# pylint: disable=g-bad-file-header
# Copyright 2016 The Bazel Authors. All rights reserved.
#
# 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.
"""Configuring the C++ toolchain on Windows."""

load(
    "@bazel_tools//tools/cpp:lib_cc_configure.bzl",
    "auto_configure_fail",
    "auto_configure_warning",
    "escape_string",
    "execute",
    "get_env_var",
    "is_cc_configure_debug",
    "resolve_labels",
    "which",
    "which_cmd",
)

def _get_escaped_windows_msys_crosstool_content(repository_ctx, use_mingw = False):
    """Return the content of msys crosstool which is still the default CROSSTOOL on Windows."""
    bazel_sh = get_env_var(repository_ctx, "BAZEL_SH").replace("\\", "/").lower()
    tokens = bazel_sh.rsplit("/", 1)
    prefix = "mingw64" if use_mingw else "usr"
    msys_root = None
    if tokens[0].endswith("/usr/bin"):
        msys_root = tokens[0][:len(tokens[0]) - len("usr/bin")]
    elif tokens[0].endswith("/bin"):
        msys_root = tokens[0][:len(tokens[0]) - len("bin")]
    if not msys_root:
        auto_configure_fail(
            "Could not determine MSYS/Cygwin root from BAZEL_SH (%s)" % bazel_sh,
        )
    escaped_msys_root = escape_string(msys_root)
    return (((
                '   abi_version: "local"\n' +
                '   abi_libc_version: "local"\n' +
                '   builtin_sysroot: ""\n' +
                '   compiler: "msys-gcc"\n' +
                '   host_system_name: "local"\n' +
                "   needsPic: false\n" +
                '   target_libc: "msys"\n' +
                '   target_cpu: "x64_windows"\n' +
                '   target_system_name: "local"\n'
            ) if not use_mingw else "") +
            '   tool_path { name: "ar" path: "%s%s/bin/ar" }\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "compat-ld" path: "%s%s/bin/ld" }\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "cpp" path: "%s%s/bin/cpp" }\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "dwp" path: "%s%s/bin/dwp" }\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "gcc" path: "%s%s/bin/gcc" }\n' % (escaped_msys_root, prefix) +
            '   artifact_name_pattern { category_name: "executable" prefix: "" extension: ".exe"}\n' +
            '   cxx_flag: "-std=gnu++0x"\n' +
            '   linker_flag: "-lstdc++"\n' +
            '   cxx_builtin_include_directory: "%s%s/"\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "gcov" path: "%s%s/bin/gcov" }\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "ld" path: "%s%s/bin/ld" }\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "nm" path: "%s%s/bin/nm" }\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "objcopy" path: "%s%s/bin/objcopy" }\n' % (escaped_msys_root, prefix) +
            '   objcopy_embed_flag: "-I"\n' +
            '   objcopy_embed_flag: "binary"\n' +
            '   tool_path { name: "objdump" path: "%s%s/bin/objdump" }\n' % (escaped_msys_root, prefix) +
            '   tool_path { name: "strip" path: "%s%s/bin/strip" }' % (escaped_msys_root, prefix) +
            '   feature { name: "targets_windows" implies: "copy_dynamic_libraries_to_binary" enabled: true }' +
            '   feature { name: "copy_dynamic_libraries_to_binary" }')

def _get_system_root(repository_ctx):
    """Get System root path on Windows, default is C:\\\Windows. Doesn't %-escape the result."""
    if "SYSTEMROOT" in repository_ctx.os.environ:
        return escape_string(repository_ctx.os.environ["SYSTEMROOT"])
    auto_configure_warning("SYSTEMROOT is not set, using default SYSTEMROOT=C:\\Windows")
    return "C:\\Windows"

def _add_system_root(repository_ctx, env):
    """Running VCVARSALL.BAT and VCVARSQUERYREGISTRY.BAT need %SYSTEMROOT%\\\\system32 in PATH."""
    if "PATH" not in env:
        env["PATH"] = ""
    env["PATH"] = env["PATH"] + ";" + _get_system_root(repository_ctx) + "\\system32"
    return env

def find_vc_path(repository_ctx):
    """Find Visual C++ build tools install path. Doesn't %-escape the result."""

    # 1. Check if BAZEL_VC or BAZEL_VS is already set by user.
    if "BAZEL_VC" in repository_ctx.os.environ:
        return repository_ctx.os.environ["BAZEL_VC"]

    if "BAZEL_VS" in repository_ctx.os.environ:
        return repository_ctx.os.environ["BAZEL_VS"] + "\\VC\\"
    auto_configure_warning("'BAZEL_VC' is not set, " +
                           "start looking for the latest Visual C++ installed.")

    # 2. Check if VS%VS_VERSION%COMNTOOLS is set, if true then try to find and use
    # vcvarsqueryregistry.bat to detect VC++.
    auto_configure_warning("Looking for VS%VERSION%COMNTOOLS environment variables, " +
                           "eg. VS140COMNTOOLS")
    for vscommontools_env in [
        "VS140COMNTOOLS",
        "VS120COMNTOOLS",
        "VS110COMNTOOLS",
        "VS100COMNTOOLS",
        "VS90COMNTOOLS",
    ]:
        if vscommontools_env not in repository_ctx.os.environ:
            continue
        vcvarsqueryregistry = repository_ctx.os.environ[vscommontools_env] + "\\vcvarsqueryregistry.bat"
        if not repository_ctx.path(vcvarsqueryregistry).exists:
            continue
        repository_ctx.file(
            "get_vc_dir.bat",
            "@echo off\n" +
            "call \"" + vcvarsqueryregistry + "\"\n" +
            "echo %VCINSTALLDIR%",
            True,
        )
        env = _add_system_root(repository_ctx, repository_ctx.os.environ)
        vc_dir = execute(repository_ctx, ["./get_vc_dir.bat"], environment = env)

        auto_configure_warning("Visual C++ build tools found at %s" % vc_dir)
        return vc_dir

    # 3. User might clean up all environment variables, if so looking for Visual C++ through registry.
    # Works for all VS versions, including Visual Studio 2017.
    auto_configure_warning("Looking for Visual C++ through registry")
    reg_binary = _get_system_root(repository_ctx) + "\\system32\\reg.exe"
    vc_dir = None
    for key, suffix in (("VC7", ""), ("VS7", "\\VC")):
        for version in ["15.0", "14.0", "12.0", "11.0", "10.0", "9.0", "8.0"]:
            if vc_dir:
                break
            result = repository_ctx.execute([reg_binary, "query", "HKEY_LOCAL_MACHINE\\SOFTWARE\\Wow6432Node\\Microsoft\\VisualStudio\\SxS\\" + key, "/v", version])
            if is_cc_configure_debug(repository_ctx):
                auto_configure_warning("registry query result for VC %s:\n\nSTDOUT(start)\n%s\nSTDOUT(end)\nSTDERR(start):\n%s\nSTDERR(end)\n" %
                                       (version, result.stdout, result.stderr))
            if not result.stderr:
                for line in result.stdout.split("\n"):
                    line = line.strip()
                    if line.startswith(version) and line.find("REG_SZ") != -1:
                        vc_dir = line[line.find("REG_SZ") + len("REG_SZ"):].strip() + suffix

    # 4. Check default directories for VC installation
    auto_configure_warning("Looking for default Visual C++ installation directory")
    program_files_dir = get_env_var(repository_ctx, "PROGRAMFILES(X86)", default = "C:\\Program Files (x86)", enable_warning = True)
    for path in [
        "Microsoft Visual Studio\\2017\\BuildTools\\VC",
        "Microsoft Visual Studio\\2017\\Community\\VC",
        "Microsoft Visual Studio\\2017\\Enterprise\\VC",
        "Microsoft Visual Studio 14.0\\VC",
    ]:
        path = program_files_dir + "\\" + path
        if repository_ctx.path(path).exists:
            vc_dir = path
            break

    if not vc_dir:
        return None
    auto_configure_warning("Visual C++ build tools found at %s" % vc_dir)
    return vc_dir

def _is_vs_2017(vc_path):
    """Check if the installed VS version is Visual Studio 2017."""

    # In VS 2017, the location of VC is like:
    # C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\
    # In VS 2015 or older version, it is like:
    # C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\
    return vc_path.find("2017") != -1

def _find_vcvarsall_bat_script(repository_ctx, vc_path):
    """Find vcvarsall.bat script. Doesn't %-escape the result."""
    if _is_vs_2017(vc_path):
        vcvarsall = vc_path + "\\Auxiliary\\Build\\VCVARSALL.BAT"
    else:
        vcvarsall = vc_path + "\\VCVARSALL.BAT"

    if not repository_ctx.path(vcvarsall).exists:
        return None

    return vcvarsall

def setup_vc_env_vars(repository_ctx, vc_path):
    """Get environment variables set by VCVARSALL.BAT. Doesn't %-escape the result!"""
    vcvarsall = _find_vcvarsall_bat_script(repository_ctx, vc_path)
    if not vcvarsall:
        return None
    repository_ctx.file(
        "get_env.bat",
        "@echo off\n" +
        "call \"" + vcvarsall + "\" amd64 > NUL \n" +
        "echo PATH=%PATH%,INCLUDE=%INCLUDE%,LIB=%LIB%,WINDOWSSDKDIR=%WINDOWSSDKDIR% \n",
        True,
    )
    env = _add_system_root(
        repository_ctx,
        {"PATH": "", "INCLUDE": "", "LIB": "", "WINDOWSSDKDIR": ""},
    )
    envs = execute(repository_ctx, ["./get_env.bat"], environment = env).split(",")
    env_map = {}
    for env in envs:
        key, value = env.split("=", 1)
        env_map[key] = escape_string(value.replace("\\", "\\\\"))
    return env_map

def find_msvc_tool(repository_ctx, vc_path, tool):
    """Find the exact path of a specific build tool in MSVC. Doesn't %-escape the result."""
    tool_path = ""
    if _is_vs_2017(vc_path):
        # For VS 2017, the tools are under a directory like:
        # C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Tools\MSVC\14.10.24930\bin\HostX64\x64
        dirs = repository_ctx.path(vc_path + "\\Tools\\MSVC").readdir()
        if len(dirs) < 1:
            return None

        # Normally there should be only one child directory under %VC_PATH%\TOOLS\MSVC,
        # but iterate every directory to be more robust.
        for path in dirs:
            tool_path = str(path) + "\\bin\\HostX64\\x64\\" + tool
            if repository_ctx.path(tool_path).exists:
                break
    else:
        # For VS 2015 and older version, the tools are under:
        # C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64
        tool_path = vc_path + "\\bin\\amd64\\" + tool

    if not repository_ctx.path(tool_path).exists:
        return None

    return tool_path

def _find_missing_vc_tools(repository_ctx, vc_path):
    """Check if any required tool is missing under given VC path."""
    missing_tools = []
    if not _find_vcvarsall_bat_script(repository_ctx, vc_path):
        missing_tools.append("VCVARSALL.BAT")

    for tool in ["cl.exe", "link.exe", "lib.exe", "ml64.exe"]:
        if not find_msvc_tool(repository_ctx, vc_path, tool):
            missing_tools.append(tool)

    return missing_tools

def _is_support_debug_fastlink(repository_ctx, vc_path):
    """Run MSVC linker alone to see if it supports /DEBUG:FASTLINK."""
    linker = find_msvc_tool(repository_ctx, vc_path, "link.exe")
    result = execute(repository_ctx, [linker], expect_failure = True)
    return result.find("/DEBUG[:{FASTLINK|FULL|NONE}]") != -1

def configure_windows_toolchain(repository_ctx):
    """Configure C++ toolchain on Windows."""
    paths = resolve_labels(repository_ctx, [
        "@bazel_tools//tools/cpp:BUILD.static.windows",
        "@bazel_tools//tools/cpp:CROSSTOOL",
        "@bazel_tools//tools/cpp:CROSSTOOL.tpl",
        "@bazel_tools//tools/cpp:vc_installation_error.bat.tpl",
    ])

    repository_ctx.symlink(paths["@bazel_tools//tools/cpp:BUILD.static.windows"], "BUILD")

    vc_path = find_vc_path(repository_ctx)
    missing_tools = None
    if not vc_path:
        repository_ctx.template(
            "vc_installation_error.bat",
            paths["@bazel_tools//tools/cpp:vc_installation_error.bat.tpl"],
            {"%{vc_error_message}": ""},
        )
    else:
        missing_tools = _find_missing_vc_tools(repository_ctx, vc_path)
        if missing_tools:
            message = "\r\n".join([
                "echo. 1>&2",
                "echo Visual C++ build tools seems to be installed at %s 1>&2" % vc_path,
                "echo But Bazel can't find the following tools: 1>&2",
                "echo     %s 1>&2" % ", ".join(missing_tools),
                "echo. 1>&2",
            ])
            repository_ctx.template(
                "vc_installation_error.bat",
                paths["@bazel_tools//tools/cpp:vc_installation_error.bat.tpl"],
                {"%{vc_error_message}": message},
            )

    if not vc_path or missing_tools:
        repository_ctx.template(
            "CROSSTOOL",
            paths["@bazel_tools//tools/cpp:CROSSTOOL.tpl"],
            {
                "%{cpu}": "x64_windows",
                "%{default_toolchain_name}": "msvc_x64",
                "%{toolchain_name}": "msys_x64",
                "%{msvc_env_tmp}": "",
                "%{msvc_env_path}": "",
                "%{msvc_env_include}": "",
                "%{msvc_env_lib}": "",
                "%{msvc_cl_path}": "vc_installation_error.bat",
                "%{msvc_ml_path}": "vc_installation_error.bat",
                "%{msvc_link_path}": "vc_installation_error.bat",
                "%{msvc_lib_path}": "vc_installation_error.bat",
                "%{dbg_mode_debug}": "/DEBUG",
                "%{fastbuild_mode_debug}": "/DEBUG",
                "%{compilation_mode_content}": "",
                "%{content}": _get_escaped_windows_msys_crosstool_content(repository_ctx),
                "%{msys_x64_mingw_content}": _get_escaped_windows_msys_crosstool_content(repository_ctx, use_mingw = True),
                "%{opt_content}": "",
                "%{dbg_content}": "",
                "%{link_content}": "",
                "%{cxx_builtin_include_directory}": "",
                "%{coverage}": "",
            },
        )
        return

    env = setup_vc_env_vars(repository_ctx, vc_path)
    escaped_paths = escape_string(env["PATH"])
    escaped_include_paths = escape_string(env["INCLUDE"])
    escaped_lib_paths = escape_string(env["LIB"])
    escaped_tmp_dir = escape_string(
        get_env_var(repository_ctx, "TMP", "C:\\Windows\\Temp").replace("\\", "\\\\"),
    )
    msvc_cl_path = find_msvc_tool(repository_ctx, vc_path, "cl.exe").replace("\\", "/")
    msvc_ml_path = find_msvc_tool(repository_ctx, vc_path, "ml64.exe").replace("\\", "/")
    msvc_link_path = find_msvc_tool(repository_ctx, vc_path, "link.exe").replace("\\", "/")
    msvc_lib_path = find_msvc_tool(repository_ctx, vc_path, "lib.exe").replace("\\", "/")
    escaped_cxx_include_directories = []

    for path in escaped_include_paths.split(";"):
        if path:
            escaped_cxx_include_directories.append("cxx_builtin_include_directory: \"%s\"" % path)

    support_debug_fastlink = _is_support_debug_fastlink(repository_ctx, vc_path)

    repository_ctx.template(
        "CROSSTOOL",
        paths["@bazel_tools//tools/cpp:CROSSTOOL.tpl"],
        {
            "%{cpu}": "x64_windows",
            "%{default_toolchain_name}": "msvc_x64",
            "%{toolchain_name}": "msys_x64",
            "%{msvc_env_tmp}": escaped_tmp_dir,
            "%{msvc_env_path}": escaped_paths,
            "%{msvc_env_include}": escaped_include_paths,
            "%{msvc_env_lib}": escaped_lib_paths,
            "%{msvc_cl_path}": msvc_cl_path,
            "%{msvc_ml_path}": msvc_ml_path,
            "%{msvc_link_path}": msvc_link_path,
            "%{msvc_lib_path}": msvc_lib_path,
            "%{dbg_mode_debug}": "/DEBUG:FULL" if support_debug_fastlink else "/DEBUG",
            "%{fastbuild_mode_debug}": "/DEBUG:FASTLINK" if support_debug_fastlink else "/DEBUG",
            "%{content}": _get_escaped_windows_msys_crosstool_content(repository_ctx),
            "%{msys_x64_mingw_content}": _get_escaped_windows_msys_crosstool_content(repository_ctx, use_mingw = True),
            "%{opt_content}": "",
            "%{dbg_content}": "",
            "%{link_content}": "",
            "%{cxx_builtin_include_directory}": "\n".join(escaped_cxx_include_directories),
            "%{coverage}": "",
        },
    )