#!/bin/sh

# Installation script to make the dotfiles available in ~/
#
# `git` is the only dependency for this script to run (See: https://git-scm.com)
#
# See: https://code.webartifex.biz/alexander/dotfiles#installation


set -eu


XDG_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}"  # also set in ~/.config/shell/env

DOTFILES_DIR="$XDG_DATA_HOME/dotfiles"  # also set in ~/.config/shell/env

# Defaults to the minimal/server version on the "main" branch
# => Set DOTFILES_BRANCH=desktop explicitly when installing on a desktop machine
DOTFILES_BRANCH="${DOTFILES_BRANCH:-main}"

DOTFILES_HTTPS="https://code.webartifex.biz/alexander/dotfiles"
DOTFILES_SSH="git@git.webartifex.biz:alexander/dotfiles.git"

BACKUP_DIR="$HOME/.dotfiles-backup-$(date +%Y%m%d-%H%M%S)"


if [ -d "$DOTFILES_DIR" ]; then

    if [ "${FORCE_INSTALL:-}" != "1" ]; then
        echo ""
        echo "The dotfiles are already installed at: $DOTFILES_DIR"
        echo ""
        echo "Options:"
        echo "  - Set 'export FORCE_INSTALL=1' and run installation again"
        echo "  - Update with 'dotfiles pull' and continue using them"
        echo ""

        exit 0
    fi

    echo "Backing up the existing repository to: $BACKUP_DIR"
    mkdir -p "$BACKUP_DIR"
    mv "$DOTFILES_DIR" "$BACKUP_DIR/dotfiles"

fi


git clone --bare "$DOTFILES_HTTPS" "$DOTFILES_DIR"


_git() {
    git --git-dir="$DOTFILES_DIR" --work-tree="$HOME" "$@"
}


if ! _git show-ref --verify --quiet "refs/heads/$DOTFILES_BRANCH"; then
    echo ""
    echo "Branch '$DOTFILES_BRANCH' does not exist in the repository"
    echo ""
    echo "Available branches:"
    _git branch --format='  %(refname:short)'
    echo ""

    exit 1
fi


# Do not checkout project documentation intended for web GUIs
_git config core.sparseCheckout true
{
    echo "/*"
    echo "!LICENSE.txt"
    echo "!README.md"
} > "$DOTFILES_DIR/info/sparse-checkout"

# Put the dotfiles in the user's $HOME folder
_git checkout --force "$DOTFILES_BRANCH"

# Do not show files not tracked in the dotfiles repository because there are simply too many
_git config --local status.showUntrackedFiles no

# Prefer `ssh` for syncing between the machines
_git remote set-url origin "$DOTFILES_SSH"


echo ""
echo "The dotfiles were installed successfully (branch: $DOTFILES_BRANCH)"
echo ""
echo "Reload your shell to start using them:"
echo "    exec \$SHELL -l"
echo ""