/**

 * Relational pipes

 * Copyright © 2021 František Kučera (Frantovo.cz, GlobalCode.info)

 *

 * 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, version 3 of the License.

 *

 * 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, see <http://www.gnu.org/licenses/>.

 */

#pragma once

#include <string>

#include <relpipe/writer/RelationalWriter.h>

#include "lib/ASN1ContentHandler.h"

#include "Configuration.h"

namespace relpipe {

namespace in {

namespace asn1 {

/**

 * Converts arbitrary ASN.1 stream of events to a relation

 * i.e. does not require any specific structures/schema.

 *

 * Useful especially for testing and debugging and sometimes instead of relpipe-in-asn1table,

 * because this handler supports streaming and does not depend on any third-party library (no XML dependency).

 */

class FreeformASN1ContentHandler : public lib::ASN1ContentHandler {

private:

	wstring_convert < codecvt_utf8<wchar_t>> convertor; // ASN.1 parser works with UTF-8

	std::shared_ptr<relpipe::writer::RelationalWriter> writer;

	Configuration configuration;

	std::vector<relpipe::common::type::Integer> position;

	class Record {

	public:

		const Header* header;

		const std::vector<relpipe::common::type::Integer>& position;

		relpipe::common::type::Integer level = 0;

		relpipe::common::type::StringX event;

		relpipe::common::type::StringX valueText;

		relpipe::common::type::StringX valueBinary;

		Record(const Header* header, std::vector<relpipe::common::type::Integer>& position, relpipe::common::type::StringX event) : header(header), position(position), event(event) {

		}

		virtual ~Record() {

		}

	};

	void write(const Record& r) {

		relpipe::common::type::Integer tag = r.header ? r.header->tag : -1; // TODO: null + possible integer overflow

		relpipe::common::type::Integer id = r.position.back();

		relpipe::common::type::Integer parent = r.position[r.position.size() - 2];

		relpipe::common::type::Integer level = r.position.size() - 2;

		relpipe::common::type::StringX pc;

		relpipe::common::type::StringX tagClass;

		if (r.header) {

			if (r.header->pc == PC::Primitive) pc = L"primitive";

			else if (r.header->pc == PC::Constructed) pc = L"primitive";

			else throw std::logic_error("Unexpected PC: " + std::to_string((uint8_t) r.header->pc)); // should never happen

			if (r.header->tagClass == TagClass::Universal) tagClass = L"universal";

			else if (r.header->tagClass == TagClass::ContextSpecific) tagClass = L"context";

			else if (r.header->tagClass == TagClass::Application) tagClass = L"application";

			else if (r.header->tagClass == TagClass::Private) tagClass = L"private";

			else throw std::logic_error("Unexpected TagClass: " + std::to_string((uint8_t) r.header->tagClass)); // should never happen

		}

		writer->writeAttribute(&id, typeid (id));

		writer->writeAttribute(&parent, typeid (parent));

		writer->writeAttribute(&level, typeid (level));

		writer->writeAttribute(&r.event, typeid (r.event));

		// writer->writeAttribute(&pc, typeid (pc));

		writer->writeAttribute(&tagClass, typeid (tagClass));

		writer->writeAttribute(&tag, typeid (tag));

		writer->writeAttribute(&r.valueText, typeid (r.valueText));

		writer->writeAttribute(&r.valueBinary, typeid (r.valueBinary));

	}

	/**

	 * @param header

	 * @param value an octet string

	 * @return original value if octet string was a text string; otherwise an empty string

	 */

	const std::string getText(const Header& header, const std::string& value) {

		// TODO: support also UTF-8

		for (uint8_t b : value) if (b < 32 || b >= 127) return "";

		return value;

	}

public:

	FreeformASN1ContentHandler(std::shared_ptr<relpipe::writer::RelationalWriter> writer, Configuration configuration) : writer(writer), configuration(configuration) {

	}

	bool setOption(const std::string& uri, const std::string& value) override {

	}

	void writeStreamStart() override {

		writer->startRelation(configuration.relation,{

			{L"id", relpipe::writer::TypeId::INTEGER},

			{L"parent", relpipe::writer::TypeId::INTEGER},

			{L"level", relpipe::writer::TypeId::INTEGER},

			{L"event", relpipe::writer::TypeId::STRING},

			// {L"pc", relpipe::writer::TypeId::STRING},

			{L"tag_class", relpipe::writer::TypeId::STRING},

			{L"tag", relpipe::writer::TypeId::INTEGER},

			{L"value_text", relpipe::writer::TypeId::STRING},

			{L"value_binary", relpipe::writer::TypeId::STRING}, // TODO: OctetString data type (when available) instead of text

		}, true);

		position.push_back(-1); // TODO: null

		position.push_back(1);

		Record r(nullptr, position, L"stream-start");

		write(r);

		position.push_back(position.back());

	}

	void writeStreamEnd() override {

		Record r(nullptr, position, L"stream-end");

		write(r);

		auto id = position.back() + 1;

		position.pop_back();

		position.back() = id;

	}

	void writeCollectionStart(const Header& header) override {

		position.back()++;

		Record r(&header, position, L"collection-start");

		write(r);

		position.push_back(position.back());

	}

	void writeCollectionEnd() override {

		Record r(nullptr, position, L"collection-end");

		write(r);

		auto id = position.back() + 1;

		position.pop_back();

		position.back() = id;

	}

	void writeBitString(const Header& header, std::vector<bool> value) override {

		std::stringstream bits;

		position.back()++;

		Record r(&header, position, L"bit-string");

		r.valueText = convertor.from_bytes(bits.str());

		write(r);

	}

	void writeBoolean(const Header& header, bool value) override {

		position.back()++;

		Record r(&header, position, L"boolean");

		r.valueText = value ? L"true" : L"false";

		r.valueBinary = value ? L"FF" : L"00";

		write(r);

	}

	void writeDateTime(const Header& header, DateTime value) override {

		position.back()++;

		Record r(&header, position, L"date-time");

		r.valueText = convertor.from_bytes(value.toString());

		write(r);

	}

	void writeInteger(const Header& header, Integer value) override {

		position.back()++;

		Record r(&header, position, L"integer");

		r.valueText = convertor.from_bytes(value.toString());

		r.valueBinary = convertor.from_bytes(value.toHex());

		write(r);

	}

	void writeNull(const Header& header) override {

		position.back()++;

		Record r(&header, position, L"null");

		r.valueText = L"null";

		write(r);

	}

	void writeOID(const Header& header, ObjectIdentifier value) override {

		position.back()++;

		Record r(&header, position, L"oid");

		r.valueText = convertor.from_bytes(value.toString());

		write(r);

	}

	void writeOctetString(const Header& header, std::string value) override {

		std::string text = getText(header, value);

		std::stringstream hex;

		hex << std::hex << std::setfill('0');

		for (uint8_t b : value) hex << std::setw(2) << (int) b;

		position.back()++;

		Record r(&header, position, L"octet-string");

		r.valueText = convertor.from_bytes(text);

		r.valueBinary = convertor.from_bytes(hex.str());

		write(r);

	}

	void writeTextString(const Header& header, std::string value) override {

		position.back()++;

		Record r(&header, position, L"text-string");

		r.valueText = convertor.from_bytes(value);

		write(r);

	}

	void writeSpecific(const Header& header, std::string value) override {

		std::stringstream hex;

		hex << std::hex << std::setfill('0');

		for (uint8_t b : value) hex << std::setw(2) << (int) b;

		std::stringstream ascii;

		for (uint8_t b : value) ascii << (b >= 32 && b < 127 ? (char) b : '.'); // TODO: configurable unsupported symbol?

		position.back()++;

		Record r(&header, position, L"specific");

		r.valueText = convertor.from_bytes(ascii.str());

		r.valueBinary = convertor.from_bytes(hex.str());

		write(r);

	}

};

}

}

}