import logManager from '@electron/service/logger';
import type { GatewayLifecycleState } from './process-policy';

export interface GatewayRuntimeStatus {
  state: GatewayLifecycleState;
  port: number | null;
  pid?: number;
  uptime?: number;
  error?: string;
  connectedAt?: number;
  reconnectAttempts?: number;
  gatewayReady?: boolean;
}

type GatewayStateHooks = {
  emitStatus: (status: GatewayRuntimeStatus) => void;
  onTransition?: (
    previousState: GatewayRuntimeStatus['state'],
    nextState: GatewayRuntimeStatus['state'],
  ) => void;
};

export class GatewayStateController {
  private status: GatewayRuntimeStatus = { state: 'stopped', port: null };

  constructor(private readonly hooks: GatewayStateHooks) {}

  getStatus(): GatewayRuntimeStatus {
    const snapshot = { ...this.status };
    if (snapshot.state === 'running' && snapshot.connectedAt) {
      snapshot.uptime = Date.now() - snapshot.connectedAt;
    }
    return snapshot;
  }

  isConnected(isSocketOpen: boolean): boolean {
    return this.status.state === 'running' && isSocketOpen;
  }

  setStatus(update: Partial<GatewayRuntimeStatus>): void {
    const previousState = this.status.state;
    this.status = { ...this.status, ...update };

    if (this.status.state === 'running' && this.status.connectedAt) {
      this.status.uptime = Date.now() - this.status.connectedAt;
    } else if (this.status.state !== 'running') {
      this.status.uptime = undefined;
    }

    this.hooks.emitStatus(this.status);

    if (previousState !== this.status.state) {
      logManager.debug(`Gateway state changed: ${previousState} -> ${this.status.state}`);
      this.hooks.onTransition?.(previousState, this.status.state);
    }
  }
}