// src/plugin/__tests__/editor-suggest-mode-toggle.test.ts
/**
 * Regression test for plan decision #1: the dispatcher MUST be a top-level
 * extension, NOT inside livePreviewCompartment. Reconfiguring the live
 * preview compartment must NOT tear down the dispatcher's AbortController
 * or its dropdown DOM.
 */
import { describe, it, expect, afterEach } from 'vitest'
import { EditorSuggest } from '../editor-suggest'
import { getDispatcherController } from '../../editor/extensions/editor-suggest-dispatcher'
import { livePreview } from '../../editor/extensions/live-preview'
import {
  mountCM6EditorWithSourceMode,
  typeText,
  findDropdown,
  type MountedHarness,
} from './editor-suggest-test-harness'

class BracketSuggest extends EditorSuggest<string> {
  onTrigger(cursor: { line: number; ch: number }, editor: { getLine(line: number): string }) {
    const line = editor.getLine(cursor.line)
    const before = line.slice(0, cursor.ch)
    const m = /\[\[([^\]\[]*)$/.exec(before)
    if (!m) return null
    return {
      start: { line: cursor.line, ch: m.index },
      end: { line: cursor.line, ch: cursor.ch },
      query: m[1],
    }
  }
  async getSuggestions() {
    return ['a', 'b']
  }
  renderSuggestion(item: string, el: HTMLElement) {
    el.textContent = item
  }
  selectSuggestion() {}
}

let harness: MountedHarness | null = null

afterEach(() => {
  harness?.destroy()
  harness = null
  document.body.innerHTML = ''
})

async function flush(): Promise<void> {
  await new Promise((r) => setTimeout(r, 80))
}

describe('mode-toggle regression (decision #1)', () => {
  it('survives source ↔ live-preview compartment reconfigure (dispatcher persists)', async () => {
    const h = await mountCM6EditorWithSourceMode()
    harness = h
    const sug = new BracketSuggest(h.app)
    h.app.workspace.registerEditorSuggest(sug)
    typeText(h.view, '[[')
    await flush()
    expect(findDropdown()).not.toBeNull()
    const dropdownBefore = findDropdown()
    // Dropdown active means controller is non-null AND not aborted.
    const ctrlBefore = getDispatcherController(h.view, h.app)
    expect(ctrlBefore).not.toBeNull()

    // Reconfigure the livePreview compartment to enable live-preview
    // decorations. The dispatcher (top-level) must survive this without
    // re-creating its state.
    h.view.dispatch({
      effects: h.livePreviewCompartment.reconfigure(
        livePreview({
          wikilink: { onNavigate: () => {}, resolveLink: () => true },
        }),
      ),
    })
    await flush()
    // Dropdown DOM still in the document.
    const dropdownAfter = findDropdown()
    expect(dropdownAfter).not.toBeNull()
    expect(dropdownAfter).toBe(dropdownBefore)
    // Same AbortController instance — dispatcher was NOT re-created.
    const ctrlAfter = getDispatcherController(h.view, h.app)
    expect(ctrlAfter).toBe(ctrlBefore)
  })
})