"""GET /umbrella + /api/umbrella + /api/umbrella/doc — cortex-os umbrella graph viz.

Per sot/03-PROTOCOLS/CORTEX-OS-UMBRELLA-VIZ-PRD.md.

Endpoints:
  GET /umbrella                  → static HTML page (Cytoscape.js panel)
  GET /api/umbrella              → graph/umbrella.json contents (UI-stable v1.0 schema)
  GET /api/umbrella/doc?path=X   → markdown body + frontmatter for a node's source_path

Reads graph artifact from $HERMES_REPO_ROOT/graph/umbrella.json (curator-maintained).
Doc reads are restricted to hermes/ workspace subdir (no path traversal).

Public API surface used: api.register_route, api.logger.
No upstream forced internal dependencies.
"""
import json
import os
import urllib.parse
from pathlib import Path

_DEFAULT_REPO_ROOT = "/home/svrnty/workspaces/hermes"


def _repo_root() -> Path:
    return Path(os.environ.get("HERMES_REPO_ROOT", _DEFAULT_REPO_ROOT)).resolve()


def register(api):
    """Wire umbrella panel + APIs."""
    log = api.logger("svrnty.routes.umbrella")
    api.register_route("/umbrella", "GET", _handle_panel_html)
    api.register_route("/api/umbrella", "GET", _handle_graph_json)
    api.register_route("/api/umbrella/doc", "GET", _handle_doc_body)
    log.info("umbrella panel + APIs registered")


def _send(handler, status: int, body: bytes, content_type: str) -> None:
    handler.send_response(status)
    handler.send_header("Content-Type", content_type)
    handler.send_header("Content-Length", str(len(body)))
    handler.send_header("Cache-Control", "no-store")
    handler.end_headers()
    handler.wfile.write(body)


def _handle_graph_json(handler, parsed) -> bool:
    graph_path = _repo_root() / "graph" / "umbrella.json"
    if not graph_path.exists():
        body = json.dumps({
            "error": "graph/umbrella.json not found",
            "hint": "run curator/sweep.py --grapher-only to generate",
        }).encode("utf-8")
        _send(handler, 404, body, "application/json; charset=utf-8")
        return True
    try:
        body = graph_path.read_bytes()
    except OSError as e:
        body = json.dumps({"error": str(e)}).encode("utf-8")
        _send(handler, 500, body, "application/json; charset=utf-8")
        return True
    _send(handler, 200, body, "application/json; charset=utf-8")
    return True


def _handle_doc_body(handler, parsed) -> bool:
    qs = urllib.parse.parse_qs(parsed.query or "")
    rel = (qs.get("path") or [""])[0].strip()
    if not rel:
        _send(handler, 400, b'{"error":"missing path query param"}', "application/json; charset=utf-8")
        return True
    root = _repo_root()
    try:
        target = (root / rel).resolve()
    except (OSError, RuntimeError):
        _send(handler, 400, b'{"error":"invalid path"}', "application/json; charset=utf-8")
        return True
    # Path-traversal guard: resolved target must be inside the workspace root.
    if root not in target.parents and target != root:
        _send(handler, 403, b'{"error":"path outside workspace"}', "application/json; charset=utf-8")
        return True
    if not target.exists() or not target.is_file():
        _send(handler, 404, json.dumps({"error": f"file not found: {rel}"}).encode("utf-8"),
              "application/json; charset=utf-8")
        return True
    try:
        content = target.read_text(encoding="utf-8")
    except (OSError, UnicodeDecodeError) as e:
        _send(handler, 500, json.dumps({"error": str(e)}).encode("utf-8"),
              "application/json; charset=utf-8")
        return True
    # Cap response size — UI only renders a preview pane; large docs read in full via git.
    MAX = 50_000
    truncated = len(content) > MAX
    if truncated:
        content = content[:MAX] + "\n\n*[truncated — read full file in repo]*"
    body = json.dumps({
        "path": rel,
        "size": len(content),
        "truncated": truncated,
        "body": content,
    }).encode("utf-8")
    _send(handler, 200, body, "application/json; charset=utf-8")
    return True


def _handle_panel_html(handler, parsed) -> bool:
    """Serve the static umbrella.html via Location redirect (assets live in static/)."""
    handler.send_response(302)
    handler.send_header("Location", "/plugins/svrnty/umbrella.html")
    handler.end_headers()
    return True