from sqlalchemy import insert
from backend.app.db.models.recommendations import Plan, Recommendation, RecommendationMaterials, PlanRecommendations


def create_plan(session, plan):
    """
    This function will create a record for the plan in the database if it does not exist.
    :param plan: dictionary of data representing a plan to be created
    """

    new_plan = Plan(**plan)
    session.add(new_plan)
    session.flush()

    return new_plan.id


def create_recommendation(session, recommendation):
    """
    This function will create a record for the recommendation in the database if it does not exist.
    :param session: The database session
    :param recommendation: dictionary of data representing a recommendation to be created
    """

    new_recommendation = Recommendation(**recommendation)
    session.add(new_recommendation)
    session.flush()

    return new_recommendation.id


def create_recommendation_material(session, recommendation_id, material_id, depth):
    """
    This function will create a record for the recommendation_material in the database if it does not exist.
    :param session: The databse session
    :param recommendation_id: ID of the recommendation
    :param material_id: ID of the material
    :param depth: depth of the material, may be null if a material where depth is not applicable
    """

    new_recommendation_material = RecommendationMaterials(
        recommendation_id=recommendation_id,
        material_id=material_id,
        depth=depth
    )
    session.add(new_recommendation_material)
    session.flush()

    return new_recommendation_material.id


def create_plan_recommendations(session, plan_id, recommendation_ids):
    """
    This function will create records for the plan_recommendation in the database.
    :param plan_id: ID of the plan
    :param recommendation_ids: list of recommendation IDs
    """

    # Prepare a list of dictionaries for bulk insert
    data = [{"plan_id": plan_id, "recommendation_id": rid} for rid in recommendation_ids]

    # Bulk insert using SQLAlchemy's core API
    session.execute(insert(PlanRecommendations).values(data))


def upload_recommendations(session, recommendations_to_upload, property_id):
    # Prepare data for bulk insert for Recommendation
    recommendations_data = [
        {
            "property_id": property_id,
            "type": rec["type"],
            "description": rec["description"],
            "estimated_cost": rec["cost"],
            "default": rec["default"],
            "starting_u_value": rec.get("starting_u_value"),
            "new_u_value": rec.get("new_u_value"),
            "sap_points": rec["sap_points"]
        }
        for rec in recommendations_to_upload
    ]

    session.bulk_insert_mappings(Recommendation, recommendations_data)

    # To get the IDs of the newly inserted recommendations, we need to flush the session
    session.flush()

    # Map the uploaded_recommendation_ids with the original data for reference
    uploaded_recommendation_ids = [rec.id for rec in session.query(Recommendation).filter(
        Recommendation.property_id == property_id,
        Recommendation.description.in_([rec["description"] for rec in recommendations_to_upload])
    )]

    # Prepare data for bulk insert for RecommendationMaterials
    recommendation_materials_data = [
        {
            "recommendation_id": recommendation_id,
            "material_id": part["id"],
            "depth": part["depths"][0] if part["depths"] else None,
            "quantity": part["quantity"],
            "quantity_unit": part["quantity_unit"],
            "estimated_cost": part["estimated_cost"],
        }
        for rec, recommendation_id in zip(recommendations_to_upload, uploaded_recommendation_ids)
        for part in rec["parts"]
    ]

    session.bulk_insert_mappings(RecommendationMaterials, recommendation_materials_data)

    # flush the changes to get the newly created IDs
    session.flush()

    return uploaded_recommendation_ids