"""Equipment CRUD endpoints."""

from fastapi import APIRouter, Depends, HTTPException, status, Query
from sqlalchemy import select, func, or_
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import joinedload

from app.api.deps import get_current_user, require_permission
from app.db.session import get_async_session
from app.models import User, Equipment, StockLocation, Contact
from app.schemas.equipment import (
    EquipmentCreateRequest,
    EquipmentUpdateRequest,
    EquipmentResponse,
    EquipmentListResponse,
    LocationRef,
    SupplierRef,
)

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


@router.get("", response_model=EquipmentListResponse)
async def list_equipment(
    page: int = Query(1, ge=1),
    size: int = Query(20, ge=1, le=100),
    search: str | None = Query(None, description="Search in name, brand, serial_number"),
    category: str | None = Query(None, description="Filter by category"),
    status: str | None = Query(None, description="Filter by status"),
    location_id: str | None = Query(None, description="Filter by location"),
    current_user: User = Depends(require_permission("equipment:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """List equipment with search, filters, pagination."""
    account_id = current_user.account_id

    base_q = select(Equipment).where(Equipment.account_id == account_id)

    if search:
        pattern = f"%{search}%"
        base_q = base_q.where(
            or_(
                Equipment.name.ilike(pattern),
                Equipment.brand.ilike(pattern),
                Equipment.serial_number.ilike(pattern),
                Equipment.barcode.ilike(pattern),
            )
        )

    if category:
        base_q = base_q.where(Equipment.category == category)
    if status:
        base_q = base_q.where(Equipment.status == status)
    if location_id:
        base_q = base_q.where(Equipment.location_id == location_id)

    count_q = select(func.count()).select_from(base_q.subquery())
    total = (await session.execute(count_q)).scalar() or 0

    q = (
        base_q
        .options(joinedload(Equipment.location), joinedload(Equipment.supplier))
        .order_by(Equipment.updated_at.desc())
        .offset((page - 1) * size)
        .limit(size)
    )
    result = await session.execute(q)
    items = result.unique().scalars().all()

    return EquipmentListResponse(
        items=[EquipmentResponse.model_validate(i) for i in items],
        total=total,
        page=page,
        size=size,
    )


@router.post("", response_model=EquipmentResponse, status_code=status.HTTP_201_CREATED)
async def create_equipment(
    body: EquipmentCreateRequest,
    current_user: User = Depends(require_permission("equipment:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Create a new equipment item."""
    account_id = current_user.account_id

    # Validate location if provided
    if body.location_id:
        loc_result = await session.execute(
            select(StockLocation).where(
                StockLocation.id == body.location_id,
                StockLocation.account_id == account_id,
            )
        )
        if not loc_result.scalars().first():
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="Stock location not found",
            )

    # Validate supplier if provided
    if body.supplier_id:
        sup_result = await session.execute(
            select(Contact).where(
                Contact.id == body.supplier_id,
                Contact.account_id == account_id,
            )
        )
        if not sup_result.scalars().first():
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="Supplier (contact) not found",
            )

    item = Equipment(account_id=account_id, **body.model_dump())
    session.add(item)
    await session.commit()
    await session.refresh(item)

    await session.execute(
        select(Equipment)
        .options(joinedload(Equipment.location), joinedload(Equipment.supplier))
        .where(Equipment.id == item.id)
    )
    await session.refresh(item)

    return EquipmentResponse.model_validate(item)


@router.get("/{item_id}", response_model=EquipmentResponse)
async def get_equipment(
    item_id: str,
    current_user: User = Depends(require_permission("equipment:read")),
    session: AsyncSession = Depends(get_async_session),
):
    """Get a specific equipment item."""
    account_id = current_user.account_id
    result = await session.execute(
        select(Equipment)
        .options(joinedload(Equipment.location), joinedload(Equipment.supplier))
        .where(Equipment.id == item_id, Equipment.account_id == account_id)
    )
    item = result.unique().scalars().first()
    if not item:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Equipment not found")
    return EquipmentResponse.model_validate(item)


@router.put("/{item_id}", response_model=EquipmentResponse)
async def update_equipment(
    item_id: str,
    body: EquipmentUpdateRequest,
    current_user: User = Depends(require_permission("equipment:write")),
    session: AsyncSession = Depends(get_async_session),
):
    """Update an existing equipment item."""
    account_id = current_user.account_id
    result = await session.execute(
        select(Equipment)
        .options(joinedload(Equipment.location), joinedload(Equipment.supplier))
        .where(Equipment.id == item_id, Equipment.account_id == account_id)
    )
    item = result.unique().scalars().first()
    if not item:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Equipment not found")

    update_data = body.model_dump(exclude_unset=True)
    for field, value in update_data.items():
        setattr(item, field, value)

    await session.commit()
    await session.refresh(item)
    return EquipmentResponse.model_validate(item)


@router.delete("/{item_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_equipment(
    item_id: str,
    current_user: User = Depends(require_permission("equipment:delete")),
    session: AsyncSession = Depends(get_async_session),
):
    """Delete an equipment item."""
    account_id = current_user.account_id
    result = await session.execute(
        select(Equipment).where(Equipment.id == item_id, Equipment.account_id == account_id)
    )
    item = result.scalars().first()
    if not item:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Equipment not found")

    await session.delete(item)
    await session.commit()
    return None