#!/usr/bin/env python
# Copyright (c) 2012 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.

"""Utility for checking and processing licensing information in third_party
directories.

Usage: licenses.py <command>

Commands:
  scan     scan third_party directories, verifying that we have licensing info
  credits  generate about:credits on stdout

(You can also import this as a module.)
"""

import argparse
import cgi
import os
import sys

# Paths from the root of the tree to directories to skip.
PRUNE_PATHS = set([
    # Same module occurs in crypto/third_party/nss and net/third_party/nss, so
    # skip this one.
    os.path.join('third_party','nss'),

    # Placeholder directory only, not third-party code.
    os.path.join('third_party','adobe'),

    # Apache 2.0 license. See crbug.com/140478
    os.path.join('third_party','bidichecker'),

    # Build files only, not third-party code.
    os.path.join('third_party','widevine'),

    # Only binaries, used during development.
    os.path.join('third_party','valgrind'),

    # Used for development and test, not in the shipping product.
    os.path.join('build','secondary'),
    os.path.join('third_party','bison'),
    os.path.join('third_party','blanketjs'),
    os.path.join('third_party','cygwin'),
    os.path.join('third_party','gles2_conform'),
    os.path.join('third_party','gnu_binutils'),
    os.path.join('third_party','gold'),
    os.path.join('third_party','gperf'),
    os.path.join('third_party','lighttpd'),
    os.path.join('third_party','llvm'),
    os.path.join('third_party','llvm-build'),
    os.path.join('third_party','mingw-w64'),
    os.path.join('third_party','nacl_sdk_binaries'),
    os.path.join('third_party','pefile'),
    os.path.join('third_party','perl'),
    os.path.join('third_party','psyco_win32'),
    os.path.join('third_party','pylib'),
    os.path.join('third_party','pywebsocket'),
    os.path.join('third_party','qunit'),
    os.path.join('third_party','sinonjs'),
    os.path.join('third_party','syzygy'),
    os.path.join('tools', 'profile_chrome', 'third_party'),

    # Chromium code in third_party.
    os.path.join('third_party','fuzzymatch'),
    os.path.join('tools', 'swarming_client'),

    # Stuff pulled in from chrome-internal for official builds/tools.
    os.path.join('third_party', 'clear_cache'),
    os.path.join('third_party', 'gnu'),
    os.path.join('third_party', 'googlemac'),
    os.path.join('third_party', 'pcre'),
    os.path.join('third_party', 'psutils'),
    os.path.join('third_party', 'sawbuck'),
    # See crbug.com/350472
    os.path.join('chrome', 'browser', 'resources', 'chromeos', 'quickoffice'),
    # Chrome for Android proprietary code.
    os.path.join('clank'),

    # Redistribution does not require attribution in documentation.
    os.path.join('third_party','directxsdk'),
    os.path.join('third_party','platformsdk_win2008_6_1'),
    os.path.join('third_party','platformsdk_win7'),

    # For testing only, presents on some bots.
    os.path.join('isolate_deps_dir'),
])

# Directories we don't scan through.
VCS_METADATA_DIRS = ('.svn', '.git')
PRUNE_DIRS = (VCS_METADATA_DIRS +
              ('out', 'Debug', 'Release',  # build files
               'layout_tests'))            # lots of subdirs

ADDITIONAL_PATHS = (
    os.path.join('breakpad'),
    os.path.join('chrome', 'common', 'extensions', 'docs', 'examples'),
    os.path.join('chrome', 'test', 'chromeos', 'autotest'),
    os.path.join('chrome', 'test', 'data'),
    os.path.join('native_client'),
    os.path.join('net', 'tools', 'spdyshark'),
    os.path.join('sdch', 'open-vcdiff'),
    os.path.join('testing', 'gmock'),
    os.path.join('testing', 'gtest'),
    os.path.join('tools', 'gyp'),
    os.path.join('tools', 'page_cycler', 'acid3'),
    os.path.join('url', 'third_party', 'mozilla'),
    os.path.join('v8'),
    # Fake directories to include the strongtalk and fdlibm licenses.
    os.path.join('v8', 'strongtalk'),
    os.path.join('v8', 'fdlibm'),
)


# Directories where we check out directly from upstream, and therefore
# can't provide a README.chromium.  Please prefer a README.chromium
# wherever possible.
SPECIAL_CASES = {
    os.path.join('native_client'): {
        "Name": "native client",
        "URL": "http://code.google.com/p/nativeclient",
        "License": "BSD",
    },
    os.path.join('sdch', 'open-vcdiff'): {
        "Name": "open-vcdiff",
        "URL": "https://github.com/google/open-vcdiff",
        "License": "Apache 2.0, MIT, GPL v2 and custom licenses",
        "License Android Compatible": "yes",
    },
    os.path.join('testing', 'gmock'): {
        "Name": "gmock",
        "URL": "http://code.google.com/p/googlemock",
        "License": "BSD",
        "License File": "NOT_SHIPPED",
    },
    os.path.join('testing', 'gtest'): {
        "Name": "gtest",
        "URL": "http://code.google.com/p/googletest",
        "License": "BSD",
        "License File": "NOT_SHIPPED",
    },
    os.path.join('third_party', 'angle'): {
        "Name": "Almost Native Graphics Layer Engine",
        "URL": "http://code.google.com/p/angleproject/",
        "License": "BSD",
    },
    os.path.join('third_party', 'cros_system_api'): {
        "Name": "Chromium OS system API",
        "URL": "http://www.chromium.org/chromium-os",
        "License": "BSD",
        # Absolute path here is resolved as relative to the source root.
        "License File": "/LICENSE.chromium_os",
    },
    os.path.join('third_party', 'lss'): {
        "Name": "linux-syscall-support",
        "URL": "http://code.google.com/p/linux-syscall-support/",
        "License": "BSD",
        "License File": "/LICENSE",
    },
    os.path.join('third_party', 'pdfium'): {
        "Name": "PDFium",
        "URL": "http://code.google.com/p/pdfium/",
        "License": "BSD",
    },
    os.path.join('third_party', 'pdfsqueeze'): {
        "Name": "pdfsqueeze",
        "URL": "http://code.google.com/p/pdfsqueeze/",
        "License": "Apache 2.0",
        "License File": "COPYING",
    },
    os.path.join('third_party', 'ppapi'): {
        "Name": "ppapi",
        "URL": "http://code.google.com/p/ppapi/",
    },
    os.path.join('third_party', 'scons-2.0.1'): {
        "Name": "scons-2.0.1",
        "URL": "http://www.scons.org",
        "License": "MIT",
        "License File": "NOT_SHIPPED",
    },
    os.path.join('third_party', 'catapult'): {
        "Name": "catapult",
        "URL": "https://github.com/catapult-project/catapult",
        "License": "BSD",
        "License File": "NOT_SHIPPED",
    },
    os.path.join('third_party', 'v8-i18n'): {
        "Name": "Internationalization Library for v8",
        "URL": "http://code.google.com/p/v8-i18n/",
        "License": "Apache 2.0",
    },
    os.path.join('third_party', 'WebKit'): {
        "Name": "WebKit",
        "URL": "http://webkit.org/",
        "License": "BSD and GPL v2",
        # Absolute path here is resolved as relative to the source root.
        "License File": "/third_party/WebKit/LICENSE_FOR_ABOUT_CREDITS",
    },
    os.path.join('third_party', 'webpagereplay'): {
        "Name": "webpagereplay",
        "URL": "http://code.google.com/p/web-page-replay",
        "License": "Apache 2.0",
        "License File": "NOT_SHIPPED",
    },
    os.path.join('tools', 'gyp'): {
        "Name": "gyp",
        "URL": "http://code.google.com/p/gyp",
        "License": "BSD",
        "License File": "NOT_SHIPPED",
    },
    os.path.join('v8'): {
        "Name": "V8 JavaScript Engine",
        "URL": "http://code.google.com/p/v8",
        "License": "BSD",
    },
    os.path.join('v8', 'strongtalk'): {
        "Name": "Strongtalk",
        "URL": "http://www.strongtalk.org/",
        "License": "BSD",
        # Absolute path here is resolved as relative to the source root.
        "License File": "/v8/LICENSE.strongtalk",
    },
    os.path.join('v8', 'fdlibm'): {
        "Name": "fdlibm",
        "URL": "http://www.netlib.org/fdlibm/",
        "License": "Freely Distributable",
        # Absolute path here is resolved as relative to the source root.
        "License File" : "/v8/src/third_party/fdlibm/LICENSE",
        "License Android Compatible" : "yes",
    },
    os.path.join('third_party', 'khronos_glcts'): {
        # These sources are not shipped, are not public, and it isn't
        # clear why they're tripping the license check.
        "Name": "khronos_glcts",
        "URL": "http://no-public-url",
        "License": "Khronos",
        "License File": "NOT_SHIPPED",
    },
    os.path.join('tools', 'telemetry', 'third_party', 'gsutil'): {
        "Name": "gsutil",
        "URL": "https://cloud.google.com/storage/docs/gsutil",
        "License": "Apache 2.0",
        "License File": "NOT_SHIPPED",
    },
}

# Special value for 'License File' field used to indicate that the license file
# should not be used in about:credits.
NOT_SHIPPED = "NOT_SHIPPED"


class LicenseError(Exception):
    """We raise this exception when a directory's licensing info isn't
    fully filled out."""
    pass

def AbsolutePath(path, filename, root):
    """Convert a path in README.chromium to be absolute based on the source
    root."""
    if filename.startswith('/'):
        # Absolute-looking paths are relative to the source root
        # (which is the directory we're run from).
        absolute_path = os.path.join(root, filename[1:])
    else:
        absolute_path = os.path.join(root, path, filename)
    if os.path.exists(absolute_path):
        return absolute_path
    return None

def ParseDir(path, root, require_license_file=True, optional_keys=None):
    """Examine a third_party/foo component and extract its metadata."""

    # Parse metadata fields out of README.chromium.
    # We examine "LICENSE" for the license file by default.
    metadata = {
        "License File": "LICENSE",  # Relative path to license text.
        "Name": None,               # Short name (for header on about:credits).
        "URL": None,                # Project home page.
        "License": None,            # Software license.
        }

    if optional_keys is None:
        optional_keys = []

    if path in SPECIAL_CASES:
        metadata.update(SPECIAL_CASES[path])
    else:
        # Try to find README.chromium.
        readme_path = os.path.join(root, path, 'README.chromium')
        if not os.path.exists(readme_path):
            raise LicenseError("missing README.chromium or licenses.py "
                               "SPECIAL_CASES entry")

        for line in open(readme_path):
            line = line.strip()
            if not line:
                break
            for key in metadata.keys() + optional_keys:
                field = key + ": "
                if line.startswith(field):
                    metadata[key] = line[len(field):]

    # Check that all expected metadata is present.
    errors = []
    for key, value in metadata.iteritems():
        if not value:
            errors.append("couldn't find '" + key + "' line "
                          "in README.chromium or licences.py "
                          "SPECIAL_CASES")

    # Special-case modules that aren't in the shipping product, so don't need
    # their license in about:credits.
    if metadata["License File"] != NOT_SHIPPED:
        # Check that the license file exists.
        for filename in (metadata["License File"], "COPYING"):
            license_path = AbsolutePath(path, filename, root)
            if license_path is not None:
                break

        if require_license_file and not license_path:
            errors.append("License file not found. "
                          "Either add a file named LICENSE, "
                          "import upstream's COPYING if available, "
                          "or add a 'License File:' line to "
                          "README.chromium with the appropriate path.")
        metadata["License File"] = license_path

    if errors:
        raise LicenseError(";\n".join(errors))
    return metadata


def ContainsFiles(path, root):
    """Determines whether any files exist in a directory or in any of its
    subdirectories."""
    for _, dirs, files in os.walk(os.path.join(root, path)):
        if files: