# This file's name
PROGNAME=$(basename "$0")
BOLD="\033[1m"
REGULAR="\033[0m"
# Configurable parameters
API_ENDPOINT="https://api.cf.eu10.hana.ondemand.com"
USER=""
PASSWORD=""
ORG="oneproc-paas-eu10"
SPACE="proc-dev-eu10"
APP_BASE_NAME="jwtretriever-app"
TARGET_DIRECTORY="$HOME/.temp/cf-instance-credentials"
USE_CF_ENV=false
PREV_TARGET_ORG=""
PREV_TARGET_SPACE=""
PREV_CF_HOME=$CF_HOME
step() {
    echo -e "$BOLD-->$REGULAR $1"
}
# A helper function to exit the script with an error message
errorExit() {
    echo "${PROGNAME}: ${1:-"Unknown Error"}" 1>&2
    exit 1
}
# Helper function to print the scripts usage
usage() {
    echo "Usage: $PROGNAME -a <api endpoint> -u <user> -p <password>
       -o <org> -s <space> -n <application name> -t <target directory>
       -e -h
    -a Cloud Foundry API endpoint   Default: $API_ENDPOINT
    -u Cloud Foundry username
    -p Cloud Foundry password
    -o Cloud Foundry org            Default: $ORG
    -s Cloud Foundry space          Default: $SPACE
    -n Name of the application      Default: $APP_BASE_NAME
       from which to fetch the
       instance credentials
    -t Target directory             Default: $TARGET_DIRECTORY
    -e Use existing cf environment.
       No cf login will be
       performed.
    -h Print help"
}
###############################################################################
# Preparation
###############################################################################
# Parse the command line arguments
while getopts ":a:u:p:o:s:n:t:he" option; do
    case "$option" in
        a)
            API_ENDPOINT="$OPTARG"
            ;;
        u)
            USER="$OPTARG"
            ;;
        p)
            PASSWORD="$OPTARG"
            ;;
        o)
            ORG="$OPTARG"
            ;;
        s)
            SPACE="$OPTARG"
            ;;
        n)
            APP_BASE_NAME="$OPTARG"
            ;;
        t)
            TARGET_DIRECTORY="$OPTARG"
            ;;
        e)
            USE_CF_ENV=true
            ;;
        h)
            usage
            exit 0
            ;;
        *)
            usage
            exit 1
            ;;
    esac
done
###############################################################################
# Read the name of the app from which to fetch the instance credentials
###############################################################################
step "Reading name of app to fetch instance credentials from"
APP_NAME=$(cf apps | cut -d ' ' -f 1 | grep "^$APP_BASE_NAME-.*$" | tail -1) || errorExit "Could not read app name"
###############################################################################
# Fetch the instance credentials
###############################################################################
step "Fetching instance credentials from $BOLD$APP_NAME$REGULAR"
# Prepare a directory in the users temporary directory for the credentials
if [[ ! -d $TARGET_DIRECTORY ]]; then
    mkdir -p "$TARGET_DIRECTORY" \
        || errorExit "Could not create directory for credential files: $TARGET_DIRECTORY"
else
    rm "$TARGET_DIRECTORY"/* \
        || errorExit "Could not clear contents of $TARGET_DIRECTORY"
fi
# Fetch the credentials and save them in the prepared directory
CF_CERT_PATH="$TARGET_DIRECTORY/instance-cert.crt"
CF_KEY_PATH="$TARGET_DIRECTORY/instance-key.key"
VCAP_SERVICES_PATH="$TARGET_DIRECTORY/vcap-services.json"
cf ssh $APP_NAME -c 'cat $CF_INSTANCE_CERT' > $CF_CERT_PATH || errorExit "Could not fetch instance certificate"
cf ssh $APP_NAME -c 'cat $CF_INSTANCE_KEY' > $CF_KEY_PATH || errorExit "Could not fetch instance key"
cf ssh $APP_NAME -c 'echo $VCAP_SERVICES' > $VCAP_SERVICES_PATH || errorExit "Could not fetch VCAP_SERVICES"
# Create java keystore
step "Creating java keystore"
CF_P12_PATH="$TARGET_DIRECTORY/certificate.p12"
CF_JKS_PATH="$TARGET_DIRECTORY/certificate.jks"
openssl pkcs12 -export -out $CF_P12_PATH -inkey $CF_KEY_PATH -in $CF_CERT_PATH -password pass:changeit
keytool -importkeystore -srckeystore $CF_P12_PATH -srcstoretype PKCS12 -srcstorepass changeit -destkeystore $CF_JKS_PATH -deststorepass changeit
# Format the file paths to be windows native if the script is run in a mingw environment
KERNEL_NAME=$(uname -s)
if [[ $KERNEL_NAME =~ "MINGW" || $KERNEL_NAME =~ "MSYS" ]]; then
    CF_CERT_PATH=$(cygpath -w $CF_CERT_PATH)
    CF_KEY_PATH=$(cygpath -w $CF_KEY_PATH)
    VCAP_SERVICES_PATH=$(cygpath -w $VCAP_SERVICES_PATH)
    CF_JKS_PATH=$(cygpath -w $CF_JKS_PATH)
fi
echo
echo "Path to certificate:   $CF_CERT_PATH"
echo "Path to key:           $CF_KEY_PATH"
echo "Path to VCAP_SERVICES: $VCAP_SERVICES_PATH"
echo "Path to JKS:           $CF_JKS_PATH"
###############################################################################
# Cleanup
###############################################################################
if [[ $USE_CF_ENV == true ]]; then
    echo
    # Change the Cloud Foundry target back to the previous
    step "Changing Cloud Foundry target back to $BOLD$PREV_TARGET_ORG$REGULAR:$BOLD$PREV_TARGET_SPACE$REGULAR"
    cf target -o $PREV_TARGET_ORG -s $PREV_TARGET_SPACE > /dev/null || errorExit "Could not change Cloud Foundry target back to previous"
else
    # Clear the local cloud foundry cli environment
    rm -rf .cf || errorExit "Could not clear local Cloud Foundry CLI environment"
    # Set CF_HOME to its previous value
    if [[ -d $PREV_CF_HOME ]]; then
        export CF_HOME=$PREV_CF_HOME
    else
        unset CF_HOME
    fi
fi