#!/bin/bash

startdate="20101112"
currentdate="$startdate"
enddate=`date +%Y%m%d`

addoneday() {
    seconds=`date --date "$1" +%s`
    ((seconds = seconds + 86400))
    retval=`date --date @${seconds} +%Y%m%d`
}

addoneweek() {
    seconds=`date --date "$1" +%s`
    ((seconds = seconds + 604800))
    retval=`date --date @${seconds} +%Y%m%d`
}

mkdir saved

while [ $currentdate -lt $enddate ]; do
    inweek=$currentdate
    for day in seq 0 6; do
        firstfile=`ls minimap-${inweek}* | head -n 1 2> /dev/null`
        if [ x$firstfile != x ]; then #If there's at least one file matching the date
            cp "$firstfile" saved/
            break
        fi
        addoneday $inweek
        inweek=$retval
    done
    addoneweek $currentdate
    currentdate=$retval
done