#!/bin/bash
#Manages an /etc/changelog

CHANGELOG=/etc/changelog

# functions 

msg(){ echo -e "$@"; }
panic(){ msg "${@} Exiting."; exit 1;}
template(){ 
t=$(mktemp)
cat << HEREDOC >$t

$(date "+%Y-%m-%d %H:%M") $CHANGELOG_USERNAME

$( echo -e "$@"|sed 's/^/    /' )
HEREDOC
[[ -f $CHANGELOG ]] && cat /etc/changelog >> $t 
cat "$t" > $CHANGELOG
rm -f "$t"
}

change(){
  local TMP=$(mktemp)
  while true ; do
    echo -e "\nType the nature of the change.\nExample: > mysql: do not start on boot\n"
    read -e -p "> " SUB
    echo -e "\nType the comments, how you did that.\nExample: > echo 'manual' | sudo tee -a /etc/init/mysql.override\n"
    read -e -p "> " EXP
    echo -e "* $SUB\n$EXP\n" >> $TMP
    read -e -i "n" -p "More? [yN]:" END
    [[ "${END^^}" == "N" ]] && break
  done
  echo -e "\nHere is the content you are about to add.\n\n$(cat $TMP)\n"
  read -e -p "OK? [Yn]: " -i y RETURN
  [[ "N" == ${RETURN^^} ]] && return
  template "$(cat $TMP)"
  rm $TMP
}

# Exec
echo -e "\nWelcome to Serious Changelogs Inc. Do you have something for me?\n"
# set environment variables
[[ -z "$CHANGELOG_USERNAME" ]] && read -e -p "Your name?  " NAME&& read -e -p "Your email? " EMAIL && CHANGELOG_USERNAME="${NAME^}  <$EMAIL>" && echo "export CHANGELOG_USERNAME=\"$CHANGELOG_USERNAME\""
[[ "  <>" == "$CHANGELOG_USERNAME" ]] && panic "srs.ly?"

# check changelog exists
[[ ! -f $CHANGELOG ]] && template "* Changelog: Added $CHANGELOG file\nIt was not serious. Fixed!\n\n"

# parse command 
change