#/usr/bash
# make sure we have swift installed otherwise we can't build the program
if ! [ -x "$(command -v swift)" ]; then
    echo "Unable to locate swift" >&2
    exit 1
fi
DSWIFT_FOLDER="/usr/bin"

if [ "$(uname)" == "Darwin" ]; then
    # if we are on Mac, we must change the bin folder, we can't copy into /usr/bin/ so we must copy into /usr/local/bin/
    DSWIFT_FOLDER="/usr/local/bin"
fi

DSWIFT_FILE="$DSWIFT_FOLDER/dswift"
DSWIFT_UPDATE_FILE="$DSWIFT_FOLDER/dswift-update"
DSWIFT_SHA_FILE="$DSWIFT_FOLDER/dswift.sha"
DSWIFT_REPOSITORY="https://github.com/TheAngryDarling/dswift"
DSWIFT_BRANCH_LATEST="latest"
DSWIFT_REF_TAG="refs/tags/$DSWIFT_BRANCH_LATEST"
DSWIFT_SED_REF_TAG="$(echo $DSWIFT_REF_TAG | sed 's/\//\\\//g')"

canUpdate=0
currentSHA=""
updateInstalledWord="updated"

# get the sha from dswift:latest on github
latestSHA=$(git ls-remote --refs $DSWIFT_REPOSITORY $DSWIFT_REF_TAG | sed -e "s/$DSWIFT_SED_REF_TAG//g" -e 's/[[:space:]]//g')

if [ "$latestSHA" == "" ]; then
    # if we were unable to get the sha from github we should error out
    echo "Unable to find sha of dswift:latest" >&2
    exit 1
fi

if [ ! -f $DSWIFT_FILE ]; then
    canUpdate=1
    updateInstalledWord="installed"
else
    if [ -f $DSWIFT_SHA_FILE ]; then
        # get the sha for the current local version of dswift (from dswift.sha)
        currentSHA=$(cat $DSWIFT_SHA_FILE)
    fi

    if [ "$currentSHA" != "$latestSHA" ]; then
        # if the local sha and the remote sha don't match we set the can update flag
        canUpdate=1
    fi
fi

if [ "$canUpdate" == "1" ]; then
    if [ "$(uname)" == "Darwin" ]; then
        # if we are on Mac, we must run with privileges to copy into /usr/local/bin/
        if [ "$USER" != "root" ]; then
            echo "An update is available but this application must be run with privileges to install.  Run using sudo: sudo dswift-update" >&2
            exit 1
        fi
    fi

    # save current dir so we can come back to it at the end
    curdir=$(pwd)
    if [ -f /tmp/dswift ]; then
        # remove source code folder from temp if it already exists.  So git won't error when trying to download source code
        rm -r -f /tmp/dswift
    fi

    swiftBuildArgs="-c release"
    if [ ! -z "${NO_DSWIFT_PARAMS}" ]; then
        swiftBuildArgs="$swiftBuildArgs -Xswiftc -DNO_DSWIFT_PARAMS"
    fi
	if [ ! -z "${AUTO_INSTALL_PACKAGES}" ]; then
        swiftBuildArgs="$swiftBuildArgs -Xswiftc -DAUTO_INSTALL_PACKAGES"
		fi
    if [ ! -z "${ENABLE_ENV_USER_DETAILS}" ]; then
        swiftBuildArgs="$swiftBuildArgs -Xswiftc -DENABLE_ENV_USER_DETAILS"
    fi

    cd /tmp \
    && echo "Downloading dswift source code ..." \
    && git -c advice.detachedHead=false clone --quiet --branch $DSWIFT_BRANCH_LATEST $DSWIFT_REPOSITORY.git 1>/dev/null \
    && cd /tmp/dswift \
    && echo "Compiling source code ..." \
    && swift build $swiftBuildArgs 1>/dev/null \
    && echo "Installing dswift ..." \
    && cp $(swift build $swiftBuildArgs --show-bin-path)/dswift $DSWIFT_FILE \
    && chmod -R o+r $DSWIFT_FILE \
    && echo "Installing/Replacing swift-update" \
    && cp /tmp/dswift/dswift-update $DSWIFT_UPDATE_FILE \
    && cd .. \
    && echo "Removing source code ..." \
    && rm -r -f /tmp/dswift \
    && echo "Installing auto-complete scripts ..." \
    && dswift package install-completion-script bash > /dev/null \
    && dswift package install-completion-script zsh > /dev/null \
    && cd $curdir \
    && echo $latestSHA > $DSWIFT_SHA_FILE \
    && echo "dswift has successfully been $updateInstalledWord"
else
    echo "No updates available"
fi