import re
from typing import Any, Dict, List, Optional, Tuple

import justext
from langchain_core.language_models import BaseLLM
from loguru import logger

from ...config import search_config
from ...security.safe_requests import safe_get
from ..rate_limiting import RateLimitError
from ..search_engine_base import BaseSearchEngine


class WaybackSearchEngine(BaseSearchEngine):
    """
    Internet Archive Wayback Machine search engine implementation
    Provides access to historical versions of web pages
    """

    # Mark as public search engine
    is_public = True

    def __init__(
        self,
        max_results: int = 10,
        max_snapshots_per_url: int = 3,
        llm: Optional[BaseLLM] = None,
        language: str = "English",
        max_filtered_results: Optional[int] = None,
        closest_only: bool = False,
        settings_snapshot: Optional[Dict[str, Any]] = None,
    ):
        """
        Initialize the Wayback Machine search engine.

        Args:
            max_results: Maximum number of search results
            max_snapshots_per_url: Maximum snapshots to retrieve per URL
            llm: Language model for relevance filtering
            language: Language for content processing
            max_filtered_results: Maximum number of results to keep after filtering
            closest_only: If True, only retrieves the closest snapshot for each URL
        """
        # Initialize the BaseSearchEngine with LLM, max_filtered_results, and max_results
        super().__init__(
            llm=llm,
            max_filtered_results=max_filtered_results,
            max_results=max_results,
            settings_snapshot=settings_snapshot,
        )
        self.max_snapshots_per_url = max_snapshots_per_url
        self.language = language
        self.closest_only = closest_only

        # API endpoints
        self.available_api = "https://archive.org/wayback/available"
        self.cdx_api = "https://web.archive.org/cdx/search/cdx"

    def _extract_urls_from_query(self, query: str) -> List[str]:
        """
        Extract URLs from a query string or interpret as an URL if possible.
        For non-URL queries, use a DuckDuckGo search to find relevant URLs.

        Args:
            query: The search query or URL

        Returns:
            List of URLs to search in the Wayback Machine
        """
        # Check if the query is already a URL
        url_pattern = re.compile(r"https?://(?:[-\w.]|(?:%[\da-fA-F]{2}))+")
        urls = url_pattern.findall(query)

        if urls:
            logger.info(f"Found {len(urls)} URLs in query")
            return urls

        # Check if query is a domain without http prefix
        domain_pattern = re.compile(r"^(?:[-\w.]|(?:%[\da-fA-F]{2}))+\.\w+$")
        if domain_pattern.match(query):
            logger.info(f"Query appears to be a domain: {query}")
            return [f"http://{query}"]

        # For non-URL queries, use DuckDuckGo to find relevant URLs
        logger.info(
            "Query is not a URL, using DuckDuckGo to find relevant URLs"
        )
        try:
            # Import DuckDuckGo search engine
            from langchain_community.utilities import DuckDuckGoSearchAPIWrapper

            # Use max_results from parent class, but limit to 5 for URL discovery
            url_search_limit = min(5, self.max_results)
            ddg = DuckDuckGoSearchAPIWrapper(max_results=url_search_limit)
            # Pass max_results as a positional argument
            results = ddg.results(query, url_search_limit)

            # Extract URLs from results
            ddg_urls = [
                str(result.get("link"))
                for result in results
                if result.get("link")
            ]
            if ddg_urls:
                logger.info(
                    f"Found {len(ddg_urls)} URLs from DuckDuckGo search"
                )
                return ddg_urls
        except Exception:
            logger.exception("Error using DuckDuckGo for URL discovery")

        # Fallback: treat the query as a potential domain or path
        if "/" in query and "." in query:
            logger.info(f"Treating query as a partial URL: {query}")
            return [f"http://{query}"]
        if "." in query:
            logger.info(f"Treating query as a domain: {query}")
            return [f"http://{query}"]

        # Return empty list if nothing worked
        logger.warning(f"Could not extract any URLs from query: {query}")
        return []

    def _format_timestamp(self, timestamp: str) -> str:
        """Format Wayback Machine timestamp into readable date"""
        if len(timestamp) < 14:
            return timestamp

        try:
            year = timestamp[0:4]
            month = timestamp[4:6]
            day = timestamp[6:8]
            hour = timestamp[8:10]
            minute = timestamp[10:12]
            second = timestamp[12:14]
            return f"{year}-{month}-{day} {hour}:{minute}:{second}"
        except Exception:
            logger.debug("Timestamp formatting failed, returning original")
            return timestamp

    def _get_wayback_snapshots(self, url: str) -> List[Dict[str, Any]]:
        """
        Get snapshots from the Wayback Machine for a specific URL.

        Args:
            url: URL to get snapshots for

        Returns:
            List of snapshot dictionaries
        """
        snapshots = []

        try:
            if self.closest_only:
                # Get only the closest snapshot
                response = safe_get(self.available_api, params={"url": url})

                # Check for rate limit
                if response.status_code == 429:
                    raise RateLimitError("Wayback Machine rate limit exceeded")  # noqa: TRY301 — re-raised by except RateLimitError for base class retry

                data = response.json()

                if (
                    "archived_snapshots" in data
                    and "closest" in data["archived_snapshots"]
                ):
                    snapshot = data["archived_snapshots"]["closest"]
                    snapshot_url = snapshot["url"]
                    timestamp = snapshot["timestamp"]

                    snapshots.append(
                        {
                            "timestamp": timestamp,
                            "formatted_date": self._format_timestamp(timestamp),
                            "url": snapshot_url,
                            "original_url": url,
                            "available": snapshot.get("available", True),
                            "status": snapshot.get("status", "200"),
                        }
                    )
            else:
                # Get multiple snapshots using CDX API
                response = safe_get(
                    self.cdx_api,
                    params={
                        "url": url,
                        "output": "json",
                        "fl": "timestamp,original,statuscode,mimetype",
                        "collapse": "timestamp:4",  # Group by year
                        "limit": self.max_snapshots_per_url,
                    },
                )

                # Check for rate limit
                if response.status_code == 429:
                    raise RateLimitError(  # noqa: TRY301 — re-raised by except RateLimitError for base class retry
                        "Wayback Machine CDX API rate limit exceeded"
                    )

                # Check if response is valid JSON
                data = response.json()

                # First item is the header
                if len(data) > 1:
                    headers = data[0]
                    for item in data[1:]:
                        snapshot = dict(zip(headers, item, strict=False))
                        timestamp = snapshot.get("timestamp", "")

                        wayback_url = (
                            f"https://web.archive.org/web/{timestamp}/{url}"
                        )

                        snapshots.append(
                            {
                                "timestamp": timestamp,
                                "formatted_date": self._format_timestamp(
                                    timestamp
                                ),
                                "url": wayback_url,
                                "original_url": url,
                                "available": True,
                                "status": snapshot.get("statuscode", "200"),
                            }
                        )

                # Limit to max snapshots per URL
                snapshots = snapshots[: self.max_snapshots_per_url]

        except RateLimitError:
            # Re-raise rate limit errors for base class retry handling
            raise
        except Exception:
            logger.exception(f"Error getting Wayback snapshots for {url}")

        return snapshots

    def _get_previews(self, query: str) -> List[Dict[str, Any]]:
        """
        Get preview information for Wayback Machine snapshots.

        Args:
            query: The search query

        Returns:
            List of preview dictionaries
        """
        logger.info(f"Getting Wayback Machine previews for query: {query}")

        # Extract URLs from query
        urls = self._extract_urls_from_query(query)

        if not urls:
            logger.warning(f"No URLs found in query: {query}")
            return []

        # Get snapshots for each URL
        all_snapshots = []
        for url in urls:
            snapshots = self._get_wayback_snapshots(url)
            all_snapshots.extend(snapshots)

            # Apply rate limiting between requests
            if len(urls) > 1:
                self.rate_tracker.apply_rate_limit(self.engine_type)

        # Format as previews
        previews = []
        for snapshot in all_snapshots:
            preview = {
                "id": f"{snapshot['timestamp']}_{snapshot['original_url']}",
                "title": f"Archive of {snapshot['original_url']} ({snapshot['formatted_date']})",
                "link": snapshot["url"],
                "snippet": f"Archived version from {snapshot['formatted_date']}",
                "original_url": snapshot["original_url"],
                "timestamp": snapshot["timestamp"],
                "formatted_date": snapshot["formatted_date"],
            }
            previews.append(preview)

        logger.info(f"Found {len(previews)} Wayback Machine snapshots")
        return previews

    def _remove_boilerplate(self, html: str) -> str:
        """
        Remove boilerplate content from HTML.

        Args:
            html: HTML content

        Returns:
            Cleaned text content
        """
        if not html or not html.strip():
            return ""
        try:
            paragraphs = justext.justext(
                html, justext.get_stoplist(self.language)
            )
            return "\n".join(
                [p.text for p in paragraphs if not p.is_boilerplate]
            )
        except Exception:
            logger.exception("Error removing boilerplate")
            return html

    def _get_wayback_content(self, url: str) -> Tuple[str, str]:
        """
        Retrieve content from a Wayback Machine URL.

        Args:
            url: Wayback Machine URL

        Returns:
            Tuple of (raw_html, cleaned_text)
        """
        try:
            headers = {
                "User-Agent": "Mozilla/5.0 (Local Deep Research Bot; research project)"
            }
            response = safe_get(url, headers=headers, timeout=10)
            raw_html = response.text

            # Clean the HTML
            cleaned_text = self._remove_boilerplate(raw_html)

            return raw_html, cleaned_text
        except Exception as e:
            logger.exception(f"Error retrieving content from {url}")
            return "", f"Error retrieving content: {e!s}"

    def _get_full_content(
        self, relevant_items: List[Dict[str, Any]]
    ) -> List[Dict[str, Any]]:
        """
        Get full content for the relevant Wayback Machine snapshots.

        Args:
            relevant_items: List of relevant preview dictionaries

        Returns:
            List of result dictionaries with full content
        """
        # Check if we should add full content
        if (
            hasattr(search_config, "SEARCH_SNIPPETS_ONLY")
            and search_config.SEARCH_SNIPPETS_ONLY
        ):
            logger.info("Snippet-only mode, skipping full content retrieval")
            return relevant_items

        logger.info(
            f"Getting full content for {len(relevant_items)} Wayback Machine snapshots"
        )

        results = []
        for item in relevant_items:
            wayback_url = item.get("link")
            if not wayback_url:
                results.append(item)
                continue

            logger.info(f"Retrieving content from {wayback_url}")

            try:
                # Retrieve content
                raw_html, full_content = self._get_wayback_content(wayback_url)

                # Add full content to the result
                result = item.copy()
                result["raw_html"] = raw_html
                result["full_content"] = full_content

                results.append(result)

                # Apply rate limiting
                self.rate_tracker.apply_rate_limit(self.engine_type)
            except Exception:
                logger.exception(f"Error processing {wayback_url}")
                results.append(item)

        return results

    def search_by_url(
        self, url: str, max_snapshots: int | None = None
    ) -> List[Dict[str, Any]]:
        """
        Search for archived versions of a specific URL.

        Args:
            url: The URL to search for archives
            max_snapshots: Maximum number of snapshots to return

        Returns:
            List of snapshot dictionaries
        """
        max_snapshots = max_snapshots or self.max_snapshots_per_url

        snapshots = self._get_wayback_snapshots(url)
        previews = []

        for snapshot in snapshots[:max_snapshots]:
            preview = {
                "id": f"{snapshot['timestamp']}_{snapshot['original_url']}",
                "title": f"Archive of {snapshot['original_url']} ({snapshot['formatted_date']})",
                "link": snapshot["url"],
                "snippet": f"Archived version from {snapshot['formatted_date']}",
                "original_url": snapshot["original_url"],
                "timestamp": snapshot["timestamp"],
                "formatted_date": snapshot["formatted_date"],
            }
            previews.append(preview)

        # Get full content if not in snippets-only mode
        if (
            not hasattr(search_config, "SEARCH_SNIPPETS_ONLY")
            or not search_config.SEARCH_SNIPPETS_ONLY
        ):
            return self._get_full_content(previews)

        return previews

    def search_by_date_range(
        self, url: str, start_date: str, end_date: str
    ) -> List[Dict[str, Any]]:
        """
        Search for archived versions of a URL within a date range.

        Args:
            url: The URL to search for archives
            start_date: Start date in format YYYYMMDD
            end_date: End date in format YYYYMMDD

        Returns:
            List of snapshot dictionaries
        """
        try:
            # Use CDX API with date range
            response = safe_get(
                self.cdx_api,
                params={
                    "url": url,
                    "output": "json",
                    "fl": "timestamp,original,statuscode,mimetype",
                    "from": start_date,
                    "to": end_date,
                    "limit": self.max_snapshots_per_url,
                },
            )

            # Process response
            data = response.json()

            # First item is the header
            if len(data) <= 1:
                return []

            headers = data[0]
            snapshots = []

            for item in data[1:]:
                snapshot = dict(zip(headers, item, strict=False))
                timestamp = snapshot.get("timestamp", "")

                wayback_url = f"https://web.archive.org/web/{timestamp}/{url}"

                snapshots.append(
                    {
                        "id": f"{timestamp}_{url}",
                        "title": f"Archive of {url} ({self._format_timestamp(timestamp)})",
                        "link": wayback_url,
                        "snippet": f"Archived version from {self._format_timestamp(timestamp)}",
                        "original_url": url,
                        "timestamp": timestamp,
                        "formatted_date": self._format_timestamp(timestamp),
                    }
                )

            # Get full content if not in snippets-only mode
            if (
                not hasattr(search_config, "SEARCH_SNIPPETS_ONLY")
                or not search_config.SEARCH_SNIPPETS_ONLY
            ):
                return self._get_full_content(snapshots)

            return snapshots

        except Exception:
            logger.exception(f"Error searching date range for {url}")
            return []

    def get_latest_snapshot(self, url: str) -> Optional[Dict[str, Any]]:
        """
        Get the most recent snapshot of a URL.

        Args:
            url: The URL to get the latest snapshot for

        Returns:
            Dictionary with snapshot information or None if not found
        """
        try:
            response = safe_get(self.available_api, params={"url": url})
            data = response.json()

            if (
                "archived_snapshots" in data
                and "closest" in data["archived_snapshots"]
            ):
                snapshot = data["archived_snapshots"]["closest"]
                timestamp = snapshot["timestamp"]
                wayback_url = snapshot["url"]

                result = {
                    "id": f"{timestamp}_{url}",
                    "title": f"Latest archive of {url} ({self._format_timestamp(timestamp)})",
                    "link": wayback_url,
                    "snippet": f"Archived version from {self._format_timestamp(timestamp)}",
                    "original_url": url,
                    "timestamp": timestamp,
                    "formatted_date": self._format_timestamp(timestamp),
                }

                # Get full content if not in snippets-only mode
                if (
                    not hasattr(search_config, "SEARCH_SNIPPETS_ONLY")
                    or not search_config.SEARCH_SNIPPETS_ONLY
                ):
                    raw_html, full_content = self._get_wayback_content(
                        wayback_url
                    )
                    result["raw_html"] = raw_html
                    result["full_content"] = full_content

                return result

            return None

        except Exception:
            logger.exception(f"Error getting latest snapshot for {url}")
            return None
