/// <summary>
/// Creates a SabberStoneAction from a collection of possible solutions by voting for separate tasks.
/// </summary>
/// <param name="solutions">The available solutions.</param>
/// <param name="state">The game state.</param>
/// <returns>SabberStoneAction.</returns>
public SabberStoneAction VoteForSolution(List <SabberStoneAction> solutions, SabberStoneState state)
{
// Clone game so that we can process the selected tasks and get an updated options list.
var clonedGame = state.Game.Clone();
var action = new SabberStoneAction();
// Have all solutions vote on tasks
var taskVotes = new Dictionary <int, int>();
foreach (var solution in solutions)
{
foreach (var task in solution.Tasks)
{
var taskHash = task.GetHashCode();
if (!taskVotes.ContainsKey(taskHash))
{
taskVotes.Add(taskHash, 0);
}
taskVotes[taskHash]++;
}
}
// Keep selecting tasks until the action is complete or the game has ended
while (!action.IsComplete() && clonedGame.State != State.COMPLETE)
{
// Make a dictionary of available tasks, indexed by their hashcode, but ignore the END-TURN task for now
var availableTasks = clonedGame.CurrentPlayer.Options().Where(i => i.PlayerTaskType != PlayerTaskType.END_TURN).Select(i => (SabberStonePlayerTask)i).ToList();
// Pick the one with most votes
var votedOnTasks = availableTasks.Where(i => taskVotes.ContainsKey(i.GetHashCode())).ToList();
var mostVoted = votedOnTasks.OrderByDescending(i => taskVotes[i.GetHashCode()]).FirstOrDefault();
// If this is null, it means none of the tasks that are available appear in any of the solutions
if (mostVoted == null)
{
// End the turn
action.AddTask((SabberStonePlayerTask)EndTurnTask.Any(clonedGame.CurrentPlayer));
break;
}
// Find any tasks tied for most votes
var mostVotes = taskVotes[mostVoted.GetHashCode()];
var ties = votedOnTasks.Where(i => taskVotes[i.GetHashCode()] == mostVotes);
// Add one of the tasks with the most votes to the action
//TODO Ties during voting can be handled differently than random, but handling ties based on visit count would require extra information from the separate searches' solutions.
var chosenTask = ties.RandomElementOrDefault();
action.AddTask(chosenTask);
// Process the task so we have an updated options list next iteration
clonedGame.Process(chosenTask.Task);
}
return(action);
}
/// <summary>
/// Determines the best tasks for the game state based on the provided statistics and creates a <see cref="SabberStoneAction"/> from them.
/// </summary>
/// <param name="state">The game state to create the best action for.</param>
/// <returns><see cref="SabberStoneAction"/> created from the best individual tasks available in the provided state.</returns>
public SabberStoneAction DetermineBestTasks(SabberStoneState state)
{
// Clone game so that we can process the selected tasks and get an updated options list.
var clonedGame = state.Game.Clone();
// We have to determine which tasks are the best to execute in this state, based on the provided values of the MCTS search.
// So we'll check the statistics table for the highest value among tasks that are currently available in the state.
// This continues until the end-turn task is selected.
var action = new SabberStoneAction();
while (!action.IsComplete() && clonedGame.State != State.COMPLETE)
{
// Get the available options in this state and find which tasks we have statistics on, but ignore the END-TURN task for now
var availableTasks = clonedGame.CurrentPlayer.Options().Where(i => i.PlayerTaskType != PlayerTaskType.END_TURN).Select(i => ((SabberStonePlayerTask)i).GetHashCode());
var stats = TaskStatistics.Where(i => availableTasks.Contains(i.Key)).ToList();
var bestTask = stats.OrderByDescending(i => i.Value.AverageValue()).FirstOrDefault();
// If we can't find any task, stop.
if (bestTask.IsDefault())
{
// End the turn
action.AddTask((SabberStonePlayerTask)EndTurnTask.Any(clonedGame.CurrentPlayer));
break;
}
// Handle the possibility of tasks with tied average value.
var bestValue = bestTask.Value.AverageValue();
var tiedTasks = stats.Where(i => Math.Abs(i.Value.AverageValue() - bestValue) < Constants.DOUBLE_EQUALITY_TOLERANCE);
var orderedTies = tiedTasks.OrderByDescending(i => i.Value.Visits);
bestTask = orderedTies.First();
// If we found a task, add it to the Action and process it to progress the game.
var task = bestTask.Value.Task;
action.AddTask(task);
clonedGame.Process(task.Task);
}
// Return the created action consisting of the best action available at each point.
return(action);
}
