import { describe, expect, it } from 'vitest';

import {
  buildTemplateRows,
  computeTemplateGridColumns,
  computeTemplateGridLayout,
  computeTemplateRowHeight,
  TEMPLATE_CARD_GAP,
  TEMPLATE_CARD_MIN_WIDTH,
  TEMPLATE_CARD_TEXT_HEIGHT,
} from '../src/features/template-library/templateLibraryGrid';
import type { GameTemplateEntry } from '../src/features/template-library/templateLibraryModel';

function entry(id: string): GameTemplateEntry {
  return {
    id,
    title: id,
    summary: '',
    tags: [],
    runtime: 'html',
    engine: 'phaser',
    engineVersion: '4.2.1',
    templateVersion: '0.1.0',
    updatedAt: '2026-09-17T00:00:00Z',
    entry: 'game/index.html',
    zipUrl: `https://oss.example/templates/v1/${id}/template.zip`,
    zipSizeBytes: 1024,
    zipSha256: 'a'.repeat(64),
    coverUrl: `https://oss.example/templates/v1/${id}/cover.svg`,
    coverWidth: 960,
    coverHeight: 540,
    installed: false,
    installedVersion: null,
    installedAtMillis: null,
  };
}

describe('computeTemplateGridColumns', () => {
  it('fits as many min-width columns as the container allows', () => {
    expect(computeTemplateGridColumns(0)).toBe(1);
    expect(computeTemplateGridColumns(200)).toBe(1);
    expect(computeTemplateGridColumns(TEMPLATE_CARD_MIN_WIDTH)).toBe(1);
    // 两列边界：2*250 + 14 = 514
    const twoColumnWidth = 2 * TEMPLATE_CARD_MIN_WIDTH + TEMPLATE_CARD_GAP;
    expect(computeTemplateGridColumns(twoColumnWidth)).toBe(2);
    expect(computeTemplateGridColumns(twoColumnWidth - 1)).toBe(1);
    // 1200px：4 列（(1200+14)/(250+14) = 4.59）
    expect(computeTemplateGridColumns(1200)).toBe(4);
  });
});

describe('computeTemplateRowHeight', () => {
  it('keeps cover ratio + fixed text block', () => {
    // 列宽 300 → 卡片 286 → 封面 286*9/16 = 160.875 → 161
    expect(computeTemplateRowHeight(300)).toBe(
      161 + TEMPLATE_CARD_TEXT_HEIGHT + TEMPLATE_CARD_GAP,
    );
    // 极窄时按最小卡片宽度兜底，避免行高被压成 0
    expect(computeTemplateRowHeight(10)).toBeGreaterThan(
      TEMPLATE_CARD_TEXT_HEIGHT,
    );
  });
});

describe('computeTemplateGridLayout', () => {
  it('derives columns, row height and row count for a big library', () => {
    const layout = computeTemplateGridLayout({
      containerWidth: 1200,
      itemCount: 1000,
    });
    expect(layout.columnCount).toBe(4);
    expect(layout.columnWidth).toBe(300);
    expect(layout.rowHeight).toBe(
      161 + TEMPLATE_CARD_TEXT_HEIGHT + TEMPLATE_CARD_GAP,
    );
    expect(layout.rowCount).toBe(250);
    // 虚拟列表只渲染可视行，滚动高度仍由总行数决定
    expect(layout.rowCount * layout.rowHeight).toBeGreaterThan(80000);
  });

  it('handles inline and empty libraries', () => {
    expect(
      computeTemplateGridLayout({ containerWidth: 0, itemCount: 5 }),
    ).toEqual({
      columnCount: 1,
      columnWidth: 1,
      rowHeight: computeTemplateRowHeight(1),
      rowCount: 5,
    });
    expect(
      computeTemplateGridLayout({ containerWidth: 1200, itemCount: 0 })
        .rowCount,
    ).toBe(0);
  });
});

describe('buildTemplateRows', () => {
  it('chunks entries per row and pads the tail with nulls', () => {
    const rows = buildTemplateRows([entry('a'), entry('b'), entry('c')], 2);
    expect(rows).toHaveLength(2);
    expect(rows[0]?.map((item) => item?.id)).toEqual(['a', 'b']);
    expect(rows[1]?.map((item) => item?.id ?? null)).toEqual(['c', null]);
  });

  it('returns no rows for an invalid column count', () => {
    expect(buildTemplateRows([entry('a')], 0)).toEqual([]);
  });
});