import uuid

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

from app.core.deps import get_operator_role_label, get_current_user, get_db_session, require_study_not_locked, require_api_permission
from app.crud import audit as audit_crud
from app.crud import project_milestone as milestone_crud
from app.crud import study as study_crud
from app.schemas.project_milestone import ProjectMilestoneRead, ProjectMilestoneUpdate

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="项目不存在")
    return study


def _validate_date_range(start, end, label: str):
    if (start and not end) or (not start and end):
        raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail=f"{label}开始和结束日期需同时填写")
    if start and end and end < start:
        raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail=f"{label}结束日期不能早于开始日期")


@router.get(
    "/milestones",
    response_model=list[ProjectMilestoneRead],
    dependencies=[Depends(require_api_permission("project_milestones:read"))],
)
async def list_project_milestones(
    study_id: uuid.UUID,
    db: AsyncSession = Depends(get_db_session),
) -> list[ProjectMilestoneRead]:
    await _ensure_study_exists(db, study_id)
    rows = await milestone_crud.list_project_milestones(db, study_id)
    return [ProjectMilestoneRead.model_validate(item) for item in rows]


@router.patch(
    "/milestones/{milestone_id}",
    response_model=ProjectMilestoneRead,
    dependencies=[Depends(require_api_permission("project_milestones:update")), Depends(require_study_not_locked())],
)
async def update_project_milestone(
    study_id: uuid.UUID,
    milestone_id: uuid.UUID,
    payload: ProjectMilestoneUpdate,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(get_current_user),
) -> ProjectMilestoneRead:
    await _ensure_study_exists(db, study_id)
    row = await milestone_crud.get_project_milestone(db, study_id, milestone_id)
    if not row:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="项目里程碑不存在")

    _validate_date_range(payload.adjusted_start_date, payload.adjusted_end_date, "调整计划时间")
    _validate_date_range(payload.actual_start_date, payload.actual_end_date, "实际时间")

    item = await milestone_crud.update_project_milestone(db, row, payload)
    await audit_crud.log_action(
        db,
        study_id=study_id,
        entity_type="milestone",
        entity_id=milestone_id,
        action="UPDATE_PROJECT_MILESTONE",
        detail=f"项目里程碑 {milestone_id} 已更新",
        operator_id=current_user.id,
        operator_role=await get_operator_role_label(db, study_id, current_user),
    )
    return ProjectMilestoneRead.model_validate(item)