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

from datetime import date, datetime, timedelta

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

from werkzeug.security import check_password_hash

from models import (
    get_dashboard_data,
    upsert_response,
    ensure_meal_periods,
    get_user_by_id,
    delete_user,
    delete_household,
    count_household_users,
)
from i18n import t

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(t("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),
        current_user_id=session["user_id"],
        is_admin=session["is_admin"],
    )


@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(t("Invalid meal type."), "error")
        return redirect(url_for("meals.dashboard"))

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

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

    if target_date < date.today():
        flash(t("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(t("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),
        current_user_id=session["user_id"],
        is_admin=session["is_admin"],
        history_mode=True,
    )


# ── Account / household management ────────────────────────────────────────────

@meals_bp.route("/delete-account", methods=["POST"])
@login_required
def delete_account():
    """Delete the currently logged-in user's own account."""
    password = request.form.get("password", "")
    user = get_user_by_id(session["user_id"])

    if not check_password_hash(user["password_hash"], password):
        flash(t("Incorrect password. Account not deleted."), "error")
        return redirect(url_for("meals.dashboard"))

    household_id = session["household_id"]
    is_admin = session["is_admin"]
    user_count = count_household_users(household_id)

    # If admin is the last user, delete the household too
    if is_admin and user_count == 1:
        delete_household(household_id)
        flash(t("Your account and household have been deleted."), "success")
    else:
        delete_user(session["user_id"])
        flash(t("Your account has been deleted."), "success")

    # Clear auth keys but keep the session so flash survives the redirect
    for key in ("user_id", "username", "is_admin", "household_id", "household_name"):
        session.pop(key, None)
    return redirect(url_for("auth.login"))


@meals_bp.route("/admin/remove-user/<int:user_id>", methods=["POST"])
@login_required
def admin_remove_user(user_id):
    """Admin removes a user from the household."""
    if not session["is_admin"]:
        flash(t("Only admins can remove users."), "error")
        return redirect(url_for("meals.dashboard"))

    user = get_user_by_id(user_id)
    if user is None or user["household_id"] != session["household_id"]:
        flash(t("User not found in your household."), "error")
        return redirect(url_for("meals.dashboard"))

    if user["is_admin"]:
        flash(t("Cannot remove the admin. Transfer admin role first or delete the household."), "error")
        return redirect(url_for("meals.dashboard"))

    delete_user(user_id)
    flash(t("User '{name}' has been removed.", name=user["username"]), "success")
    return redirect(url_for("meals.dashboard"))


@meals_bp.route("/admin/delete-household", methods=["POST"])
@login_required
def admin_delete_household():
    """Admin deletes the entire household."""
    if not session["is_admin"]:
        flash(t("Only admins can delete the household."), "error")
        return redirect(url_for("meals.dashboard"))

    password = request.form.get("password", "")
    user = get_user_by_id(session["user_id"])

    if not check_password_hash(user["password_hash"], password):
        flash(t("Incorrect password. Household not deleted."), "error")
        return redirect(url_for("meals.dashboard"))

    delete_household(session["household_id"])
    flash(t("Household and all members have been deleted."), "success")
    for key in ("user_id", "username", "is_admin", "household_id", "household_name"):
        session.pop(key, None)
    return redirect(url_for("auth.login"))