#!/usr/bin/env bash
#
# @license Apache-2.0
#
# Copyright (c) 2017 The Stdlib Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

#
# Prints the number of lines per author.
#
# <author_first_name> <author_last_name> <number_of_lines>
#
# Notes:
#
# -   Beware that this script can take awhile to run.

# * `git ls-files`
#   - List indexed files.
# * `xargs -n1 git blame`
#   - For each file, determine who last modified each line of the file.
# * `grep`
#   - Extract the line containing the author name.
# * `sed`
#   - Remove the 'author ' prefix.
# * `sort`
#   - Sort the author names in lexicographic order.
# * `uniq -c`
#   - Count the number of repeats and remove repeated names.
# * `sort -nr`
#   - Sort the counts in reverse numerical order.
# * `awk '{}'`
#   - Format the output.
git ls-files | xargs -n1 git blame --line-porcelain | grep 'author ' | sed -n 's/^author //p' | sort | uniq -c | sort -nr | awk '{print $2 OFS $3 OFS $1'