from collections import defaultdict
from flask import Blueprint, render_template, redirect, request, url_for, flash
import humanize
from pytz import timezone, utc
from sqlalchemy import func
from app.models import Reading, db
from app.forms import DeleteForm, ReadingForm
from flask_login import login_required, current_user
from datetime import date, datetime, timedelta
reading = Blueprint('reading', __name__)

@reading.route('/add', methods=['GET', 'POST'])
@login_required
def add_reading():
    form = ReadingForm()
    if form.validate_on_submit():
        new_reading = Reading(
            user_id=current_user.id,
            timestamp=form.timestamp.data,
            systolic=form.systolic.data,
            diastolic=form.diastolic.data,
            heart_rate=form.heart_rate.data
        )
        db.session.add(new_reading)
        db.session.commit()
        flash("Reading added successfully.", "success")
        return redirect(url_for('main.dashboard'))
    
    # Fetch the user's timezone (default to 'UTC' if none is set)
    user_timezone = current_user.profile.timezone if current_user.profile and current_user.profile.timezone else 'UTC'
    local_tz = timezone(user_timezone)

    form.timestamp.data = utc.localize(datetime.utcnow()).astimezone(local_tz)
    return render_template('reading/add_reading.html', form=form)

@reading.route('/<int:reading_id>/edit', methods=['GET', 'POST'])
@login_required
def edit_reading(reading_id):
    reading = Reading.query.get_or_404(reading_id)
    
    # Ensure the reading belongs to the logged-in user
    if reading.user_id != current_user.id:
        flash('You are not authorized to edit this reading.', 'danger')
        return redirect(url_for('main.dashboard'))
    
    # Fetch the user's timezone (default to 'UTC' if none is set)
    user_timezone = current_user.profile.timezone if current_user.profile and current_user.profile.timezone else 'UTC'
    local_tz = timezone(user_timezone)

    reading.local_timestamp = utc.localize(reading.timestamp).astimezone(local_tz)

    form = ReadingForm(obj=reading)  # Populate form with existing reading data
    form.timestamp.data = reading.local_timestamp
    if form.validate_on_submit():
        # Convert the local timestamp back to UTC for saving
        local_timestamp = form.timestamp.data
        # Ensure the local timestamp is naive before localizing
        if local_timestamp.tzinfo is not None:
            local_timestamp = local_timestamp.replace(tzinfo=None)

        reading.timestamp = local_tz.localize(local_timestamp).astimezone(utc)

        reading.systolic = form.systolic.data
        reading.diastolic = form.diastolic.data
        reading.heart_rate = form.heart_rate.data
        db.session.commit()
        flash('Reading updated successfully!', 'success')
        return redirect(url_for('main.dashboard'))

    return render_template('reading/edit_reading.html', form=form, reading=reading)

@reading.route('/<int:reading_id>/confirm_delete', methods=['GET', 'POST'])
@login_required
def confirm_delete(reading_id):
    # Fetch the reading to confirm deletion
    reading = Reading.query.filter_by(id=reading_id, user_id=current_user.id).first_or_404()

    if request.method == 'POST':
        # Handle deletion
        db.session.delete(reading)
        db.session.commit()
        flash('Reading deleted successfully!', 'success')
        return redirect(url_for('main.dashboard'))

    return render_template('reading/confirm_delete.html', reading=reading)


@reading.route('/<int:reading_id>/delete', methods=['POST'])
@login_required
def delete_reading(reading_id):
    reading = Reading.query.get_or_404(reading_id)

    # Ensure the reading belongs to the logged-in user
    if reading.user_id != current_user.id:
        flash('You are not authorized to delete this reading.', 'danger')
        return redirect(url_for('main.dashboard'))

    db.session.delete(reading)
    db.session.commit()
    flash('Reading deleted successfully!', 'success')
    return redirect(url_for('main.dashboard'))