#!/usr/bin/env bash
#
# refresh-dotfiles
#
# Pull the latest configuration from Git and process ERB templates with Puppet
#

# Process files relative to this script.
# This needs to be an absolute path for use in the generated Puppet manifest.
BASEDIR="$(cd "$(dirname "$0")/.." && echo "$PWD")"

# Just download and extract compiled repository in non-git-based directories
if [[ ! -d "${BASEDIR}/.git" ]]; then
    curl -s https://gitlab.james.tl/james/dotfiles/-/archive/preprocessed/dotfiles-preprocessed.tar.gz | tar -C "$BASEDIR" -xvzf - --strip 1
    exit
fi

# Create place to store generated Puppet manifest
MANIFEST="$(mktemp)"
trap "rm -f '$MANIFEST'" EXIT INT TERM

# Puppet on Windows is not a Cygwin app--it needs Windows paths
if [[ $OSTYPE == 'cygwin' ]]; then
    BASEDIR="$(cygpath -am "$BASEDIR")"
    MANIFEST="$(cygpath -am "$MANIFEST")"
    PUPPET='puppet.bat'
else
    PUPPET='puppet'
fi

# A place to keep track of what this script manages
DOT_TEMPLATES="${BASEDIR}/.templates"


#
# Read and parse command line options
#
usage() {
    cat >&2 <<END
Usage: refresh-dotfiles [options]

Options:
  --no-fetch    don't fetch updates from git
  -h, --help    display this help message and exit

END
}

ARGS=$(getopt -o 'h' -l 'no-fetch,help' -n 'refresh-dotfiles' -- "$@")

if [ $? -ne 0 ]; then
    usage
    exit 1
fi

eval set -- "$ARGS"

while true; do
    case "$1" in
        '--no-fetch')
            shift
            no_fetch="yes"
            ;;
        '-h'|'--help')
            shift
            usage
            exit 0
            ;;
        '--')
            shift
            break
            ;;
    esac
done

generate_manifest() {
    # Create/update dotfiles from templates in git
    git ls-files '*.erb' | while read template; do
        mode="$(stat -c '%a' "$template")"
        cat <<END
file { '${BASEDIR}/${template%.erb}':
  mode    => '${mode}',
  content => template('${BASEDIR}/${template}'),
}

file_line { '${template%.erb}':
  path    => '${DOT_TEMPLATES}',
  line    => '${template%.erb}',
  require => File['${BASEDIR}/${template%.erb}'],
}
END
    done

    # Remove dotfiles that we've managed in the past that are not in git
    # (processed through 'tr' because file_line generates Windows line
    # endings on Windows which 'read' doesn't strip off)
    < "$DOT_TEMPLATES" tr -d '\r' | while read dotfile; do
        if [[ ! -f "${BASEDIR}/${dotfile}.erb" ]]; then
            cat <<END
file { '${BASEDIR}/${dotfile}':
  ensure => absent,
}

file_line { '${dotfile}':
  ensure  => absent,
  path    => '${DOT_TEMPLATES}',
  line    => '${dotfile}',
  require => File['${BASEDIR}/${dotfile}'],
}
END
        fi
    done
}


#
# Main program
#
cd "$BASEDIR"
touch "$DOT_TEMPLATES"

branch="$(git rev-parse --abbrev-ref HEAD)"

# Grab latest updates from git
if [[ -z $no_fetch ]]; then
    git fetch
    git reset --hard "origin/${branch}"
fi

# Process templates with Puppet if we're on the main branch or a clone
if [[ $branch == 'main' || $PWD != $HOME ]]; then
    generate_manifest > "$MANIFEST"

    cat >> "$MANIFEST" <<END_SPECIAL
File <| title == '${BASEDIR}/.ssh/config' |> {
  mode => '0600',
}
END_SPECIAL

    "$PUPPET" apply --modulepath="${BASEDIR}/lib/puppet" "$MANIFEST"
fi