#!/usr/libexec/platform-python

# -*- coding: utf-8 -*-

# Authors:

#   Thomas Woerner <twoerner@redhat.com>

#

# Copyright (C) 2020 Red Hat

# see file 'COPYING' for use and warranty information

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import sys

import argparse

import subprocess

usage = "Usage: changelog [options] [<new version>]"

parser = argparse.ArgumentParser(usage=usage)

parser.add_argument("--tag", dest="tag",

                    help="git tag")

options, args = parser.parse_known_args()

if len(args) == 1:

    new_version = args[0]

elif len(args) != 0:

    parser.error("new version is not set")

else:

    new_version = None

if options.tag is None:

    tag = subprocess.check_output(

        "git describe --tags $(git rev-list --tags --max-count=1)",

        shell=True)

    options.tag = tag.decode("utf-8").strip()

version = options.tag[1:]

command = ["git", "log", "%s.." % options.tag]

process = subprocess.run(command,

                         stdout=subprocess.PIPE,

                         stderr=subprocess.PIPE)

if process.returncode != 0:

    print("git log failed: %s" % process.stderr.decode("utf8").split("\n")[0])

    sys.exit(1)

if new_version is not None:

    s = "ansible-freeipa-%s" % new_version

    print(s)

    print("=" * len(s))

    print()

commits = {}

prs = {}

authors = {}

lines = process.stdout.decode("utf-8").split("\n")

class Ref:

    def __init__(self, commit):

        self.commit = commit

def store(commits, prs, authors, commit, author, merge, msg):

    if commit is not None:

        if msg[0].startswith("Merge pull request #"):

            pr = int(msg[0].split()[3][1:])

            if len(msg) > 1:

                prs[pr] = msg[1].strip()

            else:

                prs[pr] = Ref(merge)

        else:

            commits[commit] = msg[0].strip()

            authors.setdefault(author, []).append(commit)

def get_commit(commits, commit):

    _commits = [value for key, value in commits.items()

                if key.startswith(commit)]

    if len(_commits) == 1:

        return _commits[0]

    return commit

commit = None

author = None

merge = None

msg = None

for line in lines:

    line = line.rstrip()

    if line.startswith("commit "):

        store(commits, prs, authors, commit, author, merge, msg)

        author = None

        msg = []

        commit = line[7:]

    elif line.startswith("    "):

        msg.append(line[4:])

    else:

        try:

            key, value = line.split(":", 1)

            if key == "Author":

                author = value.split("<")[0].strip()

            elif key == "Merge":

                merge = value.split()[1].strip()

            # Ignore Date, ..

        except ValueError:

            pass

# Add final commit

if commit:

    store(commits, prs, authors, commit, author, merge, msg)

s = "Changes since %s" % version

print("%s" % s)

print("-" * len(s))

print()

prs_sorted = sorted(prs.keys(), reverse=True)

for pr in prs_sorted:

    if isinstance(prs[pr], Ref):

        msg = get_commit(commits, prs[pr].commit)

    else:

        msg = prs[pr]

    print("  - %s (#%d)" % (msg, pr))

print()

s = "Detailed changelog since %s by author" % version

print("%s" % s)

print("-" * len(s))

print("  %d authors, %d commits" % (len(authors), len(commits)))

print()

authors_sorted = sorted(authors.keys())

for author in authors_sorted:

    print("%s (%d)\n" % (author, len(authors[author])))

    for commit in authors[author]:

        print("  - %s" % commits[commit])

    print()