import os
import uuid
from fastapi import APIRouter, Depends, HTTPException, Header, UploadFile, File, Form, status
from passlib.context import CryptContext
from sqlalchemy.orm import Session

from database import get_db
from models.site import Site
from models.menu_snapshot import MenuSnapshot
from models.product_image import ProductImage
from schemas.menu import MenuSyncRequest, MenuSyncResponse

router = APIRouter()
_pwd = CryptContext(schemes=["bcrypt"], deprecated="auto")

PRODUCT_IMAGE_DIR = "/app/data/product_images"


def _require_site(
    x_site_id: str = Header(..., alias="X-Site-ID"),
    x_site_key: str = Header(..., alias="X-Site-Key"),
    db: Session = Depends(get_db),
) -> Site:
    site = db.query(Site).filter(Site.site_id == x_site_id).first()
    if not site or not _pwd.verify(x_site_key, site.secret_key_hash):
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid site credentials")
    return site


# ── Public ────────────────────────────────────────────────────────────────────

@router.get("/{site_slug}")
def get_menu(site_slug: str, db: Session = Depends(get_db)):
    """Return the latest menu snapshot for a site. Used by the public menu SPA."""
    site = db.query(Site).filter(Site.site_id == site_slug).first()
    if not site:
        raise HTTPException(status_code=404, detail="Site not found")

    snapshot = db.query(MenuSnapshot).filter(MenuSnapshot.site_id == site.id).first()
    if not snapshot:
        raise HTTPException(status_code=404, detail="No menu published yet")

    import json
    data = json.loads(snapshot.snapshot_json)
    data["menu_mode"] = site.menu_mode
    data["restaurant"] = {
        "name": site.menu_display_name,
        "tagline": {"en": site.menu_tagline_en, "gr": site.menu_tagline_gr},
        "blurb": {"en": site.menu_blurb_en, "gr": site.menu_blurb_gr},
        "hours": site.menu_hours,
        "headerImageUrl": site.menu_header_image_url,
    }

    cloud_images = {
        img.product_id: img.image_url
        for img in db.query(ProductImage).filter(ProductImage.site_id == site.id).all()
    }
    for cat in data.get("categories", []):
        for product in cat.get("products", []):
            # image_url as pushed by local_backend points at the restaurant's own
            # LAN/local server and isn't reachable from the internet — always
            # replace it with the cloud-hosted copy (or None) unless a manual
            # digital_image_url override is set.
            if not product.get("digital_image_url"):
                product["image_url"] = cloud_images.get(product.get("id"))

    return data


# ── Internal (site API key) ───────────────────────────────────────────────────

@router.post("/sync", response_model=MenuSyncResponse)
def sync_menu(body: MenuSyncRequest, site: Site = Depends(_require_site), db: Session = Depends(get_db)):
    """Upsert the menu snapshot for this site. Called by local_backend on each sync."""
    snapshot = db.query(MenuSnapshot).filter(MenuSnapshot.site_id == body.site_id).first()
    if snapshot:
        snapshot.snapshot_json = body.snapshot_json
    else:
        snapshot = MenuSnapshot(site_id=body.site_id, snapshot_json=body.snapshot_json)
        db.add(snapshot)
    db.commit()
    return MenuSyncResponse(ok=True)


@router.post("/sync-image")
async def sync_product_image(
    product_id: int = Form(...),
    file: UploadFile = File(...),
    site: Site = Depends(_require_site),
    db: Session = Depends(get_db),
):
    """Upload/replace the cloud-hosted copy of a product's image. Called by
    local_backend during menu sync for products whose image changed."""
    if not file.content_type or not file.content_type.startswith("image/"):
        raise HTTPException(status_code=400, detail="File must be an image")

    contents = await file.read()

    import hashlib
    image_hash = hashlib.sha256(contents).hexdigest()

    record = (
        db.query(ProductImage)
        .filter(ProductImage.site_id == site.id, ProductImage.product_id == product_id)
        .first()
    )

    os.makedirs(PRODUCT_IMAGE_DIR, exist_ok=True)

    if record and record.image_hash == image_hash:
        return {"ok": True, "image_url": record.image_url, "unchanged": True}

    if record:
        old_path = os.path.join(PRODUCT_IMAGE_DIR, os.path.basename(record.image_url))
        if os.path.exists(old_path):
            os.remove(old_path)

    ext = file.filename.rsplit(".", 1)[-1].lower() if file.filename and "." in file.filename else "jpg"
    filename = f"{site.id}_{product_id}_{uuid.uuid4().hex[:8]}.{ext}"
    filepath = os.path.join(PRODUCT_IMAGE_DIR, filename)
    with open(filepath, "wb") as f:
        f.write(contents)

    image_url = f"/static/product_images/{filename}"
    if record:
        record.image_url = image_url
        record.image_hash = image_hash
    else:
        record = ProductImage(site_id=site.id, product_id=product_id, image_url=image_url, image_hash=image_hash)
        db.add(record)
    db.commit()

    return {"ok": True, "image_url": image_url, "unchanged": False}