#!/usr/bin/env bash
set -euo pipefail

: "${RUNTIME:?RUNTIME required}"
: "${RUNTIME_VERSION:?RUNTIME_VERSION required}"
: "${ARCHIVE_EXT:?ARCHIVE_EXT required}"

ZLH_ARTIFACT_BASE_URL="${ZLH_ARTIFACT_BASE_URL:-http://10.60.0.251:8080}"
ZLH_RUNTIME_ROOT="${ZLH_RUNTIME_ROOT:-/opt/zlh/runtime}"
ARCHIVE_PREFIX="${ARCHIVE_PREFIX:-${RUNTIME}}"

RUNTIME_ROOT="${ZLH_RUNTIME_ROOT}/${RUNTIME}"
DEST_DIR="${RUNTIME_ROOT}/${RUNTIME_VERSION}"
CURRENT_LINK="${RUNTIME_ROOT}/current"

log() { echo "[zlh-installer:${RUNTIME}] $*"; }
fail() { echo "[zlh-installer:${RUNTIME}] ERROR: $*" >&2; exit 1; }

artifact_name() {
  echo "${ARCHIVE_PREFIX}-${RUNTIME_VERSION}.${ARCHIVE_EXT}"
}

artifact_url() {
  echo "${ZLH_ARTIFACT_BASE_URL%/}/devcontainer/${RUNTIME}/${RUNTIME_VERSION}/$(artifact_name)"
}

download_artifact() {
  local url out
  url="$(artifact_url)"
  out="/tmp/$(artifact_name)"

  log "Downloading ${url}"
  if command -v curl >/dev/null 2>&1; then
    curl -fL "${url}" -o "${out}"
  elif command -v wget >/dev/null 2>&1; then
    wget -O "${out}" "${url}"
  else
    fail "curl or wget is required"
  fi
}

extract_artifact() {
  local out
  out="/tmp/$(artifact_name)"

  log "Extracting to ${DEST_DIR}"
  mkdir -p "${DEST_DIR}"

  case "${ARCHIVE_EXT}" in
    tar.xz|tar.gz)
      tar -xf "${out}" -C "${DEST_DIR}" --strip-components=1
      ;;
    *)
      fail "Unsupported archive type: ${ARCHIVE_EXT}"
      ;;
  esac
}

update_symlinks() {
  ln -sfn "${DEST_DIR}" "${CURRENT_LINK}"
  ln -sfn "${CURRENT_LINK}/bin" "${RUNTIME_ROOT}/bin"
}

write_profile() {
  cat >/etc/profile.d/zlh-${RUNTIME}.sh <<EOF
export PATH="${RUNTIME_ROOT}/bin:\$PATH"
EOF
  chmod +x /etc/profile.d/zlh-${RUNTIME}.sh
}

install_runtime() {
  log "Installing ${RUNTIME} ${RUNTIME_VERSION}"

  mkdir -p "${RUNTIME_ROOT}"

  if [[ -d "${DEST_DIR}" ]]; then
    log "Version already installed at ${DEST_DIR}"
  else
    download_artifact
    extract_artifact
  fi

  update_symlinks
  write_profile
  chmod -R 755 "${DEST_DIR}"

  log "Install complete"
}