#!/usr/bin/env bash
#              bash 4.3.11(1)     Linux Ubuntu 14.04.1        Date : 2015-03-28
#
# _______________|  gitio : custom URL shortener using Github's git.io API.
#
#           Usage:  gitio [salt]  [Github URL only, defaults to clipboard]
#                   gitio [-g]    [grepterm, to search log file]
#                   gitio [-v, to edit log file]
#
#        Examples:  $ gitio  foo  https://github.com/blog/category/hire
#                   https://git.io/foo
#
#                   $ gitio     #  default salt, Github URL from clipboard.
#                   https://git.io/dt_2015-03-28_170702
#
#           Notes:  A local log file is kept; set your directory below.
#                   Log file can be edited; specify editor via $VISUAL.
#                   Your clipboard can be used to input and output URL;
#                   thus the xclip package is needed (saves typing :-).
#
#    Dependencies:  git.io API  (No key is required.)
#                   curl
#                   xclip
#
#         API ref:  https://github.com/blog/985-git-io-github-url-shortener
#                   Our GitHub page: https://git.io/git.io
#                   Raw source code: https://git.io/git.io.sh


#  CHANGE LOG  ORIGIN: https://github.com/rsvp/gitio
#  2015-03-28  First version 1.0.0 uses googl as template.
#                 Append timestamp to insure uniqueness.


#           _____ PREAMBLE_v2: settings, variables, and error handling.
#
LC_ALL=POSIX
#      locale means "ASCII, US English, no special rules, 
#      output per ISO and RFC standards." 
#      Esp. use ASCII encoding for glob and sorting characters. 
shopt -s   extglob
#     ^set extended glob for pattern matching.
shopt -s   failglob
#         ^failed pattern matching signals error.
set -e
#   ^errors checked: immediate exit if a command has non-zero status. 
set -u
#   ^unassigned variables shall be errors.
#    Example of default VARIABLE ASSIGNMENT:  arg1=${1:-'foo'}


salt=${1:-"dt_$( date '+%Y-%m-%d_%H%M%S' )"}
#    vanity URL.
url=${2:-"$( xclip -utf8 -o )"}
#   get URL from clipboard unless a second argument is given.


program=${0##*/}   #  similar to using basename
memf=$( mktemp /dev/shm/88_${program}_tmp.XXXXXXXXXX )


cleanup () {
     #  Delete temporary files, then optionally exit given status.
     local status=${1:-'0'}
     rm -f $memf
     [ $status = '-1' ] ||  exit $status      #  thus -1 prevents exit.
} #--------------------------------------------------------------------
warn () {
     #  Message with basename to stderr.          Usage: warn "message"
     echo -e "\n !!  ${program}: $1 "  >&2
} #--------------------------------------------------------------------
die () {
     #  Exit with status of most recent command or custom status, after
     #  cleanup and warn.      Usage: command || die "message" [status]
     local status=${2:-"$?"}
     cleanup -1  &&   warn "$1"  &&  exit $status
} #--------------------------------------------------------------------
trap "die 'SIG disruption, but cleanup finished.' 114" 1 2 3 15
#    Cleanup after INTERRUPT: 1=SIGHUP, 2=SIGINT, 3=SIGQUIT, 15=SIGTERM
#
# _______________     ::  BEGIN  Script ::::::::::::::::::::::::::::::::::::::::


logdir="/home/${USER}/var/log/net"
#    ^RENAME log directory for your personal use.


#  Check directory's existence, else create it.
[ -d "$logdir" ]  ||  mkdir -p "$logdir"  ||  die "fail creating $logdir" 113
#  Set logfile:
logf="$logdir/$program.log"



case "$salt" in 
           #  If first arg is -g, then GREP the second arg:
      -g)  grep -EI -i --color "$2" $logf  |  sed -e 's/ /\n/' -e 's/$/\n/'
           #                                  sed for readability.
           cleanup                                                           ;;
           
           #  If first arg is -v, then edit the log file:
      -v)  $VISUAL $logf  &&  cleanup                                        ;;
       *)  :                                                                 ;;
esac



#  Check if url is indeed an URL:
[ "${url:0:4}" != 'http' ]  &&  die 'requires http URL argument.' 115


#  For uniqueness, TIMESTAMP original url:
url="${url}#dt_$( date '+%Y-%m-%d_%H%M%S' )"
#  else someone else's salt takes precedence.


#  MAIN API FUNCTION is a simple curl command:
#  
shortener () {
     curl -k --silent -i https://git.io -F "url=$url" -F "code=$salt" \
          ||  die "failure within curl. Try different salt."  117
}


#  #DEBUGGER 2014-12-08  Test API directly:
#  
#  echo '=====DEBUG-1-shortner-output'
#  shortener
#  echo
#  echo '=====DEBUG-2'
#  cleanup


#  2015-03-28  Sample output from shortener:
#       
#       $ gitio                # default salt, URL from clipboard
#       HTTP/1.1 100 Continue
#  
#       HTTP/1.1 201 Created
#       Server: Cowboy
#       Connection: keep-alive
#       Date: Sat, 28 Mar 2015 16:27:33 GMT
#       Status: 201 Created
#       Content-Type: text/html;charset=utf-8
#       Location: http://git.io/rsvp_2015-03-28_092735
#       Content-Length: 37
#       X-Xss-Protection: 1; mode=block
#       X-Content-Type-Options: nosniff
#       X-Frame-Options: SAMEORIGIN
#       X-Runtime: 0.093136
#       X-Node: f64349f4-8e44-4961-bfa8-17833a95c91f
#       X-Revision: 07773b075b4450646b285dbdf0ec55f6bff3a278
#       Via: 1.1 vegur
#  
#       https://github.com/blog/category/hire


#  #  Curl error code 77 means:
#  #  CURLE_SSL_CACERT_BADFILE (77)
#  #  Problem with reading the SSL CA cert (path? access rights?) 
#  #  2014-12-09  Solved by adding -k flag which causes some insecurity.



shortener  >  $memf  

#  In case we get message: "Status: 422 Unprocessable Entity"
#  the Location line for the shortened URL will be missing, thus:
if ! grep '^Location:' $memf > /dev/null ; then
     die "salt UNAVAILABLE! Must use different salt."  119
fi


# Show shortened URL using https protocol:
echo    "https://git.io/$salt"  

#  Also put shortened URL on CLIPBOARD:
echo -n "https://git.io/$salt"  |  xclip

#  Finally LOG the shortened URL, along with its long form:
echo "https://git.io/$salt $url"  >>  $logf 
#
#  To EDIT logf:  gitio -v
#          which assumes your system $VISUAL is set to e.g. vim.



cleanup
# _______________ EOS ::  END of Script ::::::::::::::::::::::::::::::::::::::::

#  vim: set fileencoding=utf-8 ff=unix tw=78 ai syn=sh :