#!/bin/bash

function helpexit() {
    echo 'Rename files in current folder, replacing with regex: arg1 -> arg2.'
    echo 'Example:    "_\([0-9]\)" "_X\1"'
    echo 'Options:'
    echo '    --ng  Do _not_ replace globally (applies to regex replace only)'
    echo '    --nc  Do _not_ color output'
    echo 'Modes:'
    echo '    -n to match non-ascii and non-printable characters, and replace to [arg1]'
    echo '    -f to replace match [arg1] with format [arg2], ex: -f "[0-9]\+" "%04d"'
    echo '    -p to replace problematic characters [^\w()[]-.] with [arg1]'
    
    exit
}
[[ -z "$1" ]] && helpexit
HIGHLIGHTSRC='\x1b[1;33;40m'
HIGHLIGHTTGT='\x1b[1;32;40m'
RESET='\x1b[0m'
GLOBAL="g"
unset TGT
MODE=regex
for (( i=1; i<=$#; i++ ))
do  [[ "${!i}" = "-h" ]] && helpexit
    [[ "${!i}" = "--nc" ]] && {
            RESET=""
            HIGHLIGHTSRC=""
            HIGHLIGHTTGT=""
            continue
        }
    [[ "${!i}" = "--ng" ]] && {
            GLOBAL=""
            continue
        }
    [[ "${!i}" = "-n" ]] && {
            MODE=nonascii
            continue
        }
    [[ "${!i}" = "-f" ]] && {
            MODE=printf
            continue
        }
    [[ "${!i}" = "-p" ]] && {
            SRC='[^]\[0-9a-zA-Z_.()-]'
            continue
        }
    [[ -z "$SRC" ]] && {
            SRC="${!i}"
            continue
        }
    TGT="${!i}"
done
IFS=$'\n'

LS="ls"
$LS --version | grep -q GNU && LS="ls -v"
LONGEST=8

c=0
if [ "$MODE" = "nonascii" ]; then
    ## Remove non-ascii characters
    for file in $( eval $LS | grep -P "[\x00-\x1F]" ); do [[ ${#file} -gt ${LONGEST} ]] && LONGEST=${#file}; done
    for file in $( eval $LS | grep -P "[\x80-\xFF]" ); do [[ ${#file} -gt ${LONGEST} ]] && LONGEST=${#file}; done
    printf "%-${LONGEST}s\t|%s\n" Matching Replaced
    for file in $( eval $LS| grep -P "[\x00-\x1F]" ); do
        printf "%-${LONGEST}s\t|%s\n" "$file" \
            "$( echo $file | tr -d \\n\\r | tr -c [:print:] '\000' | sed s/'\x0'/"$TGT"/g )"
        c=$(( $c + 1 ))
    done
    for file in $( eval $LS | grep -P "[\x80-\xFF]" ); do
        printf "%-${LONGEST}s\t|%s\n" "$file" \
            "$( echo $file | tr -d \\n\\r | tr -c [:print:] '\000' | sed s/'\x0'/"$TGT"/g )"
        c=$(( $c + 1 ))
    done
    echo $c' matches. Sure?'
    read i
    for file in $( eval $LS | grep -P "[\x00-\x1F]" ); do 
        mv -iv -- "$file" "$( echo $file | tr -d \\n\\r | tr -c [:print:] '\000' | sed s/'\x0'/"$TGT"/g )"
    done
    for file in $( eval $LS | grep -P "[\x80-\xFF]" ); do 
        mv -iv -- "$file" "$( echo $file | tr -d \\n\\r | tr -c [:print:] '\000' | sed s/'\x0'/"$TGT"/g )"
    done
    exit
fi

if [ "$MODE" = "printf" ]; then
    [[ -z "$TGT" ]] && helpexit
    ## string/number formatting
    for file in $( eval $LS | grep -- "$SRC"); do [[ ${#file} -gt ${LONGEST} ]] && LONGEST=${#file}; done

    printf "%-${LONGEST}s\t|%s\n" Matching Formatted
    for file in $( eval $LS | grep -- "$SRC" )
    do source_match=$( echo $file | grep -h -o -m 1 -- "$SRC" | head -n1 )
       # remove zeroes from beginning, if matching integers
       let source_match="10#$source_match" &> /dev/null
       target_replace=$( printf "$TGT" "$source_match" ) || FORMATTING_ERROR=1
       source_colored=$( echo $file | sed s/"\($SRC\)"/${HIGHLIGHTSRC}"\1"${RESET}/ )
       target_colored=$( echo $file | sed s/"$SRC"/${HIGHLIGHTTGT}"${target_replace}"${RESET}/ )
       length_diff=$(( ${#source_colored} - ${#file} ))
       pad_length=$(( ${LONGEST} + ${length_diff} ))
       printf "%-${pad_length}s\t|%s\n" "$source_colored" "$target_colored"
       [[ "$FORMATTING_ERROR" -eq 1 ]] && exit 1
       c=$(( $c + 1 ))
    done 
    echo $c' matches. Sure?'
    read i
    for file in $( eval $LS | grep -- "$2" )
    do source_match=$( echo $file | grep -h -o -m 1 -- "$SRC" | head -n1 )
       # remove zeroes from beginning, if matching integers
       let source_match="10#$source_match" &> /dev/null
       target_replace=$( printf "$TGT" "$source_match" )
       mv -iv -- "$file" "$( echo $file | sed s/"$SRC"/"${target_replace}"/ )"
    done
    exit
fi

## Normal regex replace 
[[ -z "$SRC" ]] && helpexit
for file in $( eval $LS | grep -- "$SRC"); do [[ ${#file} -gt ${LONGEST} ]] && LONGEST=${#file}; done

printf "%-${LONGEST}s\t|%s\n" Matching Replaced
for file in $( eval $LS | grep -- "$SRC" ); do 
    source_colored=$( echo $file | sed s/"\($SRC\)"/${HIGHLIGHTSRC}"\1"${RESET}/$GLOBAL ) || ERROR=1
    target_colored=$( echo $file | sed s/"$SRC"/${HIGHLIGHTTGT}"${TGT}"${RESET}/$GLOBAL ) || ERROR=1
    length_diff=$(( ${#source_colored} - ${#file} ))
    pad_length=$(( ${LONGEST} + ${length_diff} ))
    printf "%-${pad_length}s\t|%s\n" "$source_colored" "$target_colored"
    [[ "$ERROR" -eq 1 ]] && {
        echo "Match='$SRC'"
        echo "Replace='$TGT'"
        exit 1
    }
    c=$(( $c + 1 ))
done
echo $c' matches. Sure?'
read i
for file in $( eval $LS | grep -- "$SRC" )
do mv -iv -- "$file" "$( echo $file | sed s/"$SRC"/"$TGT"/$GLOBAL )"
done