from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from app.database import get_db
from app.models import HomePantry, Ingredient, FamilyProfile
from app.schemas import (
    HomePantryResponse,
    HomePantryCreate,
    HomePantryBulkCreate,
    HomePantryBulkResult,
    HomePantryBulkResultItem,
)
from app.security import require_session
from uuid import UUID
from typing import List

router = APIRouter()


@router.get("", response_model=List[HomePantryResponse])
def get_pantry_items(db: Session = Depends(get_db)):
    profile = db.query(FamilyProfile).first()
    if not profile:
        raise HTTPException(status_code=404, detail="Family profile not found")

    items = db.query(HomePantry).filter(
        HomePantry.family_profile_id == profile.id
    ).all()
    return items


@router.post("", response_model=HomePantryResponse, dependencies=[Depends(require_session)])
def add_pantry_item(item: HomePantryCreate, db: Session = Depends(get_db)):
    profile = db.query(FamilyProfile).first()
    if not profile:
        raise HTTPException(status_code=404, detail="Family profile not found")

    existing = db.query(HomePantry).filter(
        HomePantry.family_profile_id == profile.id,
        HomePantry.ingredient_id == item.ingredient_id
    ).first()

    if existing:
        existing.quantity = item.quantity
        existing.unit = item.unit
        existing.expires_at = item.expires_at
        db.commit()
        db.refresh(existing)
        return existing

    db_item = HomePantry(
        family_profile_id=profile.id,
        ingredient_id=item.ingredient_id,
        quantity=item.quantity,
        unit=item.unit,
        expires_at=item.expires_at
    )

    db.add(db_item)
    db.commit()
    db.refresh(db_item)
    return db_item


@router.post("/bulk", response_model=HomePantryBulkResult, dependencies=[Depends(require_session)])
def add_pantry_items_bulk(payload: HomePantryBulkCreate, db: Session = Depends(get_db)):
    """Add or upsert many pantry items in a single call.

    Used by the Shopping List "Add checked to pantry" bulk action. Each
    item follows the same semantics as POST /api/pantry (insert or
    overwrite). Items missing an ingredient link or with an
    unknown ingredient id are reported as "skipped" rather than
    aborting the batch, so the user gets a precise count of what
    actually went into their pantry.
    """
    profile = db.query(FamilyProfile).first()
    if not profile:
        raise HTTPException(status_code=404, detail="Family profile not found")

    results: List[HomePantryBulkResultItem] = []
    added = updated = skipped = 0

    for item in payload.items:
        # Validate the ingredient id before touching the DB.
        ingredient = db.query(Ingredient).filter(Ingredient.id == item.ingredient_id).first()
        if not ingredient:
            results.append(HomePantryBulkResultItem(
                ingredient_id=item.ingredient_id,
                status="skipped",
                reason="Unknown ingredient",
            ))
            skipped += 1
            continue

        existing = db.query(HomePantry).filter(
            HomePantry.family_profile_id == profile.id,
            HomePantry.ingredient_id == item.ingredient_id,
        ).first()

        if existing:
            existing.quantity = item.quantity
            existing.unit = item.unit
            existing.expires_at = item.expires_at
            db.flush()
            results.append(HomePantryBulkResultItem(
                ingredient_id=item.ingredient_id,
                id=existing.id,
                status="updated",
            ))
            updated += 1
        else:
            db_item = HomePantry(
                family_profile_id=profile.id,
                ingredient_id=item.ingredient_id,
                quantity=item.quantity,
                unit=item.unit,
                expires_at=item.expires_at,
            )
            db.add(db_item)
            db.flush()
            results.append(HomePantryBulkResultItem(
                ingredient_id=item.ingredient_id,
                id=db_item.id,
                status="added",
            ))
            added += 1

    db.commit()
    return HomePantryBulkResult(
        added=added,
        updated=updated,
        skipped=skipped,
        results=results,
    )


@router.delete("/{item_id}", dependencies=[Depends(require_session)])
def remove_pantry_item(item_id: UUID, db: Session = Depends(get_db)):
    item = db.query(HomePantry).filter(HomePantry.id == item_id).first()
    if not item:
        raise HTTPException(status_code=404, detail="Pantry item not found")

    db.delete(item)
    db.commit()
    return {"message": "Pantry item removed"}


@router.put("/{item_id}", response_model=HomePantryResponse, dependencies=[Depends(require_session)])
def update_pantry_item(item_id: UUID, update: HomePantryCreate, db: Session = Depends(get_db)):
    item = db.query(HomePantry).filter(HomePantry.id == item_id).first()
    if not item:
        raise HTTPException(status_code=404, detail="Pantry item not found")

    item.ingredient_id = update.ingredient_id
    item.quantity = update.quantity
    item.unit = update.unit
    item.expires_at = update.expires_at

    db.commit()
    db.refresh(item)
    return item