# For more information, please refer to https://aka.ms/vscode-docker-python
FROM python:3.10-slim

# Install packages we are going to need for setting up Chrome
RUN apt-get update && apt-get install -y \
    gnupg \
    wget \
    curl \
    unzip \
    && rm -rf /var/lib/apt/lists/*

# Install Google Chrome
RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -
RUN sh -c 'echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google-chrome.list'
RUN apt-get update && apt-get install -y \
    google-chrome-stable \
    && rm -rf /var/lib/apt/lists/*

# Install chromedriver
RUN wget -O /tmp/chromedriver.zip http://chromedriver.storage.googleapis.com/`curl -sS chromedriver.storage.googleapis.com/LATEST_RELEASE`/chromedriver_linux64.zip
RUN unzip /tmp/chromedriver.zip chromedriver -d /usr/local/bin/ && rm /tmp/chromedriver.zip

# Set display port to avoid crashing Chrome
ENV DISPLAY=:99

# Keeps Python from generating .pyc files in the container
ENV PYTHONDONTWRITEBYTECODE=1

# Turns off buffering for easier container logging
ENV PYTHONUNBUFFERED=1

# Install pip requirements
ADD requirements.txt .
RUN python -m pip install -r requirements.txt

WORKDIR /app
ADD ./src /app

# Switching to a non-root user, please refer to https://aka.ms/vscode-docker-python-user-rights
RUN useradd appuser && chown -R appuser /app
USER appuser

# During debugging, this entry point will be overridden. For more information, please refer to https://aka.ms/vscode-docker-python-debug
CMD ["python", "app.py"]

from selenium import webdriver
from selenium.webdriver.common.by import By
from time import sleep

class Scraper:
    def __init__(self, delay):
        # Let's grab our default settings for Chromium instance
        chrome_options = self.__build_chrome_options()
        self.delay = delay

        try:
            # Let's instantiate our scraper
            self.driver = webdriver.Chrome(options=chrome_options)
        except Exception as e:
            raise e

    def __build_chrome_options(self):
        chrome_options = webdriver.ChromeOptions()
        chrome_options.add_argument('--window-size=1920,1200')
        chrome_options.add_argument('--headless')
        chrome_options.add_argument('--single-process')
        chrome_options.add_argument('--no-sandbox')
        chrome_options.add_argument('--disable-gpu')
        chrome_options.add_argument('--enable-logging')
        chrome_options.add_argument('--user-data-dir=/tmp/user1')
        chrome_options.add_argument('--v=1')
        chrome_options.add_argument('--ignore-certificate-errors')
        chrome_options.add_argument('--disable-dev-shm-usage')

        return chrome_options

    def scroll_down(self, delay):
        while True:
            # Get scroll height.
            lastHeight = self.driver.execute_script("return document.body.scrollHeight")

            # Scroll down to the bottom. 
            print(f"Last height: [{lastHeight}] - Scrolling...") # uncomment for debugging scrolling
            self.driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")

            # Wait to load the page
            sleep(delay/2)

            # Calculate new scroll height and compare with last scroll height
            newHeight = self.driver.execute_script("return document.body.scrollHeight")

            # If the browser hasn’t scrolled any more (i.e. it’s reached the end) then stop
            if newHeight == lastHeight:
                print("Reached bottom") # uncomment for debugging scrolling
                break

    def get_with_delay(self, request_url, delay):
        self.driver.get(request_url)
        sleep(delay)
        self.scroll_down(delay)
    
    def __del__(self):
        self.driver.quit()

# use this for testing locally
if __name__ == "__main__":
    scraper = Scraper(3)

    url = "https://abcnews.go.com/"

    try:
        print("Getting url: ", url)
        scraper.get_with_delay(url, 3)
    except Exception as e:
        print(f'Error {e} while scraping url: {url}')