import { Editor } from 'codemirror'
import { EmojiData } from 'emoji-mart'
import { getEmojiShortCode } from '../../../../utils/emoji'

export const makeSelectionBold = (editor: Editor): void => wrapTextWith(editor, '**')
export const makeSelectionItalic = (editor: Editor): void => wrapTextWith(editor, '*')
export const strikeThroughSelection = (editor: Editor): void => wrapTextWith(editor, '~~')
export const underlineSelection = (editor: Editor): void => wrapTextWith(editor, '++')
export const subscriptSelection = (editor: Editor): void => wrapTextWith(editor, '~')
export const superscriptSelection = (editor: Editor): void => wrapTextWith(editor, '^')
export const markSelection = (editor: Editor): void => wrapTextWith(editor, '==')

export const addHeaderLevel = (editor: Editor): void => changeLines(editor, line => line.startsWith('#') ? `#${line}` : `# ${line}`)
export const addCodeFences = (editor: Editor): void => wrapTextWith(editor, '```\n', '\n```')
export const addQuotes = (editor: Editor): void => insertOnStartOfLines(editor, '> ')

export const addList = (editor: Editor): void => createList(editor, () => '- ')
export const addOrderedList = (editor: Editor): void => createList(editor, j => `${j}. `)
export const addTaskList = (editor: Editor): void => createList(editor, () => '- [ ] ')

export const addImage = (editor: Editor): void => addLink(editor, '!')

export const addLine = (editor: Editor): void => changeLines(editor, line => `${line}\n----`)
export const addComment = (editor: Editor): void => changeLines(editor, line => `${line}\n> []`)
export const addTable = (editor: Editor): void => changeLines(editor, line => `${line}\n| # 1  | # 2  | # 3  |\n| ---- | ---- | ---- |\n| Text | Text | Text |`)

export const addEmoji = (emoji: EmojiData, editor: Editor): void => {
  insertAtCursor(editor, getEmojiShortCode(emoji))
}

export const wrapTextWith = (editor: Editor, symbol: string, endSymbol?: string): void => {
  if (!editor.getSelection()) {
    return
  }
  const ranges = editor.listSelections()
  for (const range of ranges) {
    if (range.empty()) {
      continue
    }
    const from = range.from()
    const to = range.to()

    const selection = editor.getRange(from, to)
    editor.replaceRange(symbol + selection + (endSymbol || symbol), from, to, '+input')
    range.head.ch += symbol.length
    range.anchor.ch += endSymbol ? endSymbol.length : symbol.length
  }
  editor.setSelections(ranges)
}

export const insertOnStartOfLines = (editor: Editor, symbol: string): void => {
  const cursor = editor.getCursor()
  const ranges = editor.listSelections()
  for (const range of ranges) {
    const from = range.empty() ? { line: cursor.line, ch: 0 } : range.from()
    const to = range.empty() ? { line: cursor.line, ch: editor.getLine(cursor.line).length } : range.to()
    const selection = editor.getRange(from, to)
    const lines = selection.split('\n')
    editor.replaceRange(lines.map(line => `${symbol}${line}`).join('\n'), from, to, '+input')
  }
  editor.setSelections(ranges)
}

export const changeLines = (editor: Editor, replaceFunction: (line: string) => string): void => {
  const cursor = editor.getCursor()
  const ranges = editor.listSelections()
  for (const range of ranges) {
    const lineNumber = range.empty() ? cursor.line : range.from().line
    const line = editor.getLine(lineNumber)
    editor.replaceRange(replaceFunction(line), { line: lineNumber, ch: 0 }, {
      line: lineNumber,
      ch: line.length
    }, '+input')
  }
  editor.setSelections(ranges)
}

export const createList = (editor: Editor, listMark: (i: number) => string): void => {
  const cursor = editor.getCursor()
  const ranges = editor.listSelections()
  for (const range of ranges) {
    const from = range.empty() ? { line: cursor.line, ch: 0 } : range.from()
    const to = range.empty() ? { line: cursor.line, ch: editor.getLine(cursor.line).length } : range.to()

    const selection = editor.getRange(from, to)
    const lines = selection.split('\n')
    editor.replaceRange(lines.map((line, i) => `${listMark(i + 1)}${line}`).join('\n'), from, to, '+input')
  }
  editor.setSelections(ranges)
}

export const addLink = (editor: Editor, prefix?: string): void => {
  const cursor = editor.getCursor()
  const ranges = editor.listSelections()
  for (const range of ranges) {
    const from = range.empty() ? { line: cursor.line, ch: cursor.ch } : range.from()
    const to = range.empty() ? { line: cursor.line, ch: cursor.ch } : range.to()
    const selection = editor.getRange(from, to)
    const linkRegex = /^(?:https?|ftp|mailto):/
    if (linkRegex.exec(selection)) {
      editor.replaceRange(`${prefix || ''}[](${selection})`, from, to, '+input')
    } else {
      editor.replaceRange(`${prefix || ''}[${selection}](https://)`, from, to, '+input')
    }
  }
}

export const insertAtCursor = (editor: Editor, text: string): void => {
  const cursor = editor.getCursor()
  const ranges = editor.listSelections()
  for (const range of ranges) {
    const from = range.empty() ? { line: cursor.line, ch: cursor.ch } : range.from()
    const to = range.empty() ? { line: cursor.line, ch: cursor.ch } : range.to()
    editor.replaceRange(`${text}`, from, to, '+input')
  }
}