#!/bin/bash

# Sort files with a prefix of LIMIT length into dirs with the same name as the prefix
# E.g., log_1.txt log_2.txt have a common prefix 'log' with length 3, so
# `sorter 3` will create dir 'log' and move both files there

if [ ! -z "$2" ] && [ ! -z "$1" ]; then
    LIMIT=$2
elif [ -z "$2" ] && [ ! -z "$1" ]; then
    echo "Provide a length for the prefix or strip-from-behind"
    exit
fi

if [ "$1" ==  "f" ]; then
    # From the front
    for PATTERN in $(find . -maxdepth 1 -type f|cut -c 3-$((LIMIT + 2))|sort|uniq); do
        # Offset LIMIT by two to skip the './' in front of every filename
        echo $PATTERN
        mkdir -p "$PATTERN"
        # mv does not work :)
        #mv "${PATTERN}*.*" "$PATTERN/"
        for FILE in $(find . -maxdepth 1 -type f | grep "$PATTERN"); do
            #echo $FILE
            mv "$FILE" "${PATTERN}/"
        done
    done
elif [ "$1" ==  "fe" ]; then
    # From the front
    for PATTERN in $(find . -maxdepth 1 -type f|cut -c 3-$((LIMIT + 2))|sort|uniq); do
        echo $PATTERN
        #for FILE in $(find . -maxdepth 1 -type f | grep "$PATTERN"); do
        #    echo $FILE
        #done
    done
elif [ "$1" == "b" ]; then
    # From the back
    for PATTERN in $(find . -maxdepth 1 -type f|rev|cut -c $LIMIT-|rev|sort|uniq); do
        echo $PATTERN
        mkdir -p "$PATTERN"

        for FILE in $(find . -maxdepth 1 -type f | grep "$PATTERN"); do
            #echo $FILE
            mv "$FILE" "${PATTERN}/"
        done
    done
elif [ "$1" == "be" ]; then
    # From the back
    for PATTERN in $(find . -maxdepth 1 -type f|rev|cut -c $LIMIT-|rev|sort|uniq); do
        echo $PATTERN
        #for FILE in $(find . -maxdepth 1 -type f | grep "$PATTERN"); do
        #    echo $FILE
        #done
    done
else
    echo "sorter - Files-into-structured-directories sorter"
    echo
    echo "Sort files with a prefix of LIMIT length into dirs with the same name"
    echo "as the prefix"
    echo "E.g., log_1.txt log_2.txt have a common prefix 'log' with length 3,"
    echo "so 'sorter 3' will create dir 'log' and move both files there"
    echo
    echo "usage: sorter OPTION LIMIT"
    echo
    echo "OPTION:"
    echo " f  create directories based on the prefix from the front LIMIT"
    echo "    characters"
    echo " fe emulate the above, print would-be results"
    echo " b  create directories based on the prefix that's left when stripping"
    echo "    LIMIT characters from the back"
    echo " be emulate the above, print would-be results"
    echo
    echo "LIMIT: length of prefix or strip-from-behind"
    echo
fi