path: root/scripts/rfr

#!/usr/bin/python
#
# Simple script for formatting RFR messages for nvgpu changes.
#

import os
import re
import json
import argparse
import tempfile
import subprocess
import smtplib

from email.mime.text import MIMEText

VERSION = '1.0.1'

# Gerrit commit URL formats. These are regular expressions to match the
# incoming URLs against.
gr_fmts = [ r'http://git-master/r/(\d+)',
            r'http://git-master/r/#/c/(\d+)/',
            r'http://git-master.nvidia.com/r/(\d+)',
            r'http://git-master.nvidia.com/r/#/c/(\d+)/',
            r'https://git-master/r/(\d+)',
            r'https://git-master/r/#/c/(\d+)/',
            r'https://git-master.nvidia.com/r/(\d+)',
            r'https://git-master.nvidia.com/r/#/c/(\d+)',
            r'https://git-master.nvidia.com/r/#/c/(\d+)/' ]

# The user to use. May be overridden but the default comes from the environment.
user = os.environ['USER']

# Gerrit query command to obtain the patch URL. The substitution will be the
# gerrit Change-ID parsed from the git commit message.
gr_query_cmd = 'ssh %s@git-master -p 29418 gerrit query --format json %s'

def parse_args():
    """
    Parse arguments to rfr.
    """

    ep="""This program will format commit messages into something that can be
sent to the nvgpu mailing list for review
"""
    help_msg="""Git or gerrit commits to describe. Can be either a git or gerrit
commit ID. If the ID starts with a 'I' then it will be treated as a gerrit ID.
If the commit ID looks like a gerrit URL then it is treated as a gerrit URL.
Otherwise it's treated as a git commit ID.
"""
    parser = argparse.ArgumentParser(description='RFR formatting tool',
                                     epilog=ep)

    parser.add_argument('-V', '--version', action='store_true', default=False,
                        help='print the program version')
    parser.add_argument('-m', '--msg', action='store', default=None,
                        help='Custom message to add to the RFR email')
    parser.add_argument('-N', '--no-msg', action='store_true', default=False,
                        help='Force no message in output.')
    parser.add_argument('-e', '--email', action='store_true', default=False,
                        help='Use direct email to post the RFR.')
    parser.add_argument('-s', '--subject', action='store', default=None,
                        help='Specify the email\'s subject.')
    parser.add_argument('-R', '--sender', action='store', default=None,
                        help='Specify a special from: email address.')
    parser.add_argument('-t', '--to', action='append', default=[],
                        help='Specify an additional To: email address. '
                        'Can be repeated (-t a -t b).')
    parser.add_argument('-F', '--file', action='store', default=None,
                        help='File with commits, one per line')

    # Positionals: the gerrit URLs.
    parser.add_argument('commits', metavar='Commit-IDs',
                        nargs='*',
                        help=help_msg)

    arg_parser = parser.parse_args()

    return arg_parser

def get_gerrit_url_id(cmt):
    """
    Determines if the passed cmt is a gerrit commit URL. If it is then this
    returns the URL ID; otherwise it returns None.
    """

    for fmt in gr_fmts:
        p = re.compile(fmt)
        m = p.search(cmt)
        if m:
            return m.group(1)

    return None

def read_commit_file(filp):
    """
    Read a file full of commits and return a list of those commits.
    """

    commits = [ ]

    for line in filp:

        line = line.strip()

        # Skip empty lines and lines that start with a '#'.
        if line.find('#') == 0 or line == '':
            continue

        # Otherwise append the line to the list of commits. This will append
        # all the text, so in cases like:
        #
        #   http://git-master/r/1540705 - my commit
        #
        # Anything after the first space in the line is ignored. This lets you
        # add some descriptive text after the commit.
        commits.append(line.split()[0])

    return commits

def gerrit_query(change):
    """
    Query gerrit for the JSON change information. Return a python object
    describing the JSON data.

    change can either be a Change-Id or the numeric change number from a URL.

    Note there is an interesting limitation with this: gerrit can have multiple
    changes with the same Change-Id (./sigh). So if you query a change ID that
    points to multiple changes you get back all of them.

    This script just uses the first. Ideally one could filter by branch or by
    some other distinguishing factor.
    """

    query_cmd = gr_query_cmd % (user, change)

    prog = subprocess.Popen(query_cmd, shell=True,
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)

    stdout_data, stderr_data = prog.communicate()
    if prog.returncode != 0:
        print('`%s\' failed!' % query_cmd)
        return False

    commit = json.loads(stdout_data.decode('utf-8').splitlines()[0])
    if 'id' not in commit:
        print('%s is not a gerrit commit!?' % change)
        print('Most likely you need to push the change.')
        return None

    return commit

def commit_info_from_gerrit_change_id(change_id):
    """
    Return a dict with all the gerrit info from a gerrit change ID.
    """

    return gerrit_query(change_id)

def commit_info_from_git_sha1(rev):
    """
    Return a dict with all the gerrit info from a git sha1 rev.
    """

    return gerrit_query(rev)

def commit_info_from_gerrit_cl(cmt):
    """
    Return a dict with all the gerrit info from a Gerrit URL.
    """

    cl = get_gerrit_url_id(cmt)
    if not cl:
        return None

    return gerrit_query(cl)

def git_sha1_from_commit(commit_ish):
    """
    Return sha1 revision from a commit-ish string, or None if this doesn't
    appear to be a commit.
    """

    prog = subprocess.Popen('git rev-parse %s' % commit_ish, shell=True,
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)

    stdout_data, stderr_data = prog.communicate()
    if prog.returncode != 0:
        print('`git rev-parse %s\' failed?!' % commit_ish)
        return None

    return stdout_data.decode('utf-8')

def get_user_message(start_msg):
    """
    Get a user message from the user. This is done with the default text
    editor.
    """

    editor = os.environ.get('EDITOR', 'vim')

    with tempfile.NamedTemporaryFile(suffix=".tmp") as filp:
        filp.write(start_msg)
        filp.flush()

        edit_cmd = editor + ' ' + filp.name

        try:
            subprocess.call(edit_cmd.split())
        except:
            print('Failed to run editor: `%s\'' % edit_cmd)
            return None

        filp.seek(0)
        return filp.read()

def indent_lines(text, ind):
    """
    Prepend each new line in the passed text with ind.
    """
    return ''.join(ind + l + '\n' for l in text.splitlines())

def format_commits(commits_info, extra_message):
    """
    Takes a list of the commit info objects and returns a string with the
    text to print. This can either be directly printed or emailed.
    """

    whole_template = """
Hi All,

I would like you to review the following changes.
{extra_message}
{cmt_descriptions}
Thanks!
{cmt_verbose}"""

    cmt_template = """
+----------------------------------------
| {url}
| Author: {author}

{cmtmsg}"""

    cmt_descriptions = ''
    for c in commits_info:
        cmt_descriptions += "  %s - %s\n" % (c['url'], c['subject'])

    # Add new lines around the extra_message, if applicable. Otherwise we don't
    # want anything to show up for extra_message.
    if extra_message:
        extra_message = '\n%s\n' % extra_message
    else:
        extra_message = ''

    cmt_verbose = ''
    for c in commits_info:
        cmt_verbose += cmt_template.format(url=c['url'],
                                           author=c['owner']['name'],
                                           cmtmsg=indent_lines(
                                               c['commitMessage'], '  '))

    return whole_template.format(cmt_descriptions=cmt_descriptions,
                                 extra_message=extra_message,
                                 cmt_verbose=cmt_verbose)

def display_commits(commits_info, extra_message):
    """
    Print the list of commits to the directly to the terminal.
    """

    print(format_commits(commits_info, extra_message))

def email_commits(commits_info, sender, subject, args):
    """
    Directly email commits to the nvgpu-core mailing list for review!
    """

    to_addr = 'SW-Mobile-nvgpu-core <SW-Mobile-nvgpu-core@exchange.nvidia.com>'

    if args.no_msg:
        args.msg = None

    body = format_commits(commits_info, args.msg)

    # Most people like to write a little description of their patch series
    # in the email body. This aims to take care of that.
    #
    # If arg_parser.msg is set then we can just use that. If there's no
    # args.msg field then we will try to fire up a text editor and let the
    # user write something we will copy into the email the same way as
    # args.msg. This makes it easier to a write paragraph - passing that much
    # text on the CLI is annoying!
    #
    # However, if the user decides no message is a must then they can use
    # the '--no-msg' argument to supress this message. This arg will also
    # supress a message supplied with '--msg'.

    if not args.msg and not args.no_msg:
        text = get_user_message(body)

        if not text or text.strip() == '':
            print 'Empty user message: aborting!'
            return

        msg = MIMEText(text)
    else:
        msg = MIMEText(body)

    to_addrs = [to_addr] + args.to

    msg['To'] = ", ".join(to_addrs)
    msg['From'] = sender
    msg['Subject'] = subject

    s = smtplib.SMTP('mail.nvidia.com')
    s.sendmail(sender,
               to_addrs,
               msg.as_string())
    s.quit()

def main():
    """
    The magic happens here.
    """

    arg_parser = parse_args()
    commits_info = [ ]

    if arg_parser.version:
        print('Version: %s' % VERSION)
        exit(0)

    if arg_parser.file:
        filp = open(arg_parser.file, 'r')

        if arg_parser.commits:
            arg_parser.commits.extend(read_commit_file(filp))
        else:
            arg_parser.commits = read_commit_file(filp)

    # Oops: no commits?
    if not arg_parser.commits or len(arg_parser.commits) == 0:
        print 'No commits!'
        exit(-1)

    # Builds a dictionary of Gerrit Change-Ids. From the Change-Ids we can then
    # get the commit message and URL.
    #
    # This also builds an array of those same commit IDs to track the ordering
    # of the commits so that the user can choose the order of the patches based
    # on the order in which they pass the commits.
    for cmt in arg_parser.commits:

        if cmt[0] == 'I':
            info = commit_info_from_gerrit_change_id(cmt)
        elif get_gerrit_url_id(cmt):
            info = commit_info_from_gerrit_cl(cmt)
        else:
            info = commit_info_from_git_sha1(git_sha1_from_commit(cmt))

        if info:
            commits_info.append(info)
        else:
            print('Warning: \'%s\' doesn\'t appear to be a commit!' % cmt)

    if arg_parser.email:
        # If no subject was specified then use the first commit subject as
        # the subject.
        subject = arg_parser.subject
        if not subject:
            subject = '[RFR] %s' % commits_info[0]['subject']

        # If no specified sender then use the name from the environment as
        # the sender (plus @nvidia.com). This arg is primarily useful for
        # people who do not have a username for the Linux machine that matches
        # their SSO ID.
        sender = arg_parser.sender
        if not sender:
            sender = '%s@nvidia.com' % user

        email_commits(commits_info, sender, subject, arg_parser)
    else:
        display_commits(commits_info, arg_parser.msg)

if __name__ == '__main__':
    main()