from typing import Optional
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func

from app.database import get_db
from app.models.company import Company
from app.models.user import User
from app.schemas.company import CompanyCreate, CompanyUpdate, CompanyOut, CompanyListOut
from app.schemas.paged import PagedOut
from app.deps import get_current_user, require_role

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


@router.get("", response_model=PagedOut[CompanyListOut])
async def list_companies(
    search: Optional[str] = Query(None),
    page: int = Query(1, ge=1),
    limit: int = Query(20, ge=1, le=500),
    db: AsyncSession = Depends(get_db),
    _: User = Depends(get_current_user),
):
    filters = []
    if search:
        filters.append(Company.name.ilike(f"%{search}%"))

    count_q = select(func.count()).select_from(Company)
    if filters:
        count_q = count_q.where(*filters)
    total = await db.scalar(count_q)

    q = select(Company).order_by(Company.name)
    if filters:
        q = q.where(*filters)
    q = q.offset((page - 1) * limit).limit(limit)
    result = await db.execute(q)
    items = result.scalars().all()

    return PagedOut(items=items, total=total, page=page, limit=limit)


@router.get("/{company_id}", response_model=CompanyOut)
async def get_company(
    company_id: int,
    db: AsyncSession = Depends(get_db),
    _: User = Depends(get_current_user),
):
    result = await db.execute(select(Company).where(Company.id == company_id))
    company = result.scalar_one_or_none()
    if not company:
        raise HTTPException(status_code=404, detail="Company not found")
    return company


@router.post("", response_model=CompanyOut, status_code=201)
async def create_company(
    body: CompanyCreate,
    db: AsyncSession = Depends(get_db),
    _: User = Depends(require_role("admin")),
):
    company = Company(**body.model_dump())
    db.add(company)
    try:
        await db.commit()
        await db.refresh(company)
    except Exception:
        await db.rollback()
        raise
    return company


@router.put("/{company_id}", response_model=CompanyOut)
async def update_company(
    company_id: int,
    body: CompanyUpdate,
    db: AsyncSession = Depends(get_db),
    _: User = Depends(require_role("admin")),
):
    result = await db.execute(select(Company).where(Company.id == company_id))
    company = result.scalar_one_or_none()
    if not company:
        raise HTTPException(status_code=404, detail="Company not found")

    for k, v in body.model_dump(exclude_none=True).items():
        setattr(company, k, v)

    try:
        await db.commit()
        await db.refresh(company)
    except Exception:
        await db.rollback()
        raise
    return company


@router.delete("/{company_id}", status_code=204)
async def delete_company(
    company_id: int,
    db: AsyncSession = Depends(get_db),
    _: User = Depends(require_role("admin")),
):
    result = await db.execute(select(Company).where(Company.id == company_id))
    company = result.scalar_one_or_none()
    if not company:
        raise HTTPException(status_code=404, detail="Company not found")

    try:
        await db.delete(company)
        await db.commit()
    except Exception:
        await db.rollback()
        raise