"""Scrape HVM doc bundles into corpus/<slug>/<page_id>.{md,json}.

Reads bundles.json (produced by scrape.bundles), then for each bundle:
  - mode="toc":    walks the TOC tree, fetches each page via the render
                   endpoint, converts page_html to markdown, writes
                   <page_id>.md + <page_id>.json sidecar.
  - mode="single": fetches /document/{docId} directly, treats the whole
                   body as one page with page_id = doc_id.

After all bundles are on disk, runs a finalize pass that synthesizes
topic_cluster.clustered_topics for each page by looking up the same
GUID in sibling bundles (HPE GUIDs are stable across versions — see
reference_hpe_docs_portal_api.md).

Usage:
    python -m scrape.runner --all
    python -m scrape.runner --bundle hvm_user_manual_8_1_2
    python -m scrape.runner --all --force        # re-download already-on-disk pages
    python -m scrape.runner --finalize-only      # only redo the topic_cluster pass
"""
from __future__ import annotations

import argparse
import json
import re
import sys
import time
from concurrent.futures import ThreadPoolExecutor, as_completed
from dataclasses import dataclass
from pathlib import Path
from typing import Any

import requests
from bs4 import BeautifulSoup
from markdownify import markdownify as md

API = "https://support.hpe.com/hpesc/public/api/document"
DOC_URL = "https://support.hpe.com/hpesc/public/docDisplay?docId={doc_id}&page={page_id}.html"
DOC_URL_SINGLE = "https://support.hpe.com/hpesc/public/docDisplay?docId={doc_id}"
UA = "hvm-docs-mcp/0.1 (+https://git.jpaul.io/justin/hvm-docs; admin@jpaul.io)"
ROOT = Path(__file__).resolve().parent.parent
CORPUS = ROOT / "corpus"
BUNDLES_JSON = ROOT / "bundles.json"

GUID_RE = re.compile(r"page=(GUID-[A-F0-9-]+)\.html")


@dataclass
class TocEntry:
    page_id: str
    title: str
    ordinal: int
    parent_title: str | None


def _session() -> requests.Session:
    s = requests.Session()
    s.headers.update({"User-Agent": UA, "Accept": "application/json, text/html"})
    return s


def _get(s: requests.Session, url: str, expect_json: bool = False, retries: int = 4) -> Any:
    delay = 1.0
    for attempt in range(retries):
        r = s.get(url, timeout=30)
        if r.status_code == 200:
            return r.json() if expect_json else r.text
        if r.status_code == 404:
            return None
        if r.status_code in (429, 500, 502, 503, 504):
            time.sleep(delay)
            delay *= 2
            continue
        r.raise_for_status()
    raise RuntimeError(f"GET failed after {retries} retries: {url}")


def _flatten_toc(toc: list[dict]) -> list[TocEntry]:
    out: list[TocEntry] = []
    ordinal = 0

    def walk(nodes: list[dict] | None, parent_title: str | None) -> None:
        nonlocal ordinal
        for node in nodes or []:
            title = node.get("topicName") or ""
            link = node.get("topicLink") or ""
            m = GUID_RE.search(link)
            if m:
                ordinal += 1
                out.append(TocEntry(page_id=m.group(1), title=title, ordinal=ordinal, parent_title=parent_title))
            walk(node.get("children"), title or parent_title)

    walk(toc, None)
    return out


def _strip_dita_wrappers(html: str) -> str:
    """Remove the outer <main class="ditasrc">, drop the trademark Notices section,
    and unwrap aria-only span markup so markdownify produces clean text.

    DITA's notices boilerplate repeats across every doc; if we leave it in,
    every page chunk inherits the same trademark text and pollutes retrieval."""
    soup = BeautifulSoup(html, "html.parser")
    # Drop the Notices/Acknowledgments/Abstract boilerplate by section heading.
    # Every doc on the portal carries the same legal Notices and trademark
    # Acknowledgments; if we leave them in, every chunk inherits the same
    # text and pollutes retrieval. Abstract is one-line marketing.
    boilerplate = {"Notices", "Acknowledgments", "Abstract"}
    # Wrapped form: <article>/<section>/<div> whose first heading child is boilerplate.
    for sec in soup.select("article, section, div"):
        h = sec.find(["h1", "h2"], recursive=False)
        if h and h.get_text(strip=True) in boilerplate:
            sec.decompose()
    # Unwrapped form: bare <h1>/<h2>Boilerplate</h2> followed by its .desc/.body sibling.
    for h in soup.find_all(["h1", "h2"]):
        if h.get_text(strip=True) in boilerplate:
            sib = h.find_next_sibling()
            if sib and (sib.name in {"div", "section"}):
                cls = " ".join(sib.get("class", []) or [])
                if "desc" in cls or "body" in cls or "notices" in cls:
                    sib.decompose()
            h.decompose()
    main = soup.find("main")
    return str(main) if main else str(soup)


def html_to_md(page_html: str) -> str:
    cleaned = _strip_dita_wrappers(page_html)
    text = md(cleaned, heading_style="ATX", bullets="-")
    # collapse runs of blank lines
    text = re.sub(r"\n{3,}", "\n\n", text).strip()
    return text + "\n"


def fetch_toc_page(s: requests.Session, doc_id: str, page_id: str) -> str:
    payload = _get(s, f"{API}/{doc_id}/render?page={page_id}.html", expect_json=True)
    if not payload:
        return ""
    return payload.get("page_html") or ""


def fetch_single_doc(s: requests.Session, doc_id: str) -> tuple[str, str]:
    """Returns (page_html, title) for a single-doc-shape bundle."""
    html = _get(s, f"{API}/{doc_id}")
    if not html:
        return "", ""
    soup = BeautifulSoup(html, "html.parser")
    h1 = soup.select_one("h1.title.topictitle1")
    title = h1.get_text(" ", strip=True) if h1 else doc_id
    return html, title


def write_page(bundle_dir: Path, page_id: str, body_md: str, sidecar: dict[str, Any], force: bool) -> bool:
    bundle_dir.mkdir(parents=True, exist_ok=True)
    md_path = bundle_dir / f"{page_id}.md"
    json_path = bundle_dir / f"{page_id}.json"
    if not force and md_path.exists() and json_path.exists():
        return False
    md_path.write_text(body_md)
    json_path.write_text(json.dumps(sidecar, indent=2) + "\n")
    return True


def scrape_toc_bundle(s: requests.Session, bundle: dict, force: bool, concurrency: int) -> int:
    doc_id = bundle["doc_id"]
    slug = bundle["slug"]
    bundle_dir = CORPUS / slug

    toc = _get(s, f"{API}/{doc_id}/toc", expect_json=True) or []
    entries = _flatten_toc(toc)
    print(f"  {slug}: {len(entries)} pages", file=sys.stderr)

    written = 0
    def do_one(entry: TocEntry) -> bool:
        page_html = fetch_toc_page(s, doc_id, entry.page_id)
        if not page_html:
            return False
        body_md = html_to_md(page_html)
        sidecar = {
            "bundle_id": slug,
            "page_id": entry.page_id,
            "title": entry.title,
            "ordinal": entry.ordinal,
            "parent_title": entry.parent_title,
            "doc_id": doc_id,
            "version": bundle.get("version"),
            "product": bundle.get("product"),
            "source_url": DOC_URL.format(doc_id=doc_id, page_id=entry.page_id),
            # topic_cluster filled in by finalize()
        }
        return write_page(bundle_dir, entry.page_id, body_md, sidecar, force)

    with ThreadPoolExecutor(max_workers=concurrency) as pool:
        for fut in as_completed(pool.submit(do_one, e) for e in entries):
            if fut.result():
                written += 1
    return written


def scrape_single_bundle(s: requests.Session, bundle: dict, force: bool) -> int:
    doc_id = bundle["doc_id"]
    slug = bundle["slug"]
    bundle_dir = CORPUS / slug

    html, title = fetch_single_doc(s, doc_id)
    if not html:
        print(f"  ! {slug}: empty body", file=sys.stderr)
        return 0
    body_md = html_to_md(html)
    sidecar = {
        "bundle_id": slug,
        "page_id": doc_id,
        "title": title or bundle["title"],
        "ordinal": 1,
        "parent_title": None,
        "doc_id": doc_id,
        "version": bundle.get("version"),
        "product": bundle.get("product"),
        "source_url": DOC_URL_SINGLE.format(doc_id=doc_id),
    }
    print(f"  {slug}: 1 page (single-doc)", file=sys.stderr)
    return 1 if write_page(bundle_dir, doc_id, body_md, sidecar, force) else 0


def finalize_clusters(bundles: list[dict]) -> int:
    """Cross-link sibling pages with the same GUID across version bundles.

    For TOC bundles, page_id == GUID; same GUID across two bundles = same
    underlying topic. For single-doc bundles (page_id == doc_id), peer them
    by matching product+version-sibling on the `product` field."""
    # GUID → list[(slug, sidecar_path, sidecar_dict)]
    guid_to_pages: dict[str, list[tuple[str, Path, dict]]] = {}
    # product → list[(slug, sidecar_path, sidecar_dict)] for single-doc peering
    product_to_pages: dict[str, list[tuple[str, Path, dict]]] = {}

    for b in bundles:
        slug = b["slug"]
        bundle_dir = CORPUS / slug
        if not bundle_dir.exists():
            continue
        for jp in bundle_dir.glob("*.json"):
            data = json.loads(jp.read_text())
            pid = data["page_id"]
            if pid.startswith("GUID-"):
                guid_to_pages.setdefault(pid, []).append((slug, jp, data))
            else:
                product_to_pages.setdefault(b["product"], []).append((slug, jp, data))

    updated = 0
    # TOC pages — cluster by GUID
    for guid, peers in guid_to_pages.items():
        if len(peers) < 2:
            continue
        for slug, jp, data in peers:
            others = [
                {"bundle_id": s2, "page_id": guid, "clustering_title": d2.get("title", "")}
                for s2, _, d2 in peers if s2 != slug
            ]
            data["topic_cluster"] = {"clustering_title": data.get("title", ""), "clustered_topics": others}
            jp.write_text(json.dumps(data, indent=2) + "\n")
            updated += 1
    # Single-doc pages — cluster by product (e.g. Release Notes 8.1.0/.1/.2)
    for product, peers in product_to_pages.items():
        if len(peers) < 2:
            continue
        for slug, jp, data in peers:
            others = [
                {"bundle_id": s2, "page_id": d2["page_id"], "clustering_title": d2.get("title", "")}
                for s2, _, d2 in peers if s2 != slug
            ]
            data["topic_cluster"] = {"clustering_title": data.get("title", ""), "clustered_topics": others}
            jp.write_text(json.dumps(data, indent=2) + "\n")
            updated += 1

    return updated


def main() -> int:
    p = argparse.ArgumentParser(description="Scrape HVM bundles into corpus/.")
    p.add_argument("--all", action="store_true", help="scrape every bundle in bundles.json")
    p.add_argument("--bundle", action="append", help="scrape one bundle by slug (repeatable)")
    p.add_argument("--force", action="store_true", help="re-fetch pages already on disk")
    p.add_argument("--concurrency", type=int, default=6)
    p.add_argument("--finalize-only", action="store_true", help="only rebuild topic_cluster sidecar fields")
    args = p.parse_args()

    if not BUNDLES_JSON.exists():
        print(f"bundles.json missing — run `python -m scrape.bundles` first", file=sys.stderr)
        return 2

    bundles = json.loads(BUNDLES_JSON.read_text())

    if args.finalize_only:
        n = finalize_clusters(bundles)
        print(f"finalize: updated topic_cluster on {n} sidecars", file=sys.stderr)
        return 0

    if args.bundle:
        bundles = [b for b in bundles if b["slug"] in args.bundle]
        if not bundles:
            print(f"no bundles matched: {args.bundle}", file=sys.stderr)
            return 2
    elif not args.all:
        print("specify --all or --bundle <slug>", file=sys.stderr)
        return 2

    s = _session()
    total = 0
    for b in bundles:
        if b.get("mode") == "single":
            total += scrape_single_bundle(s, b, args.force)
        else:
            total += scrape_toc_bundle(s, b, args.force, args.concurrency)
    print(f"scraped {total} new/updated pages", file=sys.stderr)

    # Always finalize after a scrape so sidecars are consistent.
    all_bundles = json.loads(BUNDLES_JSON.read_text())
    n = finalize_clusters(all_bundles)
    print(f"finalize: updated topic_cluster on {n} sidecars", file=sys.stderr)

    return 0


if __name__ == "__main__":
    sys.exit(main())