import assert from 'node:assert/strict'
import test from 'node:test'
import {
  deleteMarkdownSelectedLines,
  getMarkdownLineIndexAtOffset,
  getMarkdownLineStartOffset,
  getMarkdownSelectionState,
  insertMarkdownBlockSnippet,
  insertMarkdownInlineLink,
  replaceMarkdownSelection,
  transformMarkdownSelectedLines,
  wrapMarkdownInlineSelection
} from '../lib/markdown-source-selection.js'

test('마크다운 줄 오프셋과 줄 번호를 계산한다', () => {
  const value = '첫 줄\n두 번째\n세 번째'

  assert.equal(getMarkdownLineStartOffset(value, 0), 0)
  assert.equal(getMarkdownLineStartOffset(value, 1), 4)
  assert.equal(getMarkdownLineStartOffset(value, 9), 9)
  assert.equal(getMarkdownLineIndexAtOffset(value, 0), 0)
  assert.equal(getMarkdownLineIndexAtOffset(value, 5), 1)
  assert.equal(getMarkdownLineIndexAtOffset(value, 100), 2)
})

test('textarea 선택 정보가 없으면 본문 끝을 선택 상태로 사용한다', () => {
  assert.deepEqual(getMarkdownSelectionState({
    value: '본문',
    textarea: null
  }), {
    start: 2,
    end: 2,
    value: '본문'
  })
})

test('선택 영역을 교체하고 다음 선택 범위를 반환한다', () => {
  const result = replaceMarkdownSelection({
    value: 'hello world',
    start: 6,
    end: 11,
    replacement: 'link',
    cursorOffset: 1,
    selectionLength: 2
  })

  assert.deepEqual(result, {
    value: 'hello link',
    selectionStart: 7,
    selectionEnd: 9
  })
})

test('블록 조각 삽입은 앞뒤 줄바꿈을 보정한다', () => {
  const result = insertMarkdownBlockSnippet({
    value: '앞뒤',
    start: 1,
    end: 1,
    snippet: '```\ncode\n```'
  })

  assert.equal(result.value, '앞\n\n```\ncode\n```\n\n뒤')
  assert.equal(result.selectionStart, result.value.length - 1)
})

test('인라인 감싸기는 선택 텍스트를 유지하고 내부를 선택한다', () => {
  const result = wrapMarkdownInlineSelection({
    value: 'hello',
    start: 0,
    end: 5,
    prefix: '**',
    suffix: '**',
    placeholder: '굵게'
  })

  assert.deepEqual(result, {
    value: '**hello**',
    selectionStart: 2,
    selectionEnd: 7
  })
})

test('링크 삽입은 URL 영역을 다음 선택 범위로 반환한다', () => {
  const result = insertMarkdownInlineLink({
    value: '링크',
    start: 0,
    end: 2
  })

  assert.deepEqual(result, {
    value: '[링크](https://)',
    selectionStart: 5,
    selectionEnd: 13
  })
})

test('선택된 여러 줄을 변환한다', () => {
  const result = transformMarkdownSelectedLines({
    value: 'a\nb\nc',
    start: 0,
    end: 3,
    transformLine: (line) => `- ${line}`
  })

  assert.deepEqual(result, {
    value: '- a\n- b\nc',
    selectionStart: 0,
    selectionEnd: 7
  })
})

test('선택된 줄 전체를 삭제한다', () => {
  const result = deleteMarkdownSelectedLines({
    value: 'a\nb\nc',
    start: 2,
    end: 3
  })

  assert.deepEqual(result, {
    value: 'a\nc',
    selectionStart: 0,
    selectionEnd: 0
  })
})