#!/bin/bash
# Copyright (C) 2016 Ian Kelling

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

gitget() {
    local help="Usage: gitget [--help] [REPO_URL] [REPO_DIR]
Idempotent git clone/pull

If repo exists, pull.
Without arguments, just git pull.
REPO_DIR is, or will become the root of the repo."

    if [[ $1 == --help ]]; then
        echo "$help"
        return
    fi
    if (( $# >= 3 )); then
        echo error: expected 2 or less arguments, got $#
        echo "$help"
        return 1
    fi
    if [[ $# == 0 ]]; then
        git pull
        return $?
    fi

    local workingdir
    local orig_dir="$PWD"
    local ret
    if [[ $1 == *[^/].git ]]; then
        if [[ $2 ]]; then
            workingdir="$2"
        else
            workingdir="${1##*/}"
            workingdir="${workingdir%.git}"
        fi
    elif (( $# == 2 )); then
        echo error: 2 arguments given but the first does not end in .git
        echo "$help"
        return 1
    else
        workingdir="$1"
        if [[ ! -d $workingdir/.git ]]; then
            echo "error: expected $workingdir/.git to exist"
            return 1
        fi
    fi
    [[ -d $workingdir ]] || mkdir -p "$workingdir"
    cd "$workingdir"
    if [[ -d .git ]]; then
        git pull
        ret=$?
    else
        git clone "$1" .
        ret=$?
    fi
    cd "$orig_dir"
    return $ret
}
gitget "$@"