get('allday', True),
                    'linkurl': notif_dict.get('linkurl'),
                    'affectedsystems': notif_dict.get('affectedsystems'),
                    'isactive': notif_dict.get('isactive', True),
                    'createddate': notif_dict.get('createddate', datetime.utcnow()),
                })

                migrated += 1

            except Exception as e:
                logger.error(f"Error migrating notification: {e}")
                errors += 1

        if dry_run:
            logger.info("Dry run - rolling back changes")
            target_session.rollback()
        else:
            target_session.commit()

        logger.info(f"Migration complete: {migrated} migrated, {errors} errors")

    finally:
        source_session.close()
        target_session.close()


def main():
    parser = argparse.ArgumentParser(description='Migrate notifications')
    parser.add_argument('--source', required=True, help='Source database connection string')
    parser.add_argument('--target', help='Target database connection string')
    parser.add_argument('--dry-run', action='store_true', help='Dry run without committing')

    args = parser.parse_args()

    target = args.target
    if not target:
        import os
        import sys
        sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.dirname(__file__))))
        from shopdb import create_app
        app = create_app()
        target = app.config['SQLALCHEMY_DATABASE_URI']

    run_migration(args.source, target, args.dry_run)


if __name__ == '__main__':
    main()