#!/usr/bin/env python3
"""
Bellazon Forum Thread Image Scraper

Downloads all full-size images from a Bellazon forum thread.
Bellazon uses <a href="full.jpg"><img src="full_thumb.jpg"></a> pattern.
"""

import re
import sys
import time
import hashlib
import requests
from pathlib import Path
from urllib.parse import urlparse, urljoin
from html import unescape

THREAD_URL = sys.argv[1] if len(sys.argv) > 1 else "https://www.bellazon.com/main/topic/39089-india-reynolds/"
OUTPUT_DIR = sys.argv[2] if len(sys.argv) > 2 else "/opt/media-downloader/data/bellazon/india-reynolds"

HEADERS = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8',
    'Accept-Language': 'en-US,en;q=0.5',
    'Referer': 'https://www.bellazon.com/',
}

IMAGE_EXTENSIONS = {'.jpg', '.jpeg', '.png', '.gif', '.webp', '.bmp', '.tiff'}
VIDEO_EXTENSIONS = {'.mp4', '.webm', '.mov', '.avi', '.mkv'}
MEDIA_EXTENSIONS = IMAGE_EXTENSIONS | VIDEO_EXTENSIONS

SKIP_PATTERNS = [
    'avatar', 'emoji', 'icon', '/public/', 'rep_', 'style_',
    'star_', '/js/', '/css/', 'button', 'logo', 'loading',
    'spinner', 'pixel', 'spacer', '/default_photo',
    'profile_photo', '/skin_', '/set_resources/', 'screenshot',
]


def get_page_count(html: str) -> int:
    match = re.search(r'Page\s+\d+\s+of\s+(\d+)', html)
    return int(match.group(1)) if match else 1


def is_media_url(url: str) -> bool:
    parsed = urlparse(url)
    ext = Path(parsed.path).suffix.lower()
    return ext in MEDIA_EXTENSIONS


def should_skip(url: str) -> bool:
    lower = url.lower()
    return any(skip in lower for skip in SKIP_PATTERNS)


def extract_images_from_html(html: str, base_url: str) -> list:
    """Extract full-size image URLs from page HTML.

    Priority: <a href="full.jpg"> wrapping <img src="thumb.jpg">
    Fallback: standalone <img src="image.jpg"> (non-thumb)
    """
    images = []
    thumb_urls = set()  # track thumbnails so we don't add them as standalone

    # Pattern 1: <a href="full-size"><img src="thumb"></a>
    # This catches the bellazon pattern where thumbnails link to full images
    for match in re.finditer(
        r'<a[^>]+href=["\']([^"\']+)["\'][^>]*>\s*<img[^>]+src=["\']([^"\']+)["\']',
        html, re.IGNORECASE | re.DOTALL
    ):
        href = unescape(match.group(1))
        img_src = unescape(match.group(2))

        if is_media_url(href) and not should_skip(href):
            full_url = urljoin(base_url, href)
            images.append(full_url)
            # Track the thumbnail so we skip it later
            thumb_urls.add(urljoin(base_url, img_src))

    # Pattern 2: Standalone <img> tags not wrapped in links to full-size
    for match in re.finditer(r'<img[^>]+src=["\']([^"\']+)["\']', html, re.IGNORECASE):
        url = unescape(match.group(1))
        if should_skip(url):
            continue
        full_url = urljoin(base_url, url)
        # Skip if this is a thumbnail we already have the full version of
        if full_url in thumb_urls:
            continue
        # Skip anything with _thumb or .thumb in the name
        if '_thumb' in url or '.thumb.' in url:
            continue
        if is_media_url(url):
            images.append(full_url)

    # Pattern 3: Links to external image files (not bellazon)
    for match in re.finditer(r'href=["\']([^"\']+)["\']', html, re.IGNORECASE):
        url = unescape(match.group(1))
        parsed = urlparse(url)
        if parsed.netloc and 'bellazon' not in parsed.netloc and is_media_url(url):
            images.append(url)

    # Pattern 4: Forum attachments (attachment.php?id=XXX) with video/image filenames
    # e.g. <a href="...attachment.php?id=6887160">B7A65853...MP4</a>
    for match in re.finditer(
        r'<a[^>]+href=["\']([^"\']*attachment\.php\?id=\d+)["\'][^>]*>([^<]+)</a>',
        html, re.IGNORECASE
    ):
        href = unescape(match.group(1))
        link_text = match.group(2).strip()
        ext = Path(link_text).suffix.lower()
        if ext in MEDIA_EXTENSIONS:
            full_url = urljoin(base_url, href)
            images.append((full_url, link_text))  # tuple: (url, filename)

    # Deduplicate preserving order
    seen = set()
    unique = []
    for item in images:
        key = item[0] if isinstance(item, tuple) else item
        if key not in seen:
            seen.add(key)
            unique.append(item)
    return unique


def download_media(item, output_dir: Path, session: requests.Session, seen_hashes: set) -> bool:
    # item is either a URL string or a (url, filename) tuple
    if isinstance(item, tuple):
        url, orig_filename = item
    else:
        url, orig_filename = item, None

    try:
        resp = session.get(url, timeout=60)
        if resp.status_code != 200:
            return False

        content_type = resp.headers.get('content-type', '')
        if not any(t in content_type for t in ['image', 'video', 'octet-stream']):
            return False

        data = resp.content
        if len(data) < 5000:  # Skip tiny files (icons/placeholders)
            return False

        file_hash = hashlib.md5(data).hexdigest()
        if file_hash in seen_hashes:
            return False
        seen_hashes.add(file_hash)

        if orig_filename:
            filename = re.sub(r'[^\w\-_.]', '_', orig_filename)
        else:
            parsed = urlparse(url)
            filename = Path(parsed.path).name
            filename = re.sub(r'[^\w\-_.]', '_', filename)
        if not filename or filename == '_':
            filename = f"{file_hash}.jpg"

        filepath = output_dir / filename
        if filepath.exists():
            filepath = output_dir / f"{filepath.stem}_{file_hash[:8]}{filepath.suffix}"

        filepath.write_bytes(data)
        return True

    except Exception as e:
        display = url[:80] if not orig_filename else orig_filename
        print(f"  Error: {display}: {e}", flush=True)
        return False


def main():
    output_dir = Path(OUTPUT_DIR)
    output_dir.mkdir(parents=True, exist_ok=True)

    session = requests.Session()
    session.headers.update(HEADERS)

    print(f"Fetching: {THREAD_URL}", flush=True)
    resp = session.get(THREAD_URL, timeout=30)
    resp.raise_for_status()

    total_pages = get_page_count(resp.text)
    print(f"Total pages: {total_pages}", flush=True)

    seen_hashes = set()
    total_downloaded = 0
    total_skipped = 0

    for page_num in range(1, total_pages + 1):
        if page_num == 1:
            page_url = THREAD_URL
            html = resp.text
        else:
            page_url = f"{THREAD_URL.rstrip('/')}/page/{page_num}/"
            try:
                resp = session.get(page_url, timeout=30)
                resp.raise_for_status()
                html = resp.text
            except Exception as e:
                print(f"  Error fetching page {page_num}: {e}", flush=True)
                continue

        images = extract_images_from_html(html, page_url)
        page_dl = 0

        for img_url in images:
            if download_media(img_url, output_dir, session, seen_hashes):
                page_dl += 1
                total_downloaded += 1
            else:
                total_skipped += 1

        print(f"Page {page_num}/{total_pages}: {page_dl} downloaded ({len(images)} found, {total_downloaded} total)", flush=True)

        if page_num < total_pages:
            time.sleep(1)

    print(f"\nDone! {total_downloaded} images saved to {output_dir}", flush=True)
    print(f"Skipped: {total_skipped}", flush=True)


if __name__ == "__main__":
    main()