import { Test, TestingModule } from '@nestjs/testing';
import { getDataSourceToken } from '@nestjs/typeorm';
import { DatabaseMigrationsService } from './database-migrations.service';

function createRunner(columns: string[]) {
  return {
    connect: jest.fn(),
    release: jest.fn(),
    query: jest.fn().mockResolvedValue([]),
    getTables: jest.fn().mockResolvedValue(columns.length ? [{ name: 'deposits' }] : []),
    getTable: jest.fn().mockResolvedValue({
      name: 'deposits',
      columns: columns.map((name) => ({ name })),
    }),
    renameColumn: jest.fn().mockResolvedValue(undefined),
    dropColumn: jest.fn().mockResolvedValue(undefined),
  };
}

async function createService(runner: ReturnType<typeof createRunner>) {
  const module: TestingModule = await Test.createTestingModule({
    providers: [
      DatabaseMigrationsService,
      {
        provide: getDataSourceToken(),
        useValue: {
          options: { type: 'better-sqlite3' },
          createQueryRunner: jest.fn().mockReturnValue(runner),
        },
      },
    ],
  }).compile();
  return module.get(DatabaseMigrationsService) as DatabaseMigrationsService & {
    cleanupDepositRefundColumns(): Promise<void>;
  };
}

describe('DatabaseMigrationsService — deposit refund cleanup', () => {
  it('renames refund audit fields and drops approval-flow remnants', async () => {
    const runner = createRunner([
      'id',
      'refund_status',
      'refund_requested_at',
      'refund_approved_by',
      'refund_approved_at',
      'refund_rejected_reason',
    ]);
    const service = await createService(runner);

    await service.cleanupDepositRefundColumns();

    expect(runner.renameColumn).toHaveBeenCalledWith(
      'deposits',
      'refund_approved_by',
      'refunded_by',
    );
    expect(runner.renameColumn).toHaveBeenCalledWith(
      'deposits',
      'refund_approved_at',
      'refunded_at',
    );
    expect(runner.dropColumn).toHaveBeenCalledWith('deposits', 'refund_status');
    expect(runner.dropColumn).toHaveBeenCalledWith('deposits', 'refund_requested_at');
    expect(runner.dropColumn).toHaveBeenCalledWith('deposits', 'refund_rejected_reason');
    expect(runner.release).toHaveBeenCalled();
  });

  it('merges legacy audit values before dropping duplicate legacy columns', async () => {
    const runner = createRunner([
      'id',
      'refund_approved_by',
      'refund_approved_at',
      'refunded_by',
      'refunded_at',
    ]);
    const service = await createService(runner);

    await service.cleanupDepositRefundColumns();

    expect(runner.query).toHaveBeenCalledWith(
      'UPDATE deposits SET refunded_by = COALESCE(refunded_by, refund_approved_by)',
    );
    expect(runner.query).toHaveBeenCalledWith(
      'UPDATE deposits SET refunded_at = COALESCE(refunded_at, refund_approved_at)',
    );
    expect(runner.dropColumn).toHaveBeenCalledWith('deposits', 'refund_approved_by');
    expect(runner.dropColumn).toHaveBeenCalledWith('deposits', 'refund_approved_at');
    expect(runner.renameColumn).not.toHaveBeenCalled();
  });

  it('does nothing when the deposits table is absent', async () => {
    const runner = createRunner([]);
    const service = await createService(runner);

    await service.cleanupDepositRefundColumns();

    expect(runner.renameColumn).not.toHaveBeenCalled();
    expect(runner.dropColumn).not.toHaveBeenCalled();
    expect(runner.release).toHaveBeenCalled();
  });
});