"""AI Agent configuration for the Todo Chatbot.

Uses OpenAI Agents SDK with Gemini 2.0 Flash via OpenAI-compatible endpoint.
"""

from typing import List, Dict, Any, Optional
from uuid import UUID

from ..config import settings
from .prompts import SYSTEM_PROMPT


# Lazy initialization - only create when needed
_todo_agent = None


def get_todo_agent():
    """Get or create the Todo Agent (lazy initialization)."""
    global _todo_agent
    if _todo_agent is None:
        from openai import AsyncOpenAI
        from agents import Agent, OpenAIChatCompletionsModel
        from .tools import add_task, list_tasks, complete_task, update_task, delete_task

        if not settings.GEMINI_API_KEY:
            raise ValueError("GEMINI_API_KEY environment variable is required")

        client = AsyncOpenAI(
            api_key=settings.GEMINI_API_KEY,
            base_url=settings.GEMINI_API_ENDPOINT
        )

        model = OpenAIChatCompletionsModel(
            model=settings.GEMINI_MODEL,
            openai_client=client
        )

        _todo_agent = Agent(
            name="TodoAssistant",
            instructions=SYSTEM_PROMPT,
            model=model,
            tools=[
                add_task,
                list_tasks,
                complete_task,
                update_task,
                delete_task,
            ]
        )

    return _todo_agent


# For backwards compatibility
todo_agent = None  # Will be initialized lazily


async def run_agent(
    user_id: UUID,
    message: str,
    conversation_history: Optional[List[Dict[str, str]]] = None
) -> Dict[str, Any]:
    """
    Run the agent with a user message.

    Args:
        user_id: The authenticated user's UUID
        message: The user's input message
        conversation_history: Optional list of previous messages for context

    Returns:
        Dictionary with response and any tool calls made
    """
    from openai import AsyncOpenAI
    from agents import Agent, Runner, OpenAIChatCompletionsModel
    from .tools import add_task, list_tasks, complete_task, update_task, delete_task

    # Build input messages with context
    messages = []

    # Add conversation history if provided (limited to max context)
    if conversation_history:
        # Take only the last N messages as per config
        recent_history = conversation_history[-settings.AGENT_MAX_CONTEXT_MESSAGES:]
        messages.extend(recent_history)

    # Add the current user message
    messages.append({
        "role": "user",
        "content": message
    })

    # Check for API key
    if not settings.GEMINI_API_KEY:
        return {
            "response": "AI assistant is not configured. Please set GEMINI_API_KEY.",
            "tool_calls": [],
            "status": "error",
            "error": "GEMINI_API_KEY not configured"
        }

    try:
        # Create client for this request
        client = AsyncOpenAI(
            api_key=settings.GEMINI_API_KEY,
            base_url=settings.GEMINI_API_ENDPOINT
        )

        model = OpenAIChatCompletionsModel(
            model=settings.GEMINI_MODEL,
            openai_client=client
        )

        # Inject user_id into the context so tools can access it
        user_context = f"\n\nCurrent user_id: {str(user_id)}"
        agent_with_context = Agent(
            name="TodoAssistant",
            instructions=SYSTEM_PROMPT + user_context,
            model=model,
            tools=[
                add_task,
                list_tasks,
                complete_task,
                update_task,
                delete_task,
            ]
        )

        # Run the agent using Runner
        result = await Runner.run(
            agent_with_context,
            messages,
            context={"user_id": str(user_id)}
        )

        # Extract tool calls if any
        tool_calls = []
        if hasattr(result, 'tool_calls') and result.tool_calls:
            for tool_call in result.tool_calls:
                tool_calls.append({
                    "tool": tool_call.name,
                    "result": tool_call.result if hasattr(tool_call, 'result') else {}
                })

        return {
            "response": result.final_output if hasattr(result, 'final_output') else str(result),
            "tool_calls": tool_calls,
            "status": "success"
        }

    except Exception as e:
        return {
            "response": f"I encountered an error: {str(e)}. Please try again.",
            "tool_calls": [],
            "status": "error",
            "error": str(e)
        }