"""
MkDocs Hook for Environment Variable Injection

Injects environment variables into the site as JavaScript configuration.
This allows client-side code to access server-side config values.
"""

import os
import logging
from typing import Dict, Any

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

def on_config(config: Dict[str, Any]) -> Dict[str, Any]:
    """
    Hook that runs when MkDocs loads the configuration.
    Injects environment variables as extra JavaScript.
    """
    import re

    # Read environment variables (with fallbacks)
    media_api_url = os.environ.get('MEDIA_API_PUBLIC_URL', 'http://localhost:4100')
    media_api_port = os.environ.get('MEDIA_API_PORT', '4100')
    admin_port = os.environ.get('ADMIN_PORT', '3000')
    admin_url = os.environ.get('ADMIN_URL', '')
    base_domain = os.environ.get('BASE_DOMAIN', '')

    if base_domain and not base_domain.startswith('http'):
        base_domain = f'https://{base_domain}'

    # Helper: detect Docker container hostnames (not browser-accessible)
    def is_docker_hostname(url: str) -> bool:
        """Check if URL uses a Docker container hostname instead of localhost/domain."""
        host = re.sub(r'^https?://', '', url).split(':')[0].split('/')[0]
        # Docker hostnames typically contain hyphens and no dots (not localhost, not a domain)
        return host != 'localhost' and '.' not in host

    # Resolve media API URL — must be browser-accessible (not Docker hostname)
    if is_docker_hostname(media_api_url):
        media_api_url = f'http://localhost:{media_api_port}'

    # Resolve public URL (admin app)
    if admin_url and not is_docker_hostname(admin_url) and 'localhost' not in admin_url:
        # Production domain — use as-is
        public_url = admin_url
    else:
        # Dev: use ADMIN_PORT (most reliable source of truth)
        public_url = f'http://localhost:{admin_port}'

    # Create inline JavaScript with config
    config_script = f"""
// Auto-generated video player configuration from environment variables
// Generated by mkdocs/docs/hooks/env_config_hook.py
(function() {{
  window.MEDIA_API_URL = '{media_api_url}';
  window.PUBLIC_URL = '{public_url}';
  window.VIDEO_PLAYER_DEBUG = {str(os.environ.get('VIDEO_PLAYER_DEBUG', 'false')).lower()};

  console.log('[Video Config] Loaded from environment:', {{
    mediaApiUrl: window.MEDIA_API_URL,
    publicUrl: window.PUBLIC_URL,
    debug: window.VIDEO_PLAYER_DEBUG
  }});
}})();
""".strip()

    # Inject as extra_javascript (inline script)
    # MkDocs will include this before other scripts
    if 'extra_javascript' not in config:
        config['extra_javascript'] = []

    # Prepend inline config script (load before video-player.js)
    # Note: We'll need to create a file for this
    env_config_path = 'assets/js/env-config.js'

    # Write the generated config to a file (only if content changed to avoid
    # triggering MkDocs file watcher rebuild loop in serve mode)
    import pathlib
    docs_dir = pathlib.Path(config['docs_dir'])
    env_config_file = docs_dir / env_config_path
    env_config_file.parent.mkdir(parents=True, exist_ok=True)

    existing_content = ''
    if env_config_file.exists():
        existing_content = env_config_file.read_text()

    if existing_content != config_script:
        with open(env_config_file, 'w') as f:
            f.write(config_script)
        logger.info(f"✓ Generated video config: {env_config_file}")
        logger.info(f"  MEDIA_API_URL: {media_api_url}")
        logger.info(f"  PUBLIC_URL: {public_url}")
    else:
        logger.info(f"✓ Video config unchanged, skipping write")

    # Insert at the beginning of extra_javascript list
    if env_config_path not in config['extra_javascript']:
        config['extra_javascript'].insert(0, env_config_path)

    return config

def on_pre_build(config: Dict[str, Any]) -> None:
    """
    Hook that runs before build starts.
    Ensures config is regenerated on each build.
    """
    logger.info("Video player configuration will be generated from environment variables")