"""
Comic data loader for YAML-based comic management.

This module scans the data/comics/ directory for .yaml files,
loads each comic's configuration, and builds the COMICS list.
"""

import yaml
from pathlib import Path


def load_comics_from_yaml(comics_dir='data/comics'):
    """
    Load all comic data from YAML files in the specified directory.

    Args:
        comics_dir: Path to directory containing comic YAML files

    Returns:
        List of comic dictionaries, sorted by comic number
    """
    comics = []
    comics_path = Path(comics_dir)

    if not comics_path.exists():
        print(f"Warning: Comics directory '{comics_dir}' does not exist. Creating it...")
        comics_path.mkdir(parents=True, exist_ok=True)
        return []

    # Find all .yaml and .yml files
    yaml_files = list(comics_path.glob('*.yaml')) + list(comics_path.glob('*.yml'))

    # Filter out template and README files
    yaml_files = [f for f in yaml_files if f.stem.upper() not in ('TEMPLATE', 'README')]

    if not yaml_files:
        print(f"Warning: No YAML files found in '{comics_dir}'")
        return []

    for yaml_file in yaml_files:
        try:
            with open(yaml_file, 'r', encoding='utf-8') as f:
                comic_data = yaml.safe_load(f)

            if comic_data is None:
                print(f"Warning: '{yaml_file.name}' is empty, skipping")
                continue

            if 'number' not in comic_data:
                print(f"Warning: '{yaml_file.name}' missing required 'number' field, skipping")
                continue

            if 'filename' not in comic_data:
                print(f"Warning: '{yaml_file.name}' missing required 'filename' field, skipping")
                continue

            if 'date' not in comic_data:
                print(f"Warning: '{yaml_file.name}' missing required 'date' field, skipping")
                continue

            if 'alt_text' not in comic_data:
                print(f"Warning: '{yaml_file.name}' missing required 'alt_text' field, skipping")
                continue

            comics.append(comic_data)

        except yaml.YAMLError as e:
            print(f"Error parsing '{yaml_file.name}': {e}")
            continue
        except Exception as e:
            print(f"Error loading '{yaml_file.name}': {e}")
            continue

    # Sort by comic number
    comics.sort(key=lambda c: c['number'])

    return comics


def validate_comics(comics):
    """
    Validate the loaded comics for common issues.

    Args:
        comics: List of comic dictionaries

    Returns:
        True if validation passes, False otherwise
    """
    if not comics:
        return True

    numbers = [c['number'] for c in comics]

    # Check for duplicate comic numbers
    if len(numbers) != len(set(numbers)):
        duplicates = [n for n in numbers if numbers.count(n) > 1]
        print(f"Warning: Duplicate comic numbers found: {set(duplicates)}")
        return False

    # Check for gaps in comic numbering (optional warning)
    for i in range(len(comics) - 1):
        if comics[i+1]['number'] - comics[i]['number'] > 1:
            print(f"Info: Gap in comic numbering between {comics[i]['number']} and {comics[i+1]['number']}")

    return True


if __name__ == '__main__':
    # Test the loader
    print("Loading comics from data/comics/...")
    comics = load_comics_from_yaml()
    print(f"Loaded {len(comics)} comics")

    if validate_comics(comics):
        print("Validation passed!")
        for comic in comics:
            title = comic.get('title', f"#{comic['number']}")
            print(f"  - Comic {comic['number']}: {title} ({comic['date']})")
    else:
        print("Validation failed!")