prepare-commit-msg

#!/usr/bin/python

import sys
import os
import subprocess

def fetch_sample_name(dir_path, processed_dirs):
	if dir_path in processed_dirs:
		return None

	if not os.path.exists(dir_path):
		processed_dirs.add(dir_path)
		return None

	parent_dir_path = os.path.dirname(dir_path)
	file_names = os.listdir(dir_path)
	sln_name = next((f for f in file_names if f.endswith(".sln")), None)
	processed_dirs.add(dir_path)

	if sln_name is None and os.getcwd() != dir_path:
		sln_name = fetch_sample_name(parent_dir_path, processed_dirs)
	return sln_name


def fetch_affected_dirs(modified_files):
	dir_paths = [os.path.dirname(f) for f in modified_files]
	dir_paths = list(set(dir_paths))
	return dir_paths


def fetch_sln_names(modified_files):
	sample_names = []
	dir_paths = fetch_affected_dirs(modified_files)
	processed_dirs = set()

	for dir_path in dir_paths:
		name = fetch_sample_name(dir_path, processed_dirs)
		if name is not None:
			sample_names.append(name)

	sample_names = list(set(sample_names))
	sample_names = [f_name[:-4] for f_name in sample_names]
	return sample_names


def create_prefix(sample_names):
	prefix = ""
	if len(sample_names) > 0:
		sample_names = ["[{0}]".format(s_name) for s_name in sample_names]
		prefix = "".join(sample_names)
		prefix += " "
	return prefix


def prepare_commit_msg(file_path, prefix):
	with open(file_path, 'r+') as f:
		content = f.read()
		f.seek(0)
		f.write("{0}{1}".format(prefix, content))
		f.truncate()

def get_framework_versions():
	bash_cmd = "ls -l /Library/Frameworks/Xamarin.{0}.framework/Versions/ | grep Current | sed -n 's/.*Current -> //p'"
	ios_version, error1 = subprocess.Popen(bash_cmd.format("iOS"), shell=True, stdout=subprocess.PIPE).communicate()
	mac_version, error2 = subprocess.Popen(bash_cmd.format("Mac"), shell=True, stdout=subprocess.PIPE).communicate()

	ios_version = ios_version.strip().split("/")[-1]
	mac_version = mac_version.strip().split("/")[-1]

	versions = "#Xamarin.iOS {ios_ver}\n#Xamarin.Mac {mac_ver}".format(ios_ver=ios_version, mac_ver=mac_version)
	return versions

result = subprocess.check_output(["git", "diff-index", "--cached", "--name-only", "HEAD"])
modified_files = result.split()
modified_files = [os.path.abspath(f) for f in modified_files]

# the path to the file that holds the commit message
arg_len = len(sys.argv)
msg_file_path = sys.argv[1]
commit_type = sys.argv[2] if arg_len > 2 else None
sha = sys.argv[3] if arg_len > 3 else None

if commit_type is None:
	names = fetch_sln_names(modified_files)
	prefix = create_prefix(names)
	prefix += '\n' + get_framework_versions()

	prepare_commit_msg(msg_file_path, prefix)