import {
  Controller,
  Get,
  Post,
  Patch,
  Body,
  Param,
  Query,
  UseGuards,
  Request,
} from '@nestjs/common';
import { AuthGuard } from '@nestjs/passport';
import { ApiTags, ApiOperation, ApiBearerAuth } from '@nestjs/swagger';
import { BillingService } from './billing.service';
import { BillingOpsService } from './billing-ops.service';
import { assertStubGatewayAllowed } from './payment-gateway.util';
import {
  ChargeWalletDto,
  InitiateInvoicePaymentDto,
  VerifyInvoiceGatewayDto,
  UpdateInvoiceStatusDto,
} from './dto/billing.dto';
import { RolesGuard } from '../common/guards/roles.guard';
import { Roles } from '../common/decorators/roles.decorator';
import { UserRole, InvoiceStatus, PaymentMethod } from '../common/enums';

@ApiTags('Billing')
@ApiBearerAuth()
@Controller('billing')
@UseGuards(AuthGuard('jwt'), RolesGuard)
export class BillingInvoicesController {
  constructor(
    private readonly billingService: BillingService,
    private readonly billingOpsService: BillingOpsService,
  ) {}

  // ─── Invoices ─────────────────────────────────────────────────────

  @Get('invoices')
  @ApiOperation({ summary: 'List my invoices' })
  async listMyInvoices(
    @Request() req: any,
    @Query('status') status?: InvoiceStatus,
    @Query('applicationId') applicationId?: string,
    @Query('limit') limit?: string,
  ) {
    return this.billingService.listInvoices(req.user, {
      status,
      applicationId,
      limit: limit ? parseInt(limit, 10) : undefined,
    });
  }

  @Get('invoices/:id')
  @ApiOperation({ summary: 'Get one invoice with line items and transactions' })
  async getInvoice(@Request() req: any, @Param('id') id: string) {
    return this.billingService.getInvoiceForUser(id, req.user);
  }

  @Post('invoices/:id/pay/mixed')
  @ApiOperation({ summary: 'Pay invoice with wallet first, then gateway for the remaining amount' })
  async initiateInvoiceMixed(
    @Request() req: any,
    @Param('id') id: string,
    @Body() dto: InitiateInvoicePaymentDto,
  ) {
    const result = await this.billingService.initiateInvoiceMixedPayment(id, req.user, dto.callbackUrl);
    const effect = await this.billingOpsService.completePaidInvoiceEffect(result.invoice);
    return { ...result, effect };
  }

  @Post('invoices/:id/gateway/verify')
  @ApiOperation({ summary: 'Verify invoice gateway payment' })
  async verifyInvoiceGateway(
    @Request() req: any,
    @Param('id') id: string,
    @Body() dto: VerifyInvoiceGatewayDto,
  ) {
    assertStubGatewayAllowed();
    const result = await this.billingService.verifyInvoiceGatewayPayment(
      id,
      req.user,
      dto.trackingCode,
      dto.amount,
    );
    const effect = await this.billingOpsService.completePaidInvoiceEffect(result.invoice);
    return { ...result, effect };
  }

  // ─── Invoice Admin ────────────────────────────────────────────────

  @Get('admin/invoices')
  @Roles(UserRole.ADMIN)
  @ApiOperation({ summary: 'List all invoices (Admin)' })
  async listAdminInvoices(
    @Request() req: any,
    @Query('status') status?: InvoiceStatus,
    @Query('userId') userId?: string,
    @Query('applicationId') applicationId?: string,
    @Query('paymentMethod') paymentMethod?: PaymentMethod,
    @Query('search') search?: string,
    @Query('limit') limit?: string,
  ) {
    return this.billingService.listInvoices(req.user, {
      status,
      userId,
      applicationId,
      paymentMethod,
      search,
      limit: limit ? parseInt(limit, 10) : undefined,
    });
  }

  @Get('admin/invoices/:id')
  @Roles(UserRole.ADMIN)
  @ApiOperation({ summary: 'Get invoice details (Admin)' })
  async getAdminInvoice(@Request() req: any, @Param('id') id: string) {
    return this.billingService.getInvoiceForUser(id, req.user);
  }

  @Patch('admin/invoices/:id/status')
  @Roles(UserRole.ADMIN)
  @ApiOperation({ summary: 'Update invoice status with reason (Admin)' })
  async updateAdminInvoiceStatus(
    @Param('id') id: string,
    @Body() dto: UpdateInvoiceStatusDto,
  ) {
    return this.billingService.updateInvoiceStatus(id, dto.status, dto.reason);
  }

  // ─── Wallet Admin ─────────────────────────────────────────────────

  @Get('admin/wallets')
  @Roles(UserRole.ADMIN)
  @ApiOperation({ summary: 'List all wallets (Admin)' })
  async getAllWallets() {
    return this.billingService.getAllWallets();
  }

  @Post('admin/wallets/:userId/charge')
  @Roles(UserRole.ADMIN)
  @ApiOperation({ summary: 'Charge a user\'s wallet (Admin)' })
  async adminChargeWallet(
    @Param('userId') userId: string,
    @Body() dto: ChargeWalletDto,
  ) {
    return this.billingService.adminChargeWallet(userId, dto.amount, dto.description);
  }
}