private static int CompareRecords(AcceptRecord Rec1, AcceptRecord Rec2)
{
int i = Rec1.Quality.CompareTo(Rec2.Quality);
if (i != 0)
{
return(i);
}
i = Rec2.Detail - Rec1.Detail;
if (i != 0)
{
return(i);
}
return(Rec1.Order - Rec2.Order);
}
/// <summary>
/// Parses an accept header string.
/// </summary>
/// <param name="Value">Accept header string</param>
/// <returns>Parsed items.</returns>
public static AcceptRecord[] Parse(string Value)
{
List <AcceptRecord> Records = new List <AcceptRecord>();
List <KeyValuePair <string, string> > Parameters = null;
StringBuilder sb = new StringBuilder();
AcceptRecord Record = null;
string ParameterName = null;
string ParameterValue = null;
double q;
int State = 0;
int Order = 0;
foreach (char ch in Value)
{
switch (State)
{
case 0: // Item name.
if (ch <= 32)
{
break;
}
else if (ch == ';' || ch == ',')
{
Record = new AcceptRecord()
{
Item = sb.ToString().Trim(),
Order = Order++
};
sb.Clear();
if (ch == ';')
{
State++;
}
else
{
Records.Add(Record);
Record = null;
}
}
else
{
sb.Append(ch);
}
break;
case 1: // Parameter Name
if (ch == '=')
{
ParameterName = sb.ToString().Trim();
sb.Clear();
State++;
}
else if (ch == ';' || ch == ',')
{
ParameterName = sb.ToString().Trim();
sb.Clear();
if (Parameters is null)
{
Parameters = new List <KeyValuePair <string, string> >();
}
Parameters.Add(new KeyValuePair <string, string>(ParameterName, string.Empty));
ParameterName = null;
if (ch == ',')
{
Record.Parameters = Parameters.ToArray();
Records.Add(Record);
Record = null;
Parameters = null;
State = 0;
}
}
else
{
sb.Append(ch);
}
break;
case 2: // Parameter value.
if (ch == '"')
{
State++;
}
else if (ch == '\'')
{
State += 3;
}
else if (ch == ';' || ch == ',')
{
ParameterValue = sb.ToString().Trim();
sb.Clear();
if (ParameterName == "q" && CommonTypes.TryParse(ParameterValue, out q))
{
Record.Quality = q;
}
else
{
if (Parameters is null)
{
Parameters = new List <KeyValuePair <string, string> >();
}
Parameters.Add(new KeyValuePair <string, string>(ParameterName, ParameterValue));
}
ParameterName = null;
ParameterValue = null;
if (ch == ',')
{
if (!(Parameters is null))
{
Record.Parameters = Parameters.ToArray();
}
Records.Add(Record);
Record = null;
Parameters = null;
State = 0;
}
else
{
State--;
}
}
else
{
sb.Append(ch);
}
break;
case 3: // "Value"
if (ch == '"')
{
State--;
}
else if (ch == '\\')
{
State++;
}
else
{
sb.Append(ch);
}
break;
case 4: // Escape
sb.Append(ch);
State--;
break;
case 5: // 'Value'
if (ch == '\'')
{
State -= 3;
}
else if (ch == '\\')
{
State++;
}
else
{
sb.Append(ch);
}
break;
case 6: // Escape
sb.Append(ch);
State--;
break;
}
}
switch (State)
{
case 0:
Record = new AcceptRecord()
{
Item = sb.ToString().Trim(),
Order = Order++
};
if (!string.IsNullOrEmpty(Record.Item))
{
Records.Add(Record);
}
break;
case 1:
ParameterName = sb.ToString().Trim();
if (!string.IsNullOrEmpty(ParameterName))
{
if (Parameters is null)
{
Parameters = new List <KeyValuePair <string, string> >();
}
Parameters.Add(new KeyValuePair <string, string>(ParameterName, string.Empty));
}
if (!(Parameters is null))
{
Record.Parameters = Parameters.ToArray();
}
Records.Add(Record);
break;
case 2:
case 3:
case 4:
case 5:
case 6:
ParameterValue = sb.ToString().Trim();
if (ParameterName == "q" && CommonTypes.TryParse(ParameterValue, out q))
{
Record.Quality = q;
}
else
{
if (Parameters is null)
{
Parameters = new List <KeyValuePair <string, string> >();
}
Parameters.Add(new KeyValuePair <string, string>(ParameterName, ParameterValue));
}
if (!(Parameters is null))
{
Record.Parameters = Parameters.ToArray();
}
Records.Add(Record);
break;
}
Records.Sort(CompareRecords);
return(Records.ToArray());
}
