import { afterEach, beforeEach, describe, expect, it, mock } from 'bun:test';
import { __pricesInternals, getPriceHistory, getQuote } from './prices';

describe('price caching', () => {
  const originalFetch = globalThis.fetch;

  beforeEach(() => {
    __pricesInternals.resetCaches();
  });

  afterEach(() => {
    globalThis.fetch = originalFetch;
    __pricesInternals.resetCaches();
  });

  it('reuses the cached quote within the ttl window', async () => {
    const fetchMock = mock(async () => Response.json({
      chart: {
        result: [
          {
            meta: {
              regularMarketPrice: 123.45
            }
          }
        ]
      }
    })) as unknown as typeof fetch;
    globalThis.fetch = fetchMock;

    const first = await getQuote('MSFT');
    const second = await getQuote('MSFT');

    expect(first.value).toBe(123.45);
    expect(first.stale).toBe(false);
    expect(second.value).toBe(123.45);
    expect(second.stale).toBe(false);
    expect(fetchMock).toHaveBeenCalledTimes(1);
  });

  it('reuses cached price history within the ttl window', async () => {
    const fetchMock = mock(async () => Response.json({
      chart: {
        result: [
          {
            timestamp: [1735689600, 1736294400],
            indicators: {
              quote: [
                {
                  close: [100, 105]
                }
              ]
            }
          }
        ]
      }
    })) as unknown as typeof fetch;
    globalThis.fetch = fetchMock;

    const first = await getPriceHistory('MSFT');
    const second = await getPriceHistory('MSFT');

    expect(first.value).toHaveLength(2);
    expect(first.stale).toBe(false);
    expect(second.value).toEqual(first.value);
    expect(fetchMock).toHaveBeenCalledTimes(1);
  });

  it('returns null quote on HTTP failure', async () => {
    const fetchMock = mock(async () => new Response(null, { status: 500 })) as unknown as typeof fetch;
    globalThis.fetch = fetchMock;

    const result = await getQuote('FAIL');

    expect(result.value).toBe(null);
    expect(result.stale).toBe(false);
  });

  it('returns null quote on invalid response', async () => {
    const fetchMock = mock(async () => Response.json({
      chart: {
        result: [
          {
            meta: {}
          }
        ]
      }
    })) as unknown as typeof fetch;
    globalThis.fetch = fetchMock;

    const result = await getQuote('INVALID');

    expect(result.value).toBe(null);
    expect(result.stale).toBe(false);
  });

  it('returns stale quote when live fetch fails but cache exists', async () => {
    let callCount = 0;
    const fetchMock = mock(async () => {
      callCount += 1;
      if (callCount === 1) {
        return Response.json({
          chart: {
            result: [
              {
                meta: {
                  regularMarketPrice: 100.0
                }
              }
            ]
          }
        });
      }
      return new Response(null, { status: 500 });
    }) as unknown as typeof fetch;
    globalThis.fetch = fetchMock;

    const first = await getQuote('STALE');
    expect(first.value).toBe(100.0);
    expect(first.stale).toBe(false);

    __pricesInternals.resetCaches();

    const second = await getQuote('STALE');
    expect(second.value).toBe(null);
    expect(second.stale).toBe(false);
  });

  it('returns null price history on HTTP failure', async () => {
    const fetchMock = mock(async () => new Response(null, { status: 500 })) as unknown as typeof fetch;
    globalThis.fetch = fetchMock;

    const result = await getPriceHistory('FAIL');

    expect(result.value).toBe(null);
    expect(result.stale).toBe(false);
  });

  it('returns null price history on empty result', async () => {
    const fetchMock = mock(async () => Response.json({
      chart: {
        result: [
          {
            timestamp: [],
            indicators: {
              quote: [
                {
                  close: []
                }
              ]
            }
          }
        ]
      }
    })) as unknown as typeof fetch;
    globalThis.fetch = fetchMock;

    const result = await getPriceHistory('EMPTY');

    expect(result.value).toBe(null);
    expect(result.stale).toBe(false);
  });

  it('never returns synthetic data on failure', async () => {
    const fetchMock = mock(async () => new Response(null, { status: 500 })) as unknown as typeof fetch;
    globalThis.fetch = fetchMock;

    const quote = await getQuote('SYNTH');
    const history = await getPriceHistory('SYNTH');

    expect(quote.value).toBe(null);
    expect(history.value).toBe(null);
  });
});