#!/bin/bash

# find_new_files.sh
# Meryll Larkin
# 20200904
# 20210809 Added determine_days function
# Helpful for incremental backups
# 20210814 Added excludes ability

dir=$1
newer=$2
pid=$$
today=$(date +"%Y%m%d")
today_s=$(date +%s)
year=$(date +%Y)
cwdir=`pwd`
outfile="${cwdir}/new_files_${today}_${pid}.txt"

function determine_days {
    echo "    Determine days using date of last backup"
    echo -n "    Year of last backup?  (4 digits or <enter> for $year): "
    read yr
    if [  -z "$yr" ] ; then
        yr=$year
    fi
    echo -n "    Month of last backup? (2 digits - use 01 for Jan): "
    read mon
    echo -n "    Day of last month? (1 or 2 digits): " 
    read day
    # date in seconds since last epoch (1970)
    # date -d '2008-12-18 12:01:00' +%s
    lastbup=`date -d "${yr}-${mon}-${day} 12:01:00" +%s`
    # convert to days since last epoch
    lastbup=$((lastbup/86400))
    today_s=$((today_s/86400))
    newer=$((today_s-lastbup))
    # Add 2 days padding
    newer=$((newer+2))
    echo
    echo "    Finding files newer than $newer days old"
    echo
    echo -n "    Does that look right? [Y|n]: "
    read looksright
    looksright=`echo $looksright | tr '[:upper:]' '[:lower:]'`
    if [ "$looksright" = "n" ] ; then 
        echo
        echo "    Quitting due to confusion."
        exit
    fi
}


if [ !  -d "$dir" ] ; then
    echo -n "    Absolute path to target directory? "
    read dir
    echo -n "    Do you know the number of days since last backup? [y|N]: "
    read daysknown
    daysknown=`echo $daysknown | tr '[:upper:]' '[:lower:]'`
    if [ "$daysknown" != "y" ] ; then 
        # go to the function determine_days
        determine_days
    else
        echo -n "    Find files newer than how many days? "
        read newer
    fi
fi

if [  -z "$newer" ] ; then
    echo -n "    Find files newer than how many days? "
    read newer
fi
echo
echo -n "    Are there any directories deep to $dir that you would like to exclude? [y|N]: "
read exclude
exclude=`echo $exclude | tr '[:upper:]' '[:lower:]'`
if [ "$exclude" != "y" ] ; then 
        # go to the function determine_days
        echo "    Continuing..."
else
    echo -n "    Provide a space-separated list of directories to exclude (no slashes): "
    read excludes
    echo "excludes = $excludes"
    exclude_array=($excludes)
fi

echo "Today is $today" > $outfile
echo
echo "    Find files in $dir that are less than $newer days old" | tee -a $outfile
for i in ${dir}/* ; do 
    ignore="n"
    for j in ${exclude_array[@]} ; do
        if [[ $i = *"$j" ]]; then
            echo "Ignoring $i because $j is on Excludes list"  | tee -a $outfile
            echo "" | tee -a $outfile
            echo "****************************************************" | tee -a $outfile
            ignore="y"
        fi
    done
    if [[ $ignore == "n" ]] ; then
        echo "find $i -type f -mtime -${newer}" | tee -a $outfile
        echo "" | tee -a $outfile
        find $i -type f -mtime -${newer} | tee -a $outfile
        echo "****************************************************" | tee -a $outfile
    fi
done 
echo
echo "Results also printed to outfile $outfile"
exit