const { writeFile } = require('./wx-promisify')

function sanitizeFilename(filename) {
  return String(filename || 'font2svg')
    .replace(/[<>:"/\\|?*\x00-\x1F]/g, '_')
    .replace(/\s+/g, '_')
    .slice(0, 80)
}

function buildFilename(fontName, text, ext) {
  const safeFont = sanitizeFilename(fontName || 'font')
  const safeText = sanitizeFilename(Array.from(text || '').slice(0, 8).join('') || 'text')
  return `${safeFont}_${safeText}.${ext}`
}

async function writeTextToUserPath(text, ext, preferredName) {
  const filename = preferredName || `font2svg_${Date.now()}.${ext}`
  const filePath = `${wx.env.USER_DATA_PATH}/${filename}`
  await writeFile(filePath, text, 'utf8')
  return filePath
}

async function saveSvgToUserPath(svgText, fontName, text) {
  const filename = buildFilename(fontName, text, 'svg')
  return writeTextToUserPath(svgText, 'svg', filename)
}

function saveSvgToUserPathSync(svgText, fontName, text) {
  const filename = buildFilename(fontName, text, 'svg')
  const filePath = `${wx.env.USER_DATA_PATH}/${filename}`
  const fs = wx.getFileSystemManager()
  fs.writeFileSync(filePath, svgText, 'utf8')
  return {
    filePath,
    fileName: filename,
  }
}

async function shareLocalFile(filePath, fileName) {
  if (typeof wx.shareFileMessage !== 'function') {
    throw new Error('当前微信版本不支持文件分享')
  }

  return new Promise((resolve, reject) => {
    wx.shareFileMessage({
      filePath,
      fileName,
      success: resolve,
      fail: reject,
    })
  })
}

function shareSvgFromUserTap(svgText, fontName, text) {
  if (typeof wx.shareFileMessage !== 'function') {
    throw new Error('当前微信版本不支持文件分享')
  }

  const { filePath, fileName } = saveSvgToUserPathSync(svgText, fontName, text)

  return new Promise((resolve, reject) => {
    wx.shareFileMessage({
      filePath,
      fileName,
      success: resolve,
      fail: reject,
    })
  })
}

module.exports = {
  sanitizeFilename,
  buildFilename,
  writeTextToUserPath,
  saveSvgToUserPath,
  saveSvgToUserPathSync,
  shareLocalFile,
  shareSvgFromUserTap,
}