#!/usr/bin/env bash

# A simple script that uses ag <https://github.com/ggreer/the_silver_searcher> and perl
# to do a project-wide search/replace.
#
# Usage: ag-replace [pattern] [replace]

sanitize() {
    echo "$1" | sed -e "s_/_\\\/_g"
}

input=$(sanitize "$1")
replace=$(sanitize "$2")

RED=$(printf "\033[31m")
NC=$(printf "\033[0m")

# Show the search/replace results
ag "$1" $3 -s --group --color --break --stats \
    | perl -pe "s/(?<=.)$input/\033[4m$NC$RED$replace$NC/g" \
    | perl -pe "s/^([0-9]+ matches$)/\n\$1/g" \
    | less -XF

# Ask for confirmation
echo
echo -n "Apply changes? (y/n) "
read -n1 REPLY
echo

if [[ $REPLY =~ ^[Yy]$ ]]; then
    # Now actually do the search replace! This is destructive. No, no
    # backups are made. You better have read the earlier prompt!
    files=`ag "$1" $3 -s --nogroup --nocolor --files-with-matches`
    echo "$files" | xargs perl -pi -e "s/$input/$replace/g"
    echo "$files" | sed -e "s/^/  ✓ /g"

    echo
    echo "Done!"
else
    echo "Aborted!"
    exit 2
fi