"""Temporal worker entrypoint for activity-core.

Starts two workers (wired up in T20):
  - orchestrator-tq: RunActivityWorkflow + its activities
  - task-execution-tq: TaskExecutorWorkflow

T23: Calls sync_schedules before entering the worker run loop to ensure
     all cron ActivityDefinitions have live Temporal Schedules.

T31: Exposes Prometheus metrics via the Temporal SDK runtime on :9090/metrics.

Run with:
    TEMPORAL_HOST=localhost:7233 \
    ACTCORE_DB_URL=postgresql+asyncpg://actcore:actcore@localhost:5433/actcore \
        python -m activity_core.worker

Environment variables:
    TEMPORAL_HOST         Temporal frontend address (default: localhost:7233)
    TEMPORAL_NAMESPACE    Temporal namespace       (default: default)
    ACTCORE_DB_URL        App DB connection string (required)
    PROMETHEUS_BIND_ADDR  Prometheus metrics bind  (default: 0.0.0.0:9090)
"""

from __future__ import annotations

import asyncio
import logging
import os
import signal

from temporalio.client import Client
from temporalio.runtime import PrometheusConfig, Runtime, TelemetryConfig
from temporalio.worker import Worker

from activity_core.activities import (
    emit_tasks,
    evaluate_rules,
    init_session_factory,
    load_activity_definition,
    log_run,
    persist_task_instance,
    resolve_context,
)
from activity_core.db import make_engine
from sqlalchemy.ext.asyncio import async_sessionmaker
from activity_core.sync_activity_definitions import sync as sync_activity_defs
from activity_core.sync_schedules import sync as sync_schedules
from activity_core.workflows import RunActivityWorkflow, TaskExecutorWorkflow

logger = logging.getLogger(__name__)

TEMPORAL_HOST = os.environ.get("TEMPORAL_HOST", "localhost:7233")
TEMPORAL_NAMESPACE = os.environ.get("TEMPORAL_NAMESPACE", "default")
PROMETHEUS_BIND_ADDR = os.environ.get("PROMETHEUS_BIND_ADDR", "0.0.0.0:9090")

ORCHESTRATOR_TASK_QUEUE = "orchestrator-tq"
TASK_EXECUTION_TASK_QUEUE = "task-execution-tq"


async def run() -> None:
    db_url = os.environ.get("ACTCORE_DB_URL")
    if not db_url:
        raise RuntimeError("ACTCORE_DB_URL is required")
    init_session_factory(db_url)

    # T31: Configure the Temporal SDK runtime to emit metrics in Prometheus format.
    runtime = Runtime(
        telemetry=TelemetryConfig(
            metrics=PrometheusConfig(bind_address=PROMETHEUS_BIND_ADDR)
        )
    )

    client = await Client.connect(
        TEMPORAL_HOST, namespace=TEMPORAL_NAMESPACE, runtime=runtime
    )

    # T45: Sync ActivityDefinition files into DB before schedule sync.
    logger.info("Syncing ActivityDefinition files...")
    try:
        session_factory = async_sessionmaker(make_engine(db_url), expire_on_commit=False)
        await sync_activity_defs(session_factory)
    except Exception:
        logger.exception("activity definition sync failed — continuing worker startup")

    # T23: Sync Temporal Schedules with the DB before workers start accepting tasks.
    logger.info("Syncing Temporal Schedules with ActivityDefinition DB...")
    try:
        await sync_schedules(client, db_url)
    except Exception:
        logger.exception("schedule sync failed — continuing worker startup")

    orchestrator_worker = Worker(
        client,
        task_queue=ORCHESTRATOR_TASK_QUEUE,
        workflows=[RunActivityWorkflow],
        activities=[load_activity_definition, resolve_context, log_run, evaluate_rules, emit_tasks],
    )

    task_worker = Worker(
        client,
        task_queue=TASK_EXECUTION_TASK_QUEUE,
        workflows=[TaskExecutorWorkflow],
        activities=[persist_task_instance],
    )

    loop = asyncio.get_running_loop()
    stop = asyncio.Event()
    loop.add_signal_handler(signal.SIGTERM, stop.set)
    loop.add_signal_handler(signal.SIGINT, stop.set)

    async with orchestrator_worker, task_worker:
        logger.info(
            "Workers running — queues: %r, %r (namespace=%r)",
            ORCHESTRATOR_TASK_QUEUE,
            TASK_EXECUTION_TASK_QUEUE,
            TEMPORAL_NAMESPACE,
        )
        await stop.wait()
        logger.info("Shutdown signal received — draining workers")
    logger.info("Workers stopped cleanly")


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    asyncio.run(run())