"""Meals blueprint — dashboard, responses, history."""

from datetime import date, datetime, timedelta

from flask import (
    Blueprint,
    render_template,
    request,
    redirect,
    url_for,
    session,
    flash,
)

from models import get_dashboard_data, upsert_response, ensure_meal_periods

meals_bp = Blueprint("meals", __name__)


def login_required(f):
    """Decorator: redirect to login if not authenticated or session is stale."""
    from functools import wraps

    @wraps(f)
    def wrapper(*args, **kwargs):
        if "user_id" not in session or "household_id" not in session:
            session.clear()
            return redirect(url_for("auth.login"))
        return f(*args, **kwargs)

    return wrapper


@meals_bp.route("/")
def index():
    if "user_id" in session:
        return redirect(url_for("meals.dashboard"))
    return redirect(url_for("auth.login"))


@meals_bp.route("/dashboard")
@login_required
def dashboard():
    today = date.today()
    household_id = session["household_id"]

    # Allow viewing other dates via query param
    date_str = request.args.get("date")
    if date_str:
        try:
            today = datetime.strptime(date_str, "%Y-%m-%d").date()
        except ValueError:
            flash("Invalid date format. Use YYYY-MM-DD.", "error")

    if household_id is None:
        session.clear()
        return redirect(url_for("auth.login"))

    data = get_dashboard_data(today, household_id)
    return render_template(
        "dashboard.html",
        dashboard=data,
        viewing_date=today,
        today=date.today(),
        prev_date=today - timedelta(days=1),
        next_date=today + timedelta(days=1),
    )


@meals_bp.route("/respond", methods=["POST"])
@login_required
def respond():
    meal_type = request.form.get("meal_type", "").strip()
    status = request.form.get("status", "").strip()
    date_str = request.form.get("date", date.today().isoformat())

    if meal_type not in ("lunch", "dinner"):
        flash("Invalid meal type.", "error")
        return redirect(url_for("meals.dashboard"))

    if status not in ("yes", "no"):
        flash("Invalid status.", "error")
        return redirect(url_for("meals.dashboard"))

    try:
        target_date = datetime.strptime(date_str, "%Y-%m-%d").date()
    except ValueError:
        flash("Invalid date.", "error")
        return redirect(url_for("meals.dashboard"))

    if target_date < date.today():
        flash("Cannot change responses for past dates.", "error")
        return redirect(url_for("meals.dashboard"))

    periods = ensure_meal_periods(target_date)
    period = next((p for p in periods if p["meal_type"] == meal_type), None)
    if period is None:
        flash("Meal period not found.", "error")
        return redirect(url_for("meals.dashboard"))

    upsert_response(session["user_id"], period["id"], status)
    return redirect(url_for("meals.dashboard"))


@meals_bp.route("/history")
@login_required
def history():
    date_str = request.args.get("date", date.today().isoformat())
    try:
        target_date = datetime.strptime(date_str, "%Y-%m-%d").date()
    except ValueError:
        target_date = date.today()

    data = get_dashboard_data(target_date, session["household_id"])
    return render_template(
        "dashboard.html",
        dashboard=data,
        viewing_date=target_date,
        today=date.today(),
        prev_date=target_date - timedelta(days=1),
        next_date=target_date + timedelta(days=1),
        history_mode=True,
    )