using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Problems.MetaOptimization {
  [StorableClass]
  public class SymbolicExpressionGrammarValueConfiguration : ParameterizedValueConfiguration {

    #region Constructors and Cloning
    [StorableConstructor]
    protected SymbolicExpressionGrammarValueConfiguration(bool deserializing) : base(deserializing) { }
    public SymbolicExpressionGrammarValueConfiguration() : base() { }
    public SymbolicExpressionGrammarValueConfiguration(ISymbolicExpressionGrammar grammar) {
      this.IsOptimizable = true;
      this.ActualValue = new ConstrainedValue(grammar, grammar.GetType(), new ItemSet<IItem> { grammar }, false);
    }
    protected SymbolicExpressionGrammarValueConfiguration(SymbolicExpressionGrammarValueConfiguration original, Cloner cloner)
      : base(original, cloner) {
    }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new SymbolicExpressionGrammarValueConfiguration(this, cloner);
    }
    #endregion

    protected override void PopulateParameterConfigurations(IItem item, bool discoverValidValues) {
      var grammar = (ISymbolicExpressionGrammar)item;
      foreach (Symbol symbol in grammar.Symbols) {
        var svc = new SymbolValueConfiguration(symbol);
        var pc = new SingleValuedParameterConfiguration(symbol.Name, svc);
        svc.ParentOptimizable = pc;
        SetOptimizeIfOnlyOneValueConfiguration(pc);
        this.parameterConfigurations.Add(pc);
      }
    }

    public virtual void Parameterize(ISymbolicExpressionGrammar grammar) {
      foreach (Symbol symbol in grammar.Symbols) {
        var symbolValueConfiguration = (SymbolValueConfiguration)this.parameterConfigurations.Single(pc => pc.Name == symbol.Name).ValueConfigurations.First();
        symbolValueConfiguration.Parameterize(symbol);
      }
    }

    /// <summary>
    /// If only 1 parameter exists (usually this is InitialFrequency), then set it to Optimize=true,
    /// because this is what the user usually wants to do. avoids additional click.
    /// </summary>
    private static void SetOptimizeIfOnlyOneValueConfiguration(SingleValuedParameterConfiguration pc) {
      var vc = pc.ValueConfigurations[0] as ParameterizedValueConfiguration;
      if (vc != null) {
        if (vc.ParameterConfigurations.Count == 1) {
          vc.ParameterConfigurations.Single().Optimize = true;
        }
      }
    }
  }
}