import { Inject, Injectable } from "@nestjs/common";
import { PrismaService } from "../prisma/prisma.service.js";
import { PushTokenService } from "./push-token.service.js";
import { PUSH_PROVIDER, type PushProvider } from "./push-provider.js";

export interface SendToUserResult {
  attempted: number;
  succeeded: number;
}

// Q-3 推播通知：提醒觸發（J 群組）、角色主動訊息、鎖屏通知都走這個服務——同一個使用者可能有
// 多台裝置，逐一送出並各自留一筆記錄（成功或失敗皆記），方便之後追查「提醒有沒有真的送達」。
@Injectable()
export class PushNotificationService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly pushToken: PushTokenService,
    @Inject(PUSH_PROVIDER) private readonly provider: PushProvider,
  ) {}

  async sendToUser(userId: string, title: string, body: string, data?: Record<string, unknown>): Promise<SendToUserResult> {
    const tokens = await this.pushToken.listForUser(userId);
    let succeeded = 0;
    for (const { token } of tokens) {
      const result = await this.provider.send({ token, title, body, data });
      await this.prisma.client.pushNotificationLog.create({
        data: { userId, title, body, success: result.success, errorText: result.errorText },
      });
      if (result.success) {
        succeeded += 1;
      }
    }
    return { attempted: tokens.length, succeeded };
  }
}