"""
Podcast generation tool for the SurfSense agent.

This module provides a factory function for creating the generate_podcast tool
that submits a Celery task for background podcast generation. The frontend
polls for completion and auto-updates when the podcast is ready.
"""

from typing import Any

from langchain_core.tools import tool
from sqlalchemy.ext.asyncio import AsyncSession

from app.db import Podcast, PodcastStatus, shielded_async_session


def create_generate_podcast_tool(
    search_space_id: int,
    db_session: AsyncSession,
    thread_id: int | None = None,
):
    """
    Factory function to create the generate_podcast tool with injected dependencies.

    Pre-creates podcast record with pending status so podcast_id is available
    immediately for frontend polling.

    Args:
        search_space_id: The user's search space ID
        db_session: Reserved for future read-side use; the row is written via a
            fresh, tool-local session so parallel tool calls (e.g. podcast +
            video presentation in the same agent step) don't share an
            ``AsyncSession`` (which is not concurrency-safe).
        thread_id: The chat thread ID for associating the podcast

    Returns:
        A configured tool function for generating podcasts
    """
    del db_session  # writes use a fresh tool-local session, see below

    @tool
    async def generate_podcast(
        source_content: str,
        podcast_title: str = "SurfSense Podcast",
        user_prompt: str | None = None,
    ) -> dict[str, Any]:
        """
        Generate a podcast from the provided content.

        Use this tool when the user asks to create, generate, or make a podcast.
        Common triggers include phrases like:
        - "Give me a podcast about this"
        - "Create a podcast from this conversation"
        - "Generate a podcast summary"
        - "Make a podcast about..."
        - "Turn this into a podcast"

        Args:
            source_content: The text content to convert into a podcast.
            podcast_title: Title for the podcast (default: "SurfSense Podcast")
            user_prompt: Optional instructions for podcast style, tone, or format.

        Returns:
            A dictionary containing:
            - status: PodcastStatus value (pending, generating, or failed)
            - podcast_id: The podcast ID for polling (when status is pending or generating)
            - title: The podcast title
            - message: Status message (or "error" field if status is failed)
        """
        try:
            # Open a fresh session per call. The streaming task's session is
            # shared between every tool, and ``AsyncSession`` is NOT safe for
            # concurrent use: when the LLM emits parallel tool calls, two
            # concurrent ``add()`` / ``commit()`` paths interleave and the
            # second one hits "Session.add() during flush" → the transaction
            # is poisoned for both tools.
            async with shielded_async_session() as session:
                podcast = Podcast(
                    title=podcast_title,
                    status=PodcastStatus.PENDING,
                    search_space_id=search_space_id,
                    thread_id=thread_id,
                )
                session.add(podcast)
                await session.commit()
                await session.refresh(podcast)
                podcast_id = podcast.id

            from app.tasks.celery_tasks.podcast_tasks import (
                generate_content_podcast_task,
            )

            task = generate_content_podcast_task.delay(
                podcast_id=podcast_id,
                source_content=source_content,
                search_space_id=search_space_id,
                user_prompt=user_prompt,
            )

            print(f"[generate_podcast] Created podcast {podcast_id}, task: {task.id}")

            return {
                "status": PodcastStatus.PENDING.value,
                "podcast_id": podcast_id,
                "title": podcast_title,
                "message": "Podcast generation started. This may take a few minutes.",
            }

        except Exception as e:
            error_message = str(e)
            print(f"[generate_podcast] Error: {error_message}")
            return {
                "status": PodcastStatus.FAILED.value,
                "error": error_message,
                "title": podcast_title,
                "podcast_id": None,
            }

    return generate_podcast