"""
IssueSink adapter interface and implementations.

IssueSink is the outbound boundary between activity-core and task backends
(issue-core, State Hub progress, etc.). It receives TaskSpec objects and
returns TaskRef objects.

Active sink is selected by ISSUE_SINK_TYPE:

  state-hub (default) — State Hub progress (`activity_task_spawn`); no Forgejo
  null                — dry-run synthetic refs
  rest                — issue-core REST (explicit opt-in; may project to Forgejo)

ACTIVITY-WP-0022: default must not silently create Forgejo issues for internal
findings. Use rest only when intentionally projecting to an external tracker.
"""

from __future__ import annotations

import logging
import os
import uuid
from abc import ABC, abstractmethod

import httpx

from activity_core.rules.models import TaskRef, TaskSpec

logger = logging.getLogger(__name__)

ISSUE_CORE_URL = os.environ.get("ISSUE_CORE_URL", "http://127.0.0.1:8765")
ISSUE_CORE_API_KEY_ENV = "ISSUE_CORE_API_KEY"
# Safe default for internal fleet findings (ACTIVITY-WP-0022).
DEFAULT_ISSUE_SINK_TYPE = "state-hub"
ISSUE_SINK_TYPE = os.environ.get("ISSUE_SINK_TYPE", DEFAULT_ISSUE_SINK_TYPE)


class IssueSink(ABC):
    @abstractmethod
    def emit(self, task_spec: TaskSpec) -> TaskRef: ...


class IssueCoreRestSink(IssueSink):
    """POSTs to issue-core REST API.

    Config: ISSUE_CORE_URL and ISSUE_CORE_API_KEY env vars (shared key with
    the issue-core server).
    """

    def __init__(
        self,
        base_url: str = ISSUE_CORE_URL,
        api_key: str | None = None,
    ) -> None:
        self._base_url = base_url.rstrip("/")
        if api_key is not None:
            self._api_key = api_key.strip()
        else:
            self._api_key = os.environ.get(ISSUE_CORE_API_KEY_ENV, "").strip()

    def _auth_headers(self) -> dict[str, str]:
        if not self._api_key:
            raise RuntimeError(
                f"{ISSUE_CORE_API_KEY_ENV} is not set. "
                "Required when ISSUE_SINK_TYPE=rest."
            )
        return {"Authorization": f"Bearer {self._api_key}"}

    def emit(self, task_spec: TaskSpec) -> TaskRef:
        payload = {
            "title": task_spec.title,
            "description": task_spec.description,
            "target_repo": task_spec.target_repo,
            "priority": task_spec.priority,
            "labels": task_spec.labels,
            "due_in_days": task_spec.due_in_days,
            "source_type": task_spec.source_type,
            "source_id": task_spec.source_id,
            "triggering_event_id": (
                str(task_spec.triggering_event_id)
                if task_spec.triggering_event_id is not None
                else None
            ),
            "activity_definition_id": task_spec.activity_definition_id,
        }
        resp = httpx.post(
            f"{self._base_url}/issues/",
            json=payload,
            headers=self._auth_headers(),
            timeout=10.0,
        )
        status = getattr(resp, "status_code", None)
        if status is not None and status >= 400:
            # Surface issue-core backend detail (e.g. dead Gitea token → 503)
            # so Temporal history and operator status are actionable.
            detail = (getattr(resp, "text", None) or "")[:500]
            raise RuntimeError(
                f"IssueCoreRestSink POST {self._base_url}/issues/ "
                f"failed HTTP {status}: {detail}"
            )
        if status is None:
            # Test doubles may only implement raise_for_status/json.
            resp.raise_for_status()
        data = resp.json()
        return TaskRef(
            external_id=data["issue_id"],
            backend_url=data.get("issue_url"),
            backend=data.get("backend", ""),
        )


class NullSink(IssueSink):
    """Discards tasks and returns synthetic TaskRefs. For testing."""

    def emit(self, task_spec: TaskSpec) -> TaskRef:
        synthetic_id = f"null-{uuid.uuid4()}"
        logger.debug("NullSink: discarding task %r → %s", task_spec.title, synthetic_id)
        return TaskRef(external_id=synthetic_id, backend="null")


class StateHubProgressSink(IssueSink):
    """Record each TaskSpec as a State Hub progress event (no Forgejo issues).

    ACTIVITY-WP-0021 path B: when issue-core→Forgejo is unavailable or policy
    forbids automated Forgejo issues, operators can set ISSUE_SINK_TYPE=state-hub
    so scheduled definitions still complete with observable evidence.

    Posts event_type=activity_task_spawn (override with STATE_HUB_TASK_EVENT_TYPE).
    """

    def __init__(
        self,
        base_url: str | None = None,
        *,
        event_type: str | None = None,
        author: str = "activity-core",
        timeout_seconds: float = 10.0,
    ) -> None:
        self._base_url = (
            base_url
            or os.environ.get("STATE_HUB_URL")
            or "http://127.0.0.1:8000"
        ).rstrip("/")
        self._event_type = event_type or os.environ.get(
            "STATE_HUB_TASK_EVENT_TYPE", "activity_task_spawn"
        )
        self._author = author
        self._timeout = timeout_seconds

    def emit(self, task_spec: TaskSpec) -> TaskRef:
        from activity_core.state_hub_write import parse_state_hub_write_response

        external_id = f"sh-{uuid.uuid4()}"
        body = {
            "event_type": self._event_type,
            "author": self._author,
            "summary": task_spec.title[:240] or "activity-core task spawn",
            "detail": {
                "task_ref": external_id,
                "title": task_spec.title,
                "description": task_spec.description,
                "target_repo": task_spec.target_repo,
                "priority": task_spec.priority,
                "labels": task_spec.labels,
                "source_type": task_spec.source_type,
                "source_id": task_spec.source_id,
                "triggering_event_id": (
                    str(task_spec.triggering_event_id)
                    if task_spec.triggering_event_id is not None
                    else None
                ),
                "activity_definition_id": task_spec.activity_definition_id,
                "backend": "state-hub-progress",
            },
        }
        resp = httpx.post(
            f"{self._base_url}/progress/",
            json=body,
            timeout=self._timeout,
        )
        if resp.status_code >= 400:
            raise RuntimeError(
                f"StateHubProgressSink POST {self._base_url}/progress/ "
                f"failed HTTP {resp.status_code}: {resp.text[:500]}"
            )
        data = parse_state_hub_write_response(resp)
        progress_id = data.get("id") or data.get("outbox_id") or external_id
        return TaskRef(
            external_id=str(progress_id),
            backend_url=f"{self._base_url}/progress/",
            backend="state-hub-progress",
        )


def get_issue_sink() -> IssueSink:
    """Factory: returns the configured IssueSink based on ISSUE_SINK_TYPE.

    Re-reads the env on each call so ConfigMap/env patches apply without
    requiring a module reload (ACTIVITY-WP-0021).
    """
    sink_type = os.environ.get("ISSUE_SINK_TYPE", DEFAULT_ISSUE_SINK_TYPE).strip().lower()
    if not sink_type:
        sink_type = DEFAULT_ISSUE_SINK_TYPE
    if sink_type == "null":
        return NullSink()
    if sink_type in {"state-hub", "state_hub", "progress"}:
        return StateHubProgressSink()
    if sink_type == "rest":
        return IssueCoreRestSink()
    logger.warning(
        "unknown ISSUE_SINK_TYPE=%r — falling back to %s (safe default)",
        sink_type,
        DEFAULT_ISSUE_SINK_TYPE,
    )
    return StateHubProgressSink()