import time
import requests
from bs4 import BeautifulSoup
from urllib.parse import quote_plus

# Global session with headers
session = requests.Session()
session.headers.update({
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
                  "AppleWebKit/537.36 (KHTML, like Gecko) "
                  "Chrome/114.0.0.0 Safari/537.36",
    "Accept-Language": "en-US,en;q=0.9"
})

def fetch_soup(url):
    try:
        resp = session.get(url, timeout=10)
        resp.raise_for_status()
        time.sleep(1)  # polite delay
        return BeautifulSoup(resp.text, "html.parser")
    except requests.exceptions.HTTPError as e:
        print(f"[ERROR] HTTP error while fetching: {url}\n{e}")
        return BeautifulSoup("", "html.parser")
    except Exception as e:
        print(f"[ERROR] General error while fetching: {url}\n{e}")
        return BeautifulSoup("", "html.parser")


def scrape_amazon(query):
    print(f"Scraping Amazon for query: {query}")
    url = f"https://www.amazon.in/s?k={quote_plus(query)}"
    soup = fetch_soup(url)

    products = []
    for item in soup.select("div[data-component-type='s-search-result']"):
        name_el = item.select_one("h2 span")
        price_el = item.select_one("span.a-price-whole")
        img_el = item.select_one("img.s-image")
        link_el = item.select_one("a")

        products.append({
            "name": name_el.get_text(strip=True) if name_el else "N/A",
            "price": price_el.get_text(strip=True) if price_el else "N/A",
            "img": img_el["src"] if img_el else "",
            "link": "https://www.amazon.in" + link_el["href"] if link_el else ""
        })
    return products


def scrape_1mg(query):
    print(f"Scraping 1mg for query: {query}")
    url = f"https://www.1mg.com/search/all?name={quote_plus(query)}"
    soup = fetch_soup(url)

    products = []
    for product in soup.select("div.style__horizontal-card___1Zwmt"):
        name_el = product.select_one("div.style__product-description___1vPQe")
        price_el = product.select_one("div.style__price-tag___B2csA")
        link_el = product.select_one("a")
        img_el = product.select_one("img")

        products.append({
            "name": name_el.get_text(strip=True) if name_el else "N/A",
            "price": price_el.get_text(strip=True) if price_el else "N/A",
            "img": img_el["src"] if img_el else "",
            "link": "https://www.1mg.com" + link_el["href"] if link_el else ""
        })
    return products


def scrape_netmeds(query):
    print(f"Scraping Netmeds for query: {query}")
    url = f"https://www.netmeds.com/catalogsearch/result/{quote_plus(query)}/all"
    soup = fetch_soup(url)

    products = []
    for product in soup.select("div.cat-item"):
        name_el = product.select_one("h3")
        price_el = product.select_one("span.final-price")
        link_el = product.select_one("a")
        img_el = product.select_one("img")

        products.append({
            "name": name_el.get_text(strip=True) if name_el else "N/A",
            "price": price_el.get_text(strip=True) if price_el else "N/A",
            "img": img_el["src"] if img_el else "",
            "link": "https://www.netmeds.com" + link_el["href"] if link_el else ""
        })
    return products


def scrape_pharmeasy(query):
    print(f"Scraping PharmEasy for query: {query}")
    url = f"https://pharmeasy.in/search/all?name={quote_plus(query)}"
    soup = fetch_soup(url)

    products = []
    for product in soup.select("div.ProductCard_medicineUnitContainer__m2_zO"):
        name_el = product.select_one("h1")
        price_el = product.select_one("div.ProductCard_ourPrice__yU5GB")
        link_el = product.select_one("a")
        img_el = product.select_one("img")

        products.append({
            "name": name_el.get_text(strip=True) if name_el else "N/A",
            "price": price_el.get_text(strip=True) if price_el else "N/A",
            "img": img_el["src"] if img_el else "",
            "link": "https://pharmeasy.in" + link_el["href"] if link_el else ""
        })
    return products


def search_product(query):
    amazon_products = [{"source": "Amazon", **p} for p in scrape_amazon(query)]
    one_mg_products = [{"source": "1mg", **p} for p in scrape_1mg(query)]
    netmeds_products = [{"source": "Netmeds", **p} for p in scrape_netmeds(query)]
    pharmeasy_products = [{"source": "PharmEasy", **p} for p in scrape_pharmeasy(query)]

    combined = []
    max_len = max(len(amazon_products), len(one_mg_products), len(netmeds_products), len(pharmeasy_products))

    for i in range(max_len):
        combined.append({
            "name": (
                amazon_products[i]["name"] if i < len(amazon_products) else
                one_mg_products[i]["name"] if i < len(one_mg_products) else
                netmeds_products[i]["name"] if i < len(netmeds_products) else
                pharmeasy_products[i]["name"] if i < len(pharmeasy_products) else ""
            ),
            "img": (
                amazon_products[i]["img"] if i < len(amazon_products) else
                one_mg_products[i]["img"] if i < len(one_mg_products) else
                netmeds_products[i]["img"] if i < len(netmeds_products) else
                pharmeasy_products[i]["img"] if i < len(pharmeasy_products) else ""
            ),
            "amazon": amazon_products[i] if i < len(amazon_products) else {},
            "one_mg": one_mg_products[i] if i < len(one_mg_products) else {},
            "netmeds": netmeds_products[i] if i < len(netmeds_products) else {},
            "pharmeasy": pharmeasy_products[i] if i < len(pharmeasy_products) else {},
        })

    return combined


def search_product_with_progress(query):
    combined = search_product(query)

    # Fetch side effects using OpenFDA API
    api_url = f'https://api.fda.gov/drug/event.json?api_key=ah8n0nI6468qpS6cMfqvBM0sdGs4nO1sT3Ie7LjJ&search=patient.drug.medicinalproduct:"{query}"'

    try:
        response = requests.get(api_url)
        data = response.json()
        if data.get('results'):
            side_effects = [
                reaction.get('reactionmeddrapt', 'N/A')
                for reaction in data['results'][0].get('patient', {}).get('reaction', [])
            ]
        else:
            side_effects = ["No side effects found."]
    except Exception as e:
        print(f"Error fetching side effects: {e}")
        side_effects = ["Error fetching side effects."]

    return combined, side_effects