#!/usr/bin/env bash

usage() {
    cat <<EOF
usage: git sed [ -c ] [ -f <flags> ] <search> <replacement>

Run git grep and then send results to sed for replacement with the
given flags, if -f is provided.

Also runs git commit if -c is provided.
EOF
}

# don't commit by default
do_commit() {
    true
}

while [ "X$1" != "X" ]; do
    case "$1" in
        -c|--commit)
            if git status --porcelain | grep .; then
                echo "you need to commit your changes before running with --commit"
                exit 1
            fi
            do_commit() {
                git commit -m"replace $search with $replacement

actual command:

    $command" -a
            }
            ;;
        -f|--flags)
            if [ "X$2" = "X" ]; then
                usage
                echo "missing argument for $1"
                exit 1
            fi
            shift
            flags=$1
            ;;
        -h|--help)
            usage
            exit
            ;;
        -*)
            usage
            echo "unkonwn flag: $1"
            exit 1
            ;;
        *)
            if [ "X$search" = "X" ]; then
                search="$1"
            elif [ "X$replacement" = "X" ]; then
                replacement="$1"
            else
                usage
                echo "too many arguments: $1"
                exit 1
            fi
            ;;
    esac
    shift
done

command="git grep -l '$search' | xargs sed -i 's/$search/$replacement/$flags'"
git grep -l "$search" | xargs sed -i "s/$search/$replacement/$flags"
do_commit