"""
USPTO Patent Search

Uses the USPTO PatentsView API for patent searches.
Free, no API key required.

API Documentation: https://patentsview.org/apis/api-endpoints
"""

import logging
import requests
from typing import List, Optional, Dict, Any
from datetime import datetime

from ..search.base import BaseSearcher, SearchResult

logger = logging.getLogger(__name__)


class PatentSearcher(BaseSearcher):
    """
    Search USPTO patent database via PatentsView API.

    Patents indicate active R&D and can reveal technical approaches
    to solving capability gaps.
    """

    BASE_URL = "https://api.patentsview.org/patents/query"

    def __init__(self, timeout: int = 30):
        self.timeout = timeout

    @property
    def name(self) -> str:
        return "USPTO Patents"

    @property
    def source_type(self) -> str:
        return "patent"

    def search(
        self,
        query: str,
        max_results: int = 20,
        year_start: Optional[int] = None,
        assignee: Optional[str] = None
    ) -> List[SearchResult]:
        """
        Search USPTO patents.

        Args:
            query: Text search (searches title, abstract, claims)
            max_results: Maximum results
            year_start: Only patents from this year forward
            assignee: Filter by assignee/company name

        Returns:
            List of SearchResult objects
        """
        # Build query filter
        query_parts = [{"_text_any": {"patent_abstract": query}}]

        if year_start:
            query_parts.append({
                "_gte": {"patent_date": f"{year_start}-01-01"}
            })

        if assignee:
            query_parts.append({
                "_text_any": {"assignee_organization": assignee}
            })

        # Combine with AND
        if len(query_parts) > 1:
            query_filter = {"_and": query_parts}
        else:
            query_filter = query_parts[0]

        payload = {
            "q": query_filter,
            "f": [
                "patent_number",
                "patent_title",
                "patent_abstract",
                "patent_date",
                "assignee_organization",
                "inventor_first_name",
                "inventor_last_name"
            ],
            "o": {"per_page": min(max_results, 100)},
            "s": [{"patent_date": "desc"}]  # Most recent first
        }

        results = []

        try:
            response = requests.post(
                self.BASE_URL,
                json=payload,
                timeout=self.timeout,
                headers={"Content-Type": "application/json"}
            )
            response.raise_for_status()
            data = response.json()

            patents = data.get("patents", [])

            for rank, patent in enumerate(patents, 1):
                if rank > max_results:
                    break

                patent_number = patent.get("patent_number", "")
                url = f"https://patents.google.com/patent/US{patent_number}" if patent_number else ""

                # Get primary assignee
                assignees = patent.get("assignees", [])
                org = assignees[0].get("assignee_organization", "") if assignees else ""

                results.append(SearchResult(
                    title=patent.get("patent_title", ""),
                    url=url,
                    snippet=patent.get("patent_abstract", "")[:500] if patent.get("patent_abstract") else "",
                    source=self.name,
                    source_type=self.source_type,
                    rank=rank,
                    published_date=patent.get("patent_date"),
                    organization=org,
                    patent_number=patent_number,
                    trl_estimate=5,  # Patents typically represent mid-TRL tech
                    raw_data=patent
                ))

            logger.info(f"Patent search for '{query}' returned {len(results)} results")

        except requests.exceptions.RequestException as e:
            logger.error(f"USPTO API request failed: {e}")
        except Exception as e:
            logger.error(f"Patent search error: {e}")

        return results

    def search_defense_contractors(self, query: str, max_results: int = 20) -> List[SearchResult]:
        """Search patents from major defense contractors."""
        contractors = [
            "Lockheed Martin",
            "Raytheon",
            "Northrop Grumman",
            "Boeing",
            "General Dynamics",
            "L3Harris",
            "BAE Systems"
        ]

        all_results = []
        per_contractor = max(2, max_results // len(contractors))

        for contractor in contractors:
            results = self.search(
                query,
                max_results=per_contractor,
                assignee=contractor
            )
            all_results.extend(results)

        # Sort by date and limit
        all_results.sort(key=lambda x: x.published_date or "", reverse=True)
        return all_results[:max_results]

    def get_patent_details(self, patent_number: str) -> Optional[Dict[str, Any]]:
        """Get detailed information about a specific patent."""
        payload = {
            "q": {"patent_number": patent_number},
            "f": [
                "patent_number",
                "patent_title",
                "patent_abstract",
                "patent_date",
                "patent_type",
                "assignee_organization",
                "assignee_type",
                "inventor_first_name",
                "inventor_last_name",
                "inventor_city",
                "inventor_state",
                "cpc_section_id",
                "cpc_subsection_title"
            ]
        }

        try:
            response = requests.post(
                self.BASE_URL,
                json=payload,
                timeout=self.timeout,
                headers={"Content-Type": "application/json"}
            )
            response.raise_for_status()
            data = response.json()
            patents = data.get("patents", [])
            return patents[0] if patents else None
        except Exception as e:
            logger.error(f"Failed to get patent details: {e}")
            return None