"""Task agent — create, update, list, and suggest tasks."""

from __future__ import annotations

import json
from typing import Any

from langchain_core.messages import HumanMessage, SystemMessage
from langchain_core.tools import tool
from langchain_openai import ChatOpenAI

from app.config.settings import settings
from app.core.agent_registry import ChatAgent, registry

_SYSTEM_PROMPT = (
    "You are a task management assistant (PM-oriented). Help the user create, "
    "update, list, and suggest tasks.\n"
    "Rules:\n"
    "  - priority must be one of: low, medium, high, urgent\n"
    "  - infer priority from context clues (deadlines, urgency language, dependencies)\n"
    "  - due_date as ISO 8601 string when provided\n"
    "  - context fields beyond user_profile are optional; use them when present\n"
    "Use the available tools to act, then confirm what was done in plain language."
)


@tool
async def create_task(
    title: str,
    description: str = "",
    priority: str = "medium",
    due_date: str = "",
) -> str:
    """Create a new task. priority: low | medium | high | urgent. due_date: ISO 8601."""
    return json.dumps({
        "action": "create_record",
        "table": "tasks",
        "data": {
            "title": title,
            "description": description,
            "priority": priority,
            "due_date": due_date,
        },
    })


@tool
async def update_task(task_id: str, updates: str) -> str:
    """Update fields on an existing task. Pass updates as a JSON string, e.g. '{"priority":"high"}'."""
    return json.dumps({
        "action": "update_record",
        "table": "tasks",
        "data": {"id": task_id, "updates": updates},
    })


@tool
async def list_tasks(status: str = "", priority: str = "") -> str:
    """List tasks. Optionally filter by status (open|done|archived) or priority level."""
    return json.dumps({
        "action": "list",
        "table": "tasks",
        "filters": {"status": status, "priority": priority},
    })


@tool
async def suggest_tasks(context: str) -> str:
    """Suggest new tasks based on notes or free-form context text."""
    return json.dumps({
        "action": "suggest",
        "table": "tasks",
        "context": context,
    })


@registry.register
class TaskAgent(ChatAgent):
    def get_name(self) -> str:
        return "task_agent"

    def get_description(self) -> str:
        return "Manages tasks: create, update, list, suggest"

    def get_tools(self) -> list[Any]:
        return [create_task, update_task, list_tasks, suggest_tasks]

    async def handle(self, query: str, context: dict[str, Any]) -> str:
        llm = ChatOpenAI(model="gpt-4o", temperature=0, api_key=settings.OPENAI_API_KEY)
        messages = [
            SystemMessage(content=_SYSTEM_PROMPT),
            HumanMessage(
                content=f"User query: {query}\nContext: {json.dumps(context)[:1000]}"
            ),
        ]
        return await self._tool_loop(llm, messages, self.get_tools())