/**
 * Created by zuozhuo on 2017/7/20.
 */
'use strict'

const through = require('through2');
const gutil = require('gulp-util');
const path = require('path');
const gulp = require('gulp');
const gulpRename = require('gulp-rename');
const url = require('url');
const crypto = require('crypto');
const fs = require('fs');

/*
 测试用例：
 <link rel="apple-touch-icon" sizes="180x180" href="/favicons/apple-touch-icon.png">
 <link rel="manifest" href="/favicons/manifest.json">
 <link rel="mask-icon" href="/favicons/safari-pinned-tab.svg" color="#A92119">
 <link rel="stylesheet" href="/index.css">
 <script src="/index.js"></script>
 <link rel="stylesheet" href="//at.alicdn.com/t/font_u3v0book0tsurf6r.css">
 <div style="background-image:url(/abc.jpg)"></div>
 */

const PLUGIN_NAME = 'gulp-html-cache-buster';
const REGEX_STATIC_FILE_IN_HTML = /(src|href)\s*?\=\s*?[\"\'\(]\s*?(((\{\{[^\"\'\(\)]*?\}\})?[^\"\'\(\)]*?\.(jpg|jpeg|png|gif|cur|js|css|json|svg))(\?[^\"\'\(\)]+?)?)\s*?[\"\'\)]/gmi;
const REGEX_STATIC_FILE_IN_CSS = /(url)\s*?\(\s*?[\"\']?([^\)]*?\.(jpg|jpeg|png|gif|cur|js|css|json|svg))[\"\']?\s*?\)/gmi;

function getFileMd5String(filePath) {
  const buffer = fs.readFileSync(filePath);
  return crypto.createHash('md5').update(buffer).digest("hex");
}

function copyToHashNamedFile(file, hash) {
  const dir = path.dirname(file);
  const fileName = path.basename(file);
  if (fileName.indexOf(hash) === 0) {
    console.log(`文件${fileName}已经进过hash处理，跳过`);
    return fileName
  }
  const newFileName = hash + '.' + fileName;
  // 复制成带md5的文件
  gulp.src(file)
    .pipe(gulpRename(function (_path) {
      _path.basename = path.basename(newFileName, _path.extname);
    }))
    .pipe(gulp.dest(dir));
  //.pipe($.size({title: 'static_rename: ' + newFileName}))
//        .pipe(gulp.src(file, {read: false}))
//        .pipe($.clean())
  // 删除原文件容易报错
//
//        .pipe($.clean())

  return newFileName;
}

function replaceContent(staticRoot, content, fullUrl, staticFile) {
  var fullPath, urlObj, newFullUrl, md5HashPrefix, newFileName;


  // 替换{{ STATIC_URL }}为/static/
  var STATIC_URL_REG = /\{\{\s*?STATIC_URL\s*?\}\}/gmi;
  staticFile = staticFile.replace(STATIC_URL_REG, '/static/');

  fullPath = path.join(staticRoot, staticFile);
  if (fs.existsSync(fullPath)) {
    console.log('找到static文件：', fullPath);

    md5HashPrefix = 'c' + getFileMd5String(fullPath).slice(0, 8);
    newFileName = copyToHashNamedFile(fullPath, md5HashPrefix);

    urlObj = url.parse(fullUrl);
    urlObj.pathname = path.join(path.dirname(urlObj.pathname), newFileName);
    newFullUrl = url.format(urlObj);

    // 纠正format函数中对{{ STATIC_URL }}的encode，以便还原{{ STATIC_URL }}
    // 0.10.33 是这种格式
    newFullUrl = newFullUrl.replace(/\{\{(%20)*?STATIC_URL(%20)*?\}\}/gim, '{{ STATIC_URL }}');
    // 0.12.4 是这种格式
    newFullUrl = newFullUrl.replace(/%7B%7B(%20)*?STATIC_URL(%20)*?%7D%7D/gim, '{{ STATIC_URL }}');

    content = content.replace(fullUrl, newFullUrl);

    console.log('替换md5：', newFullUrl)
  } else {

  }
  return content;
}


// 给模板html的css和js增加版本hash
function plugin(staticRoot) {

  return through.obj(function (file, enc, callback) {
    let contents;

    if (file.isNull()) {
      this.push(file);
      return callback();
    }

    if (file.isStream()) {
      this.emit('error', new gutil.PluginError(PLUGIN_NAME, 'Streams are not supported!'));
      return callback();
    }

    console.log('搜索HTML：', file.path);

    contents = file.contents.toString().replace(REGEX_STATIC_FILE_IN_HTML, function (content, prop, fullUrl, staticFile) {
      //content, prop, fullUrl, staticFile
      var fullPath, urlObj, newFullUrl, md5HashPrefix, newFileName;

      console.log(`fullUrl: ${fullUrl}`)
      console.log(`staticFile: ${staticFile}`)

      content = replaceContent(staticRoot, content, fullUrl, staticFile);

      return content

    });
    contents = contents.replace(REGEX_STATIC_FILE_IN_CSS, function (content, a1, fileUrl, a3, a4, a5) {

      content = replaceContent(staticRoot, content, fileUrl, fileUrl);

      return content;
    });


    file.contents = new Buffer(contents);

    this.push(file);
    return callback();
  });
}

module.exports = plugin;