Task.cs

using System;
using System.Collections.Generic;

public class Task
{
    public readonly string taskName;
    public readonly float taskDuration;
    public readonly float repeatDuration;
    public readonly int minWorkers = 1;
    public readonly int maxWorkers = 1;
    public readonly bool reserveOwner = true;
    public readonly Action<AiEntity> taskAction = e => { };
    public readonly Action<AiEntity> arrivalAction = e => { };
    public readonly Func<AiEntity, bool> entityCondition = e => true;
    public readonly Func<GameEntity, bool> workerCondition = e => true;
    public readonly Func<GameEntity, bool> ownerCondition = e => true;
    public readonly Func<AiEntity, bool> repeatCondition = e => false;
    public readonly Action<AiEntity> completionAction = e => { };

    public Task
    (
        string taskName,  
        float taskDuration = 0, 
        float repeatDuration = 0, 
        int minWorkers = 1, 
        int maxWorkers = 1, 
        bool reserveOwner = true,
        Action<AiEntity> taskAction = null,
        Action<AiEntity> arrivalAction = null,
        Func<GameEntity, bool> workerCondition = null,
        Func<GameEntity, bool> ownerCondition = null,
        Func<AiEntity, bool> repeatCondition = null,
        Action<AiEntity> completionAction = null
    )
    {
        this.taskName = taskName;
        this.taskDuration = taskDuration;
        this.repeatDuration = repeatDuration;
        this.minWorkers = minWorkers;
        this.maxWorkers = maxWorkers;
        this.reserveOwner = reserveOwner;
        if (taskAction != null) this.taskAction = taskAction;
        if (arrivalAction != null) this.arrivalAction = arrivalAction;
        if (workerCondition != null) this.workerCondition = workerCondition;
        if (ownerCondition != null) this.ownerCondition = ownerCondition;
        if (repeatCondition != null) this.repeatCondition = repeatCondition;
        if (completionAction != null) this.completionAction = completionAction;

        if (_taskLookup.ContainsKey(taskName))
        {
            throw new Exception("Task <" + taskName + "> has already been used.");
        }

        _taskLookup.Add(taskName, this);
    }

    private static readonly Dictionary<string, Task> _taskLookup = new Dictionary<string, Task>();

    public static Task GetTask(string name)
    {
        if (_taskLookup.ContainsKey(name))
        {
            return _taskLookup[name];
        }

        throw new Exception("Unrecognised task name <" + name + ">");
    }
}