import requests
from bs4 import BeautifulSoup
import csv

def extract_text_from_element(element):
    """Recursively extracts text from an element, avoiding duplication."""
    if element is None:
        return ""

    text = ""
    for child in element.children:
        if isinstance(child, str):
            text += child.strip() + " "
        elif child.name in ["ul", "ol"]:
            text += "\n"
            for li in child.find_all("li"):
                text += "- " + li.text.strip() + "\n"
        elif child.name == "br":
            text += "\n"
        elif child.name == "p":
            text += child.text.strip() + "\n"
        else:
            text += extract_text_from_element(child)
    return text.strip()

def scrape_medlineplus_data():  # Renamed function for clarity
    base_url = "https://medlineplus.gov/ency/"
    start_urls = [
        "https://medlineplus.gov/ency/encyclopedia_A.htm",
        "https://medlineplus.gov/ency/encyclopedia_B.htm",
        "https://medlineplus.gov/ency/encyclopedia_C.htm",
        "https://medlineplus.gov/ency/encyclopedia_D.htm",
        "https://medlineplus.gov/ency/encyclopedia_E.htm",
        "https://medlineplus.gov/ency/encyclopedia_F.htm",
        "https://medlineplus.gov/ency/encyclopedia_G.htm",
        "https://medlineplus.gov/ency/encyclopedia_H.htm",
        "https://medlineplus.gov/ency/encyclopedia_I.htm",
        "https://medlineplus.gov/ency/encyclopedia_J.htm",
        "https://medlineplus.gov/ency/encyclopedia_K.htm",
        "https://medlineplus.gov/ency/encyclopedia_L.htm",
        "https://medlineplus.gov/ency/encyclopedia_M.htm",
        "https://medlineplus.gov/ency/encyclopedia_N.htm",
        "https://medlineplus.gov/ency/encyclopedia_O.htm",
        "https://medlineplus.gov/ency/encyclopedia_P.htm",
        "https://medlineplus.gov/ency/encyclopedia_Q.htm",
        "https://medlineplus.gov/ency/encyclopedia_R.htm",
        "https://medlineplus.gov/ency/encyclopedia_S.htm",
        "https://medlineplus.gov/ency/encyclopedia_T.htm",
        "https://medlineplus.gov/ency/encyclopedia_U.htm",
        "https://medlineplus.gov/ency/encyclopedia_V.htm",
        "https://medlineplus.gov/ency/encyclopedia_W.htm",
        "https://medlineplus.gov/ency/encyclopedia_X.htm",
        "https://medlineplus.gov/ency/encyclopedia_Y.htm",
        "https://medlineplus.gov/ency/encyclopedia_Z.htm",
        "https://medlineplus.gov/ency/encyclopedia_0-9.htm"
    ]
    all_data = []

    for start_url in start_urls: # Loop through all start URLs
        try:
            response = requests.get(start_url)
            response.raise_for_status()
            soup = BeautifulSoup(response.content, "html.parser")

            links = soup.find("ul", id="index").find_all("a")
            for link in links:
                href = link.get("href")
                if href:
                    article_url = base_url + href
                    print(f"Scraping: {article_url}")

                    try:
                        article_response = requests.get(article_url)
                        article_response.raise_for_status()
                        article_soup = BeautifulSoup(article_response.content, "html.parser")

                        topic_element = article_soup.find("h1", class_="with-also", itemprop="name")
                        topic = topic_element.text.strip() if topic_element else "N/A"

                        summary_element = article_soup.find("div", id="ency_summary")
                        summary = extract_text_from_element(summary_element) if summary_element else "N/A"

                        q_and_a = []
                        main_div = article_soup.find("div", class_="main")
                        if main_div:
                            sections = main_div.find_all("section")
                            for section in sections:
                                question_title_element = section.find("div", class_="section-title")
                                if question_title_element and question_title_element.find("h2") and \
                                        "References" not in question_title_element.text and \
                                        "Review Date" not in question_title_element.text and \
                                        "Citation" not in question_title_element.text:
                                    question_text = question_title_element.find("h2")
                                    question = f"{topic} {question_text.text.strip()}?" if question_text else f"{topic} N/A?"
                                    answer_element = section.find("div", class_="section-body")
                                    answer = extract_text_from_element(answer_element) if answer_element else "N/A"
                                    q_and_a.append({"question": question, "answer": answer})

                        if q_and_a:
                            all_data.append({
                                "topic": topic,
                                "summary": summary,
                                "q_and_a": q_and_a
                            })

                    except requests.exceptions.RequestException as e:
                        print(f"Error fetching article {article_url}: {e}")
                    except Exception as e:
                        print(f"Error processing {article_url}: {e}")

        except requests.exceptions.RequestException as e:
            print(f"Error fetching index page {start_url}: {e}")  # Print error for each index page
        except Exception as e:
            print(f"Unexpected error: {e}")

    with open("medlineplus_all.csv", "w", newline="", encoding="utf-8") as csvfile: # Changed filename
        fieldnames = ["topic", "summary", "question", "answer"]
        writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
        writer.writeheader()

        for item in all_data:
            base_row = {
                "topic": item["topic"],
                "summary": item["summary"],
            }

            if item["q_and_a"]:
                for qa in item["q_and_a"]:
                    writer.writerow({
                        **base_row,
                        "question": qa["question"],
                        "answer": qa["answer"]
                    })


if __name__ == "__main__":
    scrape_medlineplus_data()  # Call the renamed function
    print("MedlinePlus data collection complete. Saved to medlineplus_all.csv")