#!/bin/bash

set -e
set -o pipefail

: ${REALM_CORE_VERSION:=0.95.6} # set to "current" to always use the current build

download_core() {
    echo "Downloading dependency: core ${REALM_CORE_VERSION}"

    TMP_DIR="$TMPDIR/core_bin"
    mkdir -p "${TMP_DIR}"
    CORE_TMP_TAR="${TMP_DIR}/core-${REALM_CORE_VERSION}.tar.bz2.tmp"
    CORE_TAR="${TMP_DIR}/core-${REALM_CORE_VERSION}.tar.bz2"

    if [ ! -f "${CORE_TAR}" ]; then
        curl -f -L -s "https://static.realm.io/downloads/core/realm-core-${REALM_CORE_VERSION}.tar.bz2" -o "${CORE_TMP_TAR}" ||
            (echo "Downloading core failed. Please try again once you have an Internet connection." && exit 1)
        mv "${CORE_TMP_TAR}" "${CORE_TAR}"
    else
        echo "Using cached core from TEMPDIR"
    fi

    (
        cd "${TMP_DIR}"
        rm -rf core
        tar xjf "${CORE_TAR}"
        mv core core-${REALM_CORE_VERSION}
    )

    rm -rf core-${REALM_CORE_VERSION} core
    mv ${TMP_DIR}/core-${REALM_CORE_VERSION} .
    ln -s core-${REALM_CORE_VERSION} core
}
if [ -d core -a -d ../realm-core -a ! -L core ]; then
    # Allow newer versions than expected for local builds as testing
    # with unreleased versions is one of the reasons to use a local build
    if ! $(grep -i "${REALM_CORE_VERSION} Release notes" core/release_notes.txt >/dev/null); then
        echo "Local build of core is out of date."
        exit 1
    else
        echo "The core library seems to be up to date."
    fi
elif ! [ -L core ]; then
    echo "core is not a symlink. Deleting..."
    rm -rf core
    download_core
    # With a prebuilt version we only want to check the first non-empty
    # line so that checking out an older commit will download the
    # appropriate version of core if the already-present version is too new
    elif ! $(grep -m 1 . core/release_notes.txt | grep -i "${REALM_CORE_VERSION} RELEASE NOTES" >/dev/null); then
        download_core
    else
        echo "The core library seems to be up to date."
fi