#!/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 sys

import subprocess2

import gclient_utils
import git_common as git


def main(args):
    if gclient_utils.IsEnvCog():
        print(
            "upstream-diff command is not supported. Please navigate to source "
            "control view in the activity bar to check the diff.",
            file=sys.stderr,
        )
        return 1
    default_args = git.get_config_list("depot-tools.upstream-diff.default-args")
    args = default_args + args

    current_branch = git.current_branch()

    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--wordwise",
        action="store_true",
        default=False,
        help=("Print a colorized wordwise diff instead of line-wise diff"),
    )
    parser.add_argument(
        "--branch",
        default=current_branch,
        help="Show changes from a different branch. Passing "
        '"HEAD" is the same as omitting this option (it '
        "diffs against the current branch)",
    )
    opts, extra_args = parser.parse_known_args(args)

    if opts.branch == "HEAD":
        opts.branch = current_branch

    if not opts.branch or opts.branch == "HEAD":
        print("fatal: Cannot perform git-upstream-diff while not on a branch")
        return 1

    par = git.upstream(opts.branch)
    if not par:
        print("fatal: No upstream configured for branch '%s'" % opts.branch)
        return 1

    cmd = [
        git.GIT_EXE,
        "-c",
        "core.quotePath=false",
        "diff",
        "--patience",
        "-C",
        "-C",
    ]
    if opts.wordwise:
        cmd += ["--word-diff=color", r"--word-diff-regex=(\w+|[^[:space:]])"]
    cmd += [git.get_or_create_merge_base(opts.branch, par)]
    # Only specify the end commit if it is not the current branch, this lets the
    # diff include uncommitted changes when diffing the current branch.
    if opts.branch != current_branch:
        cmd += [opts.branch]

    cmd += extra_args

    return subprocess2.check_call(cmd)


if __name__ == "__main__":
    try:
        sys.exit(main(sys.argv[1:]))
    except KeyboardInterrupt:
        sys.stderr.write("interrupted\n")
        sys.exit(1)
