import uuid

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

from app.core.deps import get_db_session, require_study_member, require_study_roles
from app.crud import member as member_crud
from app.crud import study as study_crud
from app.crud import user as user_crud
from app.schemas.member import StudyMemberCreate, StudyMemberRead, StudyMemberReadWithUser, StudyMemberUpdate
from app.schemas.user import UserDisplay

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(
    "/",
    response_model=StudyMemberRead,
    status_code=status.HTTP_201_CREATED,
    dependencies=[Depends(require_study_roles(["PM"]))],
)
async def add_member(
    study_id: uuid.UUID,
    member_in: StudyMemberCreate,
    db: AsyncSession = Depends(get_db_session),
) -> StudyMemberRead:
    await _ensure_study_exists(db, study_id)
    existing = await member_crud.get_member(db, study_id, member_in.user_id)
    if existing:
        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="Member already exists")
    member = await member_crud.add_member(db, study_id, member_in)
    return member


@router.get(
    "/",
    response_model=list[StudyMemberReadWithUser],
    dependencies=[Depends(require_study_member())],
)
async def list_members(
    study_id: uuid.UUID,
    skip: int = 0,
    limit: int = 100,
    db: AsyncSession = Depends(get_db_session),
) -> list[StudyMemberReadWithUser]:
    await _ensure_study_exists(db, study_id)
    members = await member_crud.list_members(db, study_id, skip=skip, limit=limit)
    user_ids = {m.user_id for m in members}
    users_map = await user_crud.get_users_by_ids(db, user_ids)
    result: list[StudyMemberReadWithUser] = []
    for m in members:
        # 仅返回项目内启用的成员 + 账号启用的用户
        if not m.is_active:
            continue
        user = users_map.get(m.user_id)
        if not user or not user.is_active:
            continue
        result.append(
            StudyMemberReadWithUser(
                id=m.id,
                study_id=m.study_id,
                user_id=m.user_id,
                role_in_study=m.role_in_study,
                is_active=m.is_active,
                added_at=m.added_at,
                user=UserDisplay.model_validate(user) if user else None,
            )
        )
    return result


@router.patch(
    "/{member_id}",
    response_model=StudyMemberRead,
    dependencies=[Depends(require_study_roles(["PM"]))],
)
async def update_member(
    study_id: uuid.UUID,
    member_id: uuid.UUID,
    member_in: StudyMemberUpdate,
    db: AsyncSession = Depends(get_db_session),
) -> StudyMemberRead:
    await _ensure_study_exists(db, study_id)
    member = await member_crud.get_member_by_id(db, member_id)
    if not member or member.study_id != study_id:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Member not found")
    updated = await member_crud.update_member(db, member, member_in)
    return updated


@router.delete(
    "/{member_id}",
    response_model=StudyMemberRead,
    dependencies=[Depends(require_study_roles(["PM"]))],
)
async def remove_member(
    study_id: uuid.UUID,
    member_id: uuid.UUID,
    db: AsyncSession = Depends(get_db_session),
) -> StudyMemberRead:
    await _ensure_study_exists(db, study_id)
    member = await member_crud.get_member_by_id(db, member_id)
    if not member or member.study_id != study_id:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Member not found")
    removed = await member_crud.remove_member(db, member)
    return removed