#!/usr/bin/env bash

add-git-merge() {
    if [[ -z "$1" ]]; then
        echo '$1/remote is empty.' >&2
        exit 1
    fi
    if [[ -z "$2" ]]; then
        echo '$2/merge is empty.' >&2
        exit 1
    fi
    if [[ -z "$3" ]]; then
        echo '$3/path is empty.' >&2
        exit 1
    fi

    local remote_name="$1"
    local merge_ref="$2"
    local submodule_path="$3"

    echo "Add merge '${remote_name}=$merge_ref' entry for $submodule_path"
    git config -f .gitmodules --add merge."$submodule_path"."$remote_name" "$merge_ref"
}
agm() {
    add-git-merge "$@"
}