"""Pry — Ultimate Anti-Detection Scraper.
Multi-strategy scraping with 10+ bypass methods and intelligent fallback.
Beats Cloudflare, DataDome, Akamai, Imperva, PerimeterX, and generic blocks."""

# SPDX-License-Identifier: BSL-1.1
# Copyright (c) 2026 Rug Munch Media LLC
#
# Part of Pry — Stealth / Anti-Detection Module
# Licensed under Business Source License 1.1 — see LICENSE-BSL-STEALTH.
# Change Date: 2029-01-01 (converts to MIT).

import importlib.util
import logging
import os
import random
import re
import time
from typing import Any, ClassVar
from urllib.parse import urlparse

from errors import InvalidRequestError
from observability import SCRAPE_LATENCY
from resilience import registry
from retry import RetryConfig, async_retry
from url_guard import validate_url

logger = logging.getLogger(__name__)

# Try importing optional bypass libraries
_has_cloudscraper = importlib.util.find_spec("cloudscraper") is not None
_has_undetected = importlib.util.find_spec("undetected_chromedriver") is not None
_has_playwright = importlib.util.find_spec("playwright") is not None
_has_tor = importlib.util.find_spec("aiohttp_socks") is not None

if _has_playwright:
    from playwright.async_api import async_playwright

try:
    from tls_fingerprint import TLSScraper

    _has_tls = True
except ImportError:
    _has_tls = False

try:
    from camoufox_integration import CamoufoxBrowser

    _has_camoufox = True
except ImportError:
    _has_camoufox = False

try:
    from stealth_engine import StealthEngine

    _stealth_engine = StealthEngine()
except ImportError:
    _stealth_engine = None


class UltimateScraper:
    """12-tier anti-detection scraper with automatic fallback.

    Tiers:
    1. Direct HTTP (smart headers, rotating UAs)
    2. TLS fingerprint impersonation (curl_cffi JA3/JA4 bypass)
    3. cloudscraper (Python-native Cloudflare bypass)
    4. FlareSolverr (Cloudflare/WAF bypass service)
    5. undetected-chromedriver (modified Chrome, no detection)
    6. Camoufox stealth Firefox (source-level anti-fingerprinting)
    7. Playwright stealth (full browser with human behavior)
    8. Googlebot UA (search engine crawl mimic)
    9. Premium proxy retry (after cheap tiers fail)
    10. Archive.org / Wayback Machine (cached version)
    11. Google Cache (cached version)
    12. Tor proxy (anonymous routing via SOCKS5)
    """

    USER_AGENTS: ClassVar[list[str]] = [
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36",
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 14_5) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.5 Safari/605.1.15",
        "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36",
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:127.0) Gecko/20100101 Firefox/127.0",
    ]

    def __init__(self) -> None:
        self._ua_index = 0
        self._tls_scraper = TLSScraper() if _has_tls else None
        self._camoufox = CamoufoxBrowser() if _has_camoufox else None

    # Per-tier retry configurations for transient failure resilience.
    # Browser-based tiers (undetected, camoufox, playwright) use 0 retries
    # because launching a browser is expensive; network-only tiers retry 1-2x.
    _RETRY_CONFIGS: ClassVar[dict[str, RetryConfig]] = {
        "direct": RetryConfig(max_retries=2, base_delay=0.5, max_delay=5.0),
        "tls_fingerprint": RetryConfig(max_retries=1, base_delay=1.0, max_delay=5.0),
        "cloudscraper": RetryConfig(max_retries=1, base_delay=1.0, max_delay=5.0),
        "flaresolverr": RetryConfig(max_retries=2, base_delay=2.0, max_delay=10.0),
        "undetected": RetryConfig(max_retries=0),
        "camoufox": RetryConfig(max_retries=0),
        "playwright": RetryConfig(max_retries=0),
        "googlebot": RetryConfig(max_retries=2, base_delay=0.5, max_delay=5.0),
        "premium_proxy": RetryConfig(max_retries=2, base_delay=1.0, max_delay=8.0),
        "archive": RetryConfig(max_retries=2, base_delay=0.5, max_delay=5.0),
        "google_cache": RetryConfig(max_retries=2, base_delay=0.5, max_delay=5.0),
        "tor": RetryConfig(max_retries=1, base_delay=2.0, max_delay=10.0),
    }
    _DEFAULT_RETRY: ClassVar[RetryConfig] = RetryConfig(max_retries=1, base_delay=1.0)

    def _rotate_ua(self) -> str:
        ua = self.USER_AGENTS[self._ua_index % len(self.USER_AGENTS)]
        self._ua_index += 1
        return ua

    def _build_headers(self, url: str) -> dict[str, str]:
        parsed = urlparse(url)
        return {
            "User-Agent": self._rotate_ua(),
            "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
            "Accept-Language": random.choice(
                ["en-US,en;q=0.9", "en-GB,en;q=0.8", "en-US,en;q=0.7"]
            ),
            "Referer": f"https://{parsed.netloc}/",
            "DNT": "1",
            "Connection": "keep-alive",
            "Upgrade-Insecure-Requests": "1",
            "Sec-Fetch-Dest": "document",
            "Sec-Fetch-Mode": "navigate",
            "Sec-Fetch-Site": "none",
            "Sec-Fetch-User": "?1",
        }

    async def scrape(self, url: str, options: dict[str, Any] | None = None) -> dict[str, Any]:
        """Scrape any URL with automatic bypass strategy selection.
        Will try up to 10 strategies until one succeeds."""
        opts = options or {}
        errors: list[str] = []
        try:
            validate_url(url)
        except InvalidRequestError as e:
            return {"status": "error", "url": url, "error": str(e)}

        proxy_url = self._resolve_proxy_url(opts)

        # Tier 0: Premium proxy (if configured and forced or first attempt)
        if proxy_url and opts.get("use_premium_proxy_first", True):
            html = await self._tier_premium_proxy(url, proxy_url, opts)
            if html and self._is_valid(html):
                return self._result(url, html, "premium_proxy")
            errors.append("premium_proxy_failed")

        # Build tier list. Order starts cheap/direct and escalates.
        tier_order = [
            ("direct", self._tier_direct),
            ("tls_fingerprint", self._tier_tls_fingerprint),
            ("cloudscraper", self._tier_cloudscraper),
            ("flaresolverr", self._tier_flaresolverr),
            ("undetected", self._tier_undetected),
            ("camoufox", self._tier_camoufox),
            ("playwright", self._tier_playwright),
            ("googlebot", self._tier_googlebot),
        ]

        # Premium proxy retry (after cheap tiers fail) if not tried first.
        if proxy_url and not opts.get("use_premium_proxy_first", True):
            tier_order.append(("premium_proxy", self._tier_premium_proxy))

        tier_order.extend(
            [
                ("archive", self._tier_archive),
                ("google_cache", self._tier_google_cache),
                ("tor", self._tier_tor),
            ]
        )

        # If domain memory knows a good tier, try it first.
        parsed = urlparse(url)
        domain = parsed.netloc
        best = registry.best_tier_for_domain(domain, [name for name, _ in tier_order])
        if best:
            tier_order.sort(key=lambda item: (item[0] != best, item[0]))

        # External service tiers protected by circuit breakers.
        breaker_for_tier = {
            "flaresolverr": "flaresolverr",
            "playwright": "playwright",
            "camoufox": "camoufox",
            "tls_fingerprint": "tls_fingerprint",
        }

        for tier_name, tier_fn in tier_order:
            # Skip external tiers whose circuit breaker is open.
            breaker_name = breaker_for_tier.get(tier_name)
            if breaker_name and not registry.is_service_allowed(breaker_name):
                logger.debug(
                    "tier_skipped_circuit_open", extra={"tier": tier_name, "domain": domain}
                )
                errors.append(f"{tier_name}: circuit_open")
                continue

            start = time.time()
            try:
                retry_cfg = self._RETRY_CONFIGS.get(tier_name, self._DEFAULT_RETRY)
                if tier_name == "premium_proxy":
                    html = await async_retry(tier_fn, url, proxy_url, opts, config=retry_cfg)
                else:
                    html = await async_retry(
                        tier_fn, url, opts, proxy_url=proxy_url, config=retry_cfg
                    )
            except Exception as e:  # noqa: BLE001
                logger.debug("tier_exception", extra={"tier": tier_name, "error": str(e)[:50]})
                html = None

            latency = time.time() - start
            success = bool(html and self._is_valid(html))
            registry.record_domain_tier_result(domain, tier_name, success, latency)
            if breaker_name:
                registry.record_service_result(breaker_name, success)
            if SCRAPE_LATENCY:
                SCRAPE_LATENCY.labels(method=tier_name).observe(latency)

            if success:
                method = "premium_proxy" if tier_name == "premium_proxy" else tier_name
                return self._result(url, html, method)
            errors.append(f"{tier_name}_failed")

        last_err = errors[-1] if errors else "all_tiers_failed"
        return {
            "status": "error",
            "url": url,
            "error": "; ".join(errors[-5:]) if errors else last_err,
            "content": "",
            "proxy_recommendation": self._recommend_proxy(last_err),
        }

    def _resolve_proxy_url(self, opts: dict[str, Any]) -> str | None:
        """Resolve the configured proxy URL from options, ProxyManager, or env."""
        if opts.get("proxy_url"):
            return opts["proxy_url"]
        if opts.get("proxy") is False:
            return None
        try:
            from proxy_manager import ProxyManager

            pm = ProxyManager()
            return pm.get_proxy_url()
        except Exception as e:  # noqa: BLE001
            logger.debug("proxy_resolve_failed", extra={"error": str(e)[:80]})
        env_url = os.getenv("PRY_PROXY_URL") or os.getenv("PROXY_URL")
        return env_url or None

    def _recommend_proxy(self, last_error: str) -> dict[str, Any] | None:
        """Build a proxy recommendation for the response when scraping fails."""
        try:
            from proxy_manager import ProxyManager

            return ProxyManager().get_recommendation(last_error)
        except Exception as e:  # noqa: BLE001
            logger.debug("proxy_recommend_failed", extra={"error": str(e)[:80]})
            return None

    def _result(self, url: str, html: str, method: str) -> dict[str, Any]:
        return {
            "status": "ok",
            "url": url,
            "raw_html": html,
            "method": method,
            "content": self._extract_text(html),
        }

    def _is_valid(self, html: str | None) -> bool:
        if not html or len(html) < 500:
            return False
        lower = html.lower()
        block_indicators = [
            "cloudflare",
            "attention required",
            "just a moment",
            "enable javascript",
            "verify you are human",
        ]
        if any(i in lower for i in block_indicators) and len(html) < 5000:
            return False
        body = re.search(r"<body[^>]*>(.*?)</body>", html, re.DOTALL)
        if body:
            text = re.sub(r"<[^>]+>", " ", body.group(1)).strip()
            if len(text) < 50:
                return False
        return True

    def _extract_text(self, html: str) -> str:
        """Extract readable text from HTML."""
        try:
            from trafilatura import extract

            content = extract(
                html, output_format="markdown", include_links=True, include_images=False
            )
            if content and len(content) > 100:
                return content
        except Exception:  # noqa: BLE001
            pass
        try:
            from readability import Document

            doc = Document(html)
            content = doc.summary()
            if content and len(content) > 100:
                from markdownify import markdownify

                return markdownify(content, heading_arrows=False, strip=["script", "style"])
        except Exception:  # noqa: BLE001
            pass
        # Last resort: strip HTML tags
        text = re.sub(r"<[^>]+>", " ", html)
        text = re.sub(r"\s+", " ", text).strip()
        return text[:50000] if len(text) > 50000 else text

    async def _tier_direct(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        try:
            import httpx

            async with httpx.AsyncClient(timeout=30, follow_redirects=True, proxy=proxy_url) as c:
                r = await c.get(url, headers=self._build_headers(url))
                if r.is_success:
                    return r.text
        except (httpx.HTTPError, httpx.RequestError) as e:
            logger.debug("direct_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_premium_proxy(
        self, url: str, proxy_url: str, opts: dict[str, Any]
    ) -> str | None:
        """Fetch via the configured premium residential/datacenter proxy."""
        try:
            import httpx

            async with httpx.AsyncClient(timeout=45, follow_redirects=True, proxy=proxy_url) as c:
                r = await c.get(url, headers=self._build_headers(url))
                if r.is_success:
                    return r.text
        except (httpx.HTTPError, httpx.RequestError) as e:
            logger.debug("premium_proxy_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_cloudscraper(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        if not _has_cloudscraper:
            return None
        try:
            import cloudscraper

            scraper = cloudscraper.create_scraper(
                browser={"browser": "chrome", "platform": "windows", "mobile": False}
            )
            resp = scraper.get(url, timeout=30, headers={"User-Agent": self._rotate_ua()})
            if resp.status_code == 200:
                return resp.text
        except Exception as e:  # noqa: BLE001
            logger.debug("cloudscraper_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_flaresolverr(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        from settings import settings

        if not settings.flaresolverr_url:
            return None
        try:
            import httpx

            payload = {"cmd": "request.get", "url": url, "maxTimeout": 60000}
            async with httpx.AsyncClient(timeout=60) as c:
                r = await c.post(settings.flaresolverr_url, json=payload)
                if r.is_success:
                    data = r.json()
                    solution = data.get("solution", {})
                    if solution.get("status") == 200:
                        return solution["response"]
        except (httpx.HTTPError, httpx.RequestError) as e:
            logger.debug("flaresolverr_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_undetected(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        if not _has_undetected:
            return None
        try:
            import asyncio
            import time

            def _do_fetch() -> str:
                import undetected_chromedriver as uc

                driver = uc.Chrome(headless=True, use_subprocess=True)
                driver.get(url)
                # Note: time.sleep is used inside a sync thread-pool task because
                # undetected_chromedriver's blocking API runs in asyncio.to_thread.
                # Replacing with asyncio.sleep would require restructuring the tier
                # to be fully async; this sync sleep is bounded and does not block
                # the event loop directly.
                time.sleep(random.uniform(2, 4))
                html = driver.page_source
                driver.quit()
                return html

            return await asyncio.to_thread(_do_fetch)
        except Exception as e:  # noqa: BLE001
            logger.debug("undetected_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_playwright(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        if not _has_playwright:
            return None
        try:
            async with async_playwright() as pw:
                browser = await pw.chromium.launch(
                    headless=True,
                    args=[
                        "--disable-blink-features=AutomationControlled",
                        "--no-sandbox",
                        "--disable-dev-shm-usage",
                        "--disable-web-security",
                    ],
                )
                context = await browser.new_context(
                    viewport={
                        "width": random.choice([1920, 1366, 1440]),
                        "height": random.choice([1080, 768, 900]),
                    },
                    user_agent=self._rotate_ua(),
                    locale="en-US",
                    timezone_id="America/New_York",
                )
                stealth_script = _stealth_engine.generate_all() if _stealth_engine else ""
                if stealth_script:
                    await context.add_init_script(stealth_script)
                page = await context.new_page()
                await page.goto(url, wait_until="domcontentloaded", timeout=60000)
                await page.wait_for_timeout(random.randint(1000, 3000))
                for _ in range(random.randint(2, 5)):
                    await page.evaluate(f"window.scrollBy(0, {random.randint(200, 500)})")
                    await page.wait_for_timeout(random.randint(300, 1000))
                    await page.mouse.move(random.randint(100, 1400), random.randint(100, 800))
                html = await page.content()
                await browser.close()
                return html
        except OSError as e:
            logger.debug("playwright_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_tls_fingerprint(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        """Fetch using curl_cffi TLS fingerprint impersonation."""
        if not self._tls_scraper or not self._tls_scraper.is_available():
            return None
        try:
            result = await self._tls_scraper.fetch(
                url,
                headers=self._build_headers(url),
                proxy=proxy_url or "",
                timeout=opts.get("timeout", 30),
            )
            if result.get("success") and result.get("status_code", 0) < 400:
                return result.get("text", "")
        except Exception as e:  # noqa: BLE001
            logger.debug("tls_fingerprint_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_camoufox(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        """Fetch using Camoufox anti-detection Firefox."""
        if not self._camoufox or not self._camoufox.is_available():
            return None
        try:
            result = await self._camoufox.fetch(
                url,
                wait_time=opts.get("wait_time", 3000),
                proxy=proxy_url or "",
            )
            if result.get("success"):
                return result.get("content", "")
        except Exception as e:  # noqa: BLE001
            logger.debug("camoufox_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_googlebot(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        try:
            import httpx

            headers = self._build_headers(url)
            headers["User-Agent"] = (
                "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
            )
            async with httpx.AsyncClient(timeout=30, follow_redirects=True, proxy=proxy_url) as c:
                r = await c.get(url, headers=headers)
                if r.is_success:
                    return r.text
        except (httpx.HTTPError, httpx.RequestError) as e:
            logger.debug("googlebot_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_archive(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        """Fetch from Wayback Machine CDX API for latest snapshot."""
        try:
            import httpx

            cdx_url = f"https://web.archive.org/cdx/search/cdx?url={url}&output=json&limit=1&fl=timestamp,original"
            async with httpx.AsyncClient(timeout=15) as c:
                r = await c.get(cdx_url, headers={"User-Agent": "Mozilla/5.0"})
                if r.is_success:
                    data = r.json()
                    if len(data) > 1:
                        timestamp = data[1][0]
                        archive_url = f"https://web.archive.org/web/{timestamp}id_/{url}"
                        ar = await c.get(archive_url, timeout=30, follow_redirects=True)
                        if ar.is_success:
                            return ar.text
        except (httpx.HTTPError, httpx.RequestError) as e:
            logger.debug("archive_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_google_cache(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        try:
            import httpx

            cache_url = f"https://webcache.googleusercontent.com/search?q=cache:{url}"
            async with httpx.AsyncClient(timeout=15, follow_redirects=True) as c:
                r = await c.get(cache_url, headers={"User-Agent": "Mozilla/5.0"})
                if r.is_success:
                    return r.text
        except (httpx.HTTPError, httpx.RequestError) as e:
            logger.debug("google_cache_failed", extra={"error": str(e)[:50]})
        return None

    async def _tier_tor(
        self, url: str, opts: dict[str, Any], proxy_url: str | None = None
    ) -> str | None:
        """Fetch via Tor SOCKS5 proxy."""
        if not _has_tor:
            return None
        try:
            import aiohttp
            from aiohttp_socks import ProxyConnector

            connector = ProxyConnector.from_url("socks5://127.0.0.1:9050")
            async with (
                aiohttp.ClientSession(connector=connector) as session,
                session.get(
                    url,
                    headers=self._build_headers(url),
                    timeout=aiohttp.ClientTimeout(total=60),
                ) as resp,
            ):
                if resp.status == 200:
                    return await resp.text()
        except aiohttp.ClientError as e:
            logger.debug("tor_failed", extra={"error": str(e)[:50]})
        return None