# /// script
# requires-python = ">=3.12"
# dependencies = [
#     "requests",
#     "beautifulsoup4",
# ]
# ///
"""
Generic scraper. Saves all files flat in ./scraped_<domain>/ with sanitized filenames.
Writes structured error log to ./scraped_<domain>/scrape_errors.jsonl.

Usage:
    uv run scraper.py https://www.logting.fo
    uv run scraper.py https://taks.fo
"""

import hashlib
import json
import sys
import time
from collections import deque
from datetime import datetime, timezone
from pathlib import Path
from urllib.parse import urljoin, urlparse

import requests
from bs4 import BeautifulSoup

DELAY = 0.1
TIMEOUT = 60
MAX_RETRIES = 3
RETRY_BACKOFF = 5.0
USER_AGENT = "web-scraper/1.0 (research)"

CONTENT_TYPE_EXT = {
    "text/html": ".html",
    "application/pdf": ".pdf",
    "application/json": ".json",
    "application/xml": ".xml",
    "text/xml": ".xml",
    "text/plain": ".txt",
    "text/css": ".css",
    "application/javascript": ".js",
    "text/javascript": ".js",
    "image/png": ".png",
    "image/jpeg": ".jpg",
    "image/gif": ".gif",
    "image/svg+xml": ".svg",
    "image/webp": ".webp",
    "application/vnd.ms-excel": ".xls",
    "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet": ".xlsx",
    "application/msword": ".doc",
    "application/vnd.openxmlformats-officedocument.wordprocessingml.document": ".docx",
    "application/zip": ".zip",
    "application/octet-stream": ".bin",
}

SEEN: set[str] = set()


def log_error(
    log_path: Path,
    url: str,
    error_type: str,
    message: str,
    status_code: int | None = None,
) -> None:
    entry = {
        "timestamp": datetime.now(timezone.utc).isoformat(),
        "url": url,
        "error_type": error_type,
        "message": message,
        "status_code": status_code,
    }
    with open(log_path, "a", encoding="utf-8") as f:
        f.write(json.dumps(entry, ensure_ascii=False) + "\n")
    print(f"  LOGGED ERROR [{error_type}]: {message}")


def derive_base_domain(url: str) -> str:
    parsed = urlparse(url)
    hostname = parsed.hostname
    if not hostname:
        print(f"Could not parse hostname from {url}")
        sys.exit(1)
    parts = hostname.split(".")
    if len(parts) >= 2:
        return ".".join(parts[-2:])
    return hostname


def is_internal(url: str, base_domain: str) -> bool:
    parsed = urlparse(url)
    hostname = parsed.hostname
    if not hostname:
        return False
    return hostname == base_domain or hostname.endswith(f".{base_domain}")


def normalize_url(url: str) -> str:
    url = url.split("#")[0].rstrip("?&")
    parsed = urlparse(url)
    scheme = parsed.scheme.lower()
    netloc = parsed.netloc.lower()
    path = parsed.path
    query = parsed.query
    if query:
        return f"{scheme}://{netloc}{path}?{query}"
    return f"{scheme}://{netloc}{path}"


def get_extension(url: str, content_type: str) -> str:
    path_suffix = Path(urlparse(url).path).suffix.lower()
    if path_suffix:
        return path_suffix

    ct = content_type.lower().split(";")[0].strip()
    if ct in CONTENT_TYPE_EXT:
        return CONTENT_TYPE_EXT[ct]

    return ".bin"


def url_to_filename(url: str, content_type: str = "") -> str:
    parsed = urlparse(url)

    if len(url) > 200:
        hash_part = hashlib.sha256(url.encode()).hexdigest()[:16]
        ext = get_extension(url, content_type)
        return f"{hash_part}{ext}"

    host_prefix = parsed.netloc.replace(".", "_").replace(":", "_")
    path = parsed.path.lstrip("/") or "index"

    # Split extension from path so query hash goes before it
    path_obj = Path(path)
    stem = path_obj.stem
    ext = path_obj.suffix.lower()
    if not ext:
        ext = get_extension(url, content_type)

    query_suffix = ""
    if parsed.query:
        query_hash = hashlib.md5(parsed.query.encode()).hexdigest()[:8]
        query_suffix = f"_{query_hash}"

    filename = f"{host_prefix}_{stem}{query_suffix}{ext}"
    filename = "".join(c if c.isalnum() or c in "._-" else "_" for c in filename)

    return filename


def save(output_dir: Path, url: str, content: bytes, content_type: str = "") -> None:
    filename = url_to_filename(url, content_type)
    filepath = output_dir / filename
    filepath.write_bytes(content)
    print(f"  saved -> {filepath.name}")


def extract_links(base_url: str, html: str, base_domain: str) -> set[str]:
    soup = BeautifulSoup(html, "html.parser")
    links: set[str] = set()

    for tag in soup.find_all("a", href=True):
        href = tag["href"].strip()
        if not href or href.startswith(("mailto:", "tel:", "javascript:")):
            continue
        full_url = urljoin(base_url, href)
        full_url = normalize_url(full_url)
        if is_internal(full_url, base_domain):
            links.add(full_url)

    return links


def fetch(url: str, log_path: Path) -> requests.Response | None:
    for attempt in range(1, MAX_RETRIES + 1):
        try:
            return requests.get(
                url,
                timeout=TIMEOUT,
                headers={"User-Agent": USER_AGENT},
                allow_redirects=True,
            )
        except requests.Timeout:
            if attempt < MAX_RETRIES:
                wait = RETRY_BACKOFF * attempt
                print(f"  timeout, retry {attempt}/{MAX_RETRIES} in {wait}s...")
                time.sleep(wait)
            else:
                log_error(
                    log_path,
                    url,
                    "timeout",
                    f"Timed out after {MAX_RETRIES} retries ({TIMEOUT}s each)",
                )
                return None
        except requests.ConnectionError as e:
            if attempt < MAX_RETRIES:
                wait = RETRY_BACKOFF * attempt
                print(
                    f"  connection error, retry {attempt}/{MAX_RETRIES} in {wait}s..."
                )
                time.sleep(wait)
            else:
                log_error(log_path, url, "connection_error", str(e))
                return None
        except requests.RequestException as e:
            log_error(log_path, url, "request_error", str(e))
            return None
    return None


def main() -> None:
    if len(sys.argv) < 2:
        print("Usage: uv run scraper.py <start-url>")
        print("Example: uv run scraper.py https://www.logting.fo")
        sys.exit(1)

    start_url = sys.argv[1]
    base_domain = derive_base_domain(start_url)
    output_dir = Path(f"./scraped_{base_domain.replace('.', '_')}")
    log_dir = output_dir / "logs"
    log_dir.mkdir(parents=True, exist_ok=True)
    log_path = log_dir / "scrape_errors.jsonl"

    output_dir.mkdir(parents=True, exist_ok=True)
    log_path.unlink(missing_ok=True)

    queue: deque[str] = deque([start_url])
    count = 0
    error_count = 0

    print(f"Scraping: {start_url}")
    print(f"Base domain: {base_domain}")
    print(f"Output dir: {output_dir}")
    print()

    while queue:
        url = normalize_url(queue.popleft())

        if url in SEEN:
            continue
        SEEN.add(url)

        print(f"[{count}] fetching: {url}")
        resp = fetch(url, log_path)

        if resp is None:
            error_count += 1
            time.sleep(DELAY)
            continue

        if resp.status_code != 200:
            log_error(
                log_path,
                url,
                "http_error",
                f"HTTP {resp.status_code}",
                resp.status_code,
            )
            error_count += 1
            time.sleep(DELAY)
            continue

        final_url = normalize_url(resp.url)
        content_type = resp.headers.get("Content-Type", "")

        if "text/html" in content_type:
            try:
                html = resp.text
                save(output_dir, final_url, html.encode("utf-8"), content_type)
                links = extract_links(final_url, html, base_domain)
                new_links = [u for u in links if u not in SEEN]
                queue.extend(new_links)
                print(f"  found {len(links)} links ({len(new_links)} new)")
            except Exception as e:
                log_error(log_path, final_url, "parse_error", str(e))
                error_count += 1
        else:
            try:
                save(output_dir, final_url, resp.content, content_type)
                print(f"  binary: {content_type}")
            except Exception as e:
                log_error(log_path, final_url, "save_error", str(e))
                error_count += 1

        count += 1
        time.sleep(DELAY)

    print(
        f"\nDone. Fetched {count} URLs ({len(SEEN)} seen total). Errors: {error_count}."
    )
    print(f"Error log: {log_path}")


if __name__ == "__main__":
    main()