//
// VMime library (http://www.vmime.org)
// Copyright (C) 2002 Vincent Richard <vincent@vmime.org>
//
// This program 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.
//
// This program 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 this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// Linking this library statically or dynamically with other modules is making
// a combined work based on this library.  Thus, the terms and conditions of
// the GNU General Public License cover the whole combination.
//

#include "vmime/parameter.hpp"
#include "vmime/parserHelpers.hpp"

#include "vmime/text.hpp"
#include "vmime/encoding.hpp"

#include "vmime/utility/outputStreamAdapter.hpp"
#include "vmime/utility/outputStreamStringAdapter.hpp"


namespace vmime {


parameter::parameter(const string& name)
	: m_name(name),
	  m_value(make_shared <word>()) {

}


parameter::parameter(const string& name, const word& value)
	: m_name(name),
	  m_value(make_shared <word>(value)) {

}


parameter::parameter(const string& name, const string& value)
	: m_name(name),
	  m_value(make_shared <word>(value)) {

}


parameter::parameter(const parameter&)
	: component() {

}


shared_ptr <component> parameter::clone() const {

	shared_ptr <parameter> p = make_shared <parameter>(m_name);
	p->copyFrom(*this);

	return (p);
}


void parameter::copyFrom(const component& other) {

	const parameter& param = dynamic_cast <const parameter&>(other);

	m_name = param.m_name;
	m_value->copyFrom(*param.m_value);
}


parameter& parameter::operator=(const parameter& other) {

	copyFrom(other);
	return (*this);
}


const string& parameter::getName() const {

	return m_name;
}


const word& parameter::getValue() const {

	return *m_value;
}


void parameter::setValue(const component& value) {

	std::ostringstream oss;
	utility::outputStreamAdapter vos(oss);

	value.generate(vos);

	setValue(word(oss.str(), vmime::charsets::US_ASCII));
}


void parameter::setValue(const word& value) {

	*m_value = value;
}


void parameter::parseImpl(
	const parsingContext& ctx,
	const string& buffer,
	const size_t position,
	const size_t end,
	size_t* newPosition
) {

	m_value->setBuffer(string(buffer.begin() + position, buffer.begin() + end));

	if (ctx.getInternationalizedEmailSupport()) {
		m_value->setCharset(charset(charsets::UTF_8));
	} else {
		m_value->setCharset(charset(charsets::US_ASCII));
	}

	if (newPosition) {
		*newPosition = end;
	}
}


void parameter::parse(
	const parsingContext& ctx,
	const std::vector <valueChunk>& chunks
) {

	bool foundCharsetChunk = false;

	charset ch(charsets::US_ASCII);
	string lang;

	std::ostringstream value;
	value.imbue(std::locale::classic());

	for (std::vector <valueChunk>::size_type i = 0 ; i < chunks.size() ; ++i) {

		const valueChunk& chunk = chunks[i];

		// Decode following data
		if (chunk.encoded) {

			const size_t len = chunk.data.length();
			size_t pos = 0;

			// If this is the first encoded chunk, extract charset
			// and language information
			if (!foundCharsetChunk) {

				// Eg. "us-ascii'en'This%20is%20even%20more%20"
				size_t q = chunk.data.find_first_of('\'');

				if (q != string::npos) {

					const string chs = chunk.data.substr(0, q);

					if (!chs.empty()) {
						ch = charset(chs);
					}

					++q;
					pos = q;
				}

				q = chunk.data.find_first_of('\'', pos);

				if (q != string::npos) {

					// Extract language
					lang = chunk.data.substr(pos, q - pos);

					++q;
					pos = q;
				}

				foundCharsetChunk = true;
			}

			for (size_t i = pos ; i < len ; ++i) {

				const char c = chunk.data[i];

				if (c == '%' && i + 2 < len) {

					unsigned int v = 0;

					// First char
					switch (chunk.data[i + 1]) {

						case 'a': case 'A': v += 10; break;
						case 'b': case 'B': v += 11; break;
						case 'c': case 'C': v += 12; break;
						case 'd': case 'D': v += 13; break;
						case 'e': case 'E': v += 14; break;
						case 'f': case 'F': v += 15; break;
						default: // assume 0-9

							v += (chunk.data[i + 1] - '0');
							break;
					}

					v *= 16;

					// Second char
					switch (chunk.data[i + 2]) {

						case 'a': case 'A': v += 10; break;
						case 'b': case 'B': v += 11; break;
						case 'c': case 'C': v += 12; break;
						case 'd': case 'D': v += 13; break;
						case 'e': case 'E': v += 14; break;
						case 'f': case 'F': v += 15; break;
						default: // assume 0-9

							v += (chunk.data[i + 2] - '0');
							break;
					}

					value << static_cast <char>(v);

					i += 2; // skip next 2 chars

				} else {

					value << c;
				}
			}

		// Simply copy data, as it is not encoded
		} else {

			// This syntax is non-standard (expressly prohibited
			// by RFC-2047), but is used by Mozilla:
			//
    		// Content-Type: image/png;
			//    name="=?us-ascii?Q?Logo_VMime=2Epng?="

			// Using 'vmime::text' to parse the data is safe even
			// if the data is not encoded, because it can recover
			// from parsing errors.
			vmime::text t;
			t.parse(ctx, chunk.data);

			if (t.getWordCount() != 0) {

				value << t.getWholeBuffer();

				if (!foundCharsetChunk) {

					// This is still wrong. Each word can have it's own charset, and can
					// be mixed (eg. iso-8859-1 and iso-2022-jp), but very unlikely. Real
					// fix is to have parameters store a vmime::text instead of a
					// vmime::word in m_value. But that changes the interface.
					for (size_t i = 0 ; i < t.getWordCount() ; ++i) {

						if (t.getWordAt(i)->getCharset() != ch && ch == charsets::US_ASCII) {

							ch = t.getWordAt(i)->getCharset();
							break;
						}
					}
				}
			}
		}
	}

	m_value->setBuffer(value.str());
	m_value->setCharset(ch);
	m_value->setLanguage(lang);
}


void parameter::generateImpl(
	const generationContext& ctx,
	utility::outputStream& os,
	const size_t curLinePos,
	size_t* newLinePos
) const {

	const string& name = m_name;
	const string& value = m_value->getBuffer();

	// For compatibility with implementations that do not understand RFC-2231,
	// we may also generate a normal "7bit/us-ascii" parameter
	generationContext::EncodedParameterValueModes
		genMode = ctx.getEncodedParameterValueMode();

#if VMIME_ALWAYS_GENERATE_7BIT_PARAMETER
	genMode = generationContext::PARAMETER_VALUE_RFC2231_AND_RFC2047;
#endif

	// [By Eugene A. Shatokhin]
	// Note that if both the normal "7bit/us-ascii" value and the extended
	// value are present, the latter can be ignored by mail processing systems.
	// This may lead to annoying problems, for example, with strange names of
	// attachments with all but 7-bit ascii characters removed, etc. To avoid
	// this, I would suggest not to create "7bit/us-ascii" value if the extended
	// value is to be generated.

	// A stream for a temporary storage
	string sevenBitBuffer;
	utility::outputStreamStringAdapter sevenBitStream(sevenBitBuffer);

	size_t pos = curLinePos;

	if (pos + name.length() + 10 + value.length() > ctx.getMaxLineLength()) {

		sevenBitStream << NEW_LINE_SEQUENCE;
		pos = NEW_LINE_SEQUENCE_LENGTH;
	}

	bool needQuoting = false;
	bool needQuotedPrintable = false;
	size_t valueLength = 0;

	// Use worst-case length name.length()+2 for 'name=' part of line
	for (size_t i = 0 ; (i < value.length()) && (pos + name.length() + 2 + valueLength < ctx.getMaxLineLength() - 4) ; ++i, ++valueLength) {

		switch (value[i]) {

			// Characters that need to be quoted _and_ escaped
			case '"':
			case '\\':
			// Other characters that need quoting
			case ' ':
			case '\t':
			case '(':
			case ')':
			case '<':
			case '>':
			case '@':
			case ',':
			case ';':
			case ':':
			case '/':
			case '[':
			case ']':
			case '?':
			case '=':

				needQuoting = true;
				break;

			default:

				if (!parserHelpers::isAscii(value[i])) {
					needQuotedPrintable = true;
					needQuoting = true;
				}

				break;
		}
	}

	const bool cutValue = (valueLength != value.length());  // has the value been cut?

	if (needQuoting) {

		sevenBitStream << name << "=\"";
		pos += name.length() + 2;

	} else {

		sevenBitStream << name << "=";
		pos += name.length() + 1;
	}

	// Check whether there is a recommended encoding for this charset.
	// If so, the whole buffer will be encoded. Else, the number of
	// 7-bit (ASCII) bytes in the input will be used to determine if
	// we need to encode the whole buffer.
	encoding recommendedEnc;
	const bool alwaysEncode = m_value->getCharset().getRecommendedEncoding(recommendedEnc);
	bool extended = alwaysEncode;

	if ((needQuotedPrintable || cutValue || !m_value->getLanguage().empty()) &&
	    genMode != generationContext::PARAMETER_VALUE_NO_ENCODING) {

		// Send the name in quoted-printable, so outlook express et.al.
		// will understand the real filename
		size_t oldLen = sevenBitBuffer.length();
		m_value->generate(sevenBitStream);
		pos += sevenBitBuffer.length() - oldLen;
		extended = true;		// also send with RFC-2231 encoding

	} else {

		// Do not chop off this value, but just add the complete name as one header line.
		for (size_t i = 0, n = value.length(), curValueLength = 0 ;
		     i < n && curValueLength < valueLength ; ++i) {

			const char_t c = value[i];

			if (/* needQuoting && */ (c == '"' || c == '\\')) {  // 'needQuoting' is implicit

				sevenBitStream << '\\' << value[i];  // escape 'x' with '\x'
				pos += 2;

			} else if (parserHelpers::isAscii(c)) {

				sevenBitStream << value[i];
				++pos;
				++curValueLength;

			} else {

				extended = true;
			}
		}

	} // !needQuotedPrintable

	if (needQuoting) {

		sevenBitStream << '"';
		++pos;
	}

	if (genMode == generationContext::PARAMETER_VALUE_RFC2047_ONLY ||
	    genMode == generationContext::PARAMETER_VALUE_RFC2231_AND_RFC2047) {

		os << sevenBitBuffer;
	}

	// Also generate an extended parameter if the value contains 8-bit characters
	// or is too long for a single line
	if ((extended || cutValue) &&
		genMode != generationContext::PARAMETER_VALUE_NO_ENCODING &&
	    genMode != generationContext::PARAMETER_VALUE_RFC2047_ONLY) {


		if (genMode == generationContext::PARAMETER_VALUE_RFC2231_AND_RFC2047) {

			os << ';';
			++pos;

		} else {

			// The data output to 'sevenBitBuffer' will be discarded in this case
			pos = curLinePos;
		}

		/* RFC-2231
		 * ========
		 *
		 * Content-Type: message/external-body; access-type=URL;
		 *    URL*0="ftp://";
		 *    URL*1="cs.utk.edu/pub/moore/bulk-mailer/bulk-mailer.tar"
		 *
		 * Content-Type: application/x-stuff;
		 *    title*=us-ascii'en-us'This%20is%20%2A%2A%2Afun%2A%2A%2A
		 *
		 * Content-Type: application/x-stuff;
		 *    title*0*=us-ascii'en'This%20is%20even%20more%20
		 *    title*1*=%2A%2A%2Afun%2A%2A%2A%20
		 *    title*2="isn't it!"
		 */

		// Check whether there is enough space for the first section:
		// parameter name, section identifier, charset and separators
		// + at least 5 characters for the value
		const size_t firstSectionLength =
			  name.length() + 4 /* *0*= */ + 2 /* '' */
			+ m_value->getCharset().getName().length();

		if (pos + firstSectionLength + 5 >= ctx.getMaxLineLength()) {

			os << NEW_LINE_SEQUENCE;
			pos = NEW_LINE_SEQUENCE_LENGTH;
		}

		// Split text into multiple sections that fit on one line
		int sectionCount = 0;
		std::vector <string> sectionText;

		string currentSection;
		size_t currentSectionLength = firstSectionLength;

		for (size_t i = 0 ; i < value.length() ; ++i) {

			// Check whether we should start a new line (taking into
			// account the next character will be encoded = worst case)
			if (currentSectionLength + 3 >= ctx.getMaxLineLength()) {

				sectionText.push_back(currentSection);
				sectionCount++;

				currentSection.clear();
				currentSectionLength = NEW_LINE_SEQUENCE_LENGTH + name.length() + 6;
			}

			// Output next character
			const char_t c = value[i];
			bool encode = false;

			switch (c) {

				// special characters
				case ' ':
				case '\t':
				case '\r':
				case '\n':
				case '%':
				case '"':
				case ';':
				case ',':
				case '(':
				case ')':
				case '<':
				case '>':
				case '@':
				case ':':
				case '/':
				case '[':
				case ']':
				case '?':
				case '=':

					encode = true;
					break;

				default:

					encode = (!parserHelpers::isPrint(c) ||
					          !parserHelpers::isAscii(c) ||
					          alwaysEncode);

					break;
			}

			if (encode) {  // need encoding

				const int h1 = static_cast <unsigned char>(c) / 16;
				const int h2 = static_cast <unsigned char>(c) % 16;

				currentSection += '%';
				currentSection += "0123456789ABCDEF"[h1];
				currentSection += "0123456789ABCDEF"[h2];

				pos += 3;
				currentSectionLength += 3;

			} else {

				currentSection += value[i];

				++pos;
				++currentSectionLength;
			}
		}

		if (!currentSection.empty()) {

			sectionText.push_back(currentSection);
			sectionCount++;
		}

		// Output sections
		for (int sectionNumber = 0 ; sectionNumber < sectionCount ; ++sectionNumber) {

			os << name;

			if (sectionCount != 1) {  // no section specifier when only a single one

				os << '*';
				os << sectionNumber;
			}

			os << "*=";

			if (sectionNumber == 0) {

				os << m_value->getCharset().getName();
				os << '\'' << /* No language */ '\'';
			}

			os << sectionText[sectionNumber];

			if (sectionNumber + 1 < sectionCount) {

				os << ';';
				os << NEW_LINE_SEQUENCE;
				pos = NEW_LINE_SEQUENCE_LENGTH;
			}
		}

	} else if (!(genMode == generationContext::PARAMETER_VALUE_RFC2047_ONLY ||
	             genMode == generationContext::PARAMETER_VALUE_RFC2231_AND_RFC2047)) {

		// The value does not contain 8-bit characters and
		// is short enough for a single line.
		// "7bit/us-ascii" will suffice in this case.

		// Output what has been stored in temporary buffer so far
		os << sevenBitBuffer;
	}

	if (newLinePos) {
		*newLinePos = pos;
	}
}


size_t parameter::getGeneratedSize(const generationContext& ctx) {

	const string& name = m_name;
	const string& value = m_value->getBuffer();

	const size_t bytesNeedingEncoding =
		value.length() - utility::stringUtils::countASCIIchars(value.begin(), value.end());

	const size_t valueLength = value.length();

	// Compute generated length in the very worst case

	// Non-encoded parameter + value (worst case: quoting + QP)
	size_t len = name.length() + 1 /* = */ + 2 /* "" */ + 7 /* =?...?Q?...?= */
		+ m_value->getCharset().getName().length() + valueLength + bytesNeedingEncoding * 2 + 1 /* ; */;

	// Encoded parameter + value
	const size_t maxEncodedValueLengthOnLine =
		  ctx.getMaxLineLength() - 2 /* CRLF */ - NEW_LINE_SEQUENCE_LENGTH
		- name.length() - 5 /* *00*= */ - 1 /* ; */;

	const size_t encodedValueLength = (valueLength + bytesNeedingEncoding * 2)
		+ m_value->getCharset().getName().length() + m_value->getLanguage().length() + 2 /* 2 x ' */;

	const size_t numberOfSections = 1 /* worst case: generation starts at the end of a line */
		+ std::max(size_t(1), encodedValueLength / maxEncodedValueLengthOnLine);

	len += numberOfSections * (name.length() + 5 /* *00*= */ + 1 /* ; */ + 2 /* CRLF */ + NEW_LINE_SEQUENCE_LENGTH) + encodedValueLength;

	return len;

}


const std::vector <shared_ptr <component> > parameter::getChildComponents() {

	std::vector <shared_ptr <component> > list;

	list.push_back(m_value);

	return list;
}


} // vmime