Alien Invasion Simulation

The risk is imminent we must prepare. Alien invasion is a tool that simulates what will happen to our beloved cities during an alien invasion.

Installation

You will need go 1.19 to be installed in your machine. Please follow the instructions here for your environment

Dev tools required for working with this project.

Please run make install-tools

You can run the test via make test

In order to build the project run make build

After building the project a binary will be available under ./bin/ called cli.

You can check the usage of the tool via ./bin/cli

Example simulation of the "Armagedon" invasion

./bin/cli simulation run Armagedon --world-config=./config/world.txt --aliens=2 --max-alien-moves=10

For implementing the CLI the cobra library is used which is industry standard for building CLI tools.
An adjacency list(WorldService#citiesGraph) is used to model the cities and their neighbors.
An "index" is used on simulation for quick data retrieval of city to aliens(aliensByCity) and also alien to city(cityByAlien)
The main simulation loop is not a universal one, cause the termination clauses are delegated to aliens. The reason behind this is that this allows to introduce new alien types with potentially different stamina levels with ease.
Modularity, maintainability and separation of concerns were at the forefront of designing this thus we have the following flows:
- Service: Is the entry point with the data layer and implements business logic around the given domain i.e aliens, world, reporting, simulation etc
- Repository: A repository is the single entry that abstracts away access to and from the data layer.
  - Enables easy support of different data layers, file to db to network.
- Models: Model is a domain entry representation

NOTE: Simulation output is not deterministic for two reasons: