/**
 * Copyright 2013-present the PM2 project authors. All rights reserved.
 * Use of this source code is governed by a license that
 * can be found in the LICENSE file.
 */
'use strict';

var fs = require('fs');
var http = require('http');
var path = require('path');
var debug = require('debug')('pm2:serve');

// var probe = require('@pm2/io');
// var errorMeter = probe.meter({
//   name      : '404/sec',
//   samples   : 1,
//   timeframe : 60
// })
/**
 * list of supported content types.
 */
var contentTypes = {
  '3gp': 'video/3gpp',
  'a': 'application/octet-stream',
  'ai': 'application/postscript',
  'aif': 'audio/x-aiff',
  'aiff': 'audio/x-aiff',
  'asc': 'application/pgp-signature',
  'asf': 'video/x-ms-asf',
  'asm': 'text/x-asm',
  'asx': 'video/x-ms-asf',
  'atom': 'application/atom+xml',
  'au': 'audio/basic',
  'avi': 'video/x-msvideo',
  'bat': 'application/x-msdownload',
  'bin': 'application/octet-stream',
  'bmp': 'image/bmp',
  'bz2': 'application/x-bzip2',
  'c': 'text/x-c',
  'cab': 'application/vnd.ms-cab-compressed',
  'cc': 'text/x-c',
  'chm': 'application/vnd.ms-htmlhelp',
  'class': 'application/octet-stream',
  'com': 'application/x-msdownload',
  'conf': 'text/plain',
  'cpp': 'text/x-c',
  'crt': 'application/x-x509-ca-cert',
  'css': 'text/css',
  'csv': 'text/csv',
  'cxx': 'text/x-c',
  'deb': 'application/x-debian-package',
  'der': 'application/x-x509-ca-cert',
  'diff': 'text/x-diff',
  'djv': 'image/vnd.djvu',
  'djvu': 'image/vnd.djvu',
  'dll': 'application/x-msdownload',
  'dmg': 'application/octet-stream',
  'doc': 'application/msword',
  'dot': 'application/msword',
  'dtd': 'application/xml-dtd',
  'dvi': 'application/x-dvi',
  'ear': 'application/java-archive',
  'eml': 'message/rfc822',
  'eps': 'application/postscript',
  'exe': 'application/x-msdownload',
  'f': 'text/x-fortran',
  'f77': 'text/x-fortran',
  'f90': 'text/x-fortran',
  'flv': 'video/x-flv',
  'for': 'text/x-fortran',
  'gem': 'application/octet-stream',
  'gemspec': 'text/x-script.ruby',
  'gif': 'image/gif',
  'gz': 'application/x-gzip',
  'h': 'text/x-c',
  'hh': 'text/x-c',
  'htm': 'text/html',
  'html': 'text/html',
  'ico': 'image/vnd.microsoft.icon',
  'ics': 'text/calendar',
  'ifb': 'text/calendar',
  'iso': 'application/octet-stream',
  'jar': 'application/java-archive',
  'java': 'text/x-java-source',
  'jnlp': 'application/x-java-jnlp-file',
  'jpeg': 'image/jpeg',
  'jpg': 'image/jpeg',
  'js': 'application/javascript',
  'json': 'application/json',
  'log': 'text/plain',
  'm3u': 'audio/x-mpegurl',
  'm4v': 'video/mp4',
  'man': 'text/troff',
  'mathml': 'application/mathml+xml',
  'mbox': 'application/mbox',
  'mdoc': 'text/troff',
  'me': 'text/troff',
  'mid': 'audio/midi',
  'midi': 'audio/midi',
  'mime': 'message/rfc822',
  'mml': 'application/mathml+xml',
  'mng': 'video/x-mng',
  'mov': 'video/quicktime',
  'mp3': 'audio/mpeg',
  'mp4': 'video/mp4',
  'mp4v': 'video/mp4',
  'mpeg': 'video/mpeg',
  'mpg': 'video/mpeg',
  'ms': 'text/troff',
  'msi': 'application/x-msdownload',
  'odp': 'application/vnd.oasis.opendocument.presentation',
  'ods': 'application/vnd.oasis.opendocument.spreadsheet',
  'odt': 'application/vnd.oasis.opendocument.text',
  'ogg': 'application/ogg',
  'p': 'text/x-pascal',
  'pas': 'text/x-pascal',
  'pbm': 'image/x-portable-bitmap',
  'pdf': 'application/pdf',
  'pem': 'application/x-x509-ca-cert',
  'pgm': 'image/x-portable-graymap',
  'pgp': 'application/pgp-encrypted',
  'pkg': 'application/octet-stream',
  'pl': 'text/x-script.perl',
  'pm': 'text/x-script.perl-module',
  'png': 'image/png',
  'pnm': 'image/x-portable-anymap',
  'ppm': 'image/x-portable-pixmap',
  'pps': 'application/vnd.ms-powerpoint',
  'ppt': 'application/vnd.ms-powerpoint',
  'ps': 'application/postscript',
  'psd': 'image/vnd.adobe.photoshop',
  'py': 'text/x-script.python',
  'qt': 'video/quicktime',
  'ra': 'audio/x-pn-realaudio',
  'rake': 'text/x-script.ruby',
  'ram': 'audio/x-pn-realaudio',
  'rar': 'application/x-rar-compressed',
  'rb': 'text/x-script.ruby',
  'rdf': 'application/rdf+xml',
  'roff': 'text/troff',
  'rpm': 'application/x-redhat-package-manager',
  'rss': 'application/rss+xml',
  'rtf': 'application/rtf',
  'ru': 'text/x-script.ruby',
  's': 'text/x-asm',
  'sgm': 'text/sgml',
  'sgml': 'text/sgml',
  'sh': 'application/x-sh',
  'sig': 'application/pgp-signature',
  'snd': 'audio/basic',
  'so': 'application/octet-stream',
  'svg': 'image/svg+xml',
  'svgz': 'image/svg+xml',
  'swf': 'application/x-shockwave-flash',
  't': 'text/troff',
  'tar': 'application/x-tar',
  'tbz': 'application/x-bzip-compressed-tar',
  'tcl': 'application/x-tcl',
  'tex': 'application/x-tex',
  'texi': 'application/x-texinfo',
  'texinfo': 'application/x-texinfo',
  'text': 'text/plain',
  'tif': 'image/tiff',
  'tiff': 'image/tiff',
  'torrent': 'application/x-bittorrent',
  'tr': 'text/troff',
  'txt': 'text/plain',
  'vcf': 'text/x-vcard',
  'vcs': 'text/x-vcalendar',
  'vrml': 'model/vrml',
  'war': 'application/java-archive',
  'wav': 'audio/x-wav',
  'webp': 'image/webp',
  'wma': 'audio/x-ms-wma',
  'wmv': 'video/x-ms-wmv',
  'wmx': 'video/x-ms-wmx',
  'wrl': 'model/vrml',
  'wsdl': 'application/wsdl+xml',
  'xbm': 'image/x-xbitmap',
  'xhtml': 'application/xhtml+xml',
  'xls': 'application/vnd.ms-excel',
  'xml': 'application/xml',
  'xpm': 'image/x-xpixmap',
  'xsl': 'application/xml',
  'xslt': 'application/xslt+xml',
  'yaml': 'text/yaml',
  'yml': 'text/yaml',
  'zip': 'application/zip',
  'woff': 'application/font-woff',
  'woff2': 'application/font-woff',
  'otf': 'application/font-sfnt',
  'otc': 'application/font-sfnt',
  'ttf': 'application/font-sfnt'
};

var options = {
  port: process.env.PM2_SERVE_PORT || process.argv[3] || 8080,
  host: process.env.PM2_SERVE_HOST || process.argv[4] || '0.0.0.0',
  path: path.resolve(process.env.PM2_SERVE_PATH || process.argv[2] || '.'),
  spa: process.env.PM2_SERVE_SPA === 'true',
  ftp: process.env.PM2_SERVE_FTP === 'true',
  homepage: process.env.PM2_SERVE_HOMEPAGE || '/index.html',
  basic_auth: process.env.PM2_SERVE_BASIC_AUTH === 'true' ? {
    username: process.env.PM2_SERVE_BASIC_AUTH_USERNAME,
    password: process.env.PM2_SERVE_BASIC_AUTH_PASSWORD
  } : null,
  monitor: process.env.PM2_SERVE_MONITOR
};

if (typeof options.port === 'string') {
  options.port = parseInt(options.port) || 8080
}

if (typeof options.monitor === 'string' && options.monitor !== '') {
  try {
    let fileContent = fs.readFileSync(path.join(process.env.PM2_HOME, 'agent.json5')).toString()
    // Handle old configuration with json5
    fileContent = fileContent.replace(/\s(\w+):/g, '"$1":')
    // parse
    let conf = JSON.parse(fileContent)
    options.monitorBucket = conf.public_key
  } catch (e) {
    console.log('Interaction file does not exist')
  }
}

// start an HTTP server
http.createServer(function (request, response) {
  if (options.basic_auth) {
    if (!request.headers.authorization || request.headers.authorization.indexOf('Basic ') === -1) {
      return sendBasicAuthResponse(response)
    }

    var user = parseBasicAuth(request.headers.authorization)
    if (user.username !== options.basic_auth.username || user.password !== options.basic_auth.password) {
      return sendBasicAuthResponse(response)
    }
  }

  serveFile(request.url, request, response);

}).listen(options.port, options.host, function (err) {
  if (err) {
    console.error(err);
    process.exit(1);
  }
  console.log('Exposing %s directory on %s:%d', options.path, options.host, options.port);
});

function serveFile(uri, request, response) {
  var file = decodeURIComponent(new URL(uri || request.url, 'http://localhost').pathname);

  var rootPath = path.resolve(options.path);
  var filePath = path.resolve(rootPath + file);

  // since we call filesystem directly so we need to verify that the
  // url doesn't go outside the serve path
  var relative = path.relative(rootPath, filePath);
  if (relative !== '' && (relative.startsWith('..') || path.isAbsolute(relative))) {
    response.writeHead(403, { 'Content-Type': 'text/html' });
    return response.end('403 Forbidden');
  }

  fs.stat(filePath, function (err, stats) {
    if (!err && stats.isDirectory()) {
      if (options.ftp) {
        // In ftp mode, try index.html first, fall back to directory listing
        var indexPath = path.join(filePath, 'index.html');
        fs.access(indexPath, fs.constants.R_OK, function (err) {
          if (!err) {
            return serveStaticFile(indexPath, file + '/index.html', request, response);
          }
          return serveDirectoryListing(filePath, file, response);
        });
        return;
      }
      // Not ftp mode: serve homepage
      if (file === '/' || file === '') {
        file = options.homepage;
        request.wantHomepage = true;
        filePath = path.resolve(options.path + file);
      }
    } else if (file === '/' || file === '') {
      file = options.homepage;
      request.wantHomepage = true;
      filePath = path.resolve(options.path + file);
    }
    serveStaticFile(filePath, file, request, response);
  });
}

function formatFileSize(bytes) {
  if (bytes < 1024) return bytes + 'B';
  if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(1) + 'K';
  if (bytes < 1024 * 1024 * 1024) return (bytes / (1024 * 1024)).toFixed(1) + 'M';
  return (bytes / (1024 * 1024 * 1024)).toFixed(1) + 'G';
}

function serveDirectoryListing(dirPath, urlPath, response) {
  fs.readdir(dirPath, function (err, entries) {
    if (err) {
      response.writeHead(500);
      return response.end('Error reading directory');
    }

    // Ensure urlPath ends with /
    if (urlPath && urlPath[urlPath.length - 1] !== '/') urlPath += '/';
    if (!urlPath) urlPath = '/';

    var pending = entries.length;
    var items = [];

    if (pending === 0) {
      return renderDirectoryListing(dirPath, urlPath, items, response);
    }

    entries.forEach(function (entry) {
      // Skip dotfiles
      if (entry[0] === '.') {
        if (--pending === 0) renderDirectoryListing(dirPath, urlPath, items, response);
        return;
      }
      fs.stat(path.join(dirPath, entry), function (err, stats) {
        if (!err) {
          items.push({
            name: entry,
            isDir: stats.isDirectory(),
            size: stats.size,
            mtime: stats.mtime
          });
        }
        if (--pending === 0) renderDirectoryListing(dirPath, urlPath, items, response);
      });
    });
  });
}

function renderDirectoryListing(dirPath, urlPath, items, response) {
  // Directories first, then files, alphabetical within each group
  items.sort(function (a, b) {
    if (a.isDir !== b.isDir) return a.isDir ? -1 : 1;
    return a.name.localeCompare(b.name);
  });

  var escHtml = function(s) { return s.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;'); };

  var rows = '';

  // Parent directory link (unless at root)
  if (urlPath !== '/') {
    rows += '<tr><td class="name"><a href="../">../</a></td><td class="size">-</td><td class="mtime">-</td></tr>\n';
  }

  items.forEach(function (item) {
    var displayName = item.isDir ? item.name + '/' : item.name;
    var href = encodeURIComponent(item.name) + (item.isDir ? '/' : '');
    var size = item.isDir ? '-' : formatFileSize(item.size);
    var mtime = item.mtime.toISOString().replace('T', ' ').slice(0, 19);
    rows += '<tr>'
      + '<td class="name"><a href="' + escHtml(href) + '">' + escHtml(displayName) + '</a></td>'
      + '<td class="size">' + size + '</td>'
      + '<td class="mtime">' + mtime + '</td>'
      + '</tr>\n';
  });

  var html = '<!DOCTYPE html>\n<html><head><meta charset="utf-8"><meta name="viewport" content="width=device-width">'
    + '<title>Index of ' + escHtml(urlPath) + '</title>'
    + '<style>'
    + 'body{font-family:monospace;margin:20px;background:#1e1e1e;color:#ccc}'
    + 'h1{font-size:1.2em;border-bottom:1px solid #444;padding-bottom:8px}'
    + 'table{border-collapse:collapse;width:100%}'
    + 'th,td{text-align:left;padding:4px 12px}'
    + 'th{border-bottom:2px solid #444;font-size:0.9em;color:#888}'
    + 'tr:hover{background:#2a2a2a}'
    + '.size,.mtime{white-space:nowrap}'
    + '.size{text-align:right}'
    + 'a{color:#58a6ff;text-decoration:none}'
    + 'a:hover{text-decoration:underline}'
    + '</style></head><body>'
    + '<h1>Index of ' + escHtml(urlPath) + '</h1>'
    + '<table><thead><tr><th>Name</th><th class="size">Size</th><th>Last Modified</th></tr></thead>'
    + '<tbody>' + rows + '</tbody></table>'
    + '</body></html>';

  response.writeHead(200, {
    'Content-Type': 'text/html',
    'Access-Control-Allow-Origin': '*',
    'Access-Control-Allow-Methods': 'GET'
  });
  response.end(html, 'utf-8');
}

function serveStaticFile(filePath, file, request, response) {
  var contentType = contentTypes[filePath.split('.').pop().toLowerCase()] || 'text/plain';

  fs.readFile(filePath, function (error, content) {
    if (error) {
      if ((!options.spa || file === options.homepage)) {
        console.error('[%s] Error while serving %s with content-type %s : %s',
                      new Date(), filePath, contentType, error.message || error);
      }
      //errorMeter.mark();
      if (error.code === 'ENOENT') {
        if (options.spa && !request.wantHomepage) {
          request.wantHomepage = true;
          return serveFile(`/${path.basename(file)}`, request, response);
        } else if (options.spa && file !== options.homepage) {
          return serveFile(options.homepage, request, response);
        }
        fs.readFile(options.path + '/404.html', function (err, content) {
          content = err ? '404 Not Found' : content;
          response.writeHead(404, { 'Content-Type': 'text/html' });
          return response.end(content, 'utf-8');
        });
        return;
      }
      response.writeHead(500);
      return response.end('Sorry, check with the site admin for error: ' + error.code + ' ..\n');
    }

    // Add CORS headers to allow browsers to fetch data directly
    response.writeHead(200, {
      'Content-Type': contentType,
      'Access-Control-Allow-Origin': '*',
      'Access-Control-Allow-Methods': 'GET'
    });
    if (options.monitorBucket && contentType === 'text/html') {
      content = content.toString().replace('</body>', `
<script>
;(function (b,e,n,o,i,t) {
  b[o]=b[o]||function(f){(b[o].c=b[o].c||[]).push(f)};
  t=e.createElement(i);e=e.getElementsByTagName(i)[0];
  t.async=1;t.src=n;e.parentNode.insertBefore(t,e);
}(window,document,'https://apm.pm2.io/pm2-io-apm-browser.v1.js','pm2Ready','script'))

pm2Ready(function(apm) {
  apm.setBucket('${options.monitorBucket}')
  apm.setApplication('${options.monitor}')
  apm.reportTimings()
  apm.reportIssues()
})
</script>
</body>
`);
    }
    response.end(content, 'utf-8');
    debug('[%s] Serving %s with content-type %s', Date.now(), filePath, contentType);
  });
}

function parseBasicAuth(auth) {
  // auth is like `Basic Y2hhcmxlczoxMjM0NQ==`
  var tmp = auth.split(' ');

  var buf = Buffer.from(tmp[1], 'base64');
  var plain = buf.toString();

  var creds = plain.split(':');
  return {
    username: creds[0],
    password: creds[1]
  }
}

function sendBasicAuthResponse(response) {
  response.writeHead(401, {
    'Content-Type': 'text/html',
    'WWW-Authenticate': 'Basic realm="Authentication service"'
  });
  return response.end('401 Unauthorized');
}