import uuid

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.deps import get_current_user, get_db_session, require_study_member, require_study_roles
from app.crud import audit as audit_crud
from app.crud import finance_contract as contract_crud
from app.crud import study as study_crud
from app.schemas.finance_contract import FinanceContractCreate, FinanceContractRead, FinanceContractUpdate

router = APIRouter()


async def _ensure_study_exists(db: AsyncSession, study_id: uuid.UUID):
    study = await study_crud.get(db, study_id)
    if not study:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Study not found")
    return study


@router.post(
    "/contracts",
    response_model=FinanceContractRead,
    status_code=status.HTTP_201_CREATED,
    dependencies=[Depends(require_study_roles(["PM", "CRA"]))],
)
async def create_contract(
    study_id: uuid.UUID,
    contract_in: FinanceContractCreate,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> FinanceContractRead:
    await _ensure_study_exists(db, study_id)
    contract = await contract_crud.create_contract(db, study_id, contract_in, created_by=current_user.id)
    await audit_crud.log_action(
        db,
        study_id=study_id,
        entity_type="finance_contract",
        entity_id=contract.id,
        action="CREATE_FINANCE_CONTRACT",
        detail=f"Finance contract {contract.contract_no} created",
        operator_id=current_user.id,
        operator_role=current_user.role,
    )
    return FinanceContractRead.model_validate(contract)


@router.get(
    "/contracts",
    response_model=list[FinanceContractRead],
    dependencies=[Depends(require_study_member())],
)
async def list_contracts(
    study_id: uuid.UUID,
    site_name: str | None = None,
    contract_no: str | None = None,
    skip: int = 0,
    limit: int = 100,
    db: AsyncSession = Depends(get_db_session),
) -> list[FinanceContractRead]:
    await _ensure_study_exists(db, study_id)
    items = await contract_crud.list_contracts(db, study_id, site_name=site_name, contract_no=contract_no, skip=skip, limit=limit)
    return [FinanceContractRead.model_validate(item) for item in items]


@router.get(
    "/contracts/{contract_id}",
    response_model=FinanceContractRead,
    dependencies=[Depends(require_study_member())],
)
async def get_contract(
    study_id: uuid.UUID,
    contract_id: uuid.UUID,
    db: AsyncSession = Depends(get_db_session),
) -> FinanceContractRead:
    await _ensure_study_exists(db, study_id)
    contract = await contract_crud.get_contract(db, contract_id)
    if not contract or contract.study_id != study_id:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Contract not found")
    return FinanceContractRead.model_validate(contract)


@router.patch(
    "/contracts/{contract_id}",
    response_model=FinanceContractRead,
    dependencies=[Depends(require_study_roles(["PM", "CRA"]))],
)
async def update_contract(
    study_id: uuid.UUID,
    contract_id: uuid.UUID,
    contract_in: FinanceContractUpdate,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> FinanceContractRead:
    await _ensure_study_exists(db, study_id)
    contract = await contract_crud.get_contract(db, contract_id)
    if not contract or contract.study_id != study_id:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Contract not found")
    contract = await contract_crud.update_contract(db, contract, contract_in)
    await audit_crud.log_action(
        db,
        study_id=study_id,
        entity_type="finance_contract",
        entity_id=contract_id,
        action="UPDATE_FINANCE_CONTRACT",
        detail=f"Finance contract {contract_id} updated",
        operator_id=current_user.id,
        operator_role=current_user.role,
    )
    return FinanceContractRead.model_validate(contract)


@router.delete(
    "/contracts/{contract_id}",
    status_code=status.HTTP_204_NO_CONTENT,
    dependencies=[Depends(require_study_roles(["PM", "CRA"]))],
)
async def delete_contract(
    study_id: uuid.UUID,
    contract_id: uuid.UUID,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> None:
    await _ensure_study_exists(db, study_id)
    contract = await contract_crud.get_contract(db, contract_id)
    if not contract or contract.study_id != study_id:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Contract not found")
    await contract_crud.delete_contract(db, contract)
    await audit_crud.log_action(
        db,
        study_id=study_id,
        entity_type="finance_contract",
        entity_id=contract_id,
        action="DELETE_FINANCE_CONTRACT",
        detail=f"Finance contract {contract_id} deleted",
        operator_id=current_user.id,
        operator_role=current_user.role,
    )