from typing import List, Dict, Tuple
import os
from datetime import datetime, timezone
import requests

from .oob_tools.utils import load_json, save_json


# You can override this in HF Space secrets or env.
NCS_BASE_URL = os.getenv(
    "NCS_BASE_URL",
    "https://MCP-1st-Birthday-network-change-simulator.hf.space",
)
HISTORY_PATH = os.path.join(
    os.path.dirname(__file__), "..", "infra", "mcp_history.json"
)


def _timestamp() -> str:
    return datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")


def _record_history(device: str, preset: str, risk: Dict):
    history = load_json(HISTORY_PATH) or {"recent": []}
    recent = history.get("recent", [])
    entry = {
        "timestamp": _timestamp(),
        "device": device,
        "preset": preset,
        "risk": risk.get("level"),
        "score": risk.get("score"),
    }
    recent.append(entry)
    # Keep history short to avoid bloat.
    history["recent"] = recent[-50:]
    save_json(HISTORY_PATH, history)


def _simulate_single_step(step: Dict) -> Tuple[Dict, Dict]:
    """
    Call the Network Change Simulator MCP-style HTTP endpoint for one step.

    Expects step["json"] to have:
      - "change_type": "vlan" | "interface" | "bgp_neighbor"
      - "preset_id": one of the known presets
      - optional "mode": "lightning" | "full"
    """

    payload = {
        "change_type": step["json"]["change_type"],
        "preset_id": step["json"]["preset_id"],
        "mode": step["json"].get("mode", "lightning"),
    }

    url = f"{NCS_BASE_URL.rstrip('/')}/mcp/simulate"

    try:
        resp = requests.post(url, json=payload, timeout=10)
        resp.raise_for_status()
    except Exception as exc:  # broad on purpose to keep UI resilient
        # Fall back to a degraded but non-crashing experience.
        fake = {
            "risk_score": 50,
            "risk_level": "medium",
            "pre_check_summary": ["Stubbed due to MCP call failure."],
            "post_check_summary": [],
            "blast_radius_summary": "MCP call failed; using placeholder blast radius.",
            "explanation": f"Error calling MCP server: {exc}",
            "mode": payload["mode"],
            "mode_note": "Simulated response because remote MCP call failed.",
        }
        tool_call = {
            "tool": "simulate_network_change",
            "arguments": payload,
            "response": fake,
            "error": str(exc),
        }
        risk = {
            "level": fake["risk_level"],
            "score": fake["risk_score"],
            "summary": fake["explanation"],
        }
        return risk, tool_call

    data = resp.json()

    # Normalize risk structure for pipeline.
    risk = {
        "level": data.get("risk_level", "unknown"),
        "score": data.get("risk_score", 0),
        "summary": data.get("explanation", ""),
        "blast_radius_summary": data.get("blast_radius_summary", ""),
        "pre_check_summary": data.get("pre_check_summary", []),
        "post_check_summary": data.get("post_check_summary", []),
        "mode": data.get("mode"),
        "mode_note": data.get("mode_note"),
    }

    tool_call = {
        "tool": "simulate_network_change",
        "arguments": payload,
        "response": data,
    }

    return risk, tool_call


def simulate_steps_with_mcp(steps: List[Dict]) -> Tuple[List[Dict], List[Dict]]:
    """
    For each step, call the Network Change Simulator MCP server.

    Returns:
      step_risks: list[dict]
      tool_calls: list[dict]  # for logging
    """
    step_risks: List[Dict] = []
    tool_calls: List[Dict] = []

    for step in steps:
        risk, call = _simulate_single_step(step)
        step_risks.append(risk)
        tool_calls.append(call)
        # Persist history for downstream root-cause inference.
        _record_history(
            device=step["json"].get("device", "unknown"),
            preset=step["json"].get("preset_id", "unknown"),
            risk=risk,
        )

    return step_risks, tool_calls