import uuid
from datetime import date

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

from app.core.deps import get_cra_site_scope, get_current_user, get_db_session, require_study_not_locked
from app.crud import audit as audit_crud
from app.crud import member as member_crud
from app.crud import special_expense as special_crud
from app.crud import study as study_crud
from app.crud import site as site_crud
from app.schemas.fee_common import FeeApiResponse
from app.schemas.special_expense import (
    SpecialExpenseCreate,
    SpecialExpenseListItem,
    SpecialExpenseRead,
    SpecialExpenseUpdate,
)

router = APIRouter()

ALLOWED_CATEGORIES = {"travel", "meal", "meeting", "supplies", "other"}


async def _ensure_project_access(db: AsyncSession, project_id: uuid.UUID, current_user, write: bool = False):
    study = await study_crud.get(db, project_id)
    if not study:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="项目不存在")
    role_value = current_user.role.value if hasattr(current_user.role, "value") else current_user.role
    if role_value == "ADMIN":
        return None
    membership = await member_crud.get_member(db, project_id, current_user.id)
    if not membership or not membership.is_active:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="不是项目成员")
    if write and membership.role_in_study != "PM":
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="项目权限不足")
    return membership


def _validate_special_rules(payload: SpecialExpenseCreate | SpecialExpenseUpdate):
    if payload.is_verified is True and payload.is_paid is False:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="核销需先打款")
    if payload.is_paid and not payload.paid_date:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="已打款需填写打款日期")
    if payload.is_verified and not payload.verified_date:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="已核销需填写核销日期")


def _validate_category(value: str | None):
    if value and value not in ALLOWED_CATEGORIES:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="费用类别无效")


async def _ensure_center_active(db: AsyncSession, project_id: uuid.UUID, center_id: uuid.UUID | None):
    if not center_id:
        return
    site = await site_crud.get_site(db, center_id)
    if not site or site.study_id != project_id or not site.is_active:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="中心已停用")


@router.get(
    "/special",
    response_model=FeeApiResponse[list[SpecialExpenseListItem]],
    dependencies=[Depends(get_current_user)],
)
async def list_special_expenses(
    project_id: uuid.UUID = Query(..., alias="projectId"),
    center_id: uuid.UUID | None = Query(None, alias="centerId"),
    category: str | None = None,
    date_from: date | None = Query(None, alias="dateFrom"),
    date_to: date | None = Query(None, alias="dateTo"),
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> FeeApiResponse[list[SpecialExpenseListItem]]:
    await _ensure_project_access(db, project_id, current_user, write=False)
    _validate_category(category)
    cra_scope = await get_cra_site_scope(db, project_id, current_user)
    center_ids = cra_scope[0] if cra_scope else None
    if center_id and center_ids is not None and center_id not in center_ids:
        return FeeApiResponse(data=[], meta={"total": 0})
    rows = await special_crud.list_special_expenses(
        db,
        project_id,
        center_id=center_id,
        center_ids=center_ids,
        category=category,
        date_from=date_from,
        date_to=date_to,
    )
    items: list[SpecialExpenseListItem] = []
    for expense, center_name, attachments_count in rows:
        items.append(
            SpecialExpenseListItem(
                id=expense.id,
                project_id=expense.project_id,
                center_id=expense.center_id,
                category=expense.category,
                amount=expense.amount,
                happen_date=expense.happen_date,
                description=expense.description,
                is_paid=expense.is_paid,
                paid_date=expense.paid_date,
                is_verified=expense.is_verified,
                verified_date=expense.verified_date,
                created_by=expense.created_by,
                created_at=expense.created_at,
                updated_at=expense.updated_at,
                center_name=center_name,
                attachments_count=attachments_count or 0,
            )
        )
    return FeeApiResponse(data=items, meta={"total": len(items)})


@router.get(
    "/special/{expense_id}",
    response_model=FeeApiResponse[SpecialExpenseRead],
    dependencies=[Depends(get_current_user)],
)
async def get_special_expense(
    expense_id: uuid.UUID,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> FeeApiResponse[SpecialExpenseRead]:
    expense = await special_crud.get_special_expense(db, expense_id)
    if not expense:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="特殊费用不存在")
    await _ensure_project_access(db, expense.project_id, current_user, write=False)
    cra_scope = await get_cra_site_scope(db, expense.project_id, current_user)
    if cra_scope and expense.center_id not in cra_scope[0]:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="权限不足")
    return FeeApiResponse(data=SpecialExpenseRead.model_validate(expense))


@router.post(
    "/special",
    response_model=FeeApiResponse[SpecialExpenseRead],
    status_code=status.HTTP_201_CREATED,
    dependencies=[Depends(get_current_user), Depends(require_study_not_locked())],
)
async def create_special_expense(
    expense_in: SpecialExpenseCreate,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> FeeApiResponse[SpecialExpenseRead]:
    await _ensure_project_access(db, expense_in.project_id, current_user, write=True)
    _validate_category(expense_in.category)
    _validate_special_rules(expense_in)
    if expense_in.center_id:
        site = await site_crud.get_site(db, expense_in.center_id)
        if not site or site.study_id != expense_in.project_id or not site.is_active:
            raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="中心不存在或已停用")
    await _ensure_center_active(db, expense_in.project_id, expense_in.center_id)
    expense = await special_crud.create_special_expense(db, expense_in, created_by=current_user.id)
    await audit_crud.log_action(
        db,
        study_id=expense.project_id,
        entity_type="special_expense",
        entity_id=expense.id,
        action="CREATE_SPECIAL_EXPENSE",
        detail="特殊费用已创建",
        operator_id=current_user.id,
        operator_role=current_user.role,
    )
    return FeeApiResponse(data=SpecialExpenseRead.model_validate(expense))


@router.patch(
    "/special/{expense_id}",
    response_model=FeeApiResponse[SpecialExpenseRead],
    dependencies=[Depends(get_current_user), Depends(require_study_not_locked())],
)
async def update_special_expense(
    expense_id: uuid.UUID,
    expense_in: SpecialExpenseUpdate,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> FeeApiResponse[SpecialExpenseRead]:
    expense = await special_crud.get_special_expense(db, expense_id)
    if not expense:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="特殊费用不存在")
    await _ensure_project_access(db, expense.project_id, current_user, write=True)
    _validate_category(expense_in.category)
    merged = SpecialExpenseCreate(
        project_id=expense.project_id,
        center_id=expense_in.center_id if expense_in.center_id is not None else expense.center_id,
        category=expense_in.category if expense_in.category is not None else expense.category,
        amount=expense_in.amount if expense_in.amount is not None else expense.amount,
        happen_date=expense_in.happen_date if expense_in.happen_date is not None else expense.happen_date,
        description=expense_in.description if expense_in.description is not None else expense.description,
        is_paid=expense_in.is_paid if expense_in.is_paid is not None else expense.is_paid,
        paid_date=expense_in.paid_date if expense_in.paid_date is not None else expense.paid_date,
        is_verified=expense_in.is_verified if expense_in.is_verified is not None else expense.is_verified,
        verified_date=expense_in.verified_date if expense_in.verified_date is not None else expense.verified_date,
    )
    _validate_special_rules(merged)
    if expense_in.center_id:
        site = await site_crud.get_site(db, expense_in.center_id)
        if not site or site.study_id != expense.project_id or not site.is_active:
            raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="中心不存在或已停用")
        await _ensure_center_active(db, expense.project_id, expense_in.center_id)
    else:
        await _ensure_center_active(db, expense.project_id, expense.center_id)
    expense = await special_crud.update_special_expense(db, expense, expense_in)
    await audit_crud.log_action(
        db,
        study_id=expense.project_id,
        entity_type="special_expense",
        entity_id=expense_id,
        action="UPDATE_SPECIAL_EXPENSE",
        detail="特殊费用已更新",
        operator_id=current_user.id,
        operator_role=current_user.role,
    )
    return FeeApiResponse(data=SpecialExpenseRead.model_validate(expense))


@router.delete(
    "/special/{expense_id}",
    status_code=status.HTTP_204_NO_CONTENT,
    dependencies=[Depends(get_current_user), Depends(require_study_not_locked())],
)
async def delete_special_expense(
    expense_id: uuid.UUID,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> None:
    expense = await special_crud.get_special_expense(db, expense_id)
    if not expense:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="特殊费用不存在")
    await _ensure_project_access(db, expense.project_id, current_user, write=True)
    await _ensure_center_active(db, expense.project_id, expense.center_id)
    await special_crud.delete_special_expense(db, expense)
    await audit_crud.log_action(
        db,
        study_id=expense.project_id,
        entity_type="special_expense",
        entity_id=expense_id,
        action="DELETE_SPECIAL_EXPENSE",
        detail="特殊费用已删除",
        operator_id=current_user.id,
        operator_role=current_user.role,
    )