import asyncio
import logging
import re
from typing import Optional
from httpx import AsyncClient
from bs4 import BeautifulSoup
from pydantic import BaseModel


class PatentScrapResult(BaseModel):
    """Schema for the result of scraping a google patents page."""
    # The title of the patent.
    title: str
    # The abstract of the patent, if available.
    abstract: Optional[str] = None
    # The full description of the patent containing the field of the invention, background, summary, etc.
    description: Optional[str] = None
    # The full claims of the patent.
    claims: Optional[str] = None
    # The field of the invention, if available.
    field_of_invention: Optional[str] = None
    # The background of the invention, if available.
    background: Optional[str] = None


async def scrap_patent_async(client: AsyncClient, patent_url: str) -> PatentScrapResult:
    headers = {
        "User-Agent": "Mozilla/5.0 (compatible; GPTBot/1.0; +https://openai.com/gptbot)"
    }
    try:
        response = await client.get(patent_url, headers=headers)
        response.raise_for_status()

        soup = BeautifulSoup(response.text, "html.parser")

        # Abstract
        abstract_div = soup.find("div", {"class": "abstract"})
        abstract = abstract_div.get_text(
            strip=True) if abstract_div else None

        # Description
        description_section = soup.find("section", itemprop="description")
        description = description_section.get_text(
            separator="\n", strip=True) if description_section else None

        # Field of the Invention
        invention_field_match = re.findall(
            r"(FIELD OF THE INVENTION|TECHNICAL FIELD)(.*?)(?:(BACKGROUND|BACKGROUND OF THE INVENTION|SUMMARY|BRIEF SUMMARY|DETAILED DESCRIPTION|DESCRIPTION OF THE RELATED ART))", description, re.IGNORECASE | re.DOTALL) if description_section else None
        invention_field = invention_field_match[0][1].strip(
        ) if invention_field_match else None

        # Background of the Invention
        invention_background_match = re.findall(
            r"(BACKGROUND OF THE INVENTION|BACKGROUND)(.*?)(?:(SUMMARY|BRIEF SUMMARY|DETAILED DESCRIPTION|DESCRIPTION OF THE PREFERRED EMBODIMENTS|DESCRIPTION))", description, re.IGNORECASE | re.DOTALL) if description_section else None
        invention_background = invention_background_match[0][1].strip(
        ) if invention_background_match else None

        # Claims
        claims_section = soup.find("section", itemprop="claims")
        claims = claims_section.get_text(
            separator="\n", strip=True) if claims_section else None

        # Patent Title
        meta_title = soup.find("meta", {"name": "DC.title"}).get(
            "content").strip()

        # Patent publication number
        # pub_num = soup.select_one("h2#pubnum").get_text(strip=True)
        # get the h2 with id ="pubnum" and extract the text

        return PatentScrapResult(
            # publication_number=pub_num,
            abstract=abstract,
            description=description,
            claims=claims,
            title=meta_title,
            field_of_invention=invention_field,
            background=invention_background
        )
    except Exception as e:
        logging.error(f"Error scraping {patent_url}: {e}")
        return None


async def scrap_patent_bulk_async(client: AsyncClient, patent_urls: list[str]) -> list[PatentScrapResult]:
    """Scrape multiple patents asynchronously."""
    tasks = [scrap_patent_async(client, url) for url in patent_urls]
    results = await asyncio.gather(*tasks)

    # Filter out None results (failed scrapes)
    return [res for res in results if res is not None]