import { vi } from 'vitest';

/**
 * Test double for Chart.js's `Chart` class, shared by `chart-canvas.spec.ts` and
 * `overview.spec.ts`. jsdom has no canvas 2D context, so real Chart.js cannot render
 * in this project's test environment — specs mock the whole `chart.js` module via
 * `vi.mock('chart.js', () => ({ Chart: MockChart, registerables: [] }))` and assert
 * on the Chart.js lifecycle contract (constructor args, update(), destroy()) instead.
 *
 * Not a `*.spec.ts` file on purpose: it exports a class rather than defining tests,
 * so it must not be picked up by the test runner's `**\/*.spec.ts` include glob.
 */
export class MockChart {
  static register = vi.fn();
  static instances: MockChart[] = [];

  data: unknown;
  options: unknown;
  config: { type: unknown; data: unknown; options: unknown };
  destroy = vi.fn();
  update = vi.fn();

  constructor(
    public ctx: unknown,
    config: { type: unknown; data: unknown; options: unknown },
  ) {
    this.config = config;
    this.data = config.data;
    this.options = config.options;
    MockChart.instances.push(this);
  }
}