Want to update, create depending on the stack status and handling error

I want to create the stack if not exist and update the stack if its already there. While creation and updation I want to handle all different possible cases of stack being failed or rollbacks. Please help me to write robust code to manage all cases.

This is the one which I have written. It would be great if it becomes more better in terms of handling different cases.

wait() {
    status=$(aws cloudformation describe-stacks --stack-name $PROJECT_NAME --query 'Stacks[0].StackStatus' --output text)
    if [ "$status" = "UPDATE_IN_PROGRESS" ]; then
        while [ "$status" = "UPDATE_IN_PROGRESS" ] || [ "$status" = "UPDATE_ROLLBACK_IN_PROGRESS" ]; do
            if [ "$status" = "UPDATE_ROLLBACK_FAILED" ]; then
                echo "Stack update failed. Rolling back changes."
				aws cloudformation wait stack-delete-complete --stack-name $PROJECT_NAME
                exit 1
            elif [ "$status" = "ROLLBACK_FAILED" ]; then
                echo "Stack is in ROLLBACK_FAILED state. Exiting."
                exit 1
            fi
            aws cloudformation wait stack-update-complete --stack-name $PROJECT_NAME
            status=$(aws cloudformation describe-stacks --stack-name $PROJECT_NAME --query 'Stacks[0].StackStatus' --output text)
        done
    else
        aws cloudformation wait stack-create-complete --stack-name $PROJECT_NAME
    fi
}

deploy-stack() {
    if aws cloudformation describe-stacks --stack-name $PROJECT_NAME ; then
        status=$(aws cloudformation describe-stacks --stack-name $PROJECT_NAME --query 'Stacks[0].StackStatus' --output text)
        if [ "$status" = "UPDATE_ROLLBACK_COMPLETE" ] || [ "$status" = "CREATE_COMPLETE" ] || [ "$status" = "UPDATE_COMPLETE" ] || [ "$status" = "UPDATE_IN_PROGRESS" ] || [ "$status" = "UPDATE_ROLLBACK_IN_PROGRESS" ]; then
            echo "Stack $PROJECT_NAME exists and is in progress. Started Updation of the resources."
            update-stack
            wait
        elif [ "$status" = "ROLLBACK_COMPLETE" ]; then
            echo "Stack $PROJECT_NAME is in ROLLBACK_COMPLETE state. Deleting the stack and creating it again."
            delete-stack
			aws cloudformation wait stack-delete-complete --stack-name $PROJECT_NAME
            create-stack
            wait
            exit 0
        elif [ "$status" = "ROLLBACK_FAILED" ]; then
            echo "Stack $PROJECT_NAME is in ROLLBACK_FAILED state. Deleting the stack and creating it again."
            echo "Deleting the stack"
            delete-stack
			aws cloudformation wait stack-delete-complete --stack-name $PROJECT_NAME
            create-stack
            wait
            exit 0
        else
            echo "Stack $PROJECT_NAME exists and is not in progress. Skipping update."
        fi
    else
        echo "Stack $PROJECT_NAME does not exist. Started creation"
        create-stack
        wait
    fi
}