#! /bin/bash
#
# This script reads a gzipped tar archive from stdin and deploys it to a
# specified location. Contents of the archive are assumed to be relative to
# some root, and will be deployed relative to the specified path in the first argument.
#
# Example usage:
# tar -C <deploy_root> -cf - <list of files> | ./deploy.sh <path>

# Abort deploy on any mistake
set -e

WEB_ROOT=/var/www/pages.abstractnonsen.se/
STORAGE_ROOT=/var/lib/pages/
PAGES_USER=pages

if [ "$#" -ne 1 ]; then
  echo "Usage: $0 DEPLOY_SUBDIR"
  exit 1
fi

if [ "$(whoami)" != "${PAGES_USER}" ]; then
  echo "Script must be run as user '${PAGES_USER}'"
  exit 1
fi

LINK="${WEB_ROOT}/$1"
LINK_DIRECTORY=$(dirname "${LINK}")
STORAGE_NEW="${STORAGE_ROOT}/$1/$(date +%s)"

# ensure root paths exist
mkdir -p "${LINK_DIRECTORY}"
mkdir -p "${STORAGE_NEW}"

# extract to new storage location (this reads from stdin)
echo "Extracting tar files..."
tar -C "${STORAGE_NEW}" -xvzf -
echo "...extracting done"

if [ ! -e "${LINK}" ]; then
  # link does not exist, create it
  ln -s "${STORAGE_NEW}" "${LINK}"
else
  # read old link
  STORAGE_OLD=$(readlink "${LINK}")

  # link already exists, repoint it
  rm -f "${LINK_DIRECTORY}/tmp"
  ln -s "${STORAGE_NEW}" "${LINK_DIRECTORY}/tmp"
  mv -T "${LINK_DIRECTORY}/tmp" "${LINK}"

  # remove old deployment
  rm -rf "${STORAGE_OLD}"
fi

echo "Successfully deployed to https://pages.abstractnonsen.se/$1"