__init__.py

import os
import time

import boto3
import botocore
import requests
from bs4 import BeautifulSoup
from flask import (Flask, flash, make_response, redirect, render_template,
                   request, send_file, session, url_for)

from stylize import stylize

ALLOWED_EXTENSIONS = set(['png', 'jpg', 'jpeg'])

app = Flask(__name__)

# Set the secret key to some random bytes. Keep this really secret!
# Change the secret key to constant value while using gunicorn workers
app.config['SECRET_KEY'] = os.environ.get('SECRET_KEY', os.urandom(24))


def allowed_file(filename):
    return('.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS)


def scrape(filename=None):
    preLink = "https://raw.githubusercontent.com/puneet29/StyleTransferApp/master/images/style-images/"
    if(filename == None):
        page = "https://github.com/puneet29/StyleTransferApp/tree/master/images/style-images"
        links = []
        r = requests.get(page)
        soup = BeautifulSoup(r.text, "html.parser")
        tbody = soup.find("tbody")
        photo_anchors = tbody.find_all("a", {"class": "js-navigation-open"})
        for anchors in photo_anchors:
            links.append(preLink+anchors['title'])
        return(links)
    else:
        return(preLink+filename)


@app.route('/')
def homepage():
    if 'file' in session:
        # S3 Bucket
        bucketName = "styletransferbucket"
        s3 = boto3.resource('s3')
        obj = s3.Object(bucketName, session['file'])
        obj.delete()
        session.clear()
    return render_template('index.html', styles=scrape())


@app.route('/upload/', methods=['POST', 'GET'])
def upload():
    if 'file' in session:
        # S3 Bucket
        bucketName = "styletransferbucket"
        s3 = boto3.resource('s3')
        obj = s3.Object(bucketName, session['file'])
        obj.delete()
        session.clear()
    style = request.args.get('style')
    if (request.method == 'GET'):
        return render_template('upload.html', styleName= style.upper(), stylePath=scrape(style+".jpg"))
    else:
        if ('file' not in request.files):
            flash('No file part')
            return(redirect(request.url))
        file = request.files['file']
        if(file.filename == ''):
            flash('No selected file')
            return(redirect(request.url))
        if(file and allowed_file(file.filename)):

            # Get files and styled image
            style_strength = float(request.form['styleRange'])
            output_img = 'static/out/' + time.ctime().replace(' ', '_')+'.jpg'
            style_image = stylize(file, output_img,
                                  "models/"+style+".model", style_strength, 0)

            # S3 Bucket
            bucketName = "styletransferbucket"

            # S3 upload image
            s3 = boto3.client('s3')
            s3.put_object(Body=style_image, Bucket=bucketName,
                          Key=output_img, ContentType='image/jpeg')

            session['file'] = output_img
            return(render_template("uploaded.html"))

        flash('Please select right file')
        return(redirect(request.url))


@app.errorhandler(404)
def page_not_found(e):
    return render_template('404.html')


@app.errorhandler(500)
def server_error(e):
    return render_template('500.html')


@app.errorhandler(405)
def method_error(e):
    return render_template('405.html')


@app.route('/download/')
def download():

    # S3 download
    Bucket = "styletransferbucket"
    Key = session['file']
    outputName = "stylize.jpg"

    s3 = boto3.resource('s3')
    try:
        file = s3.Object(Bucket, Key).get()
        response = make_response(file['Body'].read())
        response.headers['Content-Type'] = 'image/jpeg'
        response.headers['Content-Disposition'] = 'attachment; filename=' + outputName
        return(response)
    except botocore.exceptions.ClientError as e:
        if e.response['Error']['Code'] == "404":
            print("The object does not exist.")
        else:
            raise


if __name__ == "__main__":
    app.run(host='0.0.0.0', port='80')