from fastapi import APIRouter, Depends, HTTPException, Body
from sqlalchemy.orm import Session
from datetime import datetime, timedelta
import json

from database import get_db
from schemas import GroceryListRead
from models import GroceryList, MenuPlan, Recipe, Ingredient
from services import pantry_service, ai_service

router = APIRouter(prefix="/api/grocery", tags=["grocery"])
ai_router = APIRouter(prefix="/api/ai", tags=["ai"])


def _current_monday():
    today = datetime.utcnow().date()
    return today - timedelta(days=today.weekday())


@router.get("")
async def list_grocery_lists(db: Session = Depends(get_db)):
    """List all grocery lists."""
    lists = db.query(GroceryList).order_by(GroceryList.generated_at.desc()).all()
    return [GroceryListRead.from_orm(l) for l in lists]


@router.get("/current")
async def get_current_grocery_list(db: Session = Depends(get_db)):
    """Get grocery list for current week."""
    monday = _current_monday()

    grocery_list = db.query(GroceryList).filter(GroceryList.generated_for == monday).first()
    if not grocery_list:
        raise HTTPException(status_code=404, detail="No grocery list for current week")
    return GroceryListRead.from_orm(grocery_list)


@router.get("/{id}")
async def get_grocery_list(id: int, db: Session = Depends(get_db)):
    """Get a grocery list by ID."""
    grocery_list = db.query(GroceryList).filter(GroceryList.id == id).first()
    if not grocery_list:
        raise HTTPException(status_code=404, detail="Grocery list not found")
    return GroceryListRead.from_orm(grocery_list)


@router.post("/generate")
async def generate_grocery_list(request: dict = Body(default={}), db: Session = Depends(get_db)):
    """Generate a grocery list for the current week."""
    user_notes = request.get("user_notes") if request else None

    # Get current week's Monday
    monday = _current_monday()

    # Fetch current MenuPlan
    menu_plan = db.query(MenuPlan).filter(MenuPlan.week_start == monday).first()

    pantry_context = pantry_service.build_pantry_context(db)

    try:
        if menu_plan:
            # Parse the plan JSON (now a flat array of recipe IDs)
            try:
                recipe_ids = json.loads(menu_plan.plan)
            except json.JSONDecodeError:
                raise HTTPException(status_code=500, detail="Invalid menu plan data")

            recipes = db.query(Recipe).filter(Recipe.id.in_(recipe_ids)).all() if recipe_ids else []
            recipe_map = {r.id: r for r in recipes}

            recipes_for_ai = []
            for recipe_id in recipe_ids:
                recipe = recipe_map.get(recipe_id)
                if recipe:
                    try:
                        ingredients = json.loads(recipe.ingredients)
                    except (json.JSONDecodeError, TypeError):
                        ingredients = []
                    recipes_for_ai.append({
                        "name": recipe.name,
                        "meal_type": recipe.meal_type,
                        "ingredients": ingredients,
                    })

            ai_result = await ai_service.generate_grocery_list(recipes_for_ai, pantry_context, user_notes)
        else:
            ai_result = await ai_service.generate_grocery_list_from_pantry(pantry_context, user_notes)
    except ValueError as e:
        raise HTTPException(status_code=503, detail=str(e))
    except Exception as e:
        raise HTTPException(status_code=503, detail=f"Ollama service error: {str(e)}")

    # Upsert GroceryList
    existing_list = db.query(GroceryList).filter(GroceryList.generated_for == monday).first()
    if existing_list:
        existing_list.items = json.dumps(ai_result.get("items", []))
        existing_list.total_estimate = ai_result.get("total_estimate", 0.0)
        existing_list.notes = ai_result.get("shopping_notes", "")
        existing_list.generated_at = datetime.utcnow()
        grocery_list = existing_list
    else:
        grocery_list = GroceryList(
            generated_for=monday,
            items=json.dumps(ai_result.get("items", [])),
            total_estimate=ai_result.get("total_estimate", 0.0),
            notes=ai_result.get("shopping_notes", ""),
            generated_at=datetime.utcnow(),
        )
        db.add(grocery_list)

    db.commit()
    db.refresh(grocery_list)

    return {
        "grocery_list": GroceryListRead.from_orm(grocery_list),
        "items": ai_result.get("items", []),
        "shopping_notes": ai_result.get("shopping_notes", ""),
    }


@router.delete("/current")
async def delete_current_grocery_list(db: Session = Depends(get_db)):
    """Delete the grocery list for the current week."""
    monday = _current_monday()
    grocery_list = db.query(GroceryList).filter(GroceryList.generated_for == monday).first()
    if not grocery_list:
        raise HTTPException(status_code=404, detail="No grocery list for current week")
    db.delete(grocery_list)
    db.commit()
    return {"status": "deleted"}


@router.patch("/{id}/check-item")
async def check_grocery_item(id: int, request: dict = Body(...), db: Session = Depends(get_db)):
    """Mark a grocery item as checked/unchecked."""
    grocery_list = db.query(GroceryList).filter(GroceryList.id == id).first()
    if not grocery_list:
        raise HTTPException(status_code=404, detail="Grocery list not found")

    item_name = request.get("name")
    checked = request.get("checked", False)

    if not item_name:
        raise HTTPException(status_code=400, detail="Item name is required")

    # Parse items
    try:
        items = json.loads(grocery_list.items)
    except json.JSONDecodeError:
        items = []

    # Find and update the item
    item_found = False
    for item in items:
        if isinstance(item, dict) and item.get("name") == item_name:
            item["checked"] = checked
            item_found = True
            break

    if not item_found:
        raise HTTPException(status_code=404, detail="Item not found in grocery list")

    # Save back to database
    grocery_list.items = json.dumps(items)
    db.commit()

    return {"status": "ok"}


@router.put("/{id}/purchased")
async def mark_purchased(id: int, db: Session = Depends(get_db)):
    """Mark a grocery list as purchased and update pantry."""
    grocery_list = db.query(GroceryList).filter(GroceryList.id == id).first()
    if not grocery_list:
        raise HTTPException(status_code=404, detail="Grocery list not found")

    # Mark as purchased
    grocery_list.is_purchased = True

    # Parse items
    try:
        items = json.loads(grocery_list.items)
    except json.JSONDecodeError:
        items = []

    # Update pantry for each item
    for item in items:
        if isinstance(item, dict):
            name = item.get("name")
            quantity = item.get("quantity", 0)
            unit = item.get("unit", "")

            if name:
                # Check if ingredient exists
                existing_ingredient = db.query(Ingredient).filter(Ingredient.name == name).first()
                if existing_ingredient:
                    existing_ingredient.quantity += quantity
                    existing_ingredient.updated_at = datetime.utcnow()
                else:
                    # Create new ingredient
                    new_ingredient = Ingredient(
                        name=name,
                        quantity=quantity,
                        unit=unit,
                        category=item.get("store_section"),
                    )
                    db.add(new_ingredient)

    db.commit()
    db.refresh(grocery_list)
    return GroceryListRead.from_orm(grocery_list)


@ai_router.post("/suggest-recipe")
async def suggest_recipe_endpoint(db: Session = Depends(get_db)):
    """Suggest a recipe based on current pantry."""
    try:
        context = pantry_service.build_pantry_context(db)
        result = await ai_service.suggest_recipe(context)
        return result
    except ValueError as e:
        raise HTTPException(status_code=503, detail=str(e))
    except Exception as e:
        raise HTTPException(status_code=503, detail=f"Ollama service error: {str(e)}")


@ai_router.get("/models")
async def list_models():
    """List available Ollama models."""
    models = await ai_service.get_available_models()
    return {"models": models}


@ai_router.post("/chat")
async def chat_endpoint(request: dict = Body(default={}), db: Session = Depends(get_db)):
    """Chat with Commis using current kitchen context."""
    message = request.get("message", "").strip()
    if not message:
        raise HTTPException(status_code=400, detail="Message is required")

    history = request.get("history", [])

    # Build pantry context
    pantry_context = pantry_service.build_pantry_context(db)

    # Get current week's menu recipes
    monday = _current_monday()

    menu_plan = db.query(MenuPlan).filter(MenuPlan.week_start == monday).first()
    menu_context = []
    if menu_plan:
        try:
            plan_ids = json.loads(menu_plan.plan)
            recipes = db.query(Recipe).filter(Recipe.id.in_(plan_ids)).all() if plan_ids else []
            menu_context = [{"name": r.name, "meal_type": r.meal_type} for r in recipes]
        except Exception:
            menu_context = []

    # Get current grocery list items
    grocery_list = db.query(GroceryList).filter(GroceryList.generated_for == monday).first()
    grocery_context = []
    if grocery_list:
        try:
            grocery_context = json.loads(grocery_list.items)
        except Exception:
            grocery_context = []

    try:
        response = await ai_service.chat_with_commis(message, history, pantry_context, menu_context, grocery_context)
        return {"response": response}
    except ValueError as e:
        raise HTTPException(status_code=503, detail=str(e))
    except Exception as e:
        raise HTTPException(status_code=503, detail=f"Ollama service error: {str(e)}")