"""
Analytics Specialist Agent Node
===============================
Generates data visualizations, computes statistical summary metrics,
and prepares structured chart JSON objects for frontend Recharts.
"""
from __future__ import annotations

import json
import structlog
from app.services.llm_gateway import llm_gateway
from agents.state import CopilotState

logger = structlog.get_logger(__name__)

ANALYTICS_SYSTEM_PROMPT = """You are an Analytics and Data Visualization Specialist AI.
Your job is to analyze the user's data or request and produce a structured chart configuration along with a narrative summary.

Return a JSON object with:
{
  "summary": "<Textual analysis and trend summary>",
  "chart": {
    "type": "<bar | line | pie>",
    "title": "<Chart Title>",
    "x_key": "<Category key name>",
    "y_keys": ["<Metric key name>"],
    "data": [
      {"<x_key>": "Jan", "<y_keys[0]>": 100},
      {"<x_key>": "Feb", "<y_keys[0]>": 150}
    ]
  }
}
"""


async def analytics_node(state: CopilotState) -> CopilotState:
    """
    Analytics Specialist Node.
    Analyzes trends and generates chart structure for frontend Recharts.
    """
    query = state.get("query", "")
    logger.info("Analytics Agent executing", query=query)

    try:
        response = await llm_gateway.generate(
            prompt=f"User Request: {query}\nProvide analytics summary & chart JSON:",
            system_prompt=ANALYTICS_SYSTEM_PROMPT,
            temperature=0.1,
        )

        content = response.content.strip()
        if content.startswith("```"):
            content = content.split("\n", 1)[-1].rsplit("```", 1)[0].strip()

        try:
            data = json.loads(content)
            summary = data.get("summary", content)
            chart = data.get("chart")
        except Exception:
            summary = content
            chart = None

        state["retrieved_chunks"] = [{
            "document_id": "analytics_report",
            "document_name": "Analytics Engine",
            "text": summary,
            "score": 1.0,
            "doc_type": "analytics"
        }]

        outputs = state.get("agent_outputs", [])
        outputs.append({
            "agent_name": "analytics",
            "content": summary,
            "metadata": {"chart": chart}
        })
        state["agent_outputs"] = outputs
        state["active_agent"] = "analytics"

    except Exception as e:
        logger.error("Analytics Agent error", error=str(e))
        state["error"] = f"Analytics Error: {str(e)}"
        state["retrieved_chunks"] = [{
            "document_name": "Analytics Error",
            "text": f"Could not perform analytics: {str(e)}"
        }]

    return state