from flask import render_template, flash, redirect, url_for, request
from flask_login import current_user, login_user, logout_user, login_required
from urllib.parse import urlsplit
from datetime import datetime, timezone
import sqlalchemy as sa

from app import app, db
from app.forms import LoginForm, RegistrationForm, EditProfileForm, EmptyForm, PostForm, ResetPasswordRequestForm, ResetPasswordForm
from app.models import User, Post
from app.email import send_password_reset_email

#debug:
#import sys

@app.before_request
def before_request():
    if current_user.is_authenticated:
        current_user.last_seen = datetime.now(timezone.utc)
        db.session.commit()

@app.route('/', methods=['GET', 'POST'])
@app.route('/index', methods=['GET', 'POST'])
@login_required
def index():
    app.logger.info('@@@@@@@@@@@@@@@@@ INFO LOG TEST INDEX')
    form = PostForm()
    #user = {'username': 'aaa', 'email': 'a@a.a'}
    if form.validate_on_submit():
        post = Post(body=form.post.data, author=current_user)
        db.session.add(post)
        db.session.commit()
        flash('Your post has been added.')
        return redirect(url_for('index'))
    #posts = db.session.scalars(current_user.following_posts()).all()
    page = request.args.get('page', 1, type=int)
    posts = db.paginate(current_user.following_posts(), page=page, per_page=app.config['POSTS_PER_PAGE'], error_out=False)
    next_url = url_for('index', page=posts.next_num) if posts.has_next else None
    prev_url = url_for('index', page=posts.prev_num) if posts.has_prev else None

    return render_template('index.html', title='Home', form=form, posts=posts.items, next_url=next_url, prev_url=prev_url)

@app.route('/explore')
@login_required
def explore():
    query = sa.select(Post).order_by(Post.timestamp.desc())
    page = request.args.get('page', 1, type=int)
    posts = db.paginate(query, page=page, per_page=app.config['POSTS_PER_PAGE'], error_out=False)
    next_url = url_for('explore', page=posts.next_num) if posts.has_next else None
    prev_url = url_for('explore', page=posts.prev_num) if posts.has_prev else None

    return render_template('explore.html', title='Explore', posts=posts.items, next_url=next_url, prev_url=prev_url)

@app.route('/login', methods=['GET', 'POST'])
def login():
    if current_user.is_authenticated:
        return redirect(url_for('index'))
    form = LoginForm()
    if form.validate_on_submit():
        user = db.session.scalar(sa.select(User).where(User.username == form.username.data))
        if user is None or not user.check_password(form.password.data):
            flash('Invalid u or p')
            return redirect(url_for('login'))
        login_user(user, remember=form.remember_me.data)
        next_page = request.args.get('next')
        if not next_page or urlsplit(next_page).netloc != '':
            next_page = url_for('index')
        return redirect(next_page)    
    return render_template('login.html', title='Sign In', form=form)

@app.route('/logout')
def logout():
    logout_user()
    return redirect(url_for('index'))

@app.route('/register', methods=['GET', 'POST'])
def register():
    if current_user.is_authenticated:
        return redirect(url_for('index'))
    form = RegistrationForm()
    if form.validate_on_submit():
        user = User(username=form.username.data, email=form.email.data)
        user.set_password(form.password.data)
        db.session.add(user)
        db.session.commit()
        #user.gen_avatar()
        flash('User has been created.')
        return redirect(url_for('login'))
    return render_template('register.html', title='Register', form=form)

@app.route('/reset_password/<token>', methods=['GET', 'POST'])
def reset_password(token):
    if current_user.is_authenticated:
        return redirect(url_for('index'))
    user = User.verify_reset_password_token(token)
    if not user:
        return redirect(url_for('index'))
    form = ResetPasswordForm()
    if form.validate_on_submit():
        user.set_password(form.password.data)
        db.session.commit()
        flash('Your password has been reset.')
        return redirect(url_for('login'))
    return render_template('reset_password.html', form=form)


@app.route('/user/<username>')
@login_required
def user(username):
    user = db.first_or_404(sa.select(User).where(User.username == username))
    page = request.args.get('page', 1, type=int)
    query = user.posts.select().order_by(Post.timestamp.desc())
    posts = db.paginate(query, page=page, per_page=app.config['POSTS_PER_PAGE'], error_out=False)
    next_url = url_for('user', username=user.username, page=posts.next_num) if posts.has_next else None
    prev_url = url_for('user', username=user.username, page=posts.prev_num) if posts.has_prev else None

    form = EmptyForm()
    return render_template('user.html', user=user, posts=posts.items, next_url=next_url, prev_url=prev_url, form=form)

@app.route('/edit_profile', methods=['GET', 'POST'])
@login_required
def edit_profile():
    form = EditProfileForm(current_user.username)
    if form.validate_on_submit():
        current_user.username = form.username.data
        current_user.about_me = form.about_me.data
        db.session.commit()
        flash('Profile changes have been saved.')
        return redirect(url_for('edit_profile'))
    elif request.method == 'GET':
        form.username.data = current_user.username
        form.about_me.data = current_user.about_me
    return render_template('edit_profile.html', title='Edit Profile', form=form)

@app.route('/follow/<username>', methods=['POST'])
@login_required
def follow(username):
    form = EmptyForm()
    if form.validate_on_submit():
        user = db.session.scalar(sa.select(User).where(User.username == username))
        if user is None:
            flash(f'User {username} not found.')
            return redirect(url_for('index'))
        if user == current_user:
            flash('You cannot follow yourself.')
            return redirect(url_for('user', username=username))
        current_user.follow(user)
        db.session.commit()
        flash(f'You are now following {username}.')
        return redirect(url_for('user', username=username))
    else:
        return redirect(url_for('index'))

@app.route('/unfollow/<username>', methods=['POST'])
@login_required
def unfollow(username):
    form = EmptyForm()
    if form.validate_on_submit():
        user = db.session.scalar(sa.select(User).where(User.username == username))
        if user is None:
            flash(f'User {username} not found.')
            return redirect(url_for('index'))
        if user == current_user:
            flash('You cannot unfollow yourself.')
            return redirect(url_for('user', username=username))
        current_user.unfollow(user)
        db.session.commit()
        flash(f'You have unfollowed {username}.')
        return redirect(url_for('user', username=username))
    else:
        return redirect(url_for('index'))

@app.route('/reset_password_request', methods=['GET', 'POST'])
def reset_password_request():
    if current_user.is_authenticated:
        return redirect(url_for('index'))
    form = ResetPasswordRequestForm()
    if form.validate_on_submit():
        user = db.session.scalar(sa.select(User).where(User.email == form.email.data))
        if user:
            send_password_reset_email(user)
        flash('Password reset sent.')
        return redirect(url_for('login'))
    return render_template('reset_password_request.html', title='Reset Password', form=form)