from fastapi import APIRouter, Depends, Query, UploadFile, File, HTTPException
from fastapi.responses import FileResponse
from typing import Optional
import os
import shutil
from sqlalchemy.ext.asyncio import AsyncSession

from auth.models import TokenPayload
from auth.dependencies import require_permission
from crm.models import ProductCreate, ProductUpdate, ProductInDB, ProductListResponse
from crm import service
from database.postgres import get_pg_session
from shared.audit import log_action

router = APIRouter(prefix="/api/crm/products", tags=["crm-products"])

PHOTO_DIR = os.path.join(os.path.dirname(__file__), "..", "storage", "product_images")
os.makedirs(PHOTO_DIR, exist_ok=True)


@router.get("", response_model=ProductListResponse)
def list_products(
    search: Optional[str] = Query(None),
    category: Optional[str] = Query(None),
    active_only: bool = Query(False),
    _user: TokenPayload = Depends(require_permission("crm", "view")),
):
    products = service.list_products(search=search, category=category, active_only=active_only)
    return ProductListResponse(products=products, total=len(products))


@router.get("/{product_id}", response_model=ProductInDB)
def get_product(
    product_id: str,
    _user: TokenPayload = Depends(require_permission("crm", "view")),
):
    return service.get_product(product_id)


@router.post("", response_model=ProductInDB, status_code=201)
async def create_product(
    body: ProductCreate,
    _user: TokenPayload = Depends(require_permission("crm", "edit")),
    db: AsyncSession = Depends(get_pg_session),
):
    product = service.create_product(body)
    await log_action(db, _user.sub, _user.name or _user.email, "CREATE", "product",
                     product.id, product.name)
    return product


@router.put("/{product_id}", response_model=ProductInDB)
async def update_product(
    product_id: str,
    body: ProductUpdate,
    _user: TokenPayload = Depends(require_permission("crm", "edit")),
    db: AsyncSession = Depends(get_pg_session),
):
    old = service.get_product(product_id)
    product = service.update_product(product_id, body)
    _SKIP = {"updated_at", "id", "photo_url"}
    changes = {
        k: {"old": getattr(old, k, None), "new": getattr(product, k, None)}
        for k in body.model_fields_set
        if k not in _SKIP and getattr(old, k, None) != getattr(product, k, None)
    }
    await log_action(db, _user.sub, _user.name or _user.email, "UPDATE", "product",
                     product_id, product.name, changes=changes or None)
    return product


@router.delete("/{product_id}", status_code=204)
async def delete_product(
    product_id: str,
    _user: TokenPayload = Depends(require_permission("crm", "edit")),
    db: AsyncSession = Depends(get_pg_session),
):
    product = service.get_product(product_id)
    service.delete_product(product_id)
    await log_action(db, _user.sub, _user.name or _user.email, "DELETE", "product",
                     product_id, product.name)


@router.post("/{product_id}/photo", response_model=ProductInDB)
async def upload_product_photo(
    product_id: str,
    file: UploadFile = File(...),
    _user: TokenPayload = Depends(require_permission("crm", "edit")),
):
    """Upload a product photo. Accepts JPG or PNG, stored on disk."""
    if file.content_type not in ("image/jpeg", "image/png", "image/webp"):
        raise HTTPException(status_code=400, detail="Only JPG, PNG, or WebP images are accepted.")
    ext = {"image/jpeg": "jpg", "image/png": "png", "image/webp": "webp"}.get(file.content_type, "jpg")
    photo_path = os.path.join(PHOTO_DIR, f"{product_id}.{ext}")
    # Remove any old photo files for this product
    for old_ext in ("jpg", "png", "webp"):
        old_path = os.path.join(PHOTO_DIR, f"{product_id}.{old_ext}")
        if os.path.exists(old_path) and old_path != photo_path:
            os.remove(old_path)
    with open(photo_path, "wb") as f:
        shutil.copyfileobj(file.file, f)
    photo_url = f"/crm/products/{product_id}/photo"
    return service.update_product(product_id, ProductUpdate(photo_url=photo_url))


@router.get("/{product_id}/photo")
def get_product_photo(
    product_id: str,
):
    """Serve a product photo from disk."""
    for ext in ("jpg", "png", "webp"):
        photo_path = os.path.join(PHOTO_DIR, f"{product_id}.{ext}")
        if os.path.exists(photo_path):
            return FileResponse(photo_path)
    raise HTTPException(status_code=404, detail="No photo found for this product.")