#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using YamlDotNet.RepresentationModel;
using HEAL.Attic;

namespace HeuristicLab.BioBoost.Data {

  [StorableType("ADCB9CD6-ECBD-4202-B945-0602E538D771")]
  [Item("DataItem", "Generic Item for holding various pieces of information")]
  public abstract class DataItem : ParameterizedNamedItem {

    #region Construction & Cloning
    [StorableConstructor]
    protected DataItem(StorableConstructorFlag _) : base(_) { }
    protected DataItem(DataItem orig, Cloner cloner) : base(orig, cloner) {}
    protected DataItem() {}
    #endregion

    public static IEnumerable<DataItem> ParseFile(string filename) {
      using (var reader = File.OpenText(filename)) {
        return ParseStream(reader);
      }
    }

    public abstract bool IsEquivalentTo(DataItem other);

    public static IEnumerable<DataItem> ParseStream(TextReader reader) {
      var yaml = new YamlStream();
      yaml.Load(reader);
      if (yaml.Documents.Count == 0) return Enumerable.Empty<DataItem>();
      var root = yaml.Documents[0].RootNode as YamlMappingNode;
      if (root == null) return Enumerable.Empty<DataItem>();
      return ParseItems(root);
    }

    private static IEnumerable<DataItem> ParseItems(YamlMappingNode root) {
      foreach (var child in root.Children) {
        var type = child.Key as YamlScalarNode;
        var value = child.Value as YamlSequenceNode;
        if (type == null || value == null) {
          // ignore or error?
        } else {
          switch (((string) type).ToLowerInvariant()) {
            case "products":
              foreach (var item in ParseSequence<Product>(value))
                yield return item;
              break;
            case "logistics":
              foreach (var item in ParseSequence<Logistic>(value))
                yield return item;
              break;
            case "conversions":
              foreach (var item in ParseSequence<Conversion>(value))
                yield return item;
              break;
            case "cost-factors":
              foreach (var item in ParseSequence<CostFactors>(value))
                yield return item;
              break;
          }
        }
      }
    }

    public static IEnumerable<T> ParseSequence<T>(YamlSequenceNode seq) where T : DataItem, new() {
      foreach (var node in seq.Children) {
        var mappingNode = node as YamlMappingNode;
        if (mappingNode == null) continue;
        var item = new T();
        item.Parse(mappingNode);
        yield return item;
      }
    }

    protected virtual void Parse(YamlMappingNode node) {
      foreach (var child in node) {
        var parameterNode = child.Key as YamlScalarNode;
        if (parameterNode == null) continue;
        var parameterName = ConvertNameYAML2NET(parameterNode.ToString());
        IParameter param;
        if (Parameters.TryGetValue(parameterName, out param) && param is IValueParameter) {
          SetParameter(param, child.Value);
        }
      }
      // TODO: check that all parameters have been filled
    }

    private static void SetParameter(IParameter param, YamlNode node) {
      if (node is YamlScalarNode) {
        SetScalarParameter((IValueParameter) param, (YamlScalarNode) node);
      } else if (node is YamlMappingNode) {
        SetMappingParameter((IValueParameter) param, (YamlMappingNode) node);
      } else {
        // TODO: parse error/warning?
      }
    }

    private static void SetScalarParameter(IValueParameter param, YamlScalarNode node) {
      if (param.DataType == typeof(StringValue)) {
        param.Value = new StringValue(node.ToString());
      } else if (param.DataType == typeof(DoubleValue)) {
        param.Value = new DoubleValue(Double.Parse(node.ToString(), CultureInfo.InvariantCulture));
      } else {
        // TODO: parse error/warning?
      }
    }

    private static void SetMappingParameter(IValueParameter param, YamlMappingNode node) {
      if (typeof (DataItem).IsAssignableFrom(param.DataType)) {
        var constructorInfo = param.DataType.GetConstructor(Type.EmptyTypes);
        if (constructorInfo != null) {
          var item = (DataItem) constructorInfo.Invoke(new object[0]);
          item.Parse(node);
          param.Value = item;
          return;
        }
      } else if (param.DataType.IsAssignableFrom(typeof(ValueParameterCollection))) {
        var dict = new ValueParameterCollection();
        foreach (var child in node.Children) {
          var key = child.Key as YamlScalarNode;
          if (key != null) {
            var p = new ValueParameter<DoubleValue>(key.ToString());
            SetParameter(p, child.Value);
            dict.Add(p);
          } else {
            // TODO: parse error/warning?
          }
        }
        param.Value = dict;
      }
      // TODO: parse error? warning?
    }

    public static IItem CreateItem(YamlNode node) {
      var n = node as YamlScalarNode;
      if (n == null) return null;
      double d;
      string s = n.ToString();
      if (Double.TryParse(s, NumberStyles.Float, CultureInfo.InvariantCulture, out d)) {
        return new DoubleValue(d);
      } else {
        return new StringValue(s);
      }
    }

    #region Auxiliary Methods
    public static string ConvertNameYAML2NET(string s) {
      var sb = new StringBuilder();
      foreach (var word in s.Split('-')) {
        sb.Append(CultureInfo.InvariantCulture.TextInfo.ToTitleCase(word.ToLower()));
      }
      return sb.ToString();
    }

    public static string ConvertNameNET2YAML(string s) {
      return Regex.Replace(s, "([A-Z])", "-$1", RegexOptions.Compiled).Trim().ToLower();
    }
    #endregion

  }
}