#!/usr/bin/env python

# Copyright 2019 Google LLC.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""
update_fuchsia_sdk

  Downloads both the Fuchsia SDK and Fuchsia-compatible clang
  zip archives from chrome infra (CIPD) and extracts them to
  the arg-provide |sdk_dir| and |clang_dir| respectively.  This
  provides the complete toolchain required to build Fuchsia binaries
  from the Fuchsia SDK.

"""

import argparse
import errno
import logging
import os
import platform
import shutil
import subprocess
import tempfile

def MessageExit(message):
  logging.error(message)
  sys.exit(1)

# Verify that "cipd" tool is readily available.
def CipdLives():
    err_msg = "Cipd not found, please install. See: " + \
              "https://commondatastorage.googleapis.com/chrome-infra-docs/flat" + \
              "/depot_tools/docs/html/depot_tools_tutorial.html#_setting_up"
    try:
        subprocess.call(["cipd", "--version"])
    except OSError as e:
        if e.errno == errno.ENOENT:
            MessageExit(err_msg)
        else:
            MessageExit("cipd command execution failed.")

# Download and unzip CIPD package archive.
def DownloadAndUnzip(pkg_name, version, cipd_cache_dir, output_dir):
  pkg_suffix = pkg_name.replace('/', '-') + ".zip"
  zip_file = tempfile.NamedTemporaryFile(suffix=pkg_suffix, delete=False)
  cipd_cmd = "cipd pkg-fetch " + pkg_name + " -version \"" + version + "\" -out " + \
      zip_file.name + " -cache-dir " + cipd_cache_dir
  unzip_cmd = "unzip -q " + zip_file.name + " -d " + output_dir
  os.system(cipd_cmd)
  os.system(unzip_cmd)

def Main():
  CipdLives()
  parser = argparse.ArgumentParser()
  parser.add_argument("-sdk_dir", type=str,
          help="Destination directory for the fuchsia SDK.")
  parser.add_argument("-clang_dir", type=str,
          help="Destination directory for the fuchsia toolchain.")
  parser.add_argument("-overwrite_dirs", type=bool, default=False,
          help="REMOVES existing sdk and clang dirs and makes new ones.  When false " +
               "  the unzip command issue will require file overwrite confirmation.")
  parser.add_argument("-cipd_cache_dir", type=str, default="/tmp", required=False,
          help="Cache directory for CIPD downloads to prevent redundant downloads.")
  parser.add_argument("-cipd_sdk_version", type=str, default="latest", required=False,
          help="CIPD sdk version to download, e.g.: git_revision:fce11c6904c888e6d39f71e03806a540852dec41")
  parser.add_argument("-cipd_clang_version", type=str, default="latest", required=False,
          help="CIPD clang version to download, e.g.: git_revision:fce11c6904c888e6d39f71e03806a540852dec41")
  args = parser.parse_args()

  sdk_dir = args.sdk_dir
  clang_dir = args.clang_dir
  cipd_sdk_version = args.cipd_sdk_version
  cipd_clang_version = args.cipd_clang_version

  if args.overwrite_dirs:
    dirs = [sdk_dir, clang_dir]
    for curr_dir in dirs:
      try:
        if os.path.exists(curr_dir):
            shutil.rmtree(curr_dir)
        os.makedirs(curr_dir)
      except OSError:
        MessageExit("Creation of the directory %s failed" % curr_dir)
  else:
    # Make dirs for sdk and clang.
    if not os.path.exists(sdk_dir):
        os.makedirs(sdk_dir)
    if not os.path.exists(clang_dir):
        os.makedirs(clang_dir)

    # Verify that existing dirs are writable.
    if (not os.access(sdk_dir, os.W_OK)) or (not os.path.isdir(sdk_dir)):
      MessageExit("Can't write to sdk dir " + sdk_dir)
    if (not os.access(clang_dir, os.W_OK)) or (not os.path.isdir(clang_dir)):
      MessageExit("Can't write to clang dir " + clang_dir)
 
  ostype = platform.system()
  if ostype == "Linux":
    os_string = "linux-amd64"
  elif ostype == "Darwin":
    os_string = "mac-amd64"
  else:
    MessageExit("Unknown host " + ostype)

  # |sdk_pkg| and |clang_pkg| below are prescribed paths defined by chrome-infra.
  sdk_pkg = "fuchsia/sdk/core/" + os_string
  DownloadAndUnzip(sdk_pkg, cipd_sdk_version, args.cipd_cache_dir, sdk_dir)
  clang_pkg = "fuchsia/clang/" + os_string
  DownloadAndUnzip(clang_pkg, cipd_clang_version, args.cipd_cache_dir, clang_dir)

if __name__ == "__main__":
  import sys
  Main()