/*
 Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
*/

// C5 example: Views 2004-12-29 OBSOLETE

// Compile with 
//   csc /r:C5.dll Views.cs 

using System;
using C5;
using SCG = System.Collections.Generic;

namespace Views {
  class Views {
    public static void Main(String[] args) {
      IList<char> lst = new LinkedList<char>();
      lst.AddAll<char>(new char[] { 'a', 'b', 'c', 'd' });
      IList<char> 
        A = lst.View(0, 2),
        B = lst.View(2, 0),
        C = lst.View(2, 1),
        D = lst.View(3, 1),
        E = lst.View(4, 0),
        F = lst.View(1, 2),
        G = lst.View(0, 4);
      IList<char>[] views = { A, B, C, D, E, F, G };
      Console.WriteLine("ABCDEFG overlaps with:");
      foreach (IList<char> u in views) {
        foreach (IList<char> w in views) 
          Console.Write(Overlap(u, w) ? '+' : '-');
        Console.WriteLine();
      }   
      Console.WriteLine("ABCDEFG overlap length:");
      foreach (IList<char> u in views) {
        foreach (IList<char> w in views) {
          int len = OverlapLength(u, w);
          Console.Write(len >= 0 ? String.Format("{0}", len) : " ");
        }
        Console.WriteLine();
      }   
      Console.WriteLine("ABCDEFG contained in:");
      foreach (IList<char> u in views) {
        foreach (IList<char> w in views) 
          Console.Write(ContainsView(u, w) ? '+' : '-');
        Console.WriteLine();
      }   
    }
    
    public static int LeftEndIndex<T>(IList<T> u) { 
      return u.Offset;
    }

    public static int RightEndIndex<T>(IList<T> u) { 
      return u.Offset+u.Count;
    }

    public static bool Overlap<T>(IList<T> u, IList<T> w) { 
      if (u.Underlying == null || u.Underlying != w.Underlying) 
        throw new ArgumentException("views must have same underlying list");
      else
        return u.Offset < w.Offset+w.Count && w.Offset < u.Offset+u.Count;
    }

    public static int OverlapLength<T>(IList<T> u, IList<T> w) { 
      if (Overlap(u, w))
	return Math.Min(u.Offset+u.Count, w.Offset+w.Count) 
	     - Math.Max(u.Offset, w.Offset);
      else
	return -1; // No overlap
    }

    public static bool ContainsView<T>(IList<T> u, IList<T> w) { 
      if (u.Underlying == null || u.Underlying != w.Underlying) 
        throw new ArgumentException("views must have same underlying list");
      else
        if (w.Count > 0)
          return u.Offset <= w.Offset && w.Offset+w.Count <= u.Offset+u.Count;
        else
          return u.Offset < w.Offset && w.Offset < u.Offset+u.Count;
    }

    public static bool SameUnderlying<T>(IList<T> u, IList<T> w) { 
      return (u.Underlying ?? u) == (w.Underlying ?? w);
    }

    // Replace the first occurrence of each x from xs by y in list:
    
    public static void ReplaceXsByY<T>(HashedLinkedList<T> list, T[] xs, T y) {
      foreach (T x in xs) {
        using (IList<T> view = list.ViewOf(x)) {
          if (view != null) { 
            view.Remove();
            view.Add(y);
          }
        }
      }
    }

    // Find first item that satisfies p

    public static bool Find<T>(IList<T> list, Fun<T,bool> p, out T res) {
      IList<T> view = list.View(0, 0);
      while (view.Offset < list.Count) {
        view.Slide(+1, 1);
        if (p(view.First)) {
          res = view.First;
          return true;
        }
      }
      res = default(T);
      return false;
    }

    // Or, using that the list is enumerable:

    public static bool Find1<T>(IList<T> list, Fun<T,bool> p, out T res) {
      foreach (T x in list) { 
        if (p(x)) {
          res = x;
          return true;
        }
      }
      res = default(T);
      return false;
    }

    // Find last item that satisfies p

    public static bool FindLast<T>(IList<T> list, Fun<T,bool> p, out T res) {
      IList<T> view = list.View(list.Count, 0);
      while (view.Offset > 0) {
        view.Slide(-1, 1);
        if (p(view.First)) {
          res = view.First;
          return true;
        }
      }
      res = default(T);
      return false;
    }
  }
}