import { describe, it, expect } from 'vitest';
import { AnalyticsDashboardViewDataBuilder } from './AnalyticsDashboardViewDataBuilder';
import type { GetDashboardDataOutputDTO } from '@/lib/types/generated/GetDashboardDataOutputDTO';

describe('AnalyticsDashboardViewDataBuilder', () => {
  it('builds ViewData from GetDashboardDataOutputDTO', () => {
    const inputDto: GetDashboardDataOutputDTO = {
      totalUsers: 100,
      activeUsers: 40,
      totalRaces: 10,
      totalLeagues: 5,
    };

    const viewData = AnalyticsDashboardViewDataBuilder.build(inputDto);

    expect(viewData.metrics.totalUsers).toBe(100);
    expect(viewData.metrics.activeUsers).toBe(40);
    expect(viewData.metrics.totalRaces).toBe(10);
    expect(viewData.metrics.totalLeagues).toBe(5);
    expect(viewData.metrics.userEngagementRate).toBeCloseTo(40);
    expect(viewData.metrics.formattedEngagementRate).toBe('40.0%');
    expect(viewData.metrics.activityLevel).toBe('Low');
  });

  it('computes engagement rate and formatted engagement rate', () => {
    const inputDto: GetDashboardDataOutputDTO = {
      totalUsers: 200,
      activeUsers: 50,
      totalRaces: 0,
      totalLeagues: 0,
    };

    const viewData = AnalyticsDashboardViewDataBuilder.build(inputDto);

    expect(viewData.metrics.userEngagementRate).toBeCloseTo(25);
    expect(viewData.metrics.formattedEngagementRate).toBe('25.0%');
  });

  it('handles zero users safely', () => {
    const inputDto: GetDashboardDataOutputDTO = {
      totalUsers: 0,
      activeUsers: 0,
      totalRaces: 0,
      totalLeagues: 0,
    };

    const viewData = AnalyticsDashboardViewDataBuilder.build(inputDto);

    expect(viewData.metrics.userEngagementRate).toBe(0);
    expect(viewData.metrics.formattedEngagementRate).toBe('0.0%');
    expect(viewData.metrics.activityLevel).toBe('Low');
  });

  it('derives activity level buckets from engagement rate', () => {
    const low = AnalyticsDashboardViewDataBuilder.build({
      totalUsers: 100,
      activeUsers: 30,
      totalRaces: 0,
      totalLeagues: 0,
    });
    const medium = AnalyticsDashboardViewDataBuilder.build({
      totalUsers: 100,
      activeUsers: 50,
      totalRaces: 0,
      totalLeagues: 0,
    });
    const high = AnalyticsDashboardViewDataBuilder.build({
      totalUsers: 100,
      activeUsers: 90,
      totalRaces: 0,
      totalLeagues: 0,
    });

    expect(low.metrics.activityLevel).toBe('Low');
    expect(medium.metrics.activityLevel).toBe('Medium');
    expect(high.metrics.activityLevel).toBe('High');
  });
});