# dnsrecon/providers/shodan_provider.py

import json
import os
from pathlib import Path
from typing import List, Dict, Any, Tuple
from datetime import datetime, timezone
import requests

from .base_provider import BaseProvider
from utils.helpers import _is_valid_ip, _is_valid_domain


class ShodanProvider(BaseProvider):
    """
    Provider for querying Shodan API for IP address information.
    Now uses session-specific API keys, is limited to IP-only queries, and includes caching.
    """

    def __init__(self, name=None, session_config=None):
        """Initialize Shodan provider with session-specific configuration."""
        super().__init__(
            name="shodan",
            rate_limit=60,
            timeout=30,
            session_config=session_config
        )
        self.base_url = "https://api.shodan.io"
        self.api_key = self.config.get_api_key('shodan')
        
        # Initialize cache directory
        self.cache_dir = Path('cache') / 'shodan'
        self.cache_dir.mkdir(parents=True, exist_ok=True)

    def is_available(self) -> bool:
        """Check if Shodan provider is available (has valid API key in this session)."""
        return self.api_key is not None and len(self.api_key.strip()) > 0

    def get_name(self) -> str:
        """Return the provider name."""
        return "shodan"

    def get_display_name(self) -> str:
        """Return the provider display name for the UI."""
        return "Shodan"

    def requires_api_key(self) -> bool:
        """Return True if the provider requires an API key."""
        return True

    def get_eligibility(self) -> Dict[str, bool]:
        """Return a dictionary indicating if the provider can query domains and/or IPs."""
        return {'domains': False, 'ips': True}

    def _get_cache_file_path(self, ip: str) -> Path:
        """Generate cache file path for an IP address."""
        safe_ip = ip.replace('.', '_').replace(':', '_')
        return self.cache_dir / f"{safe_ip}.json"

    def _get_cache_status(self, cache_file_path: Path) -> str:
        """
        Check cache status for an IP.
        Returns: 'not_found', 'fresh', or 'stale'
        """
        if not cache_file_path.exists():
            return "not_found"
        
        try:
            with open(cache_file_path, 'r') as f:
                cache_data = json.load(f)
            
            last_query_str = cache_data.get("last_upstream_query")
            if not last_query_str:
                return "stale"
            
            last_query = datetime.fromisoformat(last_query_str.replace('Z', '+00:00'))
            hours_since_query = (datetime.now(timezone.utc) - last_query).total_seconds() / 3600
            
            cache_timeout = self.config.cache_timeout_hours
            if hours_since_query < cache_timeout:
                return "fresh"
            else:
                return "stale"
                
        except (json.JSONDecodeError, ValueError, KeyError):
            return "stale"

    def _load_from_cache(self, cache_file_path: Path) -> Dict[str, Any]:
        """Load Shodan data from a cache file."""
        try:
            with open(cache_file_path, 'r') as f:
                return json.load(f)
        except (json.JSONDecodeError, FileNotFoundError):
            return {}

    def _save_to_cache(self, cache_file_path: Path, data: Dict[str, Any]) -> None:
        """Save Shodan data to a cache file."""
        try:
            data['last_upstream_query'] = datetime.now(timezone.utc).isoformat()
            with open(cache_file_path, 'w') as f:
                json.dump(data, f, separators=(',', ':'))
        except Exception as e:
            self.logger.logger.warning(f"Failed to save Shodan cache for {cache_file_path.name}: {e}")

    def query_domain(self, domain: str) -> List[Tuple[str, str, str, float, Dict[str, Any]]]:
        """
        Domain queries are no longer supported for the Shodan provider.
        """
        return []

    def query_ip(self, ip: str) -> List[Tuple[str, str, str, float, Dict[str, Any]]]:
        """
        Query Shodan for information about an IP address, with caching.
        """
        if not _is_valid_ip(ip) or not self.is_available():
            return []
        
        cache_file = self._get_cache_file_path(ip)
        cache_status = self._get_cache_status(cache_file)
        
        data = {}
        
        try:
            if cache_status == "fresh":
                data = self._load_from_cache(cache_file)
                self.logger.logger.info(f"Using cached Shodan data for {ip}")
            else: # "stale" or "not_found"
                url = f"{self.base_url}/shodan/host/{ip}"
                params = {'key': self.api_key}
                response = self.make_request(url, method="GET", params=params, target_indicator=ip)
                
                if response and response.status_code == 200:
                    data = response.json()
                    self._save_to_cache(cache_file, data)
                elif cache_status == "stale":
                    # If API fails on a stale cache, use the old data
                    data = self._load_from_cache(cache_file)

        except requests.exceptions.RequestException as e:
            self.logger.logger.error(f"Shodan API query failed for {ip}: {e}")
            if cache_status == "stale":
                data = self._load_from_cache(cache_file)
        
        if not data:
            return []

        return self._process_shodan_data(ip, data)

    def _process_shodan_data(self, ip: str, data: Dict[str, Any]) -> List[Tuple[str, str, str, float, Dict[str, Any]]]:
        """
        Process Shodan data to extract relationships.
        """
        relationships = []

        # Extract hostname relationships
        hostnames = data.get('hostnames', [])
        for hostname in hostnames:
            if _is_valid_domain(hostname):
                relationships.append((
                    ip,
                    hostname,
                    'a_record',
                    0.8,
                    data
                ))
                self.log_relationship_discovery(
                    source_node=ip,
                    target_node=hostname,
                    relationship_type='a_record',
                    confidence_score=0.8,
                    raw_data=data,
                    discovery_method="shodan_host_lookup"
                )

        # Extract ASN relationship
        asn = data.get('asn')
        if asn:
            asn_name = f"AS{asn[2:]}" if isinstance(asn, str) and asn.startswith('AS') else f"AS{asn}"
            relationships.append((
                ip,
                asn_name,
                'asn_membership',
                0.7,
                data
            ))
            self.log_relationship_discovery(
                source_node=ip,
                target_node=asn_name,
                relationship_type='asn_membership',
                confidence_score=0.7,
                raw_data=data,
                discovery_method="shodan_asn_lookup"
            )
            
        return relationships