deer-flow/backend/packages/harness/deerflow/community/browserless/tools.py

import asyncio
import logging
import os
import re
from datetime import UTC, datetime
from pathlib import Path
from typing import Annotated
from urllib.parse import urlparse

from langchain.tools import InjectedToolCallId, tool
from langchain_core.messages import ToolMessage
from langgraph.types import Command

from deerflow.community.url_safety import resolve_host_addresses as _resolve_host_addresses
from deerflow.community.url_safety import validate_delegated_backend_url, validate_public_http_url
from deerflow.config import get_app_config
from deerflow.config.paths import VIRTUAL_PATH_PREFIX
from deerflow.tools.types import Runtime
from deerflow.utils.atomic_write import publish_bytes_atomically as _publish_bytes_atomically
from deerflow.utils.output_names import output_name_candidates
from deerflow.utils.readability import ReadabilityExtractor

from .browserless_client import BrowserlessClient, BrowserlessFetchResult, BrowserlessScreenshotResult

logger = logging.getLogger(__name__)

# readability_extractor runs CPU-bound parsing; always call via asyncio.to_thread
_readability_extractor = ReadabilityExtractor()
_OUTPUTS_VIRTUAL_PREFIX = f"{VIRTUAL_PATH_PREFIX}/outputs"
_OUTPUT_FORMAT_TO_EXTENSION = {
    "png": "png",
    "jpeg": "jpeg",
    "webp": "webp",
}
_SAFE_FILENAME_RE = re.compile(r"[^A-Za-z0-9._-]+")
DEFAULT_BASE_URL = "http://localhost:3032"
_UNSET = object()


def _get_tool_config(tool_name: str) -> dict | None:
    """Get tool config extras safely, returning None if not configured."""
    config = get_app_config().get_tool_config(tool_name)
    if config is None:
        return None
    extras = config.model_extra
    return extras if extras is not None else {}


def _coerce_timeout(value: object, default: float) -> float:
    """Coerce a config timeout into seconds, falling back to ``default`` on bad input.

    Mirrors ``crawl4ai._coerce_timeout`` / ``jina_ai._coerce_timeout``: booleans and
    non-numeric strings fall back to the default, so ``timeout_s: off`` (YAML ``False``)
    does not become ``0.0`` and time out every request against a healthy server, and a
    typo'd value does not raise out of tool construction.
    """
    if isinstance(value, bool):
        return default
    if isinstance(value, (int, float)):
        return float(value)
    if isinstance(value, str):
        try:
            return float(value)
        except ValueError:
            logger.warning("Browserless: invalid timeout %r in config; using %ss", value, default)
    return default


def _resolve_timeout(cfg: dict, default: float) -> float:
    """Read the timeout, accepting this provider's key and the sibling providers' key.

    ``browserless`` documents ``timeout_s`` while ``crawl4ai`` and ``jina_ai`` read
    ``timeout``. An unrecognised key is dropped silently by the extra-fields tool config,
    so someone adapting another provider's snippet got the default with no diagnostic.
    Accept both, preferring the documented ``timeout_s`` when both are present.
    """
    if "timeout_s" in cfg:
        return _coerce_timeout(cfg["timeout_s"], default)
    if "timeout" in cfg:
        return _coerce_timeout(cfg["timeout"], default)
    return default


def _get_browserless_client(tool_name: str = "web_fetch", cfg: dict | None = _UNSET) -> BrowserlessClient:
    if cfg is _UNSET:
        cfg = _get_tool_config(tool_name)
    base_url = DEFAULT_BASE_URL
    token = os.getenv("BROWSERLESS_TOKEN", "")
    timeout_s = 30.0
    if cfg is not None:
        base_url = cfg.get("base_url", base_url)
        token = cfg.get("token", token)
        timeout_s = _resolve_timeout(cfg, timeout_s)
    return BrowserlessClient(base_url=base_url, token=token, timeout_s=timeout_s)


def _as_bool(value: object, default: bool) -> bool:
    if isinstance(value, bool):
        return value
    if isinstance(value, str):
        lowered = value.strip().lower()
        if lowered in {"1", "true", "yes", "on"}:
            return True
        if lowered in {"0", "false", "no", "off"}:
            return False
    return default


def _validate_backend_base_url(cfg: dict | None) -> str | None:
    """Refuse delegation to a self-hosted backend unless its egress is isolated.

    Browserless resolves the target URL, follows redirects, and loads subresources
    in the Browserless service's own network namespace, so the target-URL screen
    cannot be enforced end-to-end. Delegation is only safe when the backend's
    outbound network is isolated from private and metadata networks, which the
    operator confirms via ``network_isolation_confirmed``. A public backend
    (Browserless Cloud) needs no confirmation. Blocking; call via
    ``asyncio.to_thread``.
    """
    cfg = cfg or {}
    base_url = cfg.get("base_url", DEFAULT_BASE_URL)
    network_isolation_confirmed = _as_bool(cfg.get("network_isolation_confirmed"), False)
    return validate_delegated_backend_url(
        base_url,
        network_isolation_confirmed=network_isolation_confirmed,
        resolver=_resolve_host_addresses,
    )


def _as_int(value: object, default: int) -> int:
    if isinstance(value, int) and not isinstance(value, bool):
        return value
    if isinstance(value, str):
        try:
            return int(value.strip())
        except ValueError:
            return default
    return default


def _as_str_list(value: object) -> list[str] | None:
    """Coerce a config value into a non-empty list of strings, or ``None``.

    Accepts a list of strings and a comma-separated string, since YAML makes
    both spellings natural. Non-string sequence items are ignored. Unsupported
    top-level values, an empty list, or a blank string yield ``None`` so the
    parameter stays out of the payload instead of reaching Browserless as an
    unusable value.
    """
    if isinstance(value, str):
        parts = value.split(",")
    elif isinstance(value, (list, tuple)):
        parts = [part for part in value if isinstance(part, str)]
    else:
        return None

    items = [part.strip() for part in parts if part.strip()]
    return items or None


def _as_optional_quality(value: object, output_format: str) -> int | None:
    if output_format not in {"jpeg", "webp"}:
        return None
    quality = _as_int(value, -1)
    return quality if 0 <= quality <= 100 else None


def _normalize_output_format(value: object) -> str:
    output_format = str(value or "png").strip().lower()
    return output_format if output_format in _OUTPUT_FORMAT_TO_EXTENSION else "png"


def _validate_capture_url(url: str, allow_private_addresses: bool = False) -> str | None:
    """Validate a capture URL for scheme and (unless opted out) SSRF safety.

    Blocks requests that resolve to loopback, private, link-local (incl. the
    169.254.169.254 cloud-metadata endpoint), reserved, multicast, or
    unspecified addresses. Operators who intentionally point the tool at an
    internal Browserless target can opt out via ``allow_private_addresses``.
    """
    return validate_public_http_url(
        url,
        allow_private_addresses=allow_private_addresses,
        action="capture",
        resolver=_resolve_host_addresses,
    )


def _default_capture_stem(url: str) -> str:
    parsed = urlparse(url)
    parts = [parsed.netloc, *[part for part in parsed.path.split("/") if part]]
    raw = "-".join(parts) or "web-capture"
    return raw[:80]


def _safe_capture_filename(filename: str | None, url: str, output_format: str) -> str:
    extension = _OUTPUT_FORMAT_TO_EXTENSION[output_format]
    if filename:
        raw_name = Path(filename).name
        stem = Path(raw_name).stem or "web-capture"
    else:
        timestamp = datetime.now(UTC).strftime("%Y%m%d-%H%M%S")
        stem = f"{_default_capture_stem(url)}-{timestamp}"

    safe_stem = _SAFE_FILENAME_RE.sub("_", stem).strip("._-") or "web-capture"
    return f"{safe_stem[:100]}.{extension}"


def _thread_outputs_path(runtime: Runtime) -> Path | str:
    if runtime.state is None:
        return "Error: Thread runtime state is not available"
    thread_data = runtime.state.get("thread_data") or {}
    outputs_path = thread_data.get("outputs_path")
    if not outputs_path:
        return "Error: Thread outputs path is not available"
    return Path(outputs_path)


def _tool_message(content: str, tool_call_id: str) -> Command:
    return Command(update={"messages": [ToolMessage(content, tool_call_id=tool_call_id)]})


def _reserve_output_name(outputs_path: Path, name: str) -> bool:
    """Claim ``name`` for this capture, returning False when it is already held.

    The claim is an ``O_CREAT | O_EXCL`` open that leaves an empty placeholder
    behind, not an existence check: two writers that merely *observe* a free name
    would both go on to publish to it, and the second ``os.replace`` would
    silently replace the first capture (#6883). ``0o666`` is passed explicitly
    because ``publish_bytes_atomically`` preserves an existing file's mode, and
    ``os.open`` would otherwise default the placeholder to ``0o777 & ~umask`` and
    make every capture executable instead of the ``0o666 & ~umask`` a new file
    gets from ``Path.write_bytes``.
    """
    try:
        descriptor = os.open(outputs_path / name, os.O_CREAT | os.O_EXCL | os.O_WRONLY, 0o666)
    except FileExistsError:
        return False
    os.close(descriptor)
    return True


def _dedupe_output_name(outputs_path: Path, output_name: str) -> str:
    """Reserve and return a non-colliding filename under ``outputs_path``.

    Keeps the original name when it can be claimed, otherwise appends ``-1``,
    ``-2``, ... before the extension so an explicit filename never silently
    overwrites an earlier capture. Falls back to a timestamp suffix if the
    directory is saturated with the bounded probe range.

    Raises:
        RuntimeError: when even the timestamped names cannot be claimed, which
            means another writer is holding them; returning a name anyway would
            reintroduce the silent overwrite this function exists to prevent.
    """
    for candidate in output_name_candidates(output_name):
        if _reserve_output_name(outputs_path, candidate):
            return candidate

    raise RuntimeError(f"could not reserve an output filename for {output_name!r} in {outputs_path}")


def _write_capture_output(outputs_path: Path, output_name: str, content: bytes) -> str:
    """Write ``content`` into ``outputs_path`` and return the actual filename used."""
    outputs_path.mkdir(parents=True, exist_ok=True)
    final_name = _dedupe_output_name(outputs_path, output_name)
    destination = outputs_path / final_name
    try:
        _publish_bytes_atomically(destination, content)
    except BaseException:
        try:
            destination.unlink(missing_ok=True)
        except OSError:
            logger.warning("Could not release the reserved capture name %s", destination, exc_info=True)
        raise
    return final_name


def _target_status_warning(result: BrowserlessScreenshotResult | BrowserlessFetchResult) -> str:
    """Return a human-readable warning when the fetched/captured page itself errored.

    Browserless returns HTTP 200 for the render request even when the target
    page responded with a 4xx/5xx (or was an error/anti-bot page), so the raw
    content alone cannot be trusted as a normal successful response. The
    target's real status is surfaced via the X-Response-Code header.
    """
    code = result.target_status_code.strip()
    if not code or code.startswith(("2", "3")):
        return ""
    status = result.target_status.strip()
    detail = f"{code} {status}".strip()
    return f" (warning: target page responded {detail})"


@tool("web_fetch", parse_docstring=True)
async def web_fetch_tool(url: str) -> str:
    """Fetch the contents of a web page at a given URL using Browserless (headless Chrome).
    Only fetch EXACT URLs that have been provided directly by the user or have been returned in results from the web_search and web_fetch tools.
    This tool can NOT access content that requires authentication, such as private Google Docs or pages behind login walls.
    Do NOT add www. to URLs that do NOT have them.
    URLs must include the schema: https://example.com is a valid URL while example.com is an invalid URL.

    Args:
        url: The URL to fetch the contents of.
    """
    try:
        cfg = _get_tool_config("web_fetch") or {}
        allow_private_addresses = _as_bool(cfg.get("allow_private_addresses"), False)
        url_error = await asyncio.to_thread(
            validate_public_http_url,
            url,
            allow_private_addresses=allow_private_addresses,
            resolver=_resolve_host_addresses,
        )
        if url_error:
            return url_error

        backend_error = await asyncio.to_thread(_validate_backend_base_url, cfg)
        if backend_error:
            return backend_error

        wait_for_event = ""
        wait_for_timeout_ms = 0
        wait_for_selector = ""
        wait_for_selector_timeout_ms = 5000
        reject_resource_types = _as_str_list(cfg.get("reject_resource_types"))
        reject_request_pattern = _as_str_list(cfg.get("reject_request_pattern"))

        wait_for_event = cfg.get("wait_for_event", wait_for_event)
        wait_for_timeout_ms = _as_int(cfg.get("wait_for_timeout_ms"), wait_for_timeout_ms)
        wait_for_selector = cfg.get("wait_for_selector", wait_for_selector)
        wait_for_selector_timeout_ms = _as_int(cfg.get("wait_for_selector_timeout_ms"), wait_for_selector_timeout_ms)

        client = _get_browserless_client("web_fetch", cfg)
        result = await client.fetch_html_with_status(
            url=url,
            wait_for_event=wait_for_event,
            wait_for_timeout_ms=wait_for_timeout_ms,
            wait_for_selector=wait_for_selector,
            wait_for_selector_timeout_ms=wait_for_selector_timeout_ms,
            reject_resource_types=reject_resource_types,
            reject_request_pattern=reject_request_pattern,
        )

        if isinstance(result, str):
            return result

        article = await asyncio.to_thread(_readability_extractor.extract_article, result.html, url=url)
        return f"{article.to_markdown()[:4096]}{_target_status_warning(result)}"

    except Exception as e:
        logger.error(f"Error in web_fetch_tool: {e}")
        return f"Error: {str(e)}"


@tool("web_capture", parse_docstring=True)
async def web_capture_tool(
    runtime: Runtime,
    url: str,
    tool_call_id: Annotated[str, InjectedToolCallId],
    filename: str | None = None,
    full_page: bool | None = None,
    output_format: str | None = None,
    viewport_width: int | None = None,
    viewport_height: int | None = None,
) -> Command:
    """Capture a rendered webpage screenshot and present it as an artifact.

    Use this tool when you need a visual capture of a public webpage, especially JavaScript-heavy pages, UI states, dashboards, or visual evidence for a report.
    Only capture exact URLs provided by the user or discovered through other tools. Do not use this for private pages behind login unless the user has explicitly configured Browserless outside DeerFlow.
    URLs must include the schema: https://example.com is valid while example.com is invalid.

    Args:
        url: The http(s) URL to capture.
        filename: Optional output filename. Directories are ignored and the extension is determined by output_format.
        full_page: Optional override for full-page capture.
        output_format: Optional image format: png, jpeg, or webp.
        viewport_width: Optional viewport width in pixels.
        viewport_height: Optional viewport height in pixels.
    """
    try:
        cfg = _get_tool_config("web_capture") or {}
        allow_private_addresses = _as_bool(cfg.get("allow_private_addresses"), False)

        url_error = await asyncio.to_thread(_validate_capture_url, url, allow_private_addresses=allow_private_addresses)
        if url_error:
            return _tool_message(url_error, tool_call_id)

        backend_error = await asyncio.to_thread(_validate_backend_base_url, cfg)
        if backend_error:
            return _tool_message(backend_error, tool_call_id)

        outputs_path = _thread_outputs_path(runtime)
        if isinstance(outputs_path, str):
            return _tool_message(outputs_path, tool_call_id)

        final_format = _normalize_output_format(output_format or cfg.get("output_format", "png"))
        final_full_page = full_page if full_page is not None else _as_bool(cfg.get("full_page"), True)
        final_width = viewport_width if viewport_width is not None else _as_int(cfg.get("viewport_width"), 1280)
        final_height = viewport_height if viewport_height is not None else _as_int(cfg.get("viewport_height"), 720)
        quality = _as_optional_quality(cfg.get("quality"), final_format)
        wait_for_selector = str(cfg.get("wait_for_selector") or "")
        wait_for_selector_timeout_ms = _as_int(cfg.get("wait_for_selector_timeout_ms"), 5000)
        wait_for_timeout_ms = _as_int(cfg.get("wait_for_timeout_ms"), 0)
        best_attempt = _as_bool(cfg.get("best_attempt"), False)

        output_name = _safe_capture_filename(filename, url, final_format)

        client = _get_browserless_client("web_capture", cfg)
        result = await client.capture_screenshot(
            url=url,
            full_page=final_full_page,
            output_format=final_format,
            quality=quality,
            viewport={"width": final_width, "height": final_height},
            wait_for_selector=wait_for_selector,
            wait_for_selector_timeout_ms=wait_for_selector_timeout_ms,
            wait_for_timeout_ms=wait_for_timeout_ms,
            best_attempt=best_attempt,
        )
        if isinstance(result, str):
            return _tool_message(result, tool_call_id)

        final_name = await asyncio.to_thread(_write_capture_output, outputs_path, output_name, result.content)
        virtual_path = f"{_OUTPUTS_VIRTUAL_PREFIX}/{final_name}"
        message = f"Captured screenshot: {virtual_path}{_target_status_warning(result)}"
        return Command(
            update={
                "artifacts": [virtual_path],
                "messages": [ToolMessage(message, tool_call_id=tool_call_id)],
            }
        )

    except Exception as e:
        logger.error(f"Error in web_capture_tool: {e}")
        return _tool_message(f"Error: {str(e)}", tool_call_id)