ADD download --all feature (#139)

kleinanzeigen_bot/utils.py

@@ -11,6 +11,7 @@ from typing import Any, Final, TypeVar
 
 import coloredlogs, inflect
 from ruamel.yaml import YAML
+from selenium.webdriver.chrome.webdriver import WebDriver
 
 LOG_ROOT:Final[logging.Logger] = logging.getLogger()
 LOG:Final[logging.Logger] = logging.getLogger("kleinanzeigen_bot.utils")
@@ -270,3 +271,42 @@ def parse_datetime(date:datetime | str | None) -> datetime | None:
     if isinstance(date, datetime):
         return date
     return datetime.fromisoformat(date)
+
+
+def smooth_scroll_page(driver: WebDriver, scroll_length: int = 10, scroll_speed: int = 10000, scroll_back_top: bool = False):
+    """
+    Scrolls the current page of a web driver session.
+    :param driver: the web driver session
+    :param scroll_length: the length of a single scroll iteration, determines smoothness of scrolling, lower is smoother
+    :param scroll_speed: the speed of scrolling, higher is faster
+    :param scroll_back_top: whether to scroll the page back to the top after scrolling to the bottom
+    """
+    current_y_pos = 0
+    bottom_y_pos: int = driver.execute_script('return document.body.scrollHeight;')  # get bottom position by JS
+    while current_y_pos < bottom_y_pos:  # scroll in steps until bottom reached
+        current_y_pos += scroll_length
+        driver.execute_script(f'window.scrollTo(0, {current_y_pos});')  # scroll one step
+        time.sleep(scroll_length / scroll_speed)
+
+    if scroll_back_top:  # scroll back to top in same style
+        while current_y_pos > 0:
+            current_y_pos -= scroll_length
+            driver.execute_script(f'window.scrollTo(0, {current_y_pos});')
+            time.sleep(scroll_length / scroll_speed / 2)  # double speed
+
+
+def extract_ad_id_from_ad_link(url: str) -> int:
+    """
+    Extracts the ID of an ad, given by its reference link.
+
+    :param url: the URL to the ad page
+    :return: the ad ID, a (ten-digit) integer number
+    """
+    num_part = url.split('/')[-1]  # suffix
+    id_part = num_part.split('-')[0]
+
+    try:
+        return int(id_part)
+    except ValueError:
+        print('The ad ID could not be extracted from the given ad reference!')
+        return -1