# Copyright (c) 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Copies the given "win tool" (which the toolchain uses to wrap compiler
# invocations) and the environment blocks for the 32-bit and 64-bit builds on
# Windows to the build directory.
#
# The arguments are the visual studio install location and the location of the
# win tool. The script assumes that the root build directory is the current dir
# and the files will be written to the current directory.

from __future__ import print_function

import json
import os
import re
import subprocess
import sys

sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir, os.pardir))
import gn_helpers

SCRIPT_DIR = os.path.dirname(__file__)

def _ExtractImportantEnvironment(output_of_set):
    """Extracts environment variables required for the toolchain to run from
  a textual dump output by the cmd.exe 'set' command."""
    envvars_to_save = (
        'cipd_cache_dir',  # needed by vpython
        'homedrive',  # needed by vpython
        'homepath',  # needed by vpython
        'goma_.*',  # TODO(scottmg): This is ugly, but needed for goma.
        'include',
        'lib',
        'libpath',
        'luci_context',  # needed by vpython
        'path',
        'pathext',
        'systemroot',
        'temp',
        'tmp',
        'userprofile',  # needed by vpython
        'vpython_virtualenv_root'  # needed by vpython
    )
    env = {}
    # This occasionally happens and leads to misleading SYSTEMROOT error messages
    # if not caught here.
    if output_of_set.count('=') == 0:
        raise Exception('Invalid output_of_set. Value is:\n%s' % output_of_set)
    for line in output_of_set.splitlines():
        for envvar in envvars_to_save:
            if re.match(envvar + '=', line.lower()):
                var, setting = line.split('=', 1)
                if envvar == 'path':
                    # Our own rules and actions in Chromium rely on python being in the
                    # path. Add the path to this python here so that if it's not in the
                    # path when ninja is run later, python will still be found.
                    setting = os.path.dirname(
                        sys.executable) + os.pathsep + setting
                env[var.upper()] = setting
                break
    if sys.platform in ('win32', 'cygwin'):
        for required in ('SYSTEMROOT', 'TEMP', 'TMP'):
            if required not in env:
                raise Exception('Environment variable "%s" '
                                'required to be set to valid path' % required)
    return env


def _DetectVisualStudioPath():
    """Return path to the installed Visual Studio.
  """

    # Use the code in build/vs_toolchain.py to avoid duplicating code.
    chromium_dir = os.path.abspath(os.path.join(SCRIPT_DIR, '..', '..', '..'))
    sys.path.append(os.path.join(chromium_dir, 'build'))
    import vs_toolchain
    return vs_toolchain.DetectVisualStudioPath()


def _LoadEnvFromBat(args):
    """Given a bat command, runs it and returns env vars set by it."""
    args = args[:]
    args.extend(('&&', 'set'))
    popen = subprocess.Popen(args,
                             shell=True,
                             stdout=subprocess.PIPE,
                             stderr=subprocess.STDOUT)
    variables, _ = popen.communicate()
    if popen.returncode != 0:
        raise Exception('"%s" failed with error %d' % (args, popen.returncode))
    return variables.decode(errors='ignore')


def _LoadToolchainEnv(cpu, toolchain_root, sdk_dir, target_store):
    """Returns a dictionary with environment variables that must be set while
  running binaries from the toolchain (e.g. INCLUDE and PATH for cl.exe)."""
    # Check if we are running in the SDK command line environment and use
    # the setup script from the SDK if so. |cpu| should be either
    # 'x86' or 'x64' or 'arm' or 'arm64'.
    assert cpu in ('x86', 'x64', 'arm', 'arm64')
    if bool(int(os.environ.get('DEPOT_TOOLS_WIN_TOOLCHAIN', 1))) and sdk_dir:
        # Load environment from json file.
        env = os.path.normpath(os.path.join(sdk_dir,
                                            'bin/SetEnv.%s.json' % cpu))
        env = json.load(open(env))['env']
        if env['VSINSTALLDIR'] == [["..", "..\\"]]:
            # Old-style paths were relative to the win_sdk\bin directory.
            json_relative_dir = os.path.join(sdk_dir, 'bin')
        else:
            # New-style paths are relative to the toolchain directory.
            json_relative_dir = toolchain_root
        for k in env:
            entries = [os.path.join(*([json_relative_dir] + e)) for e in env[k]]
            # clang-cl wants INCLUDE to be ;-separated even on non-Windows,
            # lld-link wants LIB to be ;-separated even on non-Windows.  Path gets :.
            # The separator for INCLUDE here must match the one used in main() below.
            sep = os.pathsep if k == 'PATH' else ';'
            env[k] = sep.join(entries)
        # PATH is a bit of a special case, it's in addition to the current PATH.
        env['PATH'] = env['PATH'] + os.pathsep + os.environ['PATH']
        # Augment with the current env to pick up TEMP and friends.
        for k in os.environ:
            if k not in env:
                env[k] = os.environ[k]

        varlines = []
        for k in sorted(env.keys()):
            varlines.append('%s=%s' % (str(k), str(env[k])))
        variables = '\n'.join(varlines)

        # Check that the json file contained the same environment as the .cmd file.
        if sys.platform in ('win32', 'cygwin'):
            script = os.path.normpath(os.path.join(sdk_dir, 'Bin/SetEnv.cmd'))
            arg = '/' + cpu
            json_env = _ExtractImportantEnvironment(variables)
            cmd_env = _ExtractImportantEnvironment(
                _LoadEnvFromBat([script, arg]))
            assert _LowercaseDict(json_env) == _LowercaseDict(cmd_env)
    else:
        if 'GYP_MSVS_OVERRIDE_PATH' not in os.environ:
            os.environ['GYP_MSVS_OVERRIDE_PATH'] = _DetectVisualStudioPath()
        # We only support x64-hosted tools.
        script_path = os.path.normpath(
            os.path.join(os.environ['GYP_MSVS_OVERRIDE_PATH'],
                         'VC/vcvarsall.bat'))
        if not os.path.exists(script_path):
            # vcvarsall.bat for VS 2017 fails if run after running vcvarsall.bat from
            # VS 2013 or VS 2015. Fix this by clearing the vsinstalldir environment
            # variable. Since vcvarsall.bat appends to the INCLUDE, LIB, and LIBPATH
            # environment variables we need to clear those to avoid getting double
            # entries when vcvarsall.bat has been run before gn gen. vcvarsall.bat
            # also adds to PATH, but there is no clean way of clearing that and it
            # doesn't seem to cause problems.
            if 'VSINSTALLDIR' in os.environ:
                del os.environ['VSINSTALLDIR']
                del os.environ['INCLUDE']
                del os.environ['LIB']
                del os.environ['LIBPATH']
            other_path = os.path.normpath(
                os.path.join(os.environ['GYP_MSVS_OVERRIDE_PATH'],
                             'VC/Auxiliary/Build/vcvarsall.bat'))
            if not os.path.exists(other_path):
                raise Exception(
                    '%s is missing - make sure VC++ tools are installed.' %
                    script_path)
            script_path = other_path
        cpu_arg = "amd64"
        if (cpu != 'x64'):
            # x64 is default target CPU thus any other CPU requires a target set
            cpu_arg += '_' + cpu
        args = [
            script_path,
            cpu_arg,
        ]
        # Store target must come before any SDK version declaration
        if (target_store):
            args.append('store')
        # Explicitly specifying the SDK version to build with to avoid accidentally
        # building with a new and untested SDK. This should stay in sync with the
        # packaged toolchain in build/vs_toolchain.py.
        args.append('10.0.19041.0')
        variables = _LoadEnvFromBat(args)
    return _ExtractImportantEnvironment(variables)


def _FormatAsEnvironmentBlock(envvar_dict):
    """Format as an 'environment block' directly suitable for CreateProcess.
  Briefly this is a list of key=value\0, terminated by an additional \0. See
  CreateProcess documentation for more details."""
    block = ''
    nul = '\0'
    for key, value in envvar_dict.items():
        block += key + '=' + value + nul
    block += nul
    return block


def _LowercaseDict(d):
    """Returns a copy of `d` with both key and values lowercased.

  Args:
    d: dict to lowercase (e.g. {'A': 'BcD'}).

  Returns:
    A dict with both keys and values lowercased (e.g.: {'a': 'bcd'}).
  """
    return {k.lower(): d[k].lower() for k in d}


def FindFileInEnvList(env, env_name, separator, file_name, optional=False):
    parts = env[env_name].split(separator)
    for path in parts:
        if os.path.exists(os.path.join(path, file_name)):
            return os.path.realpath(path)
    assert optional, "%s is not found in %s:\n%s\nCheck if it is installed." % (
        file_name, env_name, '\n'.join(parts))
    return ''


def main():
    if len(sys.argv) != 7:
        print('Usage setup_toolchain.py '
              '<visual studio path> <win sdk path> '
              '<runtime dirs> <target_os> <target_cpu> '
              '<environment block name|none>')
        sys.exit(2)
    # toolchain_root and win_sdk_path are only read if the hermetic Windows
    # toolchain is set, that is if DEPOT_TOOLS_WIN_TOOLCHAIN is not set to 0.
    # With the hermetic Windows toolchain, the visual studio path in argv[1]
    # is the root of the Windows toolchain directory.
    toolchain_root = sys.argv[1]
    win_sdk_path = sys.argv[2]

    runtime_dirs = sys.argv[3]
    target_os = sys.argv[4]
    target_cpu = sys.argv[5]
    environment_block_name = sys.argv[6]
    if (environment_block_name == 'none'):
        environment_block_name = ''

    if (target_os == 'winuwp'):
        target_store = True
    else:
        target_store = False

    cpus = ('x86', 'x64', 'arm', 'arm64')
    assert target_cpu in cpus
    vc_bin_dir = ''
    vc_lib_path = ''
    vc_lib_atlmfc_path = ''
    vc_lib_um_path = ''
    include = ''
    lib = ''

    # TODO(scottmg|goma): Do we need an equivalent of
    # ninja_use_custom_environment_files?

    def relflag(
            s):  # Make s relative to builddir when cwd and sdk on same drive.
        try:
            return os.path.relpath(s)
        except ValueError:
            return s

    def q(s):  # Quote s if it contains spaces or other weird characters.
        return s if re.match(r'^[a-zA-Z0-9._/\\:-]*$', s) else '"' + s + '"'

    for cpu in cpus:
        if cpu == target_cpu:
            # Extract environment variables for subprocesses.
            env = _LoadToolchainEnv(cpu, toolchain_root, win_sdk_path,
                                    target_store)
            env['PATH'] = runtime_dirs + os.pathsep + env['PATH']

            vc_bin_dir = FindFileInEnvList(env, 'PATH', os.pathsep, 'cl.exe')
            vc_lib_path = FindFileInEnvList(env, 'LIB', ';', 'msvcrt.lib')
            vc_lib_atlmfc_path = FindFileInEnvList(env,
                                                   'LIB',
                                                   ';',
                                                   'atls.lib',
                                                   optional=True)
            vc_lib_um_path = FindFileInEnvList(env, 'LIB', ';', 'user32.lib')

            # The separator for INCLUDE here must match the one used in
            # _LoadToolchainEnv() above.
            include = [
                p.replace('"', r'\"') for p in env['INCLUDE'].split(';') if p
            ]
            include = list(map(relflag, include))

            lib = [p.replace('"', r'\"') for p in env['LIB'].split(';') if p]
            lib = list(map(relflag, lib))

            include_I = ' '.join([q('/I' + i) for i in include])
            include_imsvc = ' '.join([q('-imsvc' + i) for i in include])
            libpath_flags = ' '.join([q('-libpath:' + i) for i in lib])

            if (environment_block_name != ''):
                env_block = _FormatAsEnvironmentBlock(env)
                with open(environment_block_name, 'w') as f:
                    f.write(env_block)

    print('vc_bin_dir = ' + gn_helpers.ToGNString(vc_bin_dir))
    assert include_I
    print('include_flags_I = ' + gn_helpers.ToGNString(include_I))
    assert include_imsvc
    if bool(int(os.environ.get('DEPOT_TOOLS_WIN_TOOLCHAIN',
                               1))) and win_sdk_path:
        print('include_flags_imsvc = ' +
              gn_helpers.ToGNString(q('/winsysroot' + relflag(toolchain_root))))
    else:
        print('include_flags_imsvc = ' + gn_helpers.ToGNString(include_imsvc))
    print('vc_lib_path = ' + gn_helpers.ToGNString(vc_lib_path))
    # Possible atlmfc library path gets introduced in the future for store thus
    # output result if a result exists.
    if (vc_lib_atlmfc_path != ''):
        print('vc_lib_atlmfc_path = ' +
              gn_helpers.ToGNString(vc_lib_atlmfc_path))
    print('vc_lib_um_path = ' + gn_helpers.ToGNString(vc_lib_um_path))
    print('paths = ' + gn_helpers.ToGNString(env['PATH']))
    assert libpath_flags
    print('libpath_flags = ' + gn_helpers.ToGNString(libpath_flags))


if __name__ == '__main__':
    main()