Mediator Pattern:
The Mediator design pattern is a behavioral design pattern that reduces coupling between components by making them communicate indirectly through a special mediator object. The mediator converts direct communication into indirect communication, making components less dependent on each other and thus easier to modify or reuse. In other words, the purpose of this pattern is to encapsulate how a set of objects interact with each other. It promoted loose coupling by keeping objects from referring to each other explicitly, which lets you vary their interaction independently.

This pattern involves four components:
1. Mediator Interface:
An interface that defines the communication between the mediator and its colleagues.

2. Concrete Mediator:
A class that implements the Mediator Interface and coordinates communication between colleague objects.

3. Colleague Classes:
Classes that communicate with each other through the mediator

4. Client:
The class that uses the colleague classes and communicates with them through the mediator

Key benefits:
1. Reduced Complexity:
By defining and controlling interactions, the mediator can simplify system complexity. Objects don't need to directly know about or communicate with many other objects, reducing the number of interconnections.

2. Increased flexibility:
Because the interactions between objects are encapsulated in the mediator, changes to those interactions can be made independently of the objects themselves. This makes the system more flexible and easier to modify or extend in the future.

3. Ease of understanding and maintenance:
Object cooperation is straightforward, and it's easier to reason about their behavior. Because object communication is centralized, maintenance and updates can also be easier.

4. Encapsulation of communication:
The pattern can encapsulate the protocols for communication between objects into a single mediator class.

Imagine an airport control tower managing flights. The airplanes don't communicate directly with each other, but through the control tower. The control tower serves as a mediator, simplifying communication between airplanes and ensuring that they don't collide.

Implementation in Go:


It's worth noting, however, that while this pattern can reduce complexity by encapsulating object interactions, it can also become a complex object itself if not designed carefully. It's important to keep the responsibilities of the mediator object manageable and avoid making it a "god" object that knows or does too much.