import { describe, it, expect } from 'vitest';
import { estimateCost, MODEL_COSTS_PER_MILLION } from './costs.js';

describe('estimateCost', () => {
  it('returns 0 for local/unknown models', () => {
    expect(estimateCost(1000, 1000)).toBe(0);
    expect(estimateCost(1000, 1000, 'some-local-model')).toBe(0);
  });

  it('uses default costs when model name is undefined', () => {
    const cost = estimateCost(1_000_000, 1_000_000);
    expect(cost).toBe(0);
  });

  it('calculates correctly for known Anthropic models', () => {
    // claude-sonnet-4: $3/M input, $15/M output
    const cost = estimateCost(1_000_000, 1_000_000, 'claude-sonnet-4-20250514');
    expect(cost).toBe(3 + 15);
  });

  it('calculates correctly for claude-opus', () => {
    // claude-opus-4: $15/M input, $75/M output
    const cost = estimateCost(1_000_000, 500_000, 'claude-opus-4-20250514');
    expect(cost).toBe(15 + 37.5);
  });

  it('calculates correctly for OpenAI models', () => {
    // gpt-4o: $2.50/M input, $10/M output
    const cost = estimateCost(2_000_000, 1_000_000, 'gpt-4o');
    expect(cost).toBe(5 + 10);
  });

  it('handles small token counts', () => {
    // 1000 tokens of claude-sonnet input: 1000 * 3 / 1_000_000 = 0.003
    const cost = estimateCost(1000, 0, 'claude-sonnet-4-20250514');
    expect(cost).toBeCloseTo(0.003);
  });

  it('handles zero tokens', () => {
    const cost = estimateCost(0, 0, 'claude-sonnet-4-20250514');
    expect(cost).toBe(0);
  });
});

describe('MODEL_COSTS_PER_MILLION', () => {
  it('has a default entry', () => {
    expect(MODEL_COSTS_PER_MILLION['default']).toEqual({ input: 0, output: 0 });
  });

  it('has entries for all expected models', () => {
    expect(MODEL_COSTS_PER_MILLION['claude-sonnet-4-20250514']).toBeDefined();
    expect(MODEL_COSTS_PER_MILLION['claude-3-5-haiku-20241022']).toBeDefined();
    expect(MODEL_COSTS_PER_MILLION['claude-opus-4-20250514']).toBeDefined();
    expect(MODEL_COSTS_PER_MILLION['gpt-4o']).toBeDefined();
    expect(MODEL_COSTS_PER_MILLION['gpt-4o-mini']).toBeDefined();
  });
});