from datetime import date

from sqlalchemy import select

from app.db.session import Base, SessionLocal, engine
from app.models.assumption import FreightCostRule, PackagingCostRule, ProcessCostRule
from app.models.mix import Mix, MixIngredient
from app.models.product import Product
from app.models.raw_material import RawMaterial, RawMaterialPriceVersion


def seed_if_empty():
    Base.metadata.create_all(bind=engine)
    with SessionLocal() as db:
        existing = db.scalar(select(RawMaterial.id))
        if existing is not None:
            return

        maize = RawMaterial(name="Maize", supplier="Example Supplier", unit_of_measure="tonne", kg_per_unit=1000, status="active")
        barley = RawMaterial(name="Barley", supplier="Example Supplier", unit_of_measure="tonne", kg_per_unit=1000, status="active")
        acid_buf = RawMaterial(name="Acid Buf", supplier="Example Supplier", unit_of_measure="bag", kg_per_unit=25, status="active")

        maize.price_versions.append(RawMaterialPriceVersion(market_value=520, waste_percentage=0.02, effective_date=date(2026, 4, 1)))
        barley.price_versions.append(RawMaterialPriceVersion(market_value=470, waste_percentage=0.015, effective_date=date(2026, 4, 1)))
        acid_buf.price_versions.append(RawMaterialPriceVersion(market_value=39, waste_percentage=0.0, effective_date=date(2026, 4, 1)))

        db.add_all([maize, barley, acid_buf])
        db.flush()

        db.add_all(
            [
                ProcessCostRule(process_name="standard_bagging", grading_cost=0.055, bagging_cost=0.04, cracking_cost=0.0),
                ProcessCostRule(process_name="bulk_loadout", grading_cost=0.03, bagging_cost=0.0, cracking_cost=0.0),
                PackagingCostRule(sale_type="standard", unit_of_measure="20kg bag", own_bag=False, bag_cost=0.63),
                PackagingCostRule(sale_type="bulka", unit_of_measure="550kg bulka", own_bag=False, bag_cost=7.5),
                FreightCostRule(sale_type="standard", unit_of_measure="20kg bag", cost_per_unit=1.45),
                FreightCostRule(sale_type="bulka", unit_of_measure="550kg bulka", cost_per_unit=18.0),
            ]
        )
        db.flush()

        mix = Mix(client_name="Specialty Feeds", name="Pigeon Mix", status="active", version=1, notes="Seed recipe for MVP")
        db.add(mix)
        db.flush()

        db.add_all(
            [
                MixIngredient(mix_id=mix.id, raw_material_id=maize.id, quantity_kg=180),
                MixIngredient(mix_id=mix.id, raw_material_id=barley.id, quantity_kg=95),
                MixIngredient(mix_id=mix.id, raw_material_id=acid_buf.id, quantity_kg=5),
            ]
        )
        db.flush()

        db.add(
            Product(
                client_name="Specialty Feeds",
                item_id="SKU-001",
                name="Specialty Pigeon Breeder 20kg",
                mix_id=mix.id,
                sale_type="standard",
                own_bag=False,
                unit_of_measure="20kg bag",
                items_per_pallet=50,
                bagging_process="standard_bagging",
                distributor_margin=0.225,
                wholesale_margin=0.18,
                notes="Reference product for formula parity work",
            )
        )
        db.commit()


if __name__ == "__main__":
    seed_if_empty()