#!/usr/bin/env python3
# Copyright 2013 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""
Removes bundled libraries to make sure they are not used.

See README for more details.
"""

import optparse
import os.path
import sys


def DoMain(argv):
    my_dirname = os.path.abspath(os.path.dirname(__file__))
    source_tree_root = os.path.abspath(
        os.path.join(my_dirname, '..', '..', '..')
    )

    if (
        os.path.join(source_tree_root, 'build', 'linux', 'unbundle')
        != my_dirname
    ):
        print(
            'Sanity check failed: please run this script from '
            'build/linux/unbundle directory.'
        )
        return 1

    parser = optparse.OptionParser()
    parser.add_option('--do-remove', action='store_true')

    options, args = parser.parse_args(argv)

    exclusion_used = {}
    for exclusion in args:
        exclusion_used[exclusion] = False

    for root, dirs, files in os.walk(source_tree_root, topdown=False):
        # Only look at paths which contain a "third_party" component
        # (note that e.g. third_party.png doesn't count).
        root_relpath = os.path.relpath(root, source_tree_root)
        if 'third_party' not in root_relpath.split(os.sep):
            continue

        for f in files:
            path = os.path.join(root, f)
            relpath = os.path.relpath(path, source_tree_root)

            excluded = False
            for exclusion in args:
                # Require precise exclusions. Find the right-most third_party
                # in the relative path, and if there is more than one ignore
                # the exclusion if it's completely contained within the part
                # before right-most third_party path component.
                split = relpath.rsplit(os.sep + 'third_party' + os.sep, 1)
                if len(split) > 1 and split[0].startswith(exclusion):
                    continue

                if relpath.startswith(exclusion):
                    # Multiple exclusions can match the same path. Go through all of them
                    # and mark each one as used.
                    exclusion_used[exclusion] = True
                    excluded = True
            if excluded:
                continue

            # Deleting gyp files almost always leads to gyp failures.
            # These files come from Chromium project, and can be replaced if needed.
            if f.endswith('.gyp') or f.endswith('.gypi'):
                continue

            # Same about GN files.
            if f.endswith('.gn') or f.endswith('.gni'):
                continue

            # Deleting .isolate files leads to gyp failures. They are usually
            # not used by a distro build anyway.
            # See http://www.chromium.org/developers/testing/isolated-testing
            # for more info.
            if f.endswith('.isolate'):
                continue

            if options.do_remove:
                # Delete the file - best way to ensure it's not used during build.
                os.remove(path)
            else:
                # By default just print paths that would be removed.
                print(path)

    exit_code = 0

    # Fail if exclusion list contains stale entries - this helps keep it
    # up to date.
    for exclusion, used in exclusion_used.items():
        if not used:
            print('%s does not exist' % exclusion)
            exit_code = 1

    if not options.do_remove:
        print(
            'To actually remove files printed above, please pass '
            '--do-remove flag.'
        )

    return exit_code


if __name__ == '__main__':
    sys.exit(DoMain(sys.argv[1:]))