// app/lib/settings.server.ts
import { PrismaClient } from '@prisma/client';
import EventEmitter from 'events';

const prisma = new PrismaClient();

type JSONValue = any;

class SettingsService extends EventEmitter {
  private cache: Map<string, JSONValue> = new Map();
  private initialized = false;

  async init() {
    if (this.initialized) return;
    const rows = await prisma.appSetting.findMany();
    rows.forEach(r => {
      try {
        this.cache.set(r.key, JSON.parse(r.value));
      } catch (e) {
        // fall back to raw string if parse fails
        this.cache.set(r.key, r.value);
      }
    });
    this.initialized = true;
  }

  async get(key: string) {
    if (!this.initialized) await this.init();
    return this.cache.has(key) ? this.cache.get(key) : null;
  }

  async set(key: string, value: JSONValue, updatedBy?: string) {
    if (!this.initialized) await this.init();
    const valueStr = typeof value === 'string' ? value : JSON.stringify(value);
    await prisma.appSetting.upsert({
      where: { key },
      update: { value: valueStr, updatedBy },
      create: { key, value: valueStr, updatedBy },
    });
    this.cache.set(key, value);
    this.emit('update', { key, value });
    return { key, value };
  }

  subscribe(fn: (payload: { key: string; value: any }) => void) {
    this.on('update', fn);
    return () => this.off('update', fn);
  }
}

export const settingsService = new SettingsService();