"""FCE agent — "Behind Every Departure" (Flight Context Engine) passenger notification agent.

Connects to: shared + passenger MCP servers.
When a flight is disrupted, gathers all operational context and generates
an empathetic passenger notification.
"""

import asyncio
import json
import time
from datetime import datetime, timezone
from typing import Any

from agents.shared.mcp_client import MCPMultiClient


async def run_fce(
    flight_id: str,
    mcp: MCPMultiClient,
    on_event: Any = None,
) -> dict:
    """Run the FCE agent for a single flight.

    Args:
        flight_id: The flight to generate a notification for.
        mcp: Connected MCPMultiClient (shared + passenger).
        on_event: Optional async callback for real-time events.

    Returns:
        Notification result dict.
    """
    run_start = time.time()
    errors = []
    tool_calls = []

    async def emit(event_type: str, **data):
        event = {"type": event_type, "timestamp": datetime.now(timezone.utc).isoformat(), **data}
        tool_calls.append(event)
        if on_event:
            await on_event(event)

    # ── Node 1: Triage ──

    await emit("node_enter", node="triage")

    t0 = time.time()
    flight_status = await mcp.call_tool("shared", "get_flight_status", {"flight_id": flight_id})
    latency = int((time.time() - t0) * 1000)
    await emit("tool_call_end", tool="get_flight_status", latency_ms=latency, is_live=False)

    if isinstance(flight_status, dict) and "error" in flight_status:
        return {"error": flight_status["error"], "flight_id": flight_id}

    status = flight_status.get("status", "")
    delay_minutes = flight_status.get("delay_minutes", 0)
    should_notify = status in ("DELAYED", "CANCELLED", "DIVERTED") and delay_minutes >= 10

    await emit("node_exit", node="triage", result={"should_notify": should_notify})

    if not should_notify:
        return {
            "flight_id": flight_id,
            "type": "NO_NOTIFICATION",
            "reason": f"Status {status}, delay {delay_minutes}min — below threshold",
            "duration_ms": int((time.time() - run_start) * 1000),
        }

    # ── Node 2: Gather Context (parallel tool calls) ──

    await emit("node_enter", node="gather_context")

    origin = flight_status.get("origin", "")
    destination = flight_status.get("destination", "")

    async def _call(server, tool, args, is_live=False):
        t = time.time()
        try:
            result = await mcp.call_tool(server, tool, args)
            lat = int((time.time() - t) * 1000)
            await emit("tool_call_end", tool=tool, latency_ms=lat, is_live=is_live)
            return result
        except Exception as e:
            lat = int((time.time() - t) * 1000)
            await emit("tool_call_error", tool=tool, error=str(e), latency_ms=lat)
            errors.append(f"{tool}: {e}")
            return None

    # Fire all independent calls in parallel
    ops_data_task = asyncio.create_task(
        _call("shared", "get_flight_details", {"flight_id": flight_id})
    )
    weather_task = asyncio.create_task(
        _call("shared", "get_route_weather", {"origin": origin, "destination": destination}, is_live=True)
    )
    airport_status_task = asyncio.create_task(
        _call("shared", "get_airport_status", {"airport_code": origin}, is_live=True)
    )
    airport_congestion_task = asyncio.create_task(
        _call("shared", "get_airport_congestion", {"airport_code": origin}, is_live=True)
    )
    crew_notes_task = asyncio.create_task(
        _call("ops", "get_crew_notes", {"flight_id": flight_id})
    )

    ops_data, weather, airport_status, airport_congestion, crew_notes = await asyncio.gather(
        ops_data_task, weather_task, airport_status_task, airport_congestion_task, crew_notes_task
    )

    await emit("node_exit", node="gather_context")

    # ── Node 3: Synthesize ──

    await emit("node_enter", node="synthesize")

    # Build weather summary
    weather_summary = ""
    if weather and isinstance(weather, dict):
        events = weather.get("significant_events", [])
        if events:
            weather_summary = ", ".join(e.get("condition", "") for e in events)
        else:
            origin_wp = weather.get("waypoints", {}).get("origin", {})
            if isinstance(origin_wp, dict) and "weather" in origin_wp:
                weather_summary = origin_wp["weather"].get("condition", "")

    # Build crew notes summary
    crew_summary = ""
    if crew_notes and isinstance(crew_notes, list):
        # Take first 2 notes for the notification
        relevant = [n for n in crew_notes if not n.startswith("CANCELLED")][:2]
        crew_summary = " ".join(relevant)

    context = {
        "flight_id": flight_id,
        "origin": origin,
        "destination": destination,
        "status": status,
        "delay_minutes": delay_minutes,
        "delay_cause": flight_status.get("delay_cause")
        or (ops_data.get("delay_cause") if isinstance(ops_data, dict) else None),
        "gate": flight_status.get("gate", ""),
        "weather_summary": weather_summary,
        "crew_notes_summary": crew_summary,
        "get_airport_status": airport_status,
        "get_airport_congestion": airport_congestion,
    }

    t0 = time.time()
    notification_text = await mcp.call_tool("passenger", "generate_notification", {"context": context})
    latency = int((time.time() - t0) * 1000)
    await emit("tool_call_end", tool="generate_notification", latency_ms=latency, is_live=False)

    await emit("node_exit", node="synthesize")

    # ── Node 4: Format Output ──

    await emit("node_enter", node="format_output")

    data_sources = ["flight_ops"]
    if weather:
        data_sources.append("weather_live")
    if airport_status:
        data_sources.append("faa_status_live")
    if crew_notes:
        data_sources.append("get_crew_notes")

    notification = {
        "flight_id": flight_id,
        "type": "DELAY_NOTIFICATION" if status == "DELAYED" else f"{status}_NOTIFICATION",
        "status": status,
        "delay_minutes": delay_minutes,
        "notification_text": notification_text if isinstance(notification_text, str) else str(notification_text),
        "generated_at": datetime.now(timezone.utc).isoformat(),
        "data_sources": data_sources,
        "human_approved": True,  # auto-approve in demo
        "errors": errors,
        "duration_ms": int((time.time() - run_start) * 1000),
    }

    await emit("node_exit", node="format_output")
    await emit("agent_end", output_summary=f"{status} notification for {flight_id}")

    return notification