"""
GovInfo API client for fetching actual bill text.

Priority order for text formats: htm > txt > pdf
"""
import logging
import re
from typing import Optional

import requests
from bs4 import BeautifulSoup
from tenacity import retry, stop_after_attempt, wait_exponential

from app.config import settings

logger = logging.getLogger(__name__)

GOVINFO_BASE = "https://api.govinfo.gov"
FORMAT_PRIORITY = ["htm", "html", "txt", "pdf"]


@retry(stop=stop_after_attempt(3), wait=wait_exponential(min=2, max=15))
def _get(url: str, params: dict = None) -> requests.Response:
    p = {"api_key": settings.DATA_GOV_API_KEY, **(params or {})}
    response = requests.get(url, params=p, timeout=60)
    response.raise_for_status()
    return response


def get_package_summary(package_id: str) -> dict:
    response = _get(f"{GOVINFO_BASE}/packages/{package_id}/summary")
    return response.json()


def get_package_content_detail(package_id: str) -> dict:
    response = _get(f"{GOVINFO_BASE}/packages/{package_id}/content-detail")
    return response.json()


def find_best_text_url(text_versions: list[dict]) -> Optional[tuple[str, str]]:
    """
    From a list of text version objects (from Congress.gov API), find the best
    available text format. Returns (url, format) or None.
    Matches by URL extension since Congress.gov type strings are "Formatted Text", "PDF", etc.
    """
    for fmt in FORMAT_PRIORITY:
        for version in text_versions:
            for fmt_info in version.get("formats", []):
                if not isinstance(fmt_info, dict):
                    continue
                url = fmt_info.get("url", "")
                if url.lower().endswith(f".{fmt}"):
                    return url, fmt
    return None, None


def fetch_text_from_url(url: str, fmt: str) -> Optional[str]:
    """Download and extract plain text from a GovInfo document URL."""
    try:
        response = requests.get(url, timeout=120)
        response.raise_for_status()

        if fmt in ("htm", "html"):
            return _extract_from_html(response.text)
        elif fmt == "txt":
            return response.text
        elif fmt == "pdf":
            return _extract_from_pdf(response.content)
    except Exception as e:
        logger.error(f"Failed to fetch text from {url}: {e}")
        return None


def _extract_from_html(html: str) -> str:
    """Strip HTML tags and clean up whitespace."""
    soup = BeautifulSoup(html, "lxml")
    # Remove script/style tags
    for tag in soup(["script", "style", "nav", "header", "footer"]):
        tag.decompose()
    text = soup.get_text(separator="\n")
    # Collapse excessive whitespace
    text = re.sub(r"\n{3,}", "\n\n", text)
    text = re.sub(r" {2,}", " ", text)
    return text.strip()


def _extract_from_pdf(content: bytes) -> Optional[str]:
    """Extract text from PDF bytes using pdfminer."""
    try:
        from io import BytesIO
        from pdfminer.high_level import extract_text as pdf_extract
        return pdf_extract(BytesIO(content))
    except Exception as e:
        logger.error(f"PDF extraction failed: {e}")
        return None