#! /bin/bash 
#title           :jpgdates
#description     :Select and print info about jpg files based on dates in jpg
#author		 :gmj@pobox.com
#date            :Sat Dec 19 15:35:06 2015
#version         :0.1
#usage		 :jpgdates [optinos] FILE [FILE...]
#dependancies	 :http://owl.phy.queensu.ca/~phil/exiftool/
#notes           :Also experimeting with well-written bash scripts
#bash_version    :
#
# Copyright (C) 2015 George M. Jones
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see http://www.gnu.org/licenses/.
#
#==============================================================================

set -u   # exit on undefined
set -e   # exit on error
# set -x # echo during execution

# Useful tips
# http://www.kfirlavi.com/blog/2012/11/14/defensive-bash-programming/
readonly PROGNAME=$(basename $0)
readonly PROGDIR=$(readlink -m $(dirname $0))
readonly ARGS=("$@")

function usage() {
    if [ $# -gt 0 ]; then echo  "${PROGNAME}: $@"; echo; fi
    cat <<- EOF
usage: $PROGNAME [options] FILE [FILE...]
    
This program determins if a JPEG file has an Original Date stored
with it and prints the filename and/or date.

OPTIONS:
   -w --withdates	Select files with dates
   -m --missingdates	Select files with no dates
   -p --path		Print path of matching files
   -t --dates		Print dates of matching files
   -i --isomtime	Print ISO-formatted mtime before file
   -v --verbose         Verbose. You can specify more then one -v to have more verbose
   -d --debug           debug
   -h --help            show this help
    
Examples:
   Fine info about a single file
       $PROGNAME sample.jpg 

   Find info about all jpg files in directory
       find . -type f -name \*.jpg -print0 | xargs -L 1 -0 $PROGNAME

   Find only Pathnames of jpg files Missing dates:
       find . -type f -name \*.jpg -print0 | xargs -L 1 -0 $PROGNAME -m -p

   Find all info about jpg files With dates
       find . -type f -name \*.jpg -print0 | xargs -L 1 -0 $PROGNAME -w 

   Horrible real world invocation to look at the last 10 files of the first 40 available:
       find . -type f -name \*.jpg -print0 | tr '\0\n' '\n\0' |  head -40 | tail -10 |  tr '\0\n' '\n\0'| xargs -L 1 -n 1 -0 $PROGNAME

EOF
}


function parseArgs() {
    
    # Option parsing courtesy of 
    # http://stackoverflow.com/questions/402377/using-getopts-in-bash-shell-script-to-get-long-and-short-command-line-options


    # NOTE: This requires GNU getopt.  On Mac OS X and FreeBSD, you have to install this
    # separately; see below.
    TEMP=`getopt -o wmptvdih --long withdates,missingdates,path,dates,isomtime,verbose,debug,help \
            	  -n 'jpghasDate' -- "$@"`

    if [ $? != 0 ] ; then echo "getopt failed. Terminating..." >&2 ; exit 1 ; fi

    # Note the quotes around `$TEMP': they are essential!
    eval set -- "$TEMP"


    # Set default values

    # Selection Parameters
    OPT_SELECT_WITH_DATES=false		# print files that have dates
    OPT_SELECT_MISSING_DATES=false	# print files with no date
    # Output Parameters
    OPT_VERBOSE=false			# verbose output
    OPT_DEBUG=false			# debugging output
    OPT_PRINT_PATH=false  		# print path
    OPT_PRINT_DATES=false		# print date
    OPT_ISO_MTIME=false			# print iso mtime of file before path
    OPT_PRINT_ALL=true			# print all (default)

    while true; do
	case "$1" in
	    -w | --withdates ) OPT_SELECT_WITH_DATES=true; shift ;;
	    -m | --missingdates ) OPT_SELECT_MISSING_DATES=true; shift ;;
	    -p | --path ) OPT_PRINT_PATH=true; shift ;;
	    -t | --dates ) OPT_PRINT_DATES=true; shift ;;
	    -i | --isomtime ) OPT_ISO_MTIME=true; shift ;;	    
	    -v | --verbose ) OPT_VERBOSE=true; shift ;;
	    -d | --debug ) OPT_DEBUG=true; shift ;;
	    -h | --help ) usage; exit 0;shift ;;        
	    -- ) shift; break ;;
	    * ) break ;;
	esac
    done
    
    if [ $# -lt 1 ] ; then usage "Missing argument.  Need at least one filename."; exit 1; fi

    # Defualt to printing all
    if ! ( $OPT_PRINT_PATH || $OPT_PRINT_DATES ); then 
	OPT_PRINT_PATH=true
	OPT_PRINT_DATES=true
    fi
    
    # Defualt to selectiing all
    if ! ( $OPT_SELECT_WITH_DATES || $OPT_SELECT_MISSING_DATES ); then 
	OPT_SELECT_WITH_DATES=true
	OPT_SELECT_MISSING_DATES=true
    fi

    # Make parsing paramters readonly

    readonly OPT_SELECT_WITH_DATES=${OPT_SELECT_WITH_DATES}	# print files that have dates
    readonly OPT_SELECT_MISSING_DATES=${OPT_SELECT_MISSING_DATES}	# print files with no date
    readonly OPT_VERBOSE=${OPT_VERBOSE}				# verbose output
    readonly OPT_DEBUG=${OPT_DEBUG}				# debugging output
    readonly OPT_PRINT_PATH=${OPT_PRINT_PATH}			# print path
    readonly OPT_PRINT_DATES=${OPT_PRINT_DATES}			# print date
    readonly OPT_PRINT_ALL=${OPT_PRINT_ALL}			# print all (default)

    OPT_ARGS=("$@")


}

function printSelectedFiles () {
    if $OPT_DEBUG; then 
	echo ARGS TO printSelectedFiles
	for ARG in "$@"; do
 	    printf 'ARG %s\n' "$ARG"
	done
    fi

    for file in "$@"; do
	if $OPT_DEBUG; then echo file $file >&2; fi
	exifDate=$(exiftool "$file" | grep Orig || echo "NONE")
	exifDate=$(echo $exifDate | sed -e 's/Date\/Time Original\s*\:\s*//')
	output=""

	if $OPT_ISO_MTIME; then 	    
	    epochTime=`stat --printf='%Y' "$file" `
	    isoTime=`date --date="@$epochTime" -Iminutes`
	    output="$isoTime $output"
	fi

	if $OPT_PRINT_PATH; then output="$output$file"; fi

	if $OPT_PRINT_DATES; then output="$output : $exifDate"; fi
	
	if $OPT_SELECT_MISSING_DATES; then 
	    if [[ $exifDate == *"NONE"* ]]; then
		echo $output
	    fi
	fi

	if $OPT_SELECT_WITH_DATES; then 
	    if [[ $exifDate != *"NONE"* ]]; then
		echo $output
	    fi
	fi    
    done
}

function main() {
    parseArgs "$@"

    printSelectedFiles "${OPT_ARGS[@]}"    
}

#main

if [ ${#ARGS[@]} -lt 1 ] ; then usage "Missing argument.  Need at least one filename."; exit 1; fi
    
main "${ARGS[@]}"