/**
 * 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 <relpipe/writer/RelationalWriter.h>
#include <relpipe/writer/RelpipeWriterException.h>
#include "lib/ASN1ContentHandler.h"
#include "Configuration.h"

namespace relpipe {
namespace in {
namespace asn1 {

class RelpipeASN1ContentHandler : 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;

	relpipe::common::type::StringX currentRelationName;
	std::vector<relpipe::writer::AttributeMetadata> currentAttributes;

	enum class State {
		Start,
		Relation,
		RelationName,
		Header,
		HeaderItem,
		AttributeName,
		AttributeType,
		AttributeNext,
		Records,
		Record,
		End,
	};

	State state = State::Start;

	void assertTag(const Header& header, uint64_t expectedTag, TagClass expectedClass = TagClass::Universal) {
		if (header.tagClass != expectedClass || header.tag != expectedTag) throw relpipe::writer::RelpipeWriterException(L"Unexpected tag."); // TODO: add actual vs. expected values
	}

	State startRelation() {
		writer->startRelation(currentRelationName, currentAttributes, true);
		currentRelationName = L"";
		currentAttributes.clear();
		return State::Records;
	}

	State setRelationName(std::string value) {
		currentRelationName = convertor.from_bytes(value);
		return State::Header;
	}

	State setAttributeName(relpipe::common::type::StringX value) {
		currentAttributes.push_back({value, relpipe::writer::TypeId::STRING});
		return State::AttributeType;
	}

	State setAttributeType(relpipe::common::type::StringX value) {
		currentAttributes.back().typeId = writer->toTypeId(value);
		return State::AttributeNext;
	}

public:

	RelpipeASN1ContentHandler(std::shared_ptr<relpipe::writer::RelationalWriter> writer, Configuration configuration) : writer(writer), configuration(configuration) {
	}

	bool setOption(const std::string& uri, const std::string& value) override {
		return false;
	}

	void writeStreamStart() override {
	}

	void writeStreamEnd() override {
	}

	void writeCollectionStart(const Header& header) override {
		assertTag(header, lib::UniversalType::Sequence);
		if (state == State::Start) state = State::Relation;
		else if (state == State::Relation) state = State::RelationName;
		else if (state == State::Header) state = State::HeaderItem;
		else if (state == State::HeaderItem) state = State::AttributeName;
		else if (state == State::Records) state = State::Record;
		else throw std::logic_error("Illegal state in writeCollectionStart(): " + std::to_string((int) state));
	}

	void writeCollectionEnd() override {
		if (state == State::AttributeNext) state = State::HeaderItem;
		else if (state == State::HeaderItem) state = startRelation();
		else if (state == State::Records) state = State::Relation;
		else if (state == State::Record) state = State::Records;
		else if (state == State::Relation) state = State::End;
		else throw std::logic_error("Illegal state in writeCollectionEnd(): " + std::to_string((int) state));
	}

	void writeBitString(const Header& header, std::vector<bool> value) override {
		throw std::logic_error("Unsupported data type: BitString");
	}

	void writeBoolean(const Header& header, bool value) override {
		if (state == State::Record) writer->writeAttribute(&value, typeid (value));
		else throw std::logic_error("Illegal state in writeBoolean(): " + std::to_string((int) state));
	}

	void writeDateTime(const Header& header, DateTime value) override {
		throw std::logic_error("Unsupported data type: DateTime");
	}

	void writeInteger(const Header& header, Integer value) override {
		relpipe::common::type::Integer integer = value.toInt64();
		if (state == State::Record) writer->writeAttribute(&integer, typeid (integer));
		else throw std::logic_error("Illegal state in writeInteger(): " + std::to_string((int) state));
	}

	void writeNull(const Header& header) override {
		throw std::logic_error("Unsupported data type: Null");
	}

	void writeOID(const Header& header, ObjectIdentifier value) override {
		throw std::logic_error("Unsupported data type: OID");
	}

	void writeOctetString(const Header& header, std::string value) override {
		throw std::logic_error("Unsupported data type: OctetString");
	}

	void writeTextString(const Header& header, std::string value) override {
		assertTag(header, lib::UniversalType::UTF8String);
		relpipe::common::type::StringX str = convertor.from_bytes(value);

		if (state == State::RelationName) state = setRelationName(value);
		else if (state == State::AttributeName) state = setAttributeName(str);
		else if (state == State::AttributeType) state = setAttributeType(str);
		else if (state == State::Record) writer->writeAttribute(&str, typeid (str));
		else throw std::logic_error("Illegal state in writeTextString(): " + std::to_string((int) state));
	}

	void writeSpecific(const Header& header, std::string value) override {
		throw std::logic_error("Unsupported data type: Specific");
	}


};

}
}
}