#!/usr/bin/env python3
# Copyright 2014 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import doctest
import itertools
import os
import plistlib
import re
import subprocess
import sys

# This script prints information about the build system, the operating
# system and the iOS or Mac SDK (depending on the platform "iphonesimulator",
# "iphoneos" or "macosx" generally).


def SplitVersion(version):
    """Splits the Xcode version to 3 values.

    >>> list(SplitVersion('8.2.1.1'))
    ['8', '2', '1']
    >>> list(SplitVersion('9.3'))
    ['9', '3', '0']
    >>> list(SplitVersion('10.0'))
    ['10', '0', '0']
    """
    version = version.split('.')
    return itertools.islice(
        itertools.chain(version, itertools.repeat('0')), 0, 3
    )


def FormatVersion(version):
    """Converts Xcode version to a format required for DTXcode in Info.plist

    >>> FormatVersion('8.2.1')
    '0821'
    >>> FormatVersion('9.3')
    '0930'
    >>> FormatVersion('10.0')
    '1000'
    """
    major, minor, patch = SplitVersion(version)
    return ('%2s%s%s' % (major, minor, patch)).replace(' ', '0')


def FillXcodeVersion(settings, developer_dir):
    """Fills the Xcode version and build number into |settings|."""
    if developer_dir:
        xcode_version_plist_path = os.path.join(
            developer_dir, 'Contents/version.plist'
        )
        with open(xcode_version_plist_path, 'rb') as f:
            version_plist = plistlib.load(f)
        settings['xcode_version'] = FormatVersion(
            version_plist['CFBundleShortVersionString']
        )
        settings['xcode_version_int'] = int(settings['xcode_version'], 10)
        settings['xcode_build'] = version_plist['ProductBuildVersion']
        return

    lines = (
        subprocess.check_output(['xcodebuild', '-version'])
        .decode('UTF-8')
        .splitlines()
    )
    version_verbatim = lines[0].split()[-1]
    settings['xcode_version'] = FormatVersion(version_verbatim)
    settings['xcode_version_int'] = int(settings['xcode_version'], 10)
    settings['xcode_version_verbatim'] = version_verbatim
    settings['xcode_build'] = lines[-1].split()[-1]


def FillMachineOSBuild(settings):
    """Fills OS build number into |settings|."""
    machine_os_build = (
        subprocess.check_output(['sw_vers', '-buildVersion'])
        .decode('UTF-8')
        .strip()
    )
    settings['machine_os_build'] = machine_os_build


def FillSDKPathAndVersion(settings, platform, xcode_version):
    """Fills the SDK path and version for |platform| into |settings|."""
    settings['sdk_path'] = (
        subprocess.check_output(['xcrun', '-sdk', platform, '--show-sdk-path'])
        .decode('UTF-8')
        .strip()
    )
    settings['sdk_version'] = (
        subprocess.check_output(
            ['xcrun', '-sdk', platform, '--show-sdk-version']
        )
        .decode('UTF-8')
        .strip()
    )
    settings['sdk_platform_path'] = (
        subprocess.check_output(
            ['xcrun', '-sdk', platform, '--show-sdk-platform-path']
        )
        .decode('UTF-8')
        .strip()
    )
    settings['sdk_build'] = (
        subprocess.check_output(
            ['xcrun', '-sdk', platform, '--show-sdk-build-version']
        )
        .decode('UTF-8')
        .strip()
    )
    settings['toolchains_path'] = os.path.join(
        subprocess.check_output(['xcode-select', '-print-path'])
        .decode('UTF-8')
        .strip(),
        'Toolchains/XcodeDefault.xctoolchain',
    )


def CreateXcodeSymlinkAt(src, dst, root_build_dir):
    """Create symlink to Xcode directory at target location."""

    if not os.path.isdir(dst):
        os.makedirs(dst)

    dst = os.path.join(dst, os.path.basename(src))
    updated_value = os.path.join(root_build_dir, dst)

    # Update the symlink only if it is different from the current destination.
    if os.path.islink(dst):
        current_src = os.readlink(dst)
        if current_src == src:
            return updated_value
        os.unlink(dst)
        sys.stderr.write(
            'existing symlink %s points %s; want %s. Removed.'
            % (dst, current_src, src)
        )
    os.symlink(src, dst)
    return updated_value


def main():
    doctest.testmod()

    parser = argparse.ArgumentParser()
    parser.add_argument('--developer_dir')
    parser.add_argument(
        '--get_sdk_info',
        action='store_true',
        default=False,
        help='Returns SDK info in addition to xcode info.',
    )
    parser.add_argument(
        '--get_machine_info',
        action='store_true',
        default=False,
        help='Returns machine info in addition to xcode info.',
    )
    parser.add_argument(
        '--create_symlink_at',
        help='Create symlink of SDK at given location and '
        'returns the symlinked paths as SDK info instead '
        'of the original location.',
    )
    parser.add_argument(
        '--root_build_dir', default='.', help='Value of gn $root_build_dir'
    )
    parser.add_argument(
        'platform',
        choices=[
            'appletvos',
            'appletvsimulator',
            'iphoneos',
            'iphonesimulator',
            'macosx',
            'watchos',
            'watchsimulator',
        ],
    )
    args = parser.parse_args()
    if args.developer_dir:
        os.environ['DEVELOPER_DIR'] = args.developer_dir

    settings = {}
    if args.get_machine_info:
        FillMachineOSBuild(settings)
    FillXcodeVersion(settings, args.developer_dir)
    if args.get_sdk_info:
        FillSDKPathAndVersion(
            settings, args.platform, settings['xcode_version']
        )

    for key in sorted(settings):
        value = settings[key]
        if args.create_symlink_at and '_path' in key:
            value = CreateXcodeSymlinkAt(
                value, args.create_symlink_at, args.root_build_dir
            )
        if isinstance(value, str):
            value = '"%s"' % value
        print('%s=%s' % (key, value))


if __name__ == '__main__':
    sys.exit(main())