#!/usr/bin/env bash

die() {
    echo $@
    exit 1
}

if [ $# -eq 0 ]; then
    echo "xg: locate a file in the source tree and display the full git log information."
    echo "Usage: xg [filename-substring]"
    echo "Example: xg /BlockReader.java"
    echo "Example 2: xg test-patch"
    echo
    exit 1
fi

T=/tmp/$$.xg.tmp
trap "rm -rf ${T}; exit" INT TERM EXIT
find . -noleaf -xdev -name '*.java' -o -name '*.h' -o -name '*.c' \
    -o -name '*.cpp' -o -name '*.cxx' -o -name '*.cc' -o -name '*.sh' | \
        grep $@ > "${T}"
LINES=$(wc -l "${T}" | awk '{print $1}')
[ "${LINES}" -lt 1 ] && die "no results"
if [ "${LINES}" -gt 1 ]; then
    echo "multiple results: "
    cat "${T}"
    exit 1
fi

F=$(cat "${T}")
git log --follow -p "${F}"