from flask import (
    Blueprint, redirect, url_for,
    render_template, request, session,
    abort, flash, current_app
    )
from functools import wraps
from secrets import compare_digest as compare_timesafe
from wand.image import Image
from wand.color import Color
from wand.exceptions import WandException
from ..auth import (
    digest, verify, create_session,
    is_logged_in, parse_username, is_password_valid,
    login_required, revoke_session, get_active_user,
    parse_display_name, revoke_all_sessions, csrf_verified
    )
from ..models import Users, Posts, Reactions, Threads, Avatars, PostHistory, Mentions, BookmarkCollections
from ..constants import PermissionLevel, InfoboxKind
from ..util import get_form_checkbox
import math
import os
import time

AVATAR_MAX_SIZE = 1000 * 1000 # 1MB

bp = Blueprint('users', __name__, url_prefix='/users/')

def validate_and_create_avatar(input_image, filename):
    try:
        with Image(blob=input_image) as img:
            if hasattr(img, 'sequence') and len(img.sequence) > 1:
                img = Image(image=img.sequence[0])
            img.strip()
            img.gravity = 'center'

            width, height = img.width, img.height
            min_dim = min(width, height)
            if min_dim > 256:
                ratio = 256.0 / min_dim
                new_width = int(width * ratio)
                new_height = int(height * ratio)
                img.resize(new_width, new_height)

            width, height = img.width, img.height
            crop_size = min(width, height)
            x_offset = (width - crop_size) // 2
            y_offset = (height - crop_size) // 2
            img.crop(left=x_offset, top=y_offset,
                    width=crop_size, height=crop_size)

            img.resize(256, 256)
            img.background_color = Color('white')
            img.alpha_channel = 'remove'
            img.format = 'webp'
            img.compression_quality = 85
            img.save(filename=filename)
            return True
    except WandException:
        return False

def anonymize_user(user_id):
    deleted_user = Users.find({'username': 'deleteduser'})

    from ..lib.babycode import sanitize, babycode_to_html
    from ..db import db
    threads = Threads.findall({'user_id': user_id})
    posts = Posts.findall({'user_id': user_id})

    revs_q = """SELECT DISTINCT m.revision_id FROM mentions m
            WHERE m.mentioned_user_id = ?"""

    mentioned_revs = db.query(revs_q, int(user_id))
    with db.transaction():
        for thread in threads:
            thread.update({'user_id': int(deleted_user.id)})
        for post in posts:
            post.update({'user_id': int(deleted_user.id)})

        revs = {}
        for rev in mentioned_revs:
            ph = PostHistory.find({'id': int(rev['revision_id'])})
            ms = Mentions.findall({
                'mentioned_user_id': int(user_id),
                'revision_id': int(rev['revision_id']),
            })
            data = {
                'text': sanitize(ph.original_markup),
                'mentions': ms,
            }
            data['mentions'] = sorted(data['mentions'], key=lambda x: int(x.end_index), reverse=True)
            revs[rev['revision_id']] = data

        for rev_id, data in revs.items():
            text = data['text']
            for mention in data['mentions']:
                text = text[:mention.start_index] + '@deleteduser' + text[mention.end_index:]
                mention.delete()

            res = babycode_to_html(text)
            ph = PostHistory.find({'id': int(rev_id)})
            ph.update({
                'original_markup': text.unescape(),
                'content': res.result,
            })

def redirect_if_logged_in(destination='topics.all_topics'):
    def decorator(view_func):
        @wraps(view_func)
        def wrapper(*args, **kwargs):
            if is_logged_in():
                return redirect(url_for(destination))
            return view_func(*args, **kwargs)
        return wrapper
    return decorator

def redirect_to_own(view_func):
    @wraps(view_func)
    def wrapper(username, *args, **kwargs):
        user = get_active_user()
        if username.lower() != user.username:
            view_args = dict(request.view_args)
            view_args.pop('username', None)
            new_args = {**view_args, 'username': user.username}
            return redirect(url_for(request.endpoint, **new_args))
        return view_func(username, *args, **kwargs)
    return wrapper

def user_required(view_func):
    @wraps(view_func)
    def wrapper(username, *args, **kwargs):
        user = get_active_user()
        if user.is_guest():
            abort(403)

        return view_func(username, *args, **kwargs)
    return wrapper

@bp.get('/log-in/')
@redirect_if_logged_in()
def log_in():
    return render_template('users/log_in.html')

@bp.post('/log-in/')
@redirect_if_logged_in()
def log_in_post():
    username = request.form.get('username', default='').lower()
    user = Users.find({'username': username})
    if not user:
        return redirect(url_for('.log_in', error='The username or password you entered is incorrect.'))
    password = request.form.get('password', default='')
    if not verify(user.password_hash, password):
        return redirect(url_for('.log_in', error='The username or password you entered is incorrect.'))

    session['remember'] = request.form.get('remember') == 'on'
    sess = create_session(user.id, not session['remember'])
    session['pyrom_session_key'] = sess.key
    if session['remember']:
        session.permanent = True
    return redirect(request.form.get('return_to', default=url_for('topics.all_topics')))

@bp.post('/log-out/')
@login_required
def log_out():
    revoke_session(get_active_user().id)
    return redirect(url_for('topics.all_topics'))

@bp.get('/sign-up/')
@redirect_if_logged_in()
def sign_up():
    return render_template('users/sign_up.html')

@bp.post('/sign-up/')
@redirect_if_logged_in()
def sign_up_post():
    generic_error_page = redirect(url_for('.sign_up', error='The username or password you entered is invalid.'))
    invalid_username_error_page = redirect(url_for('.sign_up', error='This username cannot be used. Please pick another.'))
    passwords_error_page = redirect(url_for('.sign_up', error='The passwords do not match.'))
    username = request.form.get('username', default='')
    if not username:
        return generic_error_page
    if request.form.get('password') is None:
        return generic_error_page
    if len(request.form.getlist('password')) != 2:
        return passwords_error_page
    try:
        username_pair = parse_username(username)
    except ValueError:
        return invalid_username_error_page
    potential_user = Users.find({'username': username})
    if potential_user:
        return invalid_username_error_page

    if not compare_timesafe(request.form.getlist('password')[0], request.form.getlist('password')[1]):
        return passwords_error_page

    password_hash = digest(request.form.get('password'))

    user = Users.create({
        'username': username_pair[0],
        'password_hash': password_hash,
        'permission': PermissionLevel.GUEST.value,
        'created_at': int(time.time()),
    })

    BookmarkCollections.create_default(user.id)

    if username_pair[0] != username_pair[1]:
        user.update({
            'display_name': parse_display_name(username_pair[1])
        })

    session['remember'] = request.form.get('remember') == 'on'
    sess = create_session(user.id, not session['remember'])
    session['pyrom_session_key'] = sess.key
    if session['remember']:
        session.permanent = True

    return redirect(url_for('topics.all_topics'))

@bp.get('/<username>/')
def user_page(username):
    username = username.lower()
    target_user = Users.find({'username': username})
    if not target_user:
        abort(404)
    return render_template('users/user_page.html', target_user=target_user)

@bp.get('/<username>/posts/')
def posts(username):
    username = username.lower()
    if username == 'deleteduser':
        abort(404)
    target_user = Users.find({'username': username})
    if not target_user:
        abort(404)
    PER_PAGE = 10
    posts_count = Posts.count({'user_id': target_user.id})
    page_count = max(1, math.ceil(posts_count / PER_PAGE))
    page = 1
    try:
        page = max(1, min(int(request.args.get('page', default=1)), page_count))
    except ValueError:
        abort(404)
    posts = target_user.get_posts(PER_PAGE, page)
    return render_template(
        'users/posts.html', posts=posts,
        page=page, page_count=page_count,
        target_user=target_user, Reactions=Reactions
        )

@bp.get('/<username>/threads/')
def threads(username):
    username = username.lower()
    if username == 'deleteduser':
        abort(404)
    target_user = Users.find({'username': username})
    if not target_user:
        abort(404)
    PER_PAGE = 10
    threads_count = Threads.count({'user_id': target_user.id})
    page_count = max(1, math.ceil(threads_count / PER_PAGE))
    page = 1
    try:
        page = max(1, min(int(request.args.get('page', default=1)), page_count))
    except ValueError:
        abort(404)
    threads = target_user.get_started_threads(PER_PAGE, page)
    return render_template(
        'users/threads.html', threads=threads,
        page=page, page_count=page_count,
        target_user=target_user, Reactions=Reactions
        )

@bp.get('/<username>/comments/')
def comments(username):
    username = username.lower()
    if username == 'deleteduser':
        abort(404)
    return 'stub'

@bp.get('/<username>/settings/')
@login_required
@redirect_to_own
def settings(username):
    user = get_active_user()
    sort_by = session.get('sort_by', 'activity')
    return render_template(
        'users/settings.html', user=user,
        sort_by=sort_by
    )

@bp.post('/<username>/settings/set-avatar')
@login_required
@user_required
@redirect_to_own
def set_avatar(username):
    user = get_active_user()
    return_to = redirect(url_for('.settings', username=user.username))
    if 'avatar' not in request.files:
        abort(400)

    avi_file = request.files['avatar']

    if avi_file.filename == '':
        abort(400)

    avi_file.seek(0, os.SEEK_END)
    file_size = avi_file.tell()
    avi_file.seek(0, os.SEEK_SET)

    if file_size > AVATAR_MAX_SIZE:
        flash('Your avatar must be 1MB or less.', InfoboxKind.ERROR)
        return return_to

    avi_bytes = avi_file.read()
    now = int(time.time())
    filename = f'u{user.id}d{now}.webp'
    output_path = os.path.join(current_app.config['AVATAR_UPLOAD_PATH'], filename)
    proxied_filename = f'/static/avatars/{filename}'

    res = validate_and_create_avatar(avi_bytes, output_path)
    if res:
        flash('Avatar updated.', InfoboxKind.INFO)
        avatar = Avatars.create({
            'file_path': proxied_filename,
            'uploaded_at': now,
            })
        old_avatar = Avatars.find({'id': user.avatar_id})
        user.update({'avatar_id': avatar.id})
        if int(old_avatar.id) != 1:
            filename = os.path.join(current_app.config['AVATAR_UPLOAD_PATH'], os.path.basename(old_avatar.file_path))
            os.remove(filename)
            old_avatar.delete()
        return return_to
    else:
        flash('Something went wrong.;Please try again.', InfoboxKind.ERROR)

    return return_to

@bp.post('/<username>/settings/clear-avatar')
@login_required
@user_required
@redirect_to_own
def clear_avatar(username):
    user = get_active_user()
    if user.is_default_avatar():
        return redirect(url_for('.settings', username=username))

    old_avatar = Avatars.find({'id': user.avatar_id})
    user.update({'avatar_id': 1})
    filename = os.path.join(current_app.config['AVATAR_UPLOAD_PATH'], os.path.basename(old_avatar.file_path))
    os.remove(filename)
    old_avatar.delete()
    return redirect(url_for('.settings', username=username))

@bp.post('/<username>/settings/change-password')
@login_required
@redirect_to_own
def change_password(username):
    user = get_active_user()
    current_password = request.form.get('current_password', '')
    new_password = request.form.get('new_password', '')
    new_password2 = request.form.get('new_password2', '')

    new_hash = digest(new_password)

    old_correct = verify(user.password_hash, current_password)
    new_match = compare_timesafe(new_password, new_password2)

    if (old_correct and new_match) == False:
        flash('The current password is incorrect or the new passwords do not match.;Please try again.', InfoboxKind.ERROR)
        return redirect(url_for('.settings', username=username))

    user.update({
        'password_hash': new_hash
    })

    revoke_all_sessions(user.id)

    return redirect(url_for('.log_in'))

@bp.post('/<username>/settings/set-personalization')
@login_required
@user_required
@redirect_to_own
def set_personalization(username):
    user = get_active_user()
    session['sort_by'] = request.form.get('sort_by', 'activity')
    session['dont_subscribe_by_default'] = not get_form_checkbox('subscribe_by_default')

    user.update({
        'status': request.form.get('status', '')[:100],
        'display_name': parse_display_name(request.form.get('display_name', ''))
    })

    flash('Personalization settings updated.', InfoboxKind.INFO)
    return redirect(url_for('.settings', username=username))

@bp.post('/<username>/settings/set-sig')
@login_required
@user_required
@redirect_to_own
def set_sig(username):
    user = get_active_user()
    user.set_signature(request.form.get('babycode_content', ''))
    flash('Signature updated.', InfoboxKind.INFO)
    return redirect(url_for('.settings', username=username))

@bp.post('/<username>/settings/set-bio')
@login_required
@user_required
@redirect_to_own
def set_bio(username):
    return 'stub'

@bp.get('/<username>/inbox/')
@login_required
@redirect_to_own
def inbox(username):
    user = get_active_user()
    unread_count = user.get_unread_count()
    subscriptions = user.get_all_subscriptions()
    return render_template('users/inbox.html', unread_count=unread_count, subscriptions=subscriptions)

@bp.get('/<username>/bookmarks/')
@login_required
@redirect_to_own
def bookmarks(username):
    username = username.lower()
    return 'stub'

@bp.get('/<username>/delete-confirm/')
@login_required
@redirect_to_own
def delete_confirm(username):
    return render_template('users/delete_confirm.html')

@bp.post('/<username>/delete-confirm/')
@login_required
@redirect_to_own
@csrf_verified
def delete_confirm_post(username):
    user = get_active_user()

    password = request.form.get('password', '')
    if not verify(user.password_hash, password):
        flash('Incorrect password.', InfoboxKind.ERROR)
        return redirect(url_for('.delete_confirm', username=username))

    if user.is_admin():
        flash('You can not delete the admin account.', InfoboxKind.ERROR)
        return redirect(url_for('.delete_confirm', username=username))

    anonymize_user(user.id)
    revoke_all_sessions(user.id)
    user.delete()

    return redirect(url_for('topics.all_topics'))