// Parse a single MailAddress from the given string.
//
// Throws a FormatException or returns false if any part of the MailAddress is invalid.
internal static bool TryParseAddress(string data, out ParseAddressInfo parsedAddress, bool throwExceptionIfFail)
{
int index = data.Length - 1;
bool parseSuccess = TryParseAddress(data, false, ref index, out parsedAddress, throwExceptionIfFail);
Debug.Assert(!parseSuccess || index == -1, "The index indicates that part of the address was not parsed: " + index);
return(parseSuccess);
}
//
// Parse a single MailAddress, potentially from a list.
//
// Preconditions:
// - Index must be within the bounds of the data string.
// - The data string must not be null or empty
//
// Postconditions:
// - Returns a valid MailAddress object parsed from the string
// - For a single MailAddress index is set to -1
// - For a list data[index] is the comma separator or -1 if the end of the data string was reached.
//
// Throws a FormatException or false is returned if any part of the MailAddress is invalid.
private static bool TryParseAddress(string data, bool expectMultipleAddresses, ref int index, out ParseAddressInfo parseAddressInfo, bool throwExceptionIfFail)
{
Debug.Assert(!string.IsNullOrEmpty(data));
Debug.Assert(index >= 0 && index < data.Length, "Index out of range: " + index + ", " + data.Length);
// Parsed components to be assembled as a MailAddress later
string?displayName;
// Skip comments and whitespace
if (!TryReadCfwsAndThrowIfIncomplete(data, index, out index, throwExceptionIfFail))
{
parseAddressInfo = default;
return(false);
}
// Do we expect angle brackets around the address?
// e.g. ("display name" <user@domain>)
bool expectAngleBracket = false;
if (data[index] == MailBnfHelper.EndAngleBracket)
{
expectAngleBracket = true;
index--;
}
if (!TryParseDomain(data, ref index, out string?domain, throwExceptionIfFail))
{
parseAddressInfo = default;
return(false);
}
// The next character after the domain must be the '@' symbol
if (data[index] != MailBnfHelper.At)
{
if (throwExceptionIfFail)
{
throw new FormatException(SR.MailAddressInvalidFormat);
}
else
{
parseAddressInfo = default;
return(false);
}
}
// Skip the '@' symbol
index--;
if (!TryParseLocalPart(data, ref index, expectAngleBracket, expectMultipleAddresses, out string?localPart, throwExceptionIfFail))
{
parseAddressInfo = default;
return(false);
}
// Check for a matching angle bracket around the address
if (expectAngleBracket)
{
if (index >= 0 && data[index] == MailBnfHelper.StartAngleBracket)
{
index--; // Skip the angle bracket
// Skip whitespace, but leave comments, as they may be part of the display name.
if (!WhitespaceReader.TryReadFwsReverse(data, index, out index, throwExceptionIfFail))
{
parseAddressInfo = default;
return(false);
}
}
else
{
// Mismatched angle brackets
if (throwExceptionIfFail)
{
throw new FormatException(SR.Format(SR.MailHeaderFieldInvalidCharacter,
(index >= 0 ? data[index] : MailBnfHelper.EndAngleBracket)));
}
else
{
parseAddressInfo = default;
return(false);
}
}
}
// Is there anything left to parse?
// There could still be a display name or another address
if (index >= 0 && !(expectMultipleAddresses && data[index] == MailBnfHelper.Comma))
{
if (!TryParseDisplayName(data, ref index, expectMultipleAddresses, out displayName, throwExceptionIfFail))
{
parseAddressInfo = default;
return(false);
}
}
else
{
displayName = string.Empty;
}
parseAddressInfo = new ParseAddressInfo(displayName, localPart, domain);
return(true);
}