import * as fs from 'fs';
import * as path from 'path';
import { Injectable } from '@nestjs/common';
import type { EmailSettingsVo } from './email-settings.dto';

const SETTINGS_DIR = path.resolve(process.cwd(), 'config', 'runtime');
const SETTINGS_FILE = path.resolve(SETTINGS_DIR, 'email.settings.json');

const DEFAULT_SETTINGS: EmailSettingsVo = {
  enabled: false,
  host: '',
  port: 465,
  secure: true,
  user: '',
  pass: '',
  from: '',
};

@Injectable()
export class EmailSettingsService {
  async getSettings(): Promise<EmailSettingsVo> {
    try {
      const buf = await fs.promises.readFile(SETTINGS_FILE, 'utf8');
      const json = JSON.parse(buf);
      return { ...DEFAULT_SETTINGS, ...json };
    } catch {
      return { ...DEFAULT_SETTINGS };
    }
  }

  async updateSettings(patch: Partial<EmailSettingsVo>): Promise<EmailSettingsVo> {
    const current = await this.getSettings();
    const next: EmailSettingsVo = { ...current, ...patch };
    await fs.promises.mkdir(SETTINGS_DIR, { recursive: true });
    await fs.promises.writeFile(SETTINGS_FILE, JSON.stringify(next, null, 2), 'utf8');
    return next;
  }

  static getSettingsPath() {
    return SETTINGS_FILE;
  }
}