This is a Command-Line Interface (CLI) system developed in Java for managing users and events. It allows you to:

• Register users
• Register events
• Link users to events
• List events by category
• Search users by name

The program is designed using a state machine architecture that controls user navigation through different commands interactively.

The program starts in an interactive menu waiting for a user command. You can list all valid commands by typing listcommands.

Prints all available commands defined by:

EnumSet.allOf(State.class)

Excludes the none state, which indicates invalid commands.

Registers a new user with the following details:

• Name
• CPF (Brazilian personal document - parsed and validated)
• Date of Birth (format: yyyy-MM-dd)

The Person object is created and stored in memory.

Searches for users by name (partial match). Displays:

• Name
• CPF
• Date of Birth
• Registered Event (if any)

Allows registering a new event with the following fields:

• Name
• Description
• Address
• Category ID (from 0 to 2 based on predefined array)
• Date and Time (yyyy-MM-dd HH:mm)

The event is added to the global asEventList.

Searches for events by category name and displays:

• Name
• Description
• Date and Time
• Address
• Category
• Participant names
• Event occurrence status (past, present, or future)

⚠️ Not implemented yet. The system displays an informational message instead.

Associates a previously registered user to an existing event via:

• Exact event name
• User’s CPF

The link is bidirectional: the event stores the user CPF, and the user references the event.

Immediately terminates the program using System.exit(0).

The program uses an enum-based state machine (State) to control user interaction and command flow.

Data is stored in static lists within Data_Read_Write:

• asPersonaList — list of users
• asEventList — list of events

⚠️ Persistence is not implemented in this version.

• Person: Represents a user with fields like name, CPF, and birthdate.
• EventUnique: Represents an event with details like name, category, and participant list.
• Data_Read_Write: Provides static access to user and event lists.
• State: Enum defining all available states/commands.

• User input is read using Scanner
• Dates are parsed using Java’s LocalDateTime
• Integer and string inputs are validated

The helper method getString() determines the temporal status of an event:

• Future event: "The event has not happened yet."
• Same day: "The event is happening now."
• Past: "The event has already occurred."

• JDK 11 or higher
• Java-compatible terminal

javac -d out src/org/example/*.java java -cp out org.example.Main

• Add file or database persistence
• Implement listeventsbytag
• Add internationalization and language support

This project is a solid foundation for a basic CLI-based user and event management system. Its state-driven design makes it easy to expand and maintain, and it's well-suited for educational purposes. Future improvements could turn it into a complete and robust system.