"""
IssueSink adapter interface and implementations.

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

Active sink is selected by ISSUE_SINK_TYPE env var: "rest" (default) | "null".
"""

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://127.0.0.1:8010")
ISSUE_SINK_TYPE = os.environ.get("ISSUE_SINK_TYPE", "rest")


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


class IssueCoreRestSink(IssueSink):
    """POSTs to issue-core REST API. Config: ISSUE_CORE_URL env var."""

    def __init__(self, base_url: str = ISSUE_CORE_URL) -> None:
        self._base_url = base_url.rstrip("/")

    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": task_spec.triggering_event_id,
            "activity_definition_id": task_spec.activity_definition_id,
        }
        resp = httpx.post(f"{self._base_url}/issues/", json=payload, timeout=10.0)
        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")


def get_issue_sink() -> IssueSink:
    """Factory: returns the configured IssueSink based on ISSUE_SINK_TYPE."""
    sink_type = ISSUE_SINK_TYPE.lower()
    if sink_type == "null":
        return NullSink()
    return IssueCoreRestSink()