from flask import render_template, flash, redirect, session, url_for, request, g
from flask_login import login_user, logout_user, current_user, login_required
from datetime import datetime
from app import app, db, lm, oid
from .forms import LoginForm, EditForm, PostForm
from .models import User, Post
from config import POSTS_PER_PAGE
from .emails import follower_notification

@lm.user_loader
def load_user(id):
    return User.query.get(int(id))

@app.before_request
def before_request():
    g.user = current_user
    if g.user.is_authenticated:
        g.user.last_seen = datetime.utcnow()
        db.session.add(g.user)
        db.session.commit()


@app.errorhandler(404)
def not_found_error(error):
    return render_template('404.html'), 404


@app.errorhandler(500)
def internal_error(error):
    db.session.rollback()
    return render_template('500.html'), 500


@app.route('/', methods=['GET', 'POST'])
@app.route('/index', methods=['GET', 'POST'])
@app.route('/index/<int:page>', methods=['GET', 'POST'])
@login_required
def index(page=1):
    form = PostForm()
    if form.validate_on_submit():
        post = Post(body=form.post.data, timestamp=datetime.utcnow(), author=g.user)
        db.session.add(post)
        db.session.commit()
        flash('Your post is now live!')
        app.logger.info("%s: published a post" % g.user)
        return redirect(url_for('index'))
    posts = g.user.followed_posts().paginate(page, POSTS_PER_PAGE, False)
    return render_template('index.html',
                           title='Home',
                           form=form,
                           posts=posts)


@app.route('/login', methods=['GET', 'POST'])
@oid.loginhandler
def login():
    if g.user is not None and g.user.is_authenticated:
        return redirect(url_for('index'))
    form = LoginForm()
    if form.validate_on_submit():
        session['remember_me'] = form.remember_me.data
        return oid.try_login(form.openid.data, ask_for=['nickname', 'email'])
    return render_template('login.html',
                           title='Sign In',
                           form=form,
                           providers=app.config['OPENID_PROVIDERS'])


@oid.after_login
def after_login(resp):
    if resp.email is None or resp.email == "":
        flash('Invalid login. Please try again.')
        return redirect(url_for('login'))
    user = User.query.filter_by(email=resp.email).first()
    if user is None:
        nickname = resp.nickname
        if nickname is None or nickname == "":
            nickname = resp.email.split('@')[0]
        nickname = User.make_unique_nickname(nickname)
        user = User(nickname=nickname, email=resp.email)
        app.logger.info("Add: %s - %s" % (nickname, respo.email))
        db.session.add(user)
        db.session.commit()
        # make the user follow him/herself
        db.session.add(user.follow(user))
        db.session.commit()
    remember_me = False
    if 'remember_me' in session:
        remember_me = session['remember_me']
        session.pop('remember_me', None)
    login_user(user, remember=remember_me)
    return redirect(request.args.get('next') or url_for('index'))


@app.route('/logout')
def logout():
    app.logger.info("Logout: %s" % g.user)
    logout_user()
    return redirect(url_for('login'))


@app.route('/user/<nickname>')
@app.route('/user/<nickname>/<int:page>')
@login_required
def user(nickname, page=1):
    user = User.query.filter_by(nickname=nickname).first()
    if user is None:
        flash('User %s not found.' % nickname)
        return redirect(url_for('index'))
    posts = user.sorted_posts().paginate(page, POSTS_PER_PAGE, False)
    app.logger.info("%s: show profile" % user)
    return render_template('user.html',
                           user=user,
                           posts=posts)


@app.route('/edit', methods=['GET', 'POST'])
@login_required
def edit():
    form = EditForm(g.user.nickname)
    if form.validate_on_submit():
        g.user.nickname = form.nickname.data
        g.user.about_me = form.about_me.data
        db.session.add(g.user)
        db.session.commit()
        flash('Your changes have been saved.')
        app.logger.info("%s: updated profile" % g.user)
        return redirect(url_for('edit'))
    elif request.method != "POST":
        form.nickname.data = g.user.nickname
        form.about_me.data = g.user.about_me
    return render_template('edit.html', form=form)

@app.route('/follow/<nickname>')
@login_required
def follow(nickname):
    user = User.query.filter_by(nickname=nickname).first()
    if user is None:
        flash('User %s not found.' % nickname)
        return redirect(url_for('index'))
    if user == g.user:
        flash('You can\'t follow yourself!')
        return redirect(url_for('user', nickname=nickname))
    u = g.user.follow(user)
    if u is None:
        flash('Cannot follow ' + nickname + '.')
        return redirect(url_for('user', nickname=nickname))
    db.session.add(u)
    db.session.commit()
    flash('You are now following ' + nickname + '!')
    follower_notification(user, g.user)
    return redirect(url_for('user', nickname=nickname))

@app.route('/unfollow/<nickname>')
@login_required
def unfollow(nickname):
    user = User.query.filter_by(nickname=nickname).first()
    if user is None:
        flash('User %s not found.' % nickname)
        return redirect(url_for('index'))
    if user == g.user:
        flash('You can\'t unfollow yourself!')
        return redirect(url_for('user', nickname=nickname))
    u = g.user.unfollow(user)
    if u is None:
        flash('Cannot unfollow ' + nickname + '.')
        return redirect(url_for('user', nickname=nickname))
    db.session.add(u)
    db.session.commit()
    flash('You have stopped following ' + nickname + '.')
    return redirect(url_for('user', nickname=nickname))

@app.route('/delete/<int:id>')
@login_required
def delete(id):
    post = Post.query.get(id)
    if post is None:
        flash('Post not found.')
        return redirect(url_for('index'))
    if post.author.id != g.user.id:
        flash('You cannot delete this post.')
        return redirect(url_for('index'))
    db.session.delete(post)
    db.session.commit()
    flash('Your post has been deleted.')
    return redirect(url_for('index'))