"""Main entry point for rss2newsletter."""

import sys
import argparse
import logging
from typing import List, Dict

from .config import get_config_from_env, setup_logging
from .rss_fetcher import get_todays_articles
from .ollama_client import create_ollama_client, summarize_articles
from .html_generator import generate_newsletter_html, save_newsletter_html

logger = logging.getLogger(__name__)


def create_argument_parser() -> argparse.ArgumentParser:
    """Create command line argument parser."""
    parser = argparse.ArgumentParser(
        description="Generate HTML newsletter from RSS feed using Ollama AI summaries",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
Examples:
  python -m rss2newsletter https://feeds.example.com/rss
  python -m rss2newsletter https://blog.example.com/feed.xml --output my_newsletter.html
  python -m rss2newsletter https://news.example.com/rss --model llama3.1
        """,
    )

    parser.add_argument("rss_url", help="RSS feed URL to process")

    parser.add_argument(
        "--output",
        "-o",
        default=None,
        help="Output HTML filename (default: newsletter.html)",
    )

    parser.add_argument(
        "--model",
        "-m",
        default=None,
        help="Ollama model to use for summaries (default: llama3.2)",
    )

    parser.add_argument(
        "--ollama-url",
        default=None,
        help="Ollama server URL (default: http://localhost:11434)",
    )

    parser.add_argument(
        "--title", "-t", default=None, help="Newsletter title (default: RSS Newsletter)"
    )

    parser.add_argument(
        "--verbose", "-v", action="store_true", help="Enable verbose logging"
    )

    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="Fetch articles but don't generate summaries or save HTML",
    )

    return parser


def merge_config_with_args(config: Dict, args: argparse.Namespace) -> Dict:
    """Merge configuration with command line arguments."""
    if args.output:
        config["output"]["filename"] = args.output

    if args.model:
        config["ollama"]["model"] = args.model

    if args.ollama_url:
        config["ollama"]["base_url"] = args.ollama_url

    if args.title:
        config["output"]["feed_title"] = args.title

    if args.verbose:
        config["logging"]["level"] = "DEBUG"

    return config


def process_rss_to_newsletter(rss_url: str, config: Dict, dry_run: bool = False) -> str:
    """Main processing pipeline for RSS to newsletter conversion."""
    logger.info(f"Starting RSS newsletter generation for: {rss_url}")

    # Step 1: Fetch today's articles
    logger.info("Fetching articles from RSS feed...")
    articles = get_todays_articles(rss_url)

    if not articles:
        logger.warning("No articles found for today")
        return generate_newsletter_html([], config["output"]["feed_title"])

    logger.info(f"Found {len(articles)} articles from today")

    if dry_run:
        logger.info("Dry run mode - stopping before summarization")
        for i, article in enumerate(articles, 1):
            logger.info(f"Article {i}: {article['title']}")
        return ""

    # Step 2: Create Ollama client and summarize articles
    logger.info("Generating AI summaries...")
    ollama_client = create_ollama_client(config["ollama"]["base_url"])

    summarized_articles = summarize_articles(
        ollama_client, articles, config["ollama"]["model"]
    )

    # Step 3: Generate HTML newsletter
    logger.info("Generating HTML newsletter...")
    html_content = generate_newsletter_html(
        summarized_articles, config["output"]["feed_title"]
    )

    return html_content


def main() -> int:
    """Main entry point."""
    parser = create_argument_parser()
    args = parser.parse_args()

    # Load and merge configuration
    config = get_config_from_env()
    config = merge_config_with_args(config, args)

    # Setup logging
    setup_logging(config)

    try:
        # Process RSS feed to newsletter
        html_content = process_rss_to_newsletter(args.rss_url, config, args.dry_run)

        if not args.dry_run and html_content:
            # Save HTML file
            output_filename = save_newsletter_html(
                html_content, config["output"]["filename"]
            )
            print(f"Newsletter saved to: {output_filename}")

        return 0

    except KeyboardInterrupt:
        logger.info("Process interrupted by user")
        return 1
    except Exception as e:
        logger.error(f"Error generating newsletter: {e}")
        if config["logging"]["level"] == "DEBUG":
            logger.exception("Full error details:")
        return 1


if __name__ == "__main__":
    sys.exit(main())