#!/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.

"""Copies files to a directory."""

import argparse
import filecmp
import itertools
import os
import shutil
import sys

from util import build_utils
import action_helpers  # build_utils adds //build to sys.path.


def _get_all_files(base):
    """Returns a list of all the files in |base|. Each entry is relative to the
    last path entry of |base|."""
    result = []
    dirname = os.path.dirname(base)
    for root, _, files in os.walk(base):
        result.extend([os.path.join(root[len(dirname) :], f) for f in files])
    return result


def CopyFile(f, dest, deps):
    """Copy file or directory and update deps."""
    if os.path.isdir(f):
        shutil.copytree(f, os.path.join(dest, os.path.basename(f)))
        deps.extend(_get_all_files(f))
    else:
        if os.path.isfile(os.path.join(dest, os.path.basename(f))):
            dest = os.path.join(dest, os.path.basename(f))

        deps.append(f)

        if os.path.isfile(dest):
            if filecmp.cmp(dest, f, shallow=False):
                return
            # The shutil.copy() below would fail if the file does not have write
            # permissions. Deleting the file has similar costs to modifying the
            # permissions.
            os.unlink(dest)

        shutil.copy(f, dest)


def DoCopy(options, deps):
    """Copy files or directories given in options.files and update deps."""
    files = list(
        itertools.chain.from_iterable(
            action_helpers.parse_gn_list(f) for f in options.files
        )
    )

    for f in files:
        if os.path.isdir(f) and not options.clear:
            print(
                'To avoid stale files you must use --clear when copying '
                'directories'
            )
            sys.exit(-1)
        CopyFile(f, options.dest, deps)


def DoRenaming(options, deps):
    """Copy and rename files given in options.renaming_sources and update deps."""
    src_files = list(
        itertools.chain.from_iterable(
            action_helpers.parse_gn_list(f) for f in options.renaming_sources
        )
    )

    dest_files = list(
        itertools.chain.from_iterable(
            action_helpers.parse_gn_list(f)
            for f in options.renaming_destinations
        )
    )

    if len(src_files) != len(dest_files):
        print('Renaming source and destination files not match.')
        sys.exit(-1)

    for src, dest in zip(src_files, dest_files):
        if os.path.isdir(src):
            print('renaming diretory is not supported.')
            sys.exit(-1)
        else:
            CopyFile(src, os.path.join(options.dest, dest), deps)


def main(args):
    args = build_utils.ExpandFileArgs(args)

    parser = argparse.ArgumentParser()
    action_helpers.add_depfile_arg(parser)

    parser.add_argument('--dest', help='Directory to copy files to.')
    parser.add_argument(
        '--files', action='append', help='List of files to copy.'
    )
    parser.add_argument(
        '--clear',
        action='store_true',
        help='If set, the destination directory will be deleted '
        'before copying files to it. This is highly recommended to '
        'ensure that no stale files are left in the directory.',
    )
    parser.add_argument('--stamp', help='Path to touch on success.')
    parser.add_argument(
        '--renaming-sources',
        action='append',
        help='List of files need to be renamed while being '
        'copied to dest directory',
    )
    parser.add_argument(
        '--renaming-destinations',
        action='append',
        help='List of destination file name without path, the '
        'number of elements must match rename-sources.',
    )

    options = parser.parse_args(args)

    if options.clear:
        build_utils.DeleteDirectory(options.dest)
        build_utils.MakeDirectory(options.dest)

    deps = []

    if options.files:
        DoCopy(options, deps)

    if options.renaming_sources:
        DoRenaming(options, deps)

    if options.depfile:
        action_helpers.write_depfile(options.depfile, options.stamp, deps)

    if options.stamp:
        build_utils.Touch(options.stamp)


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