from typing import Optional, Tuple
from urllib.parse import urlparse

# Non-HTML static file extensions to ignore
IGNORED_EXTENSIONS = (
    ".jpg", ".jpeg", ".png", ".gif", ".webp", ".svg", ".ico", ".bmp", ".tiff",
    ".pdf", ".zip", ".tar", ".gz", ".bz2", ".7z", ".rar", ".exe", ".dmg", ".iso", ".bin",
    ".mp3", ".mp4", ".avi", ".mov", ".mkv", ".flv", ".wmv", ".webm", ".wav", ".ogg",
    ".css", ".js", ".json", ".xml", ".rss", ".atom", ".woff", ".woff2", ".ttf", ".eot", ".otf",
    ".doc", ".docx", ".xls", ".xlsx", ".ppt", ".pptx", ".csv"
)

# WordPress / CMS feed and API paths that are not HTML web pages
IGNORED_PATHS = (
    "/feed", "/comments/feed", "/wp-json", "/xmlrpc.php", "/wp-admin", "/wp-login.php"
)


def normalize_url(url: str, start_domain: str) -> Tuple[Optional[str], Optional[bool]]:
    """
    Normalizes a URL, strips fragments, filters out non-HTML files / endpoints,
    and determines whether the link is internal or external.

    Returns:
        (normalized_url, is_internal) or (None, None) if the link should be ignored.
    """
    if not isinstance(url, str):
        return None, None

    url = url.split("#")[0].strip()
    if not url:
        return None, None

    parsed = urlparse(url)
    if parsed.scheme not in ["http", "https"]:
        return None, None

    path = parsed.path or "/"
    path_lower = path.lower()

    # Filter out static file extensions
    if any(path_lower.endswith(ext) for ext in IGNORED_EXTENSIONS):
        return None, None

    # Filter out non-HTML WordPress / CMS endpoints
    if any(path_lower == p or path_lower.rstrip("/") == p or path_lower.startswith(p + "/") for p in IGNORED_PATHS):
        return None, None

    netloc = parsed.netloc.lower()
    if not netloc:
        return None, None

    # Check domain matching (treat apex domain and www. as identical)
    clean_start_domain = start_domain.lower().replace("www.", "")
    clean_netloc = netloc.replace("www.", "")

    is_internal = (clean_netloc == clean_start_domain)

    # Strip query parameters for internal links to avoid infinite loops and duplicate crawls
    if is_internal:
        norm_path = path.rstrip("/") if path != "/" else "/"
        norm_url = f"{parsed.scheme}://{netloc}{norm_path}"
    else:
        # Keep query parameters for external links (e.g., video IDs)
        norm_path = path.rstrip("/") if path != "/" else "/"
        query_part = f"?{parsed.query}" if parsed.query else ""
        norm_url = f"{parsed.scheme}://{netloc}{norm_path}{query_part}"

    return norm_url, is_internal