import MessageBus from 'src/sdk/MessageBus';

export default abstract class AbstractService {

  protected static readonly messageBus: MessageBus = MessageBus.getInstance();

  private static readonly CACHE_TTL = 60 * 60 * 1000; // 60 minutes cache TTL

  protected constructor() { }

  protected static setItem(key: string, processId: string, process: any): void {
    const cache: Record<string, {process: any, timestamp: number}> = 
      JSON.parse(sessionStorage.getItem(key) || '{}');
    
    cache[processId] = {
      process: process, // we overwrite existing process
      timestamp: Date.now()
    };
    
    sessionStorage.setItem(key, JSON.stringify(cache));
  }

  protected static getItem(key: string, processId: string): any | null {
    const cache: Record<string, {process: any, timestamp: number}> = 
      JSON.parse(sessionStorage.getItem(key) || '{}');
    
    const item = cache[processId];
    if (!item) {
      return null;
    }

    const now: number = Date.now();
    if ((now - item.timestamp) < this.CACHE_TTL) {
      return { process: item.process, timestamp: item.timestamp };
    }

    return null;
  }

  protected static getItems(key: string): Record<string, any> {
    const cache: Record<string, {process: any, timestamp: number}> = 
      JSON.parse(sessionStorage.getItem(key) || '{}');
    const now: number = Date.now();

    const validItems: Record<string, any> = {};
    for (const [processId, item] of Object.entries(cache)) {
      if (now - item.timestamp < this.CACHE_TTL) {
        validItems[processId] = item.process;
      }
    }

    return validItems;
  }

  protected static removeItem(key: string, processId: string): void {
    const cache: Record<string, {process: any, timestamp: number}> = 
      JSON.parse(sessionStorage.getItem(key) || '{}');

    delete cache[processId];

    sessionStorage.setItem(key, JSON.stringify(cache));
  }
}