import { useMemo } from 'react';
import { useWebSocket } from './useWebSocket';
import type { Agent, Share, FleetAlert, PoolStatus, AIActivityEntry } from '../types';

/**
 * Selector hooks reduce re-renders by only returning the specific slice of WS data.
 * Components that only need agents won't re-render when shares/alerts update.
 */

export function useAgents(): Agent[] {
  const ctx = useWebSocket();
  return useMemo(() => ctx.agents || [], [ctx.agents]);
}

export function useRecentShares(): Share[] {
  const ctx = useWebSocket();
  return useMemo(() => ctx.recentShares || [], [ctx.recentShares]);
}

export function useFleetAlerts(): FleetAlert[] {
  const ctx = useWebSocket();
  return useMemo(() => ctx.fleetAlerts || [], [ctx.fleetAlerts]);
}

export function usePoolStatus(): PoolStatus[] {
  const ctx = useWebSocket();
  return useMemo(() => ctx.poolStatus || [], [ctx.poolStatus]);
}

export function useAIActivity(): AIActivityEntry[] {
  const ctx = useWebSocket();
  return useMemo(() => ctx.aiActivity || [], [ctx.aiActivity]);
}

export function useAgentLogs(): Record<string, string> {
  const ctx = useWebSocket();
  return useMemo(() => ctx.agentLogs || {}, [ctx.agentLogs]);
}

export function useCommandResults() {
  const ctx = useWebSocket();
  return useMemo(() => ctx.commandResults || [], [ctx.commandResults]);
}

export function usePolicyAcks() {
  const ctx = useWebSocket();
  return useMemo(() => ctx.policyAcks || [], [ctx.policyAcks]);
}

export function useConnectionStatus(): boolean {
  const ctx = useWebSocket();
  return ctx.isConnected;
}

export function useSendDashboardMessage() {
  const ctx = useWebSocket();
  return ctx.sendDashboardMessage;
}

/**
 * Selector for a single agent by ID.
 * Re-renders only when that specific agent changes.
 */
export function useAgent(agentId: string): Agent | undefined {
  const agents = useAgents();
  return useMemo(() => agents.find((a) => a.id === agentId), [agents, agentId]);
}