from datetime import datetime, timezone, timedelta

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy import func, select
from sqlalchemy.exc import IntegrityError
from sqlalchemy.ext.asyncio import AsyncSession

from app.dependencies import get_db, get_current_user
from app.models.contact_request import ContactRequest
from app.models.user import User
from app.schemas.contact import ContactRequestCreate, ContactRequestListOut, ContactRequestOut
from app.utils.id_gen import generate_id

router = APIRouter(prefix="/contact", tags=["contact"])


@router.post("/request", summary="提交联系请求", status_code=status.HTTP_201_CREATED)
async def create_contact_request(
    request: ContactRequestCreate,
    db: AsyncSession = Depends(get_db),
    user: User = Depends(get_current_user),
):
    today_str = datetime.now(timezone.utc).strftime("%Y-%m-%d")
    
    async with db.begin_nested():
        user_result = await db.execute(
            select(User).where(User.id == user.id).with_for_update().limit(1)
        )
        locked_user = user_result.scalar_one_or_none()
        if not locked_user:
            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="用户不存在")
        
        existing = await db.execute(
            select(ContactRequest.id)
            .where(ContactRequest.user_id == user.id)
            .where(ContactRequest.submit_date == today_str)
            .limit(1)
        )
        if existing.scalar_one_or_none():
            raise HTTPException(
                status_code=status.HTTP_429_TOO_MANY_REQUESTS,
                detail="每个账号每天只能提交一次联系我们"
            )
    
    try:
        contact_request = ContactRequest(
            id=generate_id(),
            user_id=user.id,
            phone=request.phone,
            company_name=request.company_name,
            industry=request.industry,
            name=request.name,
            message=request.message,
            submit_date=today_str,
        )
        db.add(contact_request)
        await db.commit()
    except IntegrityError:
        await db.rollback()
        raise HTTPException(
            status_code=status.HTTP_429_TOO_MANY_REQUESTS,
            detail="每个账号每天只能提交一次联系我们"
        )
    
    return {"message": "提交成功，我们会尽快与您联系"}


@router.get("/requests", summary="获取联系请求列表", response_model=ContactRequestListOut)
async def get_contact_requests(
    page: int = 1,
    page_size: int = 20,
    is_handled: bool | None = None,
    db: AsyncSession = Depends(get_db),
    user: User = Depends(get_current_user),
):
    if not user.is_admin:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="无权限")
    
    query = select(ContactRequest)
    count_query = select(func.count(ContactRequest.id))
    
    if is_handled is not None:
        query = query.where(ContactRequest.is_handled == is_handled)
        count_query = count_query.where(ContactRequest.is_handled == is_handled)
    
    query = query.order_by(ContactRequest.created_at.desc())
    
    offset = (page - 1) * page_size
    result = await db.execute(query.offset(offset).limit(page_size))
    items = result.scalars().all()
    
    total = (await db.execute(count_query)).scalar_one()
    
    return {"items": items, "total": total}


@router.get("/requests/{request_id}", summary="获取联系请求详情", response_model=ContactRequestOut)
async def get_contact_request(
    request_id: str,
    db: AsyncSession = Depends(get_db),
    user: User = Depends(get_current_user),
):
    if not user.is_admin:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="无权限")
    
    result = await db.execute(select(ContactRequest).where(ContactRequest.id == request_id))
    contact_request = result.scalar_one_or_none()
    
    if not contact_request:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="记录不存在")
    
    return contact_request


@router.put("/requests/{request_id}/handle", summary="标记为已处理")
async def mark_as_handled(
    request_id: str,
    db: AsyncSession = Depends(get_db),
    user: User = Depends(get_current_user),
):
    if not user.is_admin:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="无权限")
    
    result = await db.execute(select(ContactRequest).where(ContactRequest.id == request_id))
    contact_request = result.scalar_one_or_none()
    
    if not contact_request:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="记录不存在")
    
    contact_request.is_handled = True
    await db.commit()
    await db.refresh(contact_request)
    
    return {"message": "已标记为处理"}


@router.delete("/requests/{request_id}", summary="删除联系请求")
async def delete_contact_request(
    request_id: str,
    db: AsyncSession = Depends(get_db),
    user: User = Depends(get_current_user),
):
    if not user.is_admin:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="无权限")
    
    result = await db.execute(select(ContactRequest).where(ContactRequest.id == request_id))
    contact_request = result.scalar_one_or_none()
    
    if not contact_request:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="记录不存在")
    
    await db.delete(contact_request)
    await db.commit()
    
    return {"message": "删除成功"}