/**
 * @fileoverview The grid holds at most TILE_GRID_MAX tiles: 6, owner decision 7
 * (docs/tile-grid-plan.md). Six was tested smooth on a real desktop; nine missed
 * the headless frame bar. The layout table still covers 7 to 9 (unreachable).
 *
 * Every way into the grid stops at the cap even where the window would fit
 * nine (the harness window is 2400x1200): opening, adding, a tile's +, a
 * session Run makes, Ctrl/Cmd+click, the picker and "Open group as tiles".
 * The texts say which limit binds: "at most 6" for the cap, "what this window
 * fits" for a smaller window.
 *
 * Real code via the shared vm harness (test/mocks/tile-grid-vm.ts). Port: N/A.
 */
import { beforeEach, describe, expect, it, vi } from 'vitest';
import { FakeEl, body, bySelector, makeGridApp, resetGridHarness, type GridApp } from './mocks/tile-grid-vm.js';

const EIGHT = Array.from({ length: 8 }, (_, i) => `s-${i + 1}`);
const SIX = EIGHT.slice(0, 6);
const AT_MOST = 'The grid holds at most 6 tiles';

let wrapRect = { width: 2400, height: 1200 };
beforeEach(() => {
  resetGridHarness();
  wrapRect = { width: 2400, height: 1200 };
  const wrap = new FakeEl();
  wrap.getBoundingClientRect = () => ({ ...wrapRect, top: 0, left: 0, right: wrapRect.width, bottom: wrapRect.height });
  bySelector.set('.terminal-wrap', wrap);
});

function fullGrid(): GridApp {
  const app = makeGridApp(EIGHT);
  app.openTileGrid(EIGHT);
  return app;
}

describe('the cap', () => {
  it('is 6, worded as the cap where the window would fit more', () => {
    const app = makeGridApp(EIGHT);
    expect(app._tileGridLimit()).toEqual({ capacity: 6, hint: 'Up to 6 tiles', full: AT_MOST });
  });

  it('a smaller window is worded by the window', () => {
    const app = makeGridApp(EIGHT);
    wrapRect = { width: 1200, height: 900 };
    expect(app._tileGridLimit()).toEqual({
      capacity: 4,
      hint: 'This window fits 4 tiles',
      full: 'The grid already holds what this window fits (4)',
    });
  });

  it('opening on eight sessions shows the first six', () => {
    const app = fullGrid();
    expect(app._tileGrid.ids).toEqual(SIX);
    expect(app._tileGrid.tiles.size).toBe(6);
  });

  it('a full grid takes no more tiles', () => {
    const app = fullGrid();
    expect(app.addTile('s-7')).toBe(false);
    expect(app._tileGrid.ids).toEqual(SIX);
  });
});

describe('every way in stops at the cap', () => {
  it("a tile's + offers the rest, disabled, and says why", () => {
    const app = fullGrid();
    app.openTileAddMenu({ stopPropagation: vi.fn(), preventDefault: vi.fn(), currentTarget: null }, 's-1');
    const menu = body.children.find((c) => c.className.includes('tile-add-menu'))!;
    const items = menu.children.filter((c) => c.textContent === 's-7' || c.textContent === 's-8');
    expect(items).toHaveLength(2);
    for (const item of items) {
      expect(item.disabled).toBe(true);
      expect(item.title).toBe(AT_MOST);
    }
    expect(menu.children.find((c) => c.className === 'tile-add-new')!.disabled).toBe(true);
  });

  it('a session Run makes opens on its own, with a toast', () => {
    const app = fullGrid();
    expect(app._joinTileGridFromRun('s-7')).toBe(false);
    expect(app._tileGrid.ids).toEqual(SIX);
    expect(app.showToast).toHaveBeenCalledWith(`${AT_MOST}: the new session opens on its own`, 'info');
  });

  it('Ctrl/Cmd+click on another tab says the grid is full', () => {
    const app = fullGrid();
    expect(app.addSessionToTiles('s-7')).toBe(true);
    expect(app._tileGrid.ids).toEqual(SIX);
    expect(app.showToast).toHaveBeenCalledWith(AT_MOST, 'info');
  });

  it('the picker greys out the seventh box', () => {
    const app = makeGridApp(EIGHT);
    app.openTilePicker({ stopPropagation: vi.fn() });
    const picker = body.children.find((c) => c.id === 'tilePickerMenu')!;
    const boxes = picker.children[0].children.map((row) => row.children[0]);
    expect(picker.children[1].children[0].textContent).toBe('Up to 6 tiles');
    for (const box of boxes) {
      // A disabled box cannot be ticked (the browser ignores the click).
      if (!EIGHT.includes(box.value) || box.checked || box.disabled) continue;
      box.checked = true;
      box.dispatch('change');
    }
    const checked = boxes.filter((b) => b.checked).map((b) => b.value);
    expect(checked).toHaveLength(6);
    const left = boxes.filter((b) => !b.checked);
    expect(left.length).toBeGreaterThan(0);
    for (const box of left) {
      expect(box.disabled).toBe(true);
      expect(box.title).toBe(AT_MOST);
    }
  });

  it('"Open group as tiles" shows the first six of a larger group', () => {
    const app = makeGridApp(EIGHT);
    app.tabLayout = { groups: [{ id: 'g', name: 'G', refs: EIGHT.map((id) => ({ kind: 'session', id })) }] };
    app.openGroupAsTiles('g');
    expect(app._tileGrid.ids).toEqual(SIX);
  });
});