import uuid
from datetime import date, timedelta
from decimal import Decimal

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.contract_fee import ContractFee
from app.models.contract_fee_payment import ContractFeePayment
from app.models.fee_attachment import FeeAttachment
from app.models.site import Site
from app.models.special_expense import SpecialExpense
from app.models.study import Study
from app.models.user import User


async def seed_demo_fees(db: AsyncSession) -> None:
    existing_contract = await db.execute(select(ContractFee.id).limit(1))
    existing_special = await db.execute(select(SpecialExpense.id).limit(1))
    if existing_contract.scalar_one_or_none() or existing_special.scalar_one_or_none():
        return

    result = await db.execute(select(Study).order_by(Study.created_at.asc()))
    study = result.scalars().first()
    if not study:
        study = Study(
            id=uuid.uuid4(),
            code="DEMO-CTMS",
            name="示例临床试验项目",
            sponsor="示例申办方",
            status="ACTIVE",
        )
        db.add(study)
        await db.commit()
        await db.refresh(study)

    result = await db.execute(select(Site).where(Site.study_id == study.id))
    sites = result.scalars().all()
    if len(sites) < 3:
        for idx in range(3 - len(sites)):
            site = Site(
                id=uuid.uuid4(),
                study_id=study.id,
                name=f"示例中心 {len(sites) + idx + 1}",
                city="上海",
                pi_name="张医生",
                contact="010-88888888",
            )
            db.add(site)
        await db.commit()
        result = await db.execute(select(Site).where(Site.study_id == study.id))
        sites = result.scalars().all()

    user_result = await db.execute(select(User).order_by(User.created_at.asc()))
    uploader = user_result.scalars().first()
    uploader_id = uploader.id if uploader else None

    today = date.today()
    for idx, site in enumerate(sites[:3], start=1):
        contract = ContractFee(
            id=uuid.uuid4(),
            project_id=study.id,
            center_id=site.id,
            contract_amount=Decimal("120000.00") + Decimal(idx * 10000),
            contract_cases=50 + idx * 5,
            actual_cases=40 + idx * 4,
            settlement_amount=Decimal("80000.00") + Decimal(idx * 5000),
            final_payment_amount=Decimal("20000.00") + Decimal(idx * 2000),
        )
        db.add(contract)
        await db.commit()
        await db.refresh(contract)

        payments = [
            ContractFeePayment(
                id=uuid.uuid4(),
                contract_fee_id=contract.id,
                seq=1,
                amount=Decimal("40000.00") + Decimal(idx * 2000),
                is_paid=True,
                paid_date=today - timedelta(days=30),
                is_verified=True,
                verified_date=today - timedelta(days=20),
                remark="首付款已核销",
            ),
            ContractFeePayment(
                id=uuid.uuid4(),
                contract_fee_id=contract.id,
                seq=2,
                amount=Decimal("30000.00") + Decimal(idx * 1000),
                is_paid=True,
                paid_date=today - timedelta(days=10),
                is_verified=False,
                remark="等待核销",
            ),
            ContractFeePayment(
                id=uuid.uuid4(),
                contract_fee_id=contract.id,
                seq=3,
                amount=Decimal("20000.00") + Decimal(idx * 1000),
                is_paid=False,
                remark="未打款",
            ),
        ]
        db.add_all(payments)
        await db.commit()

        if uploader_id:
            attachments = [
                FeeAttachment(
                    id=uuid.uuid4(),
                    entity_type="contract_fee",
                    entity_id=contract.id,
                    file_type="contract",
                    filename=f"合同-{site.name}.pdf",
                    mime_type="application/pdf",
                    size=102400,
                    storage_key=None,
                    url="https://example.com/contract-demo.pdf",
                    uploaded_by=uploader_id,
                ),
                FeeAttachment(
                    id=uuid.uuid4(),
                    entity_type="contract_fee",
                    entity_id=contract.id,
                    file_type="voucher",
                    filename=f"凭证-{site.name}.pdf",
                    mime_type="application/pdf",
                    size=20480,
                    storage_key=None,
                    url="https://example.com/voucher-demo.pdf",
                    uploaded_by=uploader_id,
                ),
            ]
            db.add_all(attachments)
            await db.commit()

    categories = ["travel", "meal", "meeting", "supplies", "other"]
    for idx, category in enumerate(categories):
        for seq in range(2):
            expense = SpecialExpense(
                id=uuid.uuid4(),
                project_id=study.id,
                center_id=sites[seq % len(sites)].id if sites else None,
                category=category,
                amount=Decimal("800.00") + Decimal(seq * 150),
                happen_date=today - timedelta(days=5 * (seq + 1)),
                description=f"{category} 费用示例",
                is_paid=seq % 2 == 0,
                paid_date=today - timedelta(days=3 * (seq + 1)) if seq % 2 == 0 else None,
                is_verified=seq == 0,
                verified_date=today - timedelta(days=2 * (seq + 1)) if seq == 0 else None,
                created_by=uploader_id,
            )
            db.add(expense)
        await db.commit()

    result = await db.execute(select(SpecialExpense).where(SpecialExpense.project_id == study.id))
    expenses = result.scalars().all()
    if uploader_id:
        for expense in expenses[:3]:
            attachment = FeeAttachment(
                id=uuid.uuid4(),
                entity_type="special_expense",
                entity_id=expense.id,
                file_type="invoice",
                filename=f"发票-{expense.id}.pdf",
                mime_type="application/pdf",
                size=40960,
                storage_key=None,
                url="https://example.com/invoice-demo.pdf",
                uploaded_by=uploader_id,
            )
            db.add(attachment)
        await db.commit()