/**
 * Tests for renderMath and finishRenderMath stub functions.
 *
 * These are stubs for Obsidian API compatibility. MathJax is not bundled
 * in Reams, so:
 * - renderMath returns a placeholder element with the raw LaTeX source
 * - finishRenderMath is a no-op that immediately resolves
 *
 * Plugins that call these functions will not crash, but actual math
 * rendering is not supported.
 */

import { describe, it, expect, vi, beforeEach } from 'vitest'
import { renderMath, finishRenderMath, _resetWarnedStubs } from '../obsidian-stubs'

beforeEach(() => {
  _resetWarnedStubs()
  vi.restoreAllMocks()
})

describe('renderMath', () => {
  it('returns an HTMLElement with the source as text content', () => {
    vi.spyOn(console, 'warn').mockImplementation(() => {})

    const el = renderMath('x^2 + y^2 = z^2', false)

    expect(el).toBeInstanceOf(HTMLElement)
    expect(el.textContent).toBe('x^2 + y^2 = z^2')
  })

  it('returns a <span> for inline math (display=false)', () => {
    vi.spyOn(console, 'warn').mockImplementation(() => {})

    const el = renderMath('E = mc^2', false)

    expect(el.tagName).toBe('SPAN')
    expect(el.classList.contains('math')).toBe(true)
    expect(el.classList.contains('math-inline')).toBe(true)
  })

  it('returns a <div> for display math (display=true)', () => {
    vi.spyOn(console, 'warn').mockImplementation(() => {})

    const el = renderMath('\\int_0^\\infty e^{-x^2} dx', true)

    expect(el.tagName).toBe('DIV')
    expect(el.classList.contains('math')).toBe(true)
    expect(el.classList.contains('math-block')).toBe(true)
  })

  it('emits a console.warn on first call', () => {
    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {})

    renderMath('x', false)

    expect(warnSpy).toHaveBeenCalledOnce()
    expect(warnSpy).toHaveBeenCalledWith(
      expect.stringContaining('[Reams] renderMath')
    )
  })

  it('emits console.warn only once per page-load (warn-once)', () => {
    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {})

    renderMath('a', false)
    renderMath('b', true)
    renderMath('c', false)

    expect(warnSpy).toHaveBeenCalledOnce()
  })

  it('handles empty source string', () => {
    vi.spyOn(console, 'warn').mockImplementation(() => {})

    const el = renderMath('', false)

    expect(el.textContent).toBe('')
  })
})

describe('finishRenderMath', () => {
  it('returns a resolved Promise<void>', async () => {
    const result = await finishRenderMath()
    expect(result).toBeUndefined()
  })

  it('does not emit a warning (no-op)', async () => {
    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {})

    await finishRenderMath()

    // finishRenderMath should not warn - renderMath already warns
    expect(warnSpy).not.toHaveBeenCalled()
  })

  it('can be called multiple times without error', async () => {
    expect(await finishRenderMath()).toBeUndefined()
    expect(await finishRenderMath()).toBeUndefined()
    expect(await finishRenderMath()).toBeUndefined()
  })
})