#!/usr/bin/env python

import base64
import cgi
import datetime
import hashlib
import importlib
import io
import json
import mimetypes
import os
import random
import subprocess
import tempfile
import urllib
from urllib.parse import urlencode, urljoin

from flask import Blueprint, redirect, current_app, url_for, request, render_template, session, flash, send_file, abort, jsonify, Markup, Response
from flask_login import login_user, logout_user, current_user, login_required
import jwt
from PIL import Image, ExifTags
import requests
from werkzeug.utils import secure_filename

from .db import db, User, UserSession, File, NoResultFound, IntegrityError
from .monkey import patch as monkey_patch
from .login import login_manager, load_user
from .file_storage.exceptions import StorageError

storage = importlib.import_module(current_app.config.get('STORAGE_MODULE', '.file_storage.filesystem'), package='fbin').Storage(current_app)

monkey_patch()

base62_alphabet = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'

if not os.path.isdir(current_app.config['THUMB_DIRECTORY']):
    os.mkdir(current_app.config['THUMB_DIRECTORY'])

def get_or_create_user(username, jab_id):
    try:
        return db.session.query(User).filter(User.jab_id == jab_id).one()
    except NoResultFound:
        try:
            user = User(username, jab_id)
            db.session.add(user)
            db.session.commit()
            db.session.refresh(user)
            return user
        except IntegrityError:
            return None

def get_file(file_hash, user_id=None, update_accessed=False):
    try:
        f = db.session.query(File).filter(File.hash == file_hash)
        if user_id:
            f = f.filter(File.user_id == user_id)
        f = f.one()
    except NoResultFound:
        return None
    if update_accessed:
        f.accessed = datetime.datetime.utcnow()
        db.session.add(f)
        db.session.commit()
        # Refresh after field update.
        db.session.refresh(f)
    return f

def get_files(user):
    try:
        db.session.add(user)
        files = user.files
    except NoResultFound:
        return []
    return files

def delete_file(file):
    db.session.delete(file)
    db.session.commit()
    storage.delete_file(file)

app = Blueprint('fbin', __name__)

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

@app.route('/u')
@app.route('/upload', methods = ['GET', 'POST'])
def upload(api=False, user=None):
    def error(message):
        if api:
            return jsonify({
                'status': False,
                'message': message,
            })
        elif old_api:
            return 'ERROR {}'.format(message)
        else:
            flash(message, 'warning')
            return render_template('upload.html', **context)

    context = {
        'title': 'Upload',
    }

    old_api = bool(request.form.get('api'))

    if request.method == 'GET':
        if api or old_api:
            # API calls shouldn't use GET.
            abort(405)
        return render_template('upload.html', **context)

    if not user and current_user.is_authenticated:
        user = current_user.user

    if not user and not current_app.config.get('ALLOW_ANONYMOUS_UPLOADS'):
        abort(403)

    uploaded_file = request.files.get('file')
    if not uploaded_file or not uploaded_file.filename:
        return error('No valid file or filename was provided.')
    file_hash = ''.join(random.choice(base62_alphabet) for x in range(5))
    try:
        new_file = storage.store_file(uploaded_file, file_hash, user, request.remote_addr)
    except StorageError as e:
        return error(str(e))

    if api:
        return jsonify({
            'status': True,
            'hash': new_file.hash,
            'urls': {
                'base': url_for('fbin.file', hash = '', _external = True),
                'full': url_for('fbin.file', hash = new_file.hash, filename = new_file.filename, _external = True),
                'ext': url_for('fbin.file', hash = new_file.hash, ext = new_file.ext, _external = True),
                'hash': url_for('fbin.file', hash = new_file.hash, _external = True),
            },
        })
    elif old_api:
        return 'OK {hash}'.format(hash = new_file.hash)
    else:
        context = {
            'file': new_file,
        }
        return redirect(url_for('.uploaded', hash = new_file.hash))

@app.route('/uploaded/<hash>')
def uploaded(hash):
    f = get_file(hash, update_accessed = False)
    if not f:
        abort(404)
    if f.user_id and (not current_user.is_authenticated or f.user_id != current_user.get_user_id()):
        abort(404)
    context = {
        'title': 'Uploaded',
        'subtitle': f.filename,
        'file': f,
    }
    return render_template('uploaded.html', **context)

@app.route('/f/<hash:hash>')
@app.route('/f/<hash:hash><ext:ext>')
@app.route('/f/<hash:hash>/<path:filename>')
@app.route('/file/<hash:hash>', endpoint = 'file')
@app.route('/file/<hash:hash><ext:ext>', endpoint = 'file')
@app.route('/file/<hash:hash>/<path:filename>', endpoint = 'file')
def _file(hash, ext=None, filename=None):
    f = get_file(hash)
    if not f or (f.blocked_reason and (f.blocked_reason['positives'] >= current_app.config['VIRUSTOTAL_MINIMUM_POSITIVES'] \
            or any(scan['detected'] and scan['result'] in current_app.config['VIRUSTOTAL_SINGULAR_MATCHES']
                    for scan in f.blocked_reason['scans'].values()))):
        abort(404)
    path = storage.get_file(f)
    if isinstance(path, Response):
        return path
    if not path or not os.path.exists(path):
        abort(404)
    return send_file(path, attachment_filename=f.filename)

@app.route('/l')
@app.route('/login')
def login():
    session['oauth_state'] = base64.urlsafe_b64encode(os.urandom(30)).decode()
    return redirect(urljoin(current_app.config['OAUTH_URL'], 'authorize') + '?' + urlencode({
        'response_type': 'code',
        'client_id': current_app.config['OAUTH_CLIENT_ID'],
        'redirect_uri': urljoin(request.host_url, url_for('.auth')),
        'state': session['oauth_state'],
    }))

@app.route('/account')
def account():
    return redirect(current_app.config['ACCOUNT_URL'])

@app.route('/o')
@app.route('/logout')
def logout():
    if not current_user.is_authenticated:
        return redirect(url_for('.index'))
    session_id = int(current_user.get_id().split(':', 1)[-1])
    try:
        db.session.query(UserSession).filter_by(id = session_id).delete()
    except:
        raise
    logout_user()
    return redirect(url_for('.index'))

@app.route('/auth')
def auth():
    if 'error' in request.args:
        error = request.args['error']
        error_description = request.args.get('error_description')
        msg = 'OAuth error: {}'.format(error)
        if error_description:
            msg += ' ({})'.format(error_description)
        flash(msg, 'error')
        return redirect(url_for('.index'))
    session_state = session.pop('oauth_state', None)
    state = request.args.get('state')
    if session_state != state:
        flash('Invalid OAuth state', 'error')
        return redirect(url_for('.index'))
    code = request.args.get('code')
    if not code:
        flash('Missing OAuth code', 'error')
        return redirect(url_for('.index'))
    rs = requests.Session()
    response = rs.post(urljoin(current_app.config['OAUTH_URL'], 'token'), data = {
        'grant_type': 'authorization_code',
        'code': code,
        'client_id': current_app.config['OAUTH_CLIENT_ID'],
        'client_secret': current_app.config['OAUTH_CLIENT_SECRET'],
        'redirect_uri': urljoin(request.host_url, url_for('.auth')),
    })
    token = response.json()
    if 'error' in token:
        msg = 'OAuth error: {}'.format(token['error'])
        flash(msg, 'error')
        return redirect(url_for('.index'))
    try:
        access_data = jwt.decode(token['access_token'], key = current_app.config['JWT_PUBLIC_KEY'], audience = current_app.config['OAUTH_CLIENT_ID'])
        refresh_data = jwt.decode(token['refresh_token'], key = current_app.config['JWT_PUBLIC_KEY'], audience = current_app.config['OAUTH_CLIENT_ID'])
    except jwt.InvalidTokenError as e:
        flash('Failed to verify token: {!s}'.format(e), 'error')
        return redirect(url_for('.index'))
    response = rs.get(urljoin(current_app.config['OAUTH_URL'], '/api/user'), headers = {'Authorization': 'Bearer {}'.format(token['access_token'])})
    user = response.json()
    user = get_or_create_user(user['username'], user['id'])
    us = UserSession(user.id, token['access_token'], token['refresh_token'])
    us.updated = datetime.datetime.utcnow()
    db.session.add(us)
    db.session.commit()
    db.session.refresh(us)
    user = load_user('{}:{}'.format(user.id, us.id))
    if not user:
        flash('Failed to retrieve user instance.', 'error')
    else:
        login_user(user, remember = True)
    return redirect(url_for('.index'))

@app.route('/m')
@app.route('/files')
@login_required
def files():
    files = get_files(current_user.user)
    context = {
        'title': 'Files',
        'files': files,
        'total_size': File.pretty_size(sum(size for size in (f.size for f in files) if size is not None)),
    }
    return render_template('files.html', **context)

@app.route('/files', methods = ['POST'])
@login_required
def file_edit():
    user_id = int(current_user.get_id().split(':')[0])
    f = get_file(request.form.get('hash'), user_id = user_id, update_accessed = False)
    if not f:
        flash('File not found.', 'error')
        return redirect(url_for('.files'))
    if 'filename' in request.form:
        filename = request.form.get('filename', f.filename)
        f.filename = filename
        db.session.add(f)
        flash('Filename changed to "{}".'.format(f.filename), 'success')
    elif 'delete' in request.form:
        try:
            delete_file(f)
        except:
            flash('Failed to delete file.', 'error')
        else:
            flash('File deleted.', 'success')
    else:
        flash('No action was performed.', 'warning')
    return redirect(url_for('.files'))

@app.route('/i')
@app.route('/images')
@login_required
def images():
    files = [f for f in get_files(current_user.user) if f.is_image()]
    context = {
        'title': 'Images',
        'fullwidth': True,
        'files': files,
        'total_size': File.pretty_size(sum(size for size in (f.size for f in files) if size is not None)),
    }
    return render_template('images.html', **context)

@app.route('/v')
@app.route('/videos')
@login_required
def videos():
    files = [f for f in get_files(current_user.user) if f.is_video()]
    context = {
        'title': 'Videos',
        'fullwidth': True,
        'files': files,
        'total_size': File.pretty_size(sum(size for size in (f.size for f in files) if size is not None)),
    }
    return render_template('images.html', **context)

@app.route('/t/<hash:hash>')
@app.route('/thumb/<hash:hash>')
def thumb(hash):
    f = get_file(hash, update_accessed=False)
    response = storage.get_thumbnail(f)
    if not response:
        with tempfile.NamedTemporaryFile(suffix='.jpg') as ttf: # temporary thumb file
            if f.is_image():
                try:
                    with storage.temp_file(f) as tf:
                        im = Image.open(tf)
                        # Check for valid JPEG modes.
                        if im.mode not in ('1', 'L', 'RGB', 'RGBX', 'CMYK', 'YCbCr'):
                            im = im.convert('RGB')
                        e = im.getexif()
                        # Get orientation EXIF tag
                        orientation = e.get(274)
                        if orientation == 3:
                            im = im.rotate(180, expand=True)
                        elif orientation == 6:
                            im = im.rotate(270, expand=True)
                        elif orientation == 8:
                            im = im.rotate(90, expand=True)
                        im.thumbnail(current_app.config.get('THUMB_SIZE', (128, 128)), Image.ANTIALIAS)
                        im.save(ttf)
                except IOError:
                    # We can't generate a thumbnail for this file, just say it doesn't exist.
                    abort(404)
            elif f.is_video():
                with storage.temp_file(f) as tf:
                    p = subprocess.run(['ffmpegthumbnailer', '-i', '-', '-o', ttf.name], stdin=tf)
                if p.returncode != 0:
                    abort(404)
            else:
                abort(404)
            ttf.seek(0)
            if not os.path.getsize(ttf.name):
                abort(404)
            storage.store_thumbnail(f, ttf)
        response = storage.get_thumbnail(f)
    if isinstance(response, Response):
        return response
    return send_file(response, attachment_filename='thumb.jpg')

@app.route('/h')
@app.route('/help')
def help():
    return redirect(url_for('.api'))

@app.route('/api')
def api():
    context = {
        'title': 'API',
        'subtitle': 'keys and usage',
    }
    return render_template('api.html', **context)

@app.route('/generate-api-key')
def generate_api_key():
    if not current_user.is_authenticated:
        abort(403)
    now = datetime.datetime.utcnow()
    user_id = int(current_user.get_id().split(':')[0])
    data = {
        'iss': request.url_root,
        'iat': now,
        'nbf': now,
        'sub': user_id,
    }
    token = jwt.encode(data, current_app.config['SECRET_KEY'])
    return token

@app.route('/invalidate-api-keys')
@login_required
def invalidate_api_keys():
    user = current_user.user
    db.session.add(user)
    user.api_key_date = datetime.datetime.utcnow()
    db.session.commit()
    flash('All API keys invalidated.', 'success')
    return redirect(request.referrer)

login_manager.login_view = '.login'