import {
  Body,
  Controller,
  HttpCode,
  HttpStatus,
  Post,
  UseFilters,
  UseGuards,
} from "@nestjs/common";
import { ApiOperation, ApiTags } from "@nestjs/swagger";
import { CbeAuthGuard } from "./cbe-auth.guard";
import { CbeExceptionFilter } from "./cbe-exception.filter";
import { CbeBillService } from "./cbe-bill.service";
import { TokenRequestDto } from "./dto/token-request.dto";
import { TokenResponseDto } from "./dto/token-response.dto";
import { CbeQueryRequestDto } from "./dto/cbe-query-request.dto";
import { CbeQueryResponseDto } from "./dto/cbe-query-response.dto";
import { CbePaymentRequestDto } from "./dto/cbe-payment-request.dto";
import { CbePaymentResponseDto } from "./dto/cbe-payment-response.dto";

/**
 * CBE Unified Bill Payment — the INBOUND surface CBE core banking calls (docs/cbe/). We are
 * the biller: CBE authenticates against /cbe/oauth/token with credentials we issued, then
 * presents the bearer token on /cbe/query and /cbe/payment. Business failures answer HTTP 200
 * with Response_Code "2"; only authentication answers 401 (plan D6/D7).
 */
@ApiTags("CBE Unified Bill (inbound)")
@Controller("cbe")
@UseFilters(CbeExceptionFilter)
export class CbeBillController {
  constructor(private readonly cbeBillService: CbeBillService) {}

  @Post("oauth/token")
  @HttpCode(HttpStatus.OK)
  @ApiOperation({ summary: "OAuth client_credentials token for CBE (we are the auth server)" })
  async token(@Body() dto: TokenRequestDto): Promise<TokenResponseDto> {
    return this.cbeBillService.generateToken(dto);
  }

  @Post("query")
  @HttpCode(HttpStatus.OK)
  @UseGuards(CbeAuthGuard)
  @ApiOperation({ summary: "Bill lookup — amount due + payer name for a Bill_Id" })
  async query(@Body() dto: CbeQueryRequestDto): Promise<CbeQueryResponseDto> {
    return this.cbeBillService.query(dto);
  }

  @Post("payment")
  @HttpCode(HttpStatus.OK)
  @UseGuards(CbeAuthGuard)
  @ApiOperation({ summary: "Settle a bill — customer already debited by CBE" })
  async payment(
    @Body() dto: CbePaymentRequestDto,
  ): Promise<CbePaymentResponseDto> {
    return this.cbeBillService.pay(dto);
  }
}