from flask import (
    Blueprint,
    redirect,
    url_for,
    render_template,
    session,
    request,
    jsonify,
    abort,
)
from flask_login import current_user
from forms import FoodItemForm, FoodLogForm
from application import db
from models import FoodItem, FoodLog
from sqlalchemy import and_, or_
from datetime import datetime, timedelta, timezone
from sqlalchemy.sql.elements import BinaryExpression
from typing import cast

bp = Blueprint(
    "add_meal",
    __name__,
    url_prefix="/add_meal",
    template_folder="templates",
)


@bp.before_request
def login_required():
    if not current_user.is_authenticated:
        return redirect(url_for("login"))


@bp.route("/select_meal/<int:meal_type>", methods=["GET"])
def step1(meal_type: int):
    assert type(meal_type) is int
    assert 0 <= meal_type <= 3
    session["meal_type"] = meal_type
    return redirect(url_for("add_meal.step2"))


@bp.route("/get_barcode", methods=["GET"])
def step2():
    return render_template("scan_barcode.html")


@bp.route("/step3/<string:input>", methods=["GET"])
def step3(input: str):
    # check if meal_type cookie is set
    if "meal_type" not in session:
        return redirect("/")

    # Check if input is a barcode
    if input.isdigit():
        item = current_user.food_items.filter_by(barcode=input).first()

    else:
        item = current_user.food_items.filter_by(name=input).first()

    if item is None:
        # Does not exist, add item
        return redirect(url_for("add_meal.step3_alt1", input=input))

    # Track item to add and continue to next step
    session["item_id"] = item.id
    return redirect(url_for("add_meal.step4"))


@bp.route("/step3_alt1/<string:input>", methods=["GET"])
def step3_alt1(input: str):
    form = FoodItemForm()

    if input.isdigit():
        form.barcode.data = input
    else:
        form.name.data = input
    return render_template("add_item.html", form=form)


@bp.route("/step3_alt1/<string:input>", methods=["POST"])
def step3_alt1_post(input: str):
    form = FoodItemForm()

    if form.validate_on_submit():
        # Form has valid input
        barcode = form.barcode.data
        name = form.name.data
        assert name
        assert form.energy.data is not None
        assert form.protein.data is not None
        assert form.carbs.data is not None
        assert form.fat.data is not None

        # Check if name or barcode already exists
        name_filter = cast(BinaryExpression, FoodItem.name == name)
        barcode_filter = cast(BinaryExpression, FoodItem.barcode == barcode)
        filter_exp = or_(name_filter, barcode_filter)
        item = current_user.food_items.filter(filter_exp).first()

        if item is None:
            # Item does not exist, add to DB
            barcode = (
                barcode if barcode else None
            )  # Turn empty strings into None
            db.session.add(
                FoodItem(
                    name=name,
                    owner_id=current_user.id,
                    energy=form.energy.data,
                    protein=form.protein.data,
                    carbs=form.carbs.data,
                    fat=form.fat.data,
                    barcode=barcode,
                    saturated_fat=form.saturated_fat.data,
                    sugar=form.sugar.data,
                )
            )
            db.session.commit()
            print("[DEBUG] New FoodItem Added")
            input = barcode if barcode else name  # update input
        else:
            print(f"Item exists: {item.barcode} {item.name}")

        # Item added or already present, return to step 3.
        return redirect(url_for("add_meal.step3", input=input))
    else:
        print("[DEBUG] Form Invalid")
        return redirect(url_for("add_meal.step3_alt1", input=input))


@bp.route("/step4", methods=["GET", "POST"])
def step4():
    if "item_id" not in session:
        return redirect(url_for("add_meal.step2"))
    form = FoodLogForm()
    item = db.session.get(FoodItem, session["item_id"])

    offset = session["offset"]
    if offset is None or item is None:
        abort(404)

    today = datetime.now(timezone.utc).date()
    day = today + timedelta(days=offset)

    if form.validate_on_submit():
        assert form.amount.data
        db.session.add(
            FoodLog(
                food_item_id=item.id,
                user_id=current_user.id,
                amount=form.amount.data,
                part_of_day=session["meal_type"],
                date_=day,
            )
        )
        db.session.commit()
        session.pop("meal_type")
        session.pop("item_id")
        return redirect(url_for("user.daily_log", offset=offset))

    match session["meal_type"]:
        case 0:
            tod = "Breakfast"
        case 1:
            tod = "Lunch"
        case 2:
            tod = "Dinner"
        case 3:
            tod = "Snack"
        case _:
            tod = "Unknown"
    return render_template("step4.html", tod=tod, item=item, form=form)


@bp.route("/query", methods=["GET"])
def query():
    q = request.args.get("q", "").strip().lower()
    if not q:
        return jsonify([])

    words = q.split()
    filters = [
        FoodItem.name.ilike(f"%{word}%") for word in words  # type: ignore
    ]

    results = current_user.food_items.filter(and_(*filters)).all()
    return jsonify([item.name for item in results])