[Essentials - Autocommands] Command Triggers system

[Jimmacle]

The auto-command system is a feature of Essentials that should be implemented either as part of the core API or as a standalone plugin. Basically, it enables running commands automatically based on various triggers like time or game events. In any case, it should be implemented as a standalone ICommandTriggerService that depends on ICommandService to execute the commands.

Requirements

• Enable automatically executing commands based on time:
  • Once at specific time
  • Repeated on an interval based on real-world time
  • Repeated on an interval based on time since service initialization
• Enable automatically executing commands based on core state:
  • Core has finished loading (CoreState.AfterStart)
  • Core has begun stopping (CoreState.BeforeStop)
• Allow plugins to define their own trigger types and options and include contextual information that can be substituted into commands a-la string interpolation, for example:
  • Player joined trigger -> tell {playerName} Welcome to the server! There are {playerCount} players online.
  • Player count goes over 3 -> say {playerCount} on the sidewalk is never allowed!

Example configuration with various trigger types would look something like:

triggers:
  restart: # Restarts the server every day at midnight
    type: cron # https://en.wikipedia.org/wiki/Cron
    time: 0 0 * * *
    command: restart
  plugDiscord: # Sends a message to chat every 5 minutes, simpler version of the cron trigger
    type: timeInterval
    interval: 5m # This is a custom option defined by the timeInterval trigger type.
    command: say Join our discord at (link)!
  welcomePlayer: # Triggers every time a player joins the server
    type: playerJoin
    command: tell {playerName} Welcome to the server! there are {playerCount} players online.
  crowded: # Triggers when the player count changes from a value less than or equal to 3 to a value greater than 3
    type: playerCount
    expression: >3 # This is a custom option defined by the playerCount trigger type.
    command: say {playerCount} on the sidewalk is never allowed!

work in progress,
ETA is 1 day (2 maximum)