git-ext-init

#!/bin/bash
#|
#| Initializes a Git repository according to a template.
#|
#| * Makes an empty root commit, which can be useful for merging or splitting
#|   whole repositories or separate trees.
#| * Applies the given template, which may define custom steps and/or commonly
#|   present files (e.g., .gitignore, licenses or README).
#| * Adds .gitignore, .gitattributes and README.md if provided.
#| * Prints the hints how to proceed then.
#|
#| Usage:
#|
#| git-ext-init [-h] | [-e] [-t TEMPLATE] [[-r REMOTE] -u URL] [DIR]
#|
#| Options:
#|   -e, --edit                 edit the configuration files
#|   -h, --help                 show this help and exit
#|   -r, --remote NAME          the NAME for the remote (default: origin)
#|   -t, --template TEMPLATE    the TEMPLATE to apply
#|   -u, --url URL              add URL for the given remote
#|
#| Arguments:
#|   DIR                        the directory of the repository (default: .)
#|
#| If DIR does not exist, the path is created (including necessary parent
#| directories).
#|
#| TEMPLATE refers to the name of the directory containing the template to apply.
#| The template has following structure:
#|
#|   {template}/
#|       resources/
#|       prepare
#|       finish
#|
#| The template is applied by following steps:
#|   1. Execute 'prepare'.
#|   2. Copy the content of 'resources/' to the root of the repository.
#|   3. Execute 'finish'.
#|
#| If any item is missing, the step is skipped. The commands are executed in the
#| the repository directory and they are supposed to perform adjustments and any
#| other suitable actions for the initialization.
#|
#| The TEMPLATE is searched in '~/.config/git/ext/init/templates/' and if not
#| found there, then in 'templates/' subdirectory of this command's directory.

FORCE_EDIT=0
REMOTE_NAME=origin
REMOTE_URL=
TEMPLATE=

SCRIPT_FILE="${BASH_SOURCE[0]}"
while [[ -n "$1" ]]; do
    case "$1" in
    -h|--help)
        sed '/#|.*/ s/^#|[[:space:]]\?//p;d' < "$SCRIPT_FILE"
        exit 1
        ;;

    -e|--edit)
        FORCE_EDIT=1
        shift
        ;;

    -r|--remote)
        REMOTE_NAME="$2"
        shift 2
        ;;

    -t|--template)
        TEMPLATE="$2"
        shift 2
        ;;

    -u|--url)
        REMOTE_URL="$2"
        shift 2
        ;;

    --)
        shift
        break
        ;;

    -*)
        echo "Unknown option encountered: '$1'" >&2
        exit 1
        ;;

    *)
        break
        ;;
    esac
done


# Preliminary sanity checks

DIR="${1:-.}"
if [[ -d "$DIR/.git" ]]; then
    echo "The repository already exists. Aborting." >&2
    exit 2
fi

if [[ -n "$TEMPLATE" ]]; then
    TEMPLATE_DIR="~/.config/git/ext/init/templates/$TEMPLATE"
    if ! [[ -d "$TEMPLATE_DIR" ]]; then
        TEMPLATE_DIR=`dirname "$SCRIPT_FILE"`"/templates/$TEMPLATE"
        if ! [[ -d "$TEMPLATE_DIR" ]]; then
            echo "Could not locate given template '$TEMPLATE'." >&2
            exit 2
        fi
    fi
fi


# Finish the script preparation steps

if [[ -z "$EDITOR" ]]; then
    EDITOR=vim
fi


# Start the actual process

if [[ "$DIR" != '.' ]]; then
    echo ":: Switching to $DIR"
    mkdir -p "$DIR"
    cd "$DIR"
fi

echo ":: Setting up repository"
git init

if [[ -n "$REMOTE_URL" ]]; then
    echo "Setting remote"
    git remote add "$REMOTE_NAME" "$REMOTE_URL"
fi

echo ":: Review the configuration"
git config --list

if [[ $FORCE_EDIT -ne 0 ]]; then
    git config --edit
fi

echo ":: Setting up the root commit"
git commit --allow-empty -m "Make the root commit"
git tag ROOT


if [[ -n "$TEMPLATE" ]]; then
    echo ":: Applying template '$TEMPLATE'"
    TEMPLATE_RESOURCES="$TEMPLATE_DIR/resources"
    test -d "$TEMPLATE_RESOURCES" && cp -R "$TEMPLATE_RESOURCES/." .
    TEMPLATE_COMMAND="$TEMPLATE_DIR/prepare"
    test -f  "$TEMPLATE_COMMAND" && "$TEMPLATE_COMMAND"
fi

echo ":: Adding .gitignore"
if [[ -z "$TEMPLATE" || $FORCE_EDIT -ne 0 ]]; then
    "$EDITOR" .gitignore
fi
if [[ -f .gitignore ]]; then
    git add .gitignore
    git commit -m "Add .gitignore"
fi

echo ":: Adding .gitattributes"
if [[ -z "$TEMPLATE" || $FORCE_EDIT -ne 0 ]]; then
    "$EDITOR" .gitattributes
fi
if [[ -f .gitattributes ]]; then
    git add .gitattributes
    git commit -m "Add .gitattributes"
fi

if [[ -f README.md ]]; then
    echo ":: Preparing README.md"
    "$EDITOR" README.md
    git add README.md
    git commit -m "Add README.md"
fi

if [[ -n "$TEMPLATE" ]]; then
    TEMPLATE_COMMAND="$TEMPLATE_DIR/finish"
    test -f  "$TEMPLATE_COMMAND" && "$TEMPLATE_COMMAND"
fi

echo ":: Finishing"
echo
echo "Keep good work:"
echo
echo "* Add a skeleton of the project that passes the build"
echo "* Update documentation accordingly"
echo "* Commit the skeleton"
echo "* Supply the rest :-)"
echo
echo "Happy coding!"
echo