import { Injectable } from "@nestjs/common";
import { Prisma } from "@prisma/client";
import { EncryptionService } from "./encryption.service";

type EncryptedRawPayload = {
  encrypted: true;
  version: 1;
  ciphertext: string;
};

@Injectable()
export class RawPayloadEncryptionService {
  constructor(private readonly encryption: EncryptionService) {}

  encrypt(payload: unknown): Prisma.InputJsonValue {
    return {
      encrypted: true,
      version: 1,
      ciphertext: this.encryption.encrypt(JSON.stringify(payload ?? null)),
    } satisfies EncryptedRawPayload as unknown as Prisma.InputJsonValue;
  }

  decrypt<T = unknown>(payload: unknown): T {
    if (!this.isEncryptedPayload(payload)) return payload as T;
    return JSON.parse(this.encryption.decrypt(payload.ciphertext)) as T;
  }

  private isEncryptedPayload(payload: unknown): payload is EncryptedRawPayload {
    return Boolean(
      payload &&
      typeof payload === "object" &&
      (payload as { encrypted?: unknown }).encrypted === true &&
      (payload as { version?: unknown }).version === 1 &&
      typeof (payload as { ciphertext?: unknown }).ciphertext === "string",
    );
  }
}