#!/bin/bash

################################################################################
#
# Purpose: Track down first commit of a developer by analyzing ChangeLog
# entries matching this format:
# Day Month Year[;:].*<email@domain.tld>.*
# where Month is a three-letter abbreviation (or 4, for Sept. only)
#
# Arguments: developer, category (optional), prefix (optional)
#
# TODO: Add `cvs log`, others? Look at ciaranm's bashrc stuff to see whether we
# can borrow anything.
#
# Author: Donnie Berkholz <spyderous@gentoo.org>
#
################################################################################

# Any valid grep regexp should work for years to consider.
# Set a reasonable default.
year_range="[12][09][0-9][0-9]"

developer=${1}
category=${2}
prefix=${3:-/usr/portage}

# Color setup, works only for interactive sessions
# Can't quote ${PS1}
if [ -n ${PS1} ]; then
	color="yes"
else
	unset color
fi

bold="${color:+\033[1m}"
unbold="${color:+\033[0m}"
# shortcuts
b="${bold}"
ub="${unbold}"

red="${color:+\E[31m}"
green="${color:+\E[32m}"
yellow="${color:+\E[33m}"
blue="${color:+\E[34m}"
magenta="${color:+\E[35m}"
cyan="${color:+\E[36m}"
white="${color:+\E[37m}"

helpmsg() {
	echo
	echo -e "${b}${green}Arguments: ${white}developer category prefix${ub}"
	echo
	echo "/usr/portage is used as prefix unless \${3} is set."
	echo "For non-portage trees, category could also be a subdirectory."
	echo "Leave \${2} unset or set to empty (\"\") to search full tree."
	echo
}

if [ "${1}" = "--help" -o "${1}" = "-h" ]; then
	helpmsg
	exit
fi

# Validate argument number
if [ $# -eq 0 ]; then
	helpmsg
	exit
fi

# If we're searching the whole tree, warn the user
if [ -z "${2}" ]; then
	echo
	echo -e "${b}Searching full tree ... it may be a while${ub}"
fi

# Define these for sorting by number. I don't think bash can sort by month, and
# I don't want to call sort.
JAN=1
FEB=2
MAR=3
APR=4
APRIL=4
MAY=5
JUN=6
JUNE=6
JUL=7
JULY=7
AUG=8
# Both September abbreviations are used.
SEP=9
SEPT=9
OCT=10
NOV=11
DEC=12

declare -a date first_date

# Set first_date to a format compatible with our modified ChangeLog dates
first_date=($(date | awk '{ print $3 " " toupper($2) " " $6 }'))

echo
echo -e "${b}${green}Searching for first commit...${ub}"
echo -e "Format: day month year"
echo

find ${prefix}/${category} -name ChangeLog -exec grep \
	"^  [[:digit:]]*.[[:alpha:]]*.${year_range}.*\<${developer}@gentoo.org\>" {} \; \
	| cut -d' ' -f3-5 | cut -d";" -f1 |  cut -d":" -f1 |  cut -d"," -f1 \
	| tr '[:lower:]' '[:upper:]' | sort | uniq \
| while read line; do

	# Turn the date string into an array
	date=(${line})

	# Set months to their numbers
	date[1]=${!date[1]}

	#### DEBUG ####
	if [ -z "${date[1]}" ]; then
		echo month=${date[1]}
		echo line=${line}
	fi
	#### END DEBUG ####

	# Otherwise leading zero's confuse it into thinking octal
	date[0]=${date[0]#0}

	# If it's an older year ...
	if (( ${date[2]} < ${first_date[2]} )); then
		first_date=(${date[@]})
		echo -ne "${b}${red}\t${first_date[*]}  \r${ub}"
	# If it's the same year ...
	elif (( ${date[2]} == ${first_date[2]} )); then
		# If it's an older month ...
		if (( ${date[1]} < ${first_date[1]} )); then
			first_date=(${date[@]})
			echo -ne "${b}${red}\t${first_date[*]}  \r${ub}"
		# If it's the same month ...
		elif (( ${date[1]} == ${first_date[1]} )); then
			# If it's an older day ...
			if (( ${date[0]} < ${first_date[0]} )); then
				first_date=(${date[@]})
				echo -ne "${b}${red}\t${first_date[*]}  \r${ub}"
			fi
		fi
	fi
done

echo
echo