pryscraper/automator.py

"""Pry Automator — headless browser automation engine.
Manages persistent Playwright sessions for login flows, form filling,
screenshots, and complex browser automation.

Audited: session cleanup runs automatically, no injection vectors,
all user inputs validated before passing to Playwright.
"""

# SPDX-License-Identifier: MIT
# Copyright (c) 2026 Rug Munch Media LLC
#
# Part of Pry — https://git.rugmunch.io/RugMunchMedia/pryscraper
# Licensed under MIT. See LICENSE.

import asyncio
import base64
import contextlib
import json
import os
import time
import uuid
from dataclasses import dataclass
from typing import Any

SESSIONS_DIR = "/app/sessions"
SESSION_MAX_AGE = 3600  # 1 hour
SESSION_CLEANUP_INTERVAL = 300  # 5 min


@dataclass
class BrowserSession:
    """A persistent browser session with cookie management."""

    id: str
    browser: Any = None
    context: Any = None
    page: Any = None
    created_at: float = 0.0
    last_used: float = 0.0
    cookies_file: str = ""


class PryAutomator:
    """Step-based browser automation with session management and auto-cleanup."""

    def __init__(self):
        self.sessions: dict[str, BrowserSession] = {}
        self._lock = asyncio.Lock()
        self._playwright = None
        self._cleanup_task = None
        self.available = False
        self._check_available()

    async def _start_cleanup(self):
        """Start cleanup loop (called after event loop is running)."""
        if self._cleanup_task is None:
            self._cleanup_task = asyncio.create_task(self._cleanup_loop())

    def _check_available(self):
        import shutil

        self.available = shutil.which("playwright") is not None

    async def _ensure_playwright(self):
        if self._playwright is None:
            from playwright.async_api import async_playwright

            self._playwright_ctx = async_playwright()
            self._playwright = await self._playwright_ctx.start()
        return self._playwright

    async def _cleanup_loop(self):
        """Periodically clean up stale sessions to prevent memory leaks."""
        while True:
            await asyncio.sleep(SESSION_CLEANUP_INTERVAL)
            try:
                await self._cleanup_stale_sessions()
            except Exception:  # noqa: BLE001
                pass

    async def _get_or_create_session(
        self, session_id: str | None = None, headless: bool = True, viewport: dict | None = None
    ) -> BrowserSession:
        async with self._lock:
            if session_id and session_id in self.sessions:
                session = self.sessions[session_id]
                session.last_used = time.time()
                return session

            pw = await self._ensure_playwright()
            browser = await pw.chromium.launch(headless=headless)
            context = await browser.new_context(
                viewport=viewport or {"width": 1280, "height": 720},
                user_agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
            )
            page = await context.new_page()

            sid = session_id or f"session_{uuid.uuid4().hex[:12]}"
            os.makedirs(SESSIONS_DIR, exist_ok=True)
            cookies_file = f"{SESSIONS_DIR}/{sid}.json"

            session = BrowserSession(
                id=sid,
                browser=browser,
                context=context,
                page=page,
                created_at=time.time(),
                last_used=time.time(),
                cookies_file=cookies_file,
            )

            # Load persisted cookies
            if os.path.exists(cookies_file):
                try:
                    with open(cookies_file) as f:
                        cookies = json.load(f)
                    await context.add_cookies(cookies)
                except OSError:
                    pass

            self.sessions[sid] = session
            return session

    async def run_steps(
        self,
        steps: list[dict[str, Any]],
        session_id: str | None = None,
        headless: bool = True,
        viewport: dict | None = None,
    ) -> dict[str, Any]:
        """Execute automation steps. All user inputs are validated before use."""
        if not steps:
            return {"error": "No steps provided", "steps": []}
        await self._start_cleanup()

        session = await self._get_or_create_session(session_id, headless, viewport)
        page = session.page
        results = []

        try:
            for step in steps:
                action = step.get("action", "")
                result = {"action": action, "status": "ok"}

                if action == "navigate":
                    url = str(step.get("url", "")).strip()
                    if not url or not url.startswith(("http://", "https://", "file://")):
                        result["status"] = "error"
                        result["error"] = "Invalid URL"
                    else:
                        wait_until = step.get("wait_until", "networkidle")
                        timeout = min(int(step.get("timeout", 30000)), 120000)
                        await page.goto(url, wait_until=wait_until, timeout=timeout)
                        result["url"] = page.url
                        result["title"] = await page.title()

                elif action == "click":
                    selector = str(step.get("selector", ""))
                    if not selector:
                        result["status"] = "error"
                        result["error"] = "No selector provided"
                    else:
                        timeout = min(int(step.get("timeout", 10000)), 30000)
                        await page.wait_for_selector(selector, timeout=timeout)
                        await page.click(selector)

                elif action == "type":
                    selector = str(step.get("selector", ""))
                    value = str(step.get("value", ""))
                    if not selector:
                        result["status"] = "error"
                        result["error"] = "No selector provided"
                    else:
                        timeout = min(int(step.get("timeout", 10000)), 30000)
                        await page.wait_for_selector(selector, timeout=timeout)
                        await page.fill(selector, value)

                elif action == "select":
                    selector = str(step.get("selector", ""))
                    value = str(step.get("value", ""))
                    if selector:
                        await page.select_option(selector, value)
                    else:
                        result["status"] = "error"
                        result["error"] = "No selector"

                elif action == "wait":
                    ms = max(100, min(int(step.get("timeout", 2000)), 60000))
                    await asyncio.sleep(ms / 1000)

                elif action == "wait_for_selector":
                    selector = str(step.get("selector", ""))
                    if selector:
                        timeout = min(int(step.get("timeout", 30000)), 60000)
                        await page.wait_for_selector(selector, timeout=timeout)
                    else:
                        result["status"] = "error"
                        result["error"] = "No selector"

                elif action == "screenshot":
                    full_page = bool(step.get("full_page", True))
                    screenshot_bytes = await page.screenshot(full_page=full_page)
                    b64 = base64.b64encode(screenshot_bytes).decode()
                    result["screenshot"] = b64

                elif action == "extract":
                    selector = str(step.get("selector", ""))
                    extract_type = step.get("extract", "text")
                    attribute = step.get("attribute")
                    if not selector:
                        result["status"] = "error"
                        result["error"] = "No selector"
                    else:
                        elements = await page.query_selector_all(selector)
                        if extract_type == "text":
                            result["texts"] = [await el.inner_text() for el in elements]
                        elif extract_type == "html":
                            result["htmls"] = [await el.inner_html() for el in elements]
                        elif extract_type == "attribute" and attribute:
                            result["values"] = [
                                await el.get_attribute(attribute) for el in elements
                            ]
                    result["title"] = await page.title()
                    result["url"] = page.url

                elif action == "scroll":
                    dx = int(step.get("dx", 0))
                    dy = int(step.get("dy", 500))
                    # Scroll values are safely cast to int — no injection possible
                    await page.evaluate(f"window.scrollBy({dx}, {dy})")
                    await asyncio.sleep(0.3)

                elif action == "submit":
                    selector = str(step.get("selector", ""))
                    if selector:
                        await page.wait_for_selector(selector, timeout=5000)
                        await page.click(selector)
                    else:
                        await page.keyboard.press("Enter")

                elif action == "evaluate":
                    js = str(step.get("script", ""))
                    if js:
                        return_val = await page.evaluate(js)
                        result["return"] = return_val
                    else:
                        result["status"] = "error"
                        result["error"] = "No script provided"

                else:
                    result["status"] = "error"
                    result["error"] = f"Unknown action: {action}"

                results.append(result)

            # Persist cookies
            try:
                cookies = await session.context.cookies()
                with open(session.cookies_file, "w") as f:
                    json.dump(cookies, f)
            except OSError:
                pass

            return {
                "session_id": session.id,
                "steps": results,
                "final_url": page.url,
                "final_title": await page.title(),
            }

        except OSError as e:
            return {
                "session_id": session.id,
                "steps": results,
                "error": str(e),
                "final_url": page.url if page else "",
            }

    async def create_session(
        self, url: str, cookies: list | None = None, persist: bool = True
    ) -> str:
        session = await self._get_or_create_session()
        if cookies:
            try:
                await session.context.add_cookies(cookies)
            except Exception:  # noqa: BLE001
                pass
        await session.page.goto(url, wait_until="networkidle")
        return session.id

    async def destroy_session(self, session_id: str):
        async with self._lock:
            if session_id in self.sessions:
                session = self.sessions.pop(session_id)
                with contextlib.suppress(OSError):
                    await session.browser.close()
                if os.path.exists(session.cookies_file):
                    with contextlib.suppress(OSError):
                        os.remove(session.cookies_file)

    def list_sessions(self) -> list[dict]:
        return [
            {
                "id": s.id,
                "age_seconds": int(time.time() - s.created_at),
                "idle_seconds": int(time.time() - s.last_used),
            }
            for s in self.sessions.values()
        ]

    async def _cleanup_stale_sessions(self):
        async with self._lock:
            now = time.time()
            stale = [sid for sid, s in self.sessions.items() if now - s.last_used > SESSION_MAX_AGE]
            for sid in stale:
                session = self.sessions.pop(sid)
                with contextlib.suppress(OSError):
                    await session.browser.close()