/* Copyright (C) 2004 - 2007 db4objects Inc. http://www.db4o.com */
using System;
using Db4objects.Db4o.Config;
namespace Db4objects.Db4o.Config
{
/// <summary>
/// Wildcard Alias functionality to create aliases for packages,
/// namespaces or multiple similar named classes.
/// </summary>
/// <remarks>
/// Wildcard Alias functionality to create aliases for packages,
/// namespaces or multiple similar named classes. One single '*'
/// wildcard character is supported in the names.
/// <br /><br />See
/// <see cref="IAlias">IAlias</see>
/// for concrete examples.
/// </remarks>
public class WildcardAlias : IAlias
{
private readonly WildcardAlias.WildcardPattern _storedPattern;
private readonly WildcardAlias.WildcardPattern _runtimePattern;
public WildcardAlias(string storedPattern, string runtimePattern)
{
if (null == storedPattern)
{
throw new ArgumentNullException("storedPattern");
}
if (null == runtimePattern)
{
throw new ArgumentNullException("runtimePattern");
}
_storedPattern = new WildcardAlias.WildcardPattern(storedPattern);
_runtimePattern = new WildcardAlias.WildcardPattern(runtimePattern);
}
/// <summary>resolving is done through simple pattern matching</summary>
public virtual string ResolveRuntimeName(string runtimeTypeName)
{
string match = _runtimePattern.Matches(runtimeTypeName);
return match != null ? _storedPattern.Inject(match) : null;
}
/// <summary>resolving is done through simple pattern matching</summary>
public virtual string ResolveStoredName(string storedTypeName)
{
string match = _storedPattern.Matches(storedTypeName);
return match != null ? _runtimePattern.Inject(match) : null;
}
internal class WildcardPattern
{
private string _head;
private string _tail;
public WildcardPattern(string pattern)
{
string[] parts = Split(pattern);
_head = parts[0];
_tail = parts[1];
}
public virtual string Inject(string s)
{
return _head + s + _tail;
}
public virtual string Matches(string s)
{
if (!s.StartsWith(_head) || !s.EndsWith(_tail))
{
return null;
}
return Sharpen.Runtime.Substring(s, _head.Length, s.Length - _tail.Length);
}
private void InvalidPattern()
{
throw new ArgumentException("only one '*' character");
}
internal virtual string[] Split(string pattern)
{
int index = pattern.IndexOf('*');
if (-1 == index || index != pattern.LastIndexOf('*'))
{
InvalidPattern();
}
return new string[] { Sharpen.Runtime.Substring(pattern, 0, index), Sharpen.Runtime.Substring
(pattern, index + 1) };
}
}
}
}