"""Controller for entity-related operations."""
from models.database import entity_collection

def retrieve_hot_entity():
    """Retrieves the top 200 unique entities from a MongoDB collection,
    sorted by the total occurrence field in descending order.
    The function returns a dict containing the count of documents and a list of documents.

    Returns:
        dict: Contains:
            - Count (int): The number of unique entities retrieved (up to 200).
            - Items (list): A list of dictionaries, each containing:
                - entity: The value of the entity field.
                - entityType: The value of the entityType field.
                - total_occurrence: The summed value of the occurrence field for the entity.
    """
    pipeline = [
        {
            "$group": {
                "_id": {
                    "entity": "$entity",
                    "entityType": "$entityType"
                },
                "total_occurrence": {"$sum": "$occurrence"}
            }
        },
        {
            "$project": {
                "_id": 0,
                "entity": "$_id.entity",
                "entityType": "$_id.entityType",
                "total_occurrence": 1
            }
        },
        {"$sort": {"total_occurrence": -1}},
        {"$limit": 200}
    ]
    
    result = list(entity_collection.aggregate(pipeline))
    res = {
        "Count": len(result),
        "Items": result
    }
    return res