from __future__ import annotations

from datetime import date

from flask import Blueprint, jsonify, redirect, render_template, request, session, url_for
from flask_login import current_user, login_required

from ..extensions import db
from ..forms import PreferencesForm, UserCategoryForm
from ..models import Category
from ..services.analytics import (
    compare_years,
    daily_totals,
    monthly_summary,
    payment_method_totals,
    quarterly_totals,
    range_totals,
    top_expenses,
    weekday_totals,
    yearly_category_totals,
    yearly_overview,
    yearly_totals,
)
from ..services.audit import log_action
from ..services.i18n import translate as _
from ..services.settings import get_bool_setting


main_bp = Blueprint('main', __name__)


@main_bp.route('/')
def index():
    if current_user.is_authenticated:
        return redirect(url_for('main.dashboard'))
    return redirect(url_for('auth.login'))


@main_bp.post('/language')
def set_language():
    lang = request.form.get('language', 'pl')
    if lang not in ['pl', 'en']:
        lang = 'pl'
    session['language'] = lang
    if current_user.is_authenticated:
        current_user.language = lang
        db.session.commit()
    return redirect(request.form.get('next') or request.referrer or url_for('main.index'))


@main_bp.route('/dashboard')
@login_required
def dashboard():
    today = date.today()
    year = request.args.get('year', today.year, type=int)
    month = request.args.get('month', today.month, type=int)
    expenses, total, category_totals, alerts = monthly_summary(current_user.id, year, month)
    chart_categories = [{'label': k, 'amount': float(v)} for k, v in category_totals.items()]
    chart_payments = payment_method_totals(current_user.id, year, month)
    return render_template('main/dashboard.html', expenses=expenses, total=total, category_totals=category_totals, alerts=alerts, selected_year=year, selected_month=month, chart_categories=chart_categories, chart_payments=chart_payments)


@main_bp.route('/statistics')
@login_required
def statistics():
    year = request.args.get('year', date.today().year, type=int)
    month = request.args.get('month', 0, type=int)
    start_year = request.args.get('start_year', max(year - 4, 2000), type=int)
    end_year = request.args.get('end_year', year, type=int)
    if start_year > end_year:
        start_year, end_year = end_year, start_year
    return render_template('main/statistics.html', selected_year=year, selected_month=month, start_year=start_year, end_year=end_year)


@main_bp.route('/analytics/data')
@login_required
def analytics_data():
    year = request.args.get('year', date.today().year, type=int)
    month = request.args.get('month', 0, type=int)
    month = month or None
    start_year = request.args.get('start_year', max(year - 4, 2000), type=int)
    end_year = request.args.get('end_year', year, type=int)
    if start_year > end_year:
        start_year, end_year = end_year, start_year
    return jsonify({
        'yearly_totals': yearly_totals(current_user.id, year, month),
        'daily_totals': daily_totals(current_user.id, year, month),
        'category_totals': yearly_category_totals(current_user.id, year, month),
        'payment_methods': payment_method_totals(current_user.id, year, month),
        'top_expenses': top_expenses(current_user.id, year, month),
        'overview': yearly_overview(current_user.id, year, month),
        'comparison': compare_years(current_user.id, year, month),
        'range_totals': range_totals(current_user.id, start_year, end_year, month),
        'quarterly_totals': quarterly_totals(current_user.id, year, month),
        'weekday_totals': weekday_totals(current_user.id, year, month),
    })


@main_bp.route('/preferences', methods=['GET', 'POST'])
@login_required
def preferences():
    form = PreferencesForm(obj=current_user)
    form.language.choices = [('pl', _('language.polish')), ('en', _('language.english'))]
    form.theme.choices = [('light', _('theme.light')), ('dark', _('theme.dark'))]
    form.report_frequency.choices = [('off', _('report.off')), ('daily', _('report.daily')), ('weekly', _('report.weekly')), ('monthly', _('report.monthly'))]
    category_form = UserCategoryForm(prefix='cat')
    if request.method == 'POST' and 'language' in request.form and form.validate():
        current_user.language = form.language.data
        current_user.theme = form.theme.data
        current_user.report_frequency = form.report_frequency.data if get_bool_setting('reports_enabled', True) else 'off'
        current_user.default_currency = form.default_currency.data
        db.session.commit()
        flash = __import__('flask').flash
        flash(_('flash.settings_saved'), 'success')
        return redirect(url_for('main.preferences'))
    if request.method == 'POST' and 'cat-key' in request.form and category_form.validate():
        key = f'u{current_user.id}_{category_form.key.data.strip().lower()}'
        category = Category.query.filter_by(user_id=current_user.id, key=key).first()
        if not category:
            category = Category(user_id=current_user.id, key=key, name=category_form.name_en.data.strip(), is_active=True)
            db.session.add(category)
        category.name = category_form.name_en.data.strip()
        category.name_pl = category_form.name_pl.data.strip()
        category.name_en = category_form.name_en.data.strip()
        category.color = category_form.color.data
        db.session.commit()
        log_action('user_category_saved', 'category', category.id, owner=current_user.id)
        flash = __import__('flask').flash
        flash(_('flash.category_saved'), 'success')
        return redirect(url_for('main.preferences'))
    my_categories = Category.query.filter_by(user_id=current_user.id).order_by(Category.name_pl).all()
    report_options_enabled = get_bool_setting('reports_enabled', True)
    return render_template('main/preferences.html', form=form, category_form=category_form, my_categories=my_categories, report_options_enabled=report_options_enabled)