text: #!/usr/bin/python2.7
  #
  # Deprecation warning: (July 2020)
  # This build script has been deprecated, please use 'npm run build' instead.
  # The script will be removed from Blockly core in Q4 of 2020.
  #
  # Compresses the core Blockly files into a single JavaScript file.
  #
  # Copyright 2012 Google LLC
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #   http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  # Usage: build.py <0 or more of core, generators, langfiles>
  # build.py with no parameters builds all files.
  # core builds blockly_compressed, blockly_uncompressed, and blocks_compressed.
  # generators builds every <language>_compressed.js.
  # langfiles builds every msg/js/<LANG>.js file.
  
  # This script generates two versions of Blockly's core files:
  #   blockly_compressed.js
  #   blockly_uncompressed.js
  # The compressed file is a concatenation of all of Blockly's core files which
  # have been run through Google's Closure Compiler.  This is done using the
  # online API (which takes a few seconds and requires an Internet connection).
  # The uncompressed file is a script that loads in each of Blockly's core files
  # one by one.  This takes much longer for a browser to load, but is useful
  # when debugging code since line numbers are meaningful and variables haven't
  # been renamed.  The uncompressed file also allows for a faster development
  # cycle since there is no need to rebuild or recompile, just reload.
  #
  # This script also generates:
  #   blocks_compressed.js: The compressed Blockly language blocks.
  #   javascript_compressed.js: The compressed JavaScript generator.
  #   python_compressed.js: The compressed Python generator.
  #   php_compressed.js: The compressed PHP generator.
  #   lua_compressed.js: The compressed Lua generator.
  #   dart_compressed.js: The compressed Dart generator.
  #   msg/js/<LANG>.js for every language <LANG> defined in msg/js/<LANG>.json.
  
  import argparse
  import codecs
  import glob
  import json
  import os
  import re
  import subprocess
  import sys
  import threading
  
  if sys.version_info[0] == 2:
    import httplib
    from urllib import urlencode
  else:
    import http.client as httplib
    from urllib.parse import urlencode
    from importlib import reload
  
  # Read package.json and extract the current Blockly version.
  blocklyVersion = json.loads(open('package.json', 'r').read())['version']
  
  def import_path(fullpath):
    """Import a file with full path specification.
    Allows one to import from any directory, something __import__ does not do.
  
    Args:
        fullpath:  Path and filename of import.
  
    Returns:
        An imported module.
    """
    path, filename = os.path.split(fullpath)
    filename, ext = os.path.splitext(filename)
    sys.path.append(path)
    module = __import__(filename)
    reload(module)  # Might be out of date.
    del sys.path[-1]
    return module
  
  
  HEADER = ("// Do not edit this file; automatically generated by build.py.\n"
            "'use strict';\n")
  
  
  class Gen_uncompressed(threading.Thread):
    """Generate a JavaScript file that loads Blockly's raw files.
    Runs in a separate thread.
    """
    def __init__(self, search_paths, target_filename):
      threading.Thread.__init__(self)
      self.search_paths = search_paths
      self.target_filename = target_filename
  
    def run(self):
      f = open(self.target_filename, 'w')
      f.write(HEADER)
      f.write("""
  this.IS_NODE_JS = !!(typeof module !== 'undefined' && module.exports);
  
  this.BLOCKLY_DIR = (function(root) {
    if (!root.IS_NODE_JS) {
      // Find name of current directory.
      var scripts = document.getElementsByTagName('script');
      var re = new RegExp('(.+)[\/]blockly_(.*)uncompressed\.js$');
      for (var i = 0, script; script = scripts[i]; i++) {
        var match = re.exec(script.src);
        if (match) {
          return match[1];
        }
      }
      alert('Could not detect Blockly\\'s directory name.');
    }
    return '';
  })(this);
  
  this.BLOCKLY_BOOT = function(root) {
    // Execute after Closure has loaded.
  """)
      add_dependency = []
      base_path = calcdeps.FindClosureBasePath(self.search_paths)
      for dep in calcdeps.BuildDependenciesFromFiles(self.search_paths):
        add_dependency.append(calcdeps.GetDepsLine(dep, base_path))
      add_dependency.sort()  # Deterministic build.
      add_dependency = '\n'.join(add_dependency)
      f.write(add_dependency + '\n')
  
      f.write('\n')
      f.write('// Load Blockly.\n')
      f.write('goog.require(\'Blockly.requires\')\n')
  
      f.write("""
  delete root.BLOCKLY_DIR;
  delete root.BLOCKLY_BOOT;
  delete root.IS_NODE_JS;
  };
  
  if (this.IS_NODE_JS) {
    this.BLOCKLY_BOOT(this);
    module.exports = Blockly;
  } else {
    document.write('<script src="' + this.BLOCKLY_DIR +
        '/closure/goog/base.js"></script>');
    document.write('<script>this.BLOCKLY_BOOT(this);</script>');
  }
  """)
      f.close()
      print("SUCCESS: " + self.target_filename)
  
  
  class Gen_compressed(threading.Thread):
    """Generate a JavaScript file that contains all of Blockly's core and all
    required parts of Closure, compiled together.
    Uses the Closure Compiler's online API.
    Runs in a separate thread.
    """
    def __init__(self, search_paths, bundles):
      threading.Thread.__init__(self)
      self.search_paths = search_paths
      self.bundles = bundles
  
    def run(self):
      if (self.bundles.core):
        self.gen_core()
        self.gen_blocks()
  
      if (self.bundles.generators):
        self.gen_generator("javascript")
        self.gen_generator("python")
        self.gen_generator("php")
        self.gen_generator("lua")
        self.gen_generator("dart")
        self.gen_generator("arduino")
  
    def gen_core(self):
      target_filename = "blockly_compressed.js"
      # Define the parameters for the POST request.
      params = [
          ("compilation_level", "SIMPLE_OPTIMIZATIONS"),
          ("use_closure_library", "false"),
          ("output_format", "json"),
          ("output_info", "compiled_code"),
          ("output_info", "warnings"),
          ("output_info", "errors"),
          ("output_info", "statistics"),
          ("warning_level", "DEFAULT"),
        ]
  
      # Read in all the source files.
      filenames = calcdeps.CalculateDependencies(self.search_paths,
          [os.path.join("core", "requires.js")])
      filenames.sort()  # Deterministic build.
      for filename in filenames:
        # Filter out the Closure files (the compiler will add them).
        if filename.startswith("closure"):
          continue
        f = codecs.open(filename, encoding="utf-8")
        code = "".join(f.readlines())
        # Inject the Blockly version.
        if filename == "core/blockly.js":
          code = code.replace("Blockly.VERSION = 'uncompiled';",
                              "Blockly.VERSION = '%s';" % blocklyVersion)
        # Strip out all requireType calls.
        code = re.sub(r"goog.requireType(.*)", "", code)
        params.append(("js_code", code.encode("utf-8")))
        f.close()
  
      self.do_compile(params, target_filename, filenames, "")
  
    def gen_blocks(self):
      target_filename = "blocks_compressed.js"
      # Define the parameters for the POST request.
      params = [
          ("compilation_level", "SIMPLE_OPTIMIZATIONS"),
          ("output_format", "json"),
          ("output_info", "compiled_code"),
          ("output_info", "warnings"),
          ("output_info", "errors"),
          ("output_info", "statistics"),
          ("warning_level", "DEFAULT")
        ]
  
      # Add Blockly, Blockly.Blocks, and all fields to be compatible with the compiler.
      params.append(("js_code", """
  goog.provide('Blockly');
  goog.provide('Blockly.Blocks');
  goog.provide('Blockly.Types');
  goog.provide('Blockly.Comment');
  goog.provide('Blockly.FieldCheckbox');
  goog.provide('Blockly.FieldColour');
  goog.provide('Blockly.FieldDropdown');
  goog.provide('Blockly.FieldImage');
  goog.provide('Blockly.FieldLabel');
  goog.provide('Blockly.FieldMultilineInput');
  goog.provide('Blockly.FieldNumber');
  goog.provide('Blockly.FieldTextInput');
  goog.provide('Blockly.FieldVariable');
  goog.provide('Blockly.Mutator');
  goog.provide('Blockly.Warning');
  """))
      # Read in all the source files.
      filenames = glob.glob(os.path.join("blocks", "*.js"))
      filenames.sort()  # Deterministic build.
      for filename in filenames:
        f = codecs.open(filename, encoding="utf-8")
        params.append(("js_code", "".join(f.readlines()).encode("utf-8")))
        f.close()
  
      # Remove Blockly, Blockly.Blocks and all fields to be compatible with Blockly.
      remove = r"var Blockly=\{[^;]*\};\n?"
      self.do_compile(params, target_filename, filenames, remove)
  
    def gen_generator(self, language):
      target_filename = language + "_compressed.js"
      # Define the parameters for the POST request.
      params = [
          ("compilation_level", "SIMPLE_OPTIMIZATIONS"),
          ("output_format", "json"),
          ("output_info", "compiled_code"),
          ("output_info", "warnings"),
          ("output_info", "errors"),
          ("output_info", "statistics"),
          ("warning_level", "DEFAULT"),
        ]
  
      # Read in all the source files.
      # Add Blockly.Generator, Blockly.StaticTyping and Blockly.utils.string to be compatible
      # with the compiler.
      params.append(("js_code", """
  goog.provide('Blockly.Generator');
  goog.provide('Blockly.StaticTyping');
  goog.provide('Blockly.utils.global');
  goog.provide('Blockly.utils.string');
  """))
      filenames = glob.glob(
          os.path.join("generators", language, "*.js"))
      filenames.sort()  # Deterministic build.
      filenames.insert(0, os.path.join("generators", language + ".js"))
      for filename in filenames:
        f = codecs.open(filename, encoding="utf-8")
        params.append(("js_code", "".join(f.readlines()).encode("utf-8")))
        f.close()
      filenames.insert(0, "[goog.provide]")
  
      # Remove Blockly.Generator and Blockly.utils.string to be compatible
      # with Blockly.
      remove = r"var Blockly=\{[^;]*\};\s*Blockly.utils.global={};\s*Blockly.utils.string={};\n?"
      self.do_compile(params, target_filename, filenames, remove)
  
    def do_compile(self, params, target_filename, filenames, remove):
      # Send the request to Google.
      headers = {"Content-type": "application/x-www-form-urlencoded"}
      conn = httplib.HTTPSConnection("closure-compiler.appspot.com")
      conn.request("POST", "/compile", urlencode(params), headers)
      response = conn.getresponse()
  
      # Decode is necessary for Python 3.4 compatibility
      json_str = response.read().decode("utf-8")
      conn.close()
  
      # Parse the JSON response.
      try:
        json_data = json.loads(json_str)
      except ValueError:
        print("ERROR: Could not parse JSON for %s.  Raw data:" % target_filename)
        print(json_str)
        return
  
      def file_lookup(name):
        if not name.startswith("Input_"):
          return "???"
        n = int(name[6:])
        return filenames[n]
  
      if "serverErrors" in json_data:
        errors = json_data["serverErrors"]
        for error in errors:
          print("SERVER ERROR: %s" % target_filename)
          print(error["error"])
      elif "errors" in json_data:
        errors = json_data["errors"]
        for error in errors:
          print("FATAL ERROR")
          print(error["error"])
          if error["file"]:
            print("%s at line %d:" % (
                file_lookup(error["file"]), error["lineno"]))
            print(error["line"])
            print((" " * error["charno"]) + "^")
          sys.exit(1)
      else:
        if "warnings" in json_data:
          warnings = json_data["warnings"]
          for warning in warnings:
            print("WARNING")
            print(warning["warning"])
            if warning["file"]:
              print("%s at line %d:" % (
                  file_lookup(warning["file"]), warning["lineno"]))
              print(warning["line"])
              print((" " * warning["charno"]) + "^")
          print()
  
        if not "compiledCode" in json_data:
          print("FATAL ERROR: Compiler did not return compiledCode.")
          sys.exit(1)
  
        code = HEADER + "\n" + json_data["compiledCode"]
        # Remove Blockly definitions to be compatible with Blockly.
        code = re.sub(remove, "", code)
        code = self.trim_licence(code)
  
        stats = json_data["statistics"]
        original_b = stats["originalSize"]
        compressed_b = stats["compressedSize"]
        if original_b > 0 and compressed_b > 0:
          f = open(target_filename, "w")
          f.write(code)
          f.close()
  
          original_kb = int(original_b / 1024 + 0.5)
          compressed_kb = int(compressed_b / 1024 + 0.5)
          ratio = int(float(compressed_b) / float(original_b) * 100 + 0.5)
          print("SUCCESS: " + target_filename)
          print("Size changed from %d KB to %d KB (%d%%)." % (
              original_kb, compressed_kb, ratio))
        else:
          print("UNKNOWN ERROR")
  
    def trim_licence(self, code):
      """Strip out Google's and MIT's Apache licences.
  
      JS Compiler preserves dozens of Apache licences in the Blockly code.
      Remove these if they belong to Google or MIT.
      MIT's permission to do this is logged in Blockly issue 2412.
  
      Args:
        code: Large blob of compiled source code.
  
      Returns:
        Code with Google's and MIT's Apache licences trimmed.
      """
      apache2 = re.compile("""/\\*
  
   (Copyright \\d+ (Google LLC|Massachusetts Institute of Technology))
  ( All rights reserved.
  )? SPDX-License-Identifier: Apache-2.0
  \\*/""")
      return re.sub(apache2, "", code)
  
  
  class Gen_langfiles(threading.Thread):
    """Generate JavaScript file for each natural language supported.
  
    Runs in a separate thread.
    """
  
    def __init__(self):
      threading.Thread.__init__(self)
  
    def run(self):
      # The files msg/json/{en,qqq,synonyms}.json depend on msg/messages.js.
      try:
        subprocess.check_call([
            "python",
            os.path.join("scripts", "i18n", "js_to_json.py"),
            "--input_file", "msg/messages.js",
            "--output_dir", "msg/json/",
            "--quiet"])
      except (subprocess.CalledProcessError, OSError) as e:
        # Documentation for subprocess.check_call says that CalledProcessError
        # will be raised on failure, but I found that OSError is also possible.
        print("Error running scripts/i18n/js_to_json.py: ", e)
        sys.exit(1)
  
      # Checking whether it is necessary to rebuild the js files would be a lot of
      # work since we would have to compare each <lang>.json file with each
      # <lang>.js file.  Rebuilding is easy and cheap, so just go ahead and do it.
      try:
        # Use create_messages.py to create .js files from .json files.
        cmd = [
            "python",
            os.path.join("scripts", "i18n", "create_messages.py"),
            "--source_lang_file", os.path.join("msg", "json", "en.json"),
            "--source_synonym_file", os.path.join("msg", "json", "synonyms.json"),
            "--source_constants_file", os.path.join("msg", "json", "constants.json"),
            "--key_file", os.path.join("msg", "json", "keys.json"),
            "--output_dir", os.path.join("msg", "js"),
            "--quiet"]
        json_files = glob.glob(os.path.join("msg", "json", "*.json"))
        json_files = [file for file in json_files if not
                      (file.endswith(("keys.json", "synonyms.json", "qqq.json", "constants.json")))]
        cmd.extend(json_files)
        subprocess.check_call(cmd)
      except (subprocess.CalledProcessError, OSError) as e:
        print("Error running scripts/i18n/create_messages.py: ", e)
        sys.exit(1)
  
      # Output list of .js files created.
      for f in json_files:
        # This assumes the path to the current directory does not contain "json".
        f = f.replace("json", "js")
        if os.path.isfile(f):
          print("SUCCESS: " + f)
        else:
          print("FAILED to create " + f)
  
  # Class to hold arguments if user passes in old argument style.
  class Arguments:
    def __init__(self):
      self.core = False
      self.generators = False
      self.langfiles = False
  
  # Gets the command line arguments.
  def get_args():
    parser = argparse.ArgumentParser(description="Decide which files to build.")
    parser.add_argument('-core', action="store_true", default=False, help="Build core")
    parser.add_argument('-generators', action="store_true", default=False, help="Build the generators")
    parser.add_argument('-langfiles', action="store_true", default=False, help="Build all the language files")
  
    # New argument style: ./build.py -core
    # Old argument style: ./build.py core
    # Changed as of July 2019.
    try:
      args = parser.parse_args()
      if (not args.core) and (not args.generators) and (not args.langfiles):
        # No arguments, use these defaults:
        args.core = True
        args.generators = True
        args.langfiles = True
    except SystemExit:
      # Fall back to old argument style.
      args = Arguments()
      args.core = 'core' in sys.argv
      args.generators = 'generators' in sys.argv
      args.langfiles = 'langfiles' in sys.argv
      if 'accessible' in sys.argv:
        print("The Blockly accessibility demo has moved to https://github.com/google/blockly-experimental")
    return args
  
  if __name__ == "__main__":
    args = get_args()
    calcdeps = import_path(os.path.join("closure", "bin", "calcdeps.py"))
    full_search_paths = calcdeps.ExpandDirectories(["core", "closure"])
    full_search_paths = sorted(full_search_paths)  # Deterministic build.
  
    print("Deprecation Warning: (July 2020)\n This build script has been " +
      "deprecated, please use 'npm run build' instead. \n The script will be " +
      "removed from Blockly core in Q4 of 2020.\n")
  
    # Uncompressed and compressed are run in parallel threads.
    # Uncompressed is limited by processor speed.
    if (args.core):
      Gen_uncompressed(full_search_paths, 'blockly_uncompressed.js').start()
  
    # Compressed is limited by network and server speed.
    Gen_compressed(full_search_paths, args).start()
  
    # This is run locally in a separate thread
    if (args.langfiles):
      Gen_langfiles().start()
  