from __future__ import annotations

import json
import urllib.error
import urllib.parse
import urllib.request
from typing import Any

DEFAULT_BASE_URL = "http://127.0.0.1:8000"
TIMEOUT_SECONDS = 5
LIST_TIMEOUT_SECONDS = 20

# Observed status vocabulary (2026-07): "requested", "completed". No fixed
# enum is published by the API (free-form string field) -- treat anything
# not in this terminal set as still-open rather than assuming a closed list.
TERMINAL_STATUSES = {"completed", "cancelled", "rejected", "resolved", "closed"}


def _request(
    method: str,
    path: str,
    base_url: str,
    *,
    body: dict[str, Any] | None = None,
    params: dict[str, str] | None = None,
    timeout: int = TIMEOUT_SECONDS,
) -> dict[str, Any] | list[Any]:
    url = f"{base_url.rstrip('/')}{path}"
    if params:
        query = "&".join(
            f"{k}={urllib.parse.quote(v)}" for k, v in params.items() if v
        )
        if query:
            url = f"{url}?{query}"
    data = json.dumps(body).encode("utf-8") if body is not None else None
    request = urllib.request.Request(
        url,
        data=data,
        method=method,
        headers={"Content-Type": "application/json", "User-Agent": "reuse-surface/0.1"},
    )
    with urllib.request.urlopen(request, timeout=timeout) as response:
        return json.loads(response.read().decode("utf-8"))


def state_hub_reachable(base_url: str = DEFAULT_BASE_URL) -> bool:
    try:
        _request("GET", "/state/health", base_url)
        return True
    except (urllib.error.URLError, TimeoutError, OSError):
        return False


def file_capability_request(
    *,
    title: str,
    description: str,
    requesting_domain: str,
    requesting_agent: str,
    capability_type: str = "reuse-surface-new-verdict",
    requesting_workplan_id: str | None = None,
    base_url: str = DEFAULT_BASE_URL,
) -> dict[str, Any] | None:
    """Files a State Hub capability request for a plan-check 'new' verdict.

    Returns the created request record, or None if the hub is unreachable
    (degrades gracefully -- plan-check never blocks on this)."""
    if not state_hub_reachable(base_url):
        return None
    body = {
        "title": title,
        "description": description,
        "capability_type": capability_type,
        "requesting_domain": requesting_domain,
        "requesting_agent": requesting_agent,
        "requesting_workplan_id": requesting_workplan_id,
    }
    try:
        return _request("POST", "/capability-requests/", base_url, body=body)
    except (urllib.error.URLError, TimeoutError, OSError):
        return None


def list_open_capability_requests(
    base_url: str = DEFAULT_BASE_URL,
) -> list[dict[str, Any]] | None:
    """Returns capability requests whose status is not terminal (see
    TERMINAL_STATUSES), or None if the hub is unreachable. A request can
    carry a catalog_entry_id while still 'requested' (routed, not
    fulfilled), so status -- not catalog_entry_id presence -- is the open
    signal. The list endpoint can be slow (observed ~7s with a handful of
    rows); a longer timeout than the health check is used deliberately."""
    if not state_hub_reachable(base_url):
        return None
    try:
        requests_ = _request(
            "GET", "/capability-requests/", base_url, timeout=LIST_TIMEOUT_SECONDS
        )
    except (urllib.error.URLError, TimeoutError, OSError):
        return None
    if not isinstance(requests_, list):
        return []
    return [r for r in requests_ if r.get("status") not in TERMINAL_STATUSES]