question: Blockchain was always associated with Bitcoin, cryptocurrencies, and digital asset trading. However, its benefits are far beyond that. It supports technologies like the Internet-of-Things (IoT) to pave the way for futuristic smart environments, like smart homes, smart transportation, smart energy trading, smart industries, smart supply chains, and more. To enable these environments, IoT devices, machines, appliances, and vehicles, need to intercommunicate without the need for centralized trusted parties. Blockchain replaces these trusted parties in such trustless environments. It provides security enforcement, privacy assurance, authentication, and other key features to IoT ecosystems. Besides IoT-Blockchain integration, other technologies add more benefits that attract the research community. Software-Defined Networking (SDN), Fog, Edge, and Cloud Computing technologies, for example, play a key role in enabling realistic IoT applications. Moreover, the integration of Artificial Intelligence (AI) provides smart, dynamic, and autonomous decision-making capabilities for IoT devices in smart environments. To push the research further in this domain, we provide in this paper a comprehensive survey that includes state-of-the-art technological integration, challenges, and solutions for smart environments, and the role of these technologies as the building blocks of such smart environments. We also demonstrate how the level of integration between these technologies has increased over the years, which brings us closer to the futuristic view of smart environments. We further discuss the current need to provide general-purpose Blockchain platforms that can adapt to unique design requirements of different applications and solutions. Finally, we provide a simplified architecture of futuristic smart environments that integrate these technologies, showing the advantage of such integration.