"""Temporal client helpers for starting report generation workflows."""

from __future__ import annotations

import logging
from typing import Any

from app.config import settings
from app.workflows.models import ReportWorkflowRequest

logger = logging.getLogger(__name__)

_client: Any = None


async def get_temporal_client() -> Any:
    global _client
    if _client is not None:
        return _client
    try:
        from temporalio.client import Client
    except ImportError as exc:  # pragma: no cover
        raise RuntimeError("temporalio is not installed; pip install 'report-genius-ai[temporal]'") from exc

    _client = await Client.connect(
        settings.temporal_host,
        namespace=settings.temporal_namespace,
    )
    return _client


async def start_report_generation_workflow(request: ReportWorkflowRequest) -> str:
    """Start ``ReportGenerationWorkflow``; returns workflow id."""
    from app.workflows.report_workflow import ReportGenerationWorkflow

    client = await get_temporal_client()
    import uuid

    wf_id = f"report-gen-{request.report_id}-{uuid.uuid4().hex[:12]}"
    handle = await client.start_workflow(
        ReportGenerationWorkflow.run,
        request,
        id=wf_id,
        task_queue=settings.temporal_task_queue,
    )
    return str(handle.id)


async def try_start_report_generation_workflow(
    request: ReportWorkflowRequest,
) -> str | None:
    """Return Temporal workflow id when start succeeded, else ``None`` (caller uses in-process task)."""
    if not settings.enable_temporal_workflow:
        return None
    try:
        from app.workflows.report_activities import temporal_activities_enabled

        if not temporal_activities_enabled():
            logger.warning(
                "Temporal enabled but temporalio unavailable — falling back to in-process "
                "generation report=%s",
                request.report_id,
            )
            return None
        return await start_report_generation_workflow(request)
    except Exception:  # noqa: BLE001
        logger.exception(
            "Temporal workflow start failed report=%s — falling back to in-process task",
            request.report_id,
        )
        return None