import logging
import asyncio
import nest_asyncio
import os
import json
import httpx
from config import settings
from pydantic import BaseModel, Field

logger = logging.getLogger(__name__)

class FormattingRules(BaseModel):
    """Schema for formatting rules extraction"""
    margins: str = Field(description="Margin requirements for the manuscript")
    font: str = Field(description="Font requirements including size, type, etc.")
    line_spacing: str = Field(description="Line spacing requirements")
    citations: str = Field(description="Citation style and formatting requirements")
    sections: str = Field(description="Required sections and their structure")
    other_rules: str = Field(description="Any other formatting requirements")
    summary: str = Field(description="A brief summary of the key formatting requirements")

def format_rules_for_display(rules_data):
    """
    Format the extracted rules data into a readable markdown string.
    """
    if not rules_data:
        return "Could not extract formatting rules from the provided URL."
    
    formatted_rules = f"""
# Manuscript Formatting Guidelines

## Margins
{rules_data.get('margins', 'Not specified')}

## Font
{rules_data.get('font', 'Not specified')}

## Line Spacing
{rules_data.get('line_spacing', 'Not specified')}

## Citations
{rules_data.get('citations', 'Not specified')}

## Section Structure
{rules_data.get('sections', 'Not specified')}

## Other Requirements
{rules_data.get('other_rules', 'Not specified')}

## Summary
{rules_data.get('summary', 'Not specified')}
"""
    return formatted_rules

def get_rules_from_url(url: str) -> str:
    """
    Extracts formatting rules from a given URL using crawl4ai.
    """
    logger.info(f"Extracting rules from URL: {url}")
    
    # Apply nest_asyncio here, when the function is called
    nest_asyncio.apply()
    
    # Import crawl4ai modules here to avoid event loop issues at module level
    from crawl4ai import AsyncWebCrawler, CacheMode, BrowserConfig, CrawlerRunConfig, LLMConfig
    from crawl4ai.extraction_strategy import LLMExtractionStrategy
    
    async def _extract_rules_async(url: str) -> str:
        """
        Asynchronously extracts formatting rules from a given URL using crawl4ai.
        """
        # Configure the browser
        browser_config = BrowserConfig(verbose=True)
        
        # Configure the LLM extraction
        extraction_strategy = LLMExtractionStrategy(
            llm_config=LLMConfig(
                provider=f"{settings.llm_provider}/{settings.llm_model_name}",
                api_token=settings.openrouter_api_key
            ),
            schema=FormattingRules.schema(),
            extraction_type="schema",
            instruction="""
            From the crawled content, extract all formatting rules for manuscript submissions.
            Focus on requirements for margins, font, line spacing, citations, section structure,
            and any other formatting guidelines. Provide a comprehensive extraction of all
            formatting-related information.
            
            If a specific requirement is not mentioned in the content, include "Not specified" in the corresponding field.
            """
        )
        
        # Configure the crawler
        run_config = CrawlerRunConfig(
            word_count_threshold=10,
            exclude_external_links=True,
            process_iframes=True,
            remove_overlay_elements=True,
            exclude_social_media_links=True,
            check_robots_txt=True,
            semaphore_count=3,
            extraction_strategy=extraction_strategy
        )

        # Initialize the crawler and run
        async with AsyncWebCrawler() as crawler:
            try:
                result = await crawler.arun(
                    url=url,
                    config=run_config
                )
                logger.info(f"Crawler result for {url}: {result}")

                # Handle robots.txt blocking
                if not result.success and "robots.txt" in str(result.error_message):
                    logger.warning(f"Crawl blocked by robots.txt for {url}. Falling back to direct download.")
                    try:
                        with httpx.Client() as client:
                            response = client.get(url, follow_redirects=True)
                            response.raise_for_status()
                        
                        raw_html = response.text
                        logger.info(f"Successfully downloaded HTML content for {url}.")
                        
                        # Re-run crawl4ai with raw HTML
                        raw_html_url = f"raw:{raw_html}"
                        result = await crawler.arun(url=raw_html_url, config=run_config)
                        logger.info(f"Crawler result for raw HTML: {result}")

                    except httpx.HTTPStatusError as e:
                        logger.error(f"HTTP error while fetching {url}: {e}", exc_info=True)
                        return "Failed to download the page content after being blocked by robots.txt."
                    except Exception as e:
                        logger.error(f"An error occurred during fallback processing for {url}: {e}", exc_info=True)
                        return "An error occurred during the fallback extraction process."

            except Exception as e:
                logger.error(f"An error occurred during crawling {url}: {e}", exc_info=True)
                return "An error occurred while trying to extract formatting rules."
            
            if result.success and result.extracted_content:
                # Format the extracted data into a readable string
                if isinstance(result.extracted_content, list) and len(result.extracted_content) > 0:
                    rules_data = result.extracted_content[0]
                elif isinstance(result.extracted_content, dict):
                    rules_data = result.extracted_content
                else:
                    # If it's a string or other type, use markdown as fallback
                    return str(result.extracted_content) if result.extracted_content else result.markdown if result.markdown else "Could not extract formatting rules from the provided URL."
                
                # Store the raw data for debugging
                logger.info(f"Extracted rules data: {json.dumps(rules_data, indent=2)}")
                
                # Format the rules for display
                formatted_rules = format_rules_for_display(rules_data)
                logger.info(f"Formatted rules: {formatted_rules[:100]}...")  # Log for debugging
                return formatted_rules
            elif result.success and result.markdown:
                # Fallback to markdown if structured extraction fails
                logger.info(f"Extraction failed, falling back to markdown for {url}")
                return result.markdown
            else:
                logger.warning(f"Failed to extract rules or markdown for {url}. Crawler success: {result.success}")
                return "Could not extract formatting rules from the provided URL. The crawler did not return any content."
    
    # Run the async function using the patched event loop
    return asyncio.run(_extract_rules_async(url))