/**
* Relational pipes
* Copyright © 2019 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, 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, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <relpipe/writer/typedefs.h>
namespace relpipe {
namespace in {
namespace recfile {
using namespace relpipe::writer;
class RecfileCommand {
private:
enum class RecfileLineType {
METADATA,
DATA,
SEPARATOR,
COMMENT,
};
class RecfileHandler {
private:
RelationalWriter* writer;
public:
RecfileHandler(RelationalWriter* writer) : writer(writer) {
}
virtual ~RecfileHandler() {
}
void logicalLine(RecfileLineType type, const string_t& name = L"", const string_t& value = L"") {
std::wcerr << L"logicalLine(" << (int) type << L", " << name << L", " << value << L");" << std::endl; // TODO: remove debug
// TODO: writer->startRelation()
// TODO: writer->writeAttribute()
}
};
enum class ParserState {
START,
NAME,
VALUE,
VALUE_CONTINUATION,
COMMENT,
END,
};
class RecfileParser {
private:
wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings or are recfiles always in UTF-8?
RecfileHandler& handler;
void emitLogicalLine(RecfileLineType& type, std::stringstream& name, std::stringstream& value) {
handler.logicalLine(type, convertor.from_bytes(name.str()), convertor.from_bytes(value.str()));
name.str("");
name.clear();
value.str("");
value.clear();
type = RecfileLineType::DATA;
}
public:
RecfileParser(RecfileHandler& handler) : handler(handler) {
}
virtual ~RecfileParser() {
}
void parse(std::istream& input) {
ParserState state = ParserState::START;
RecfileLineType type = RecfileLineType::DATA;
std::stringstream name;
std::stringstream value;
char ch;
while (state != ParserState::END && input.good()) {
ch = input.get();
if (input.eof()) continue;
switch (state) {
case ParserState::START:
if (ch == '%') {
type = RecfileLineType::METADATA;
break;
} else if (ch == ' ') {
break;
} else if (ch == '\n') {
handler.logicalLine(RecfileLineType::SEPARATOR);
break;
} else if (ch == '#') {
type = RecfileLineType::COMMENT;
state = ParserState::COMMENT;
if (input.get() != ' ') input.unget();
break;
} // else → name
case ParserState::NAME:
if (ch == ':') {
state = ParserState::VALUE;
if (input.get() != ' ') input.unget();
} else {
name << ch;
}
break;
case ParserState::VALUE:
if (ch == '\n') state = ParserState::VALUE_CONTINUATION;
else value << ch;
break;
case ParserState::VALUE_CONTINUATION:
if (ch == '+') {
state = ParserState::VALUE;
if (value.tellp()) value << '\n';
if (input.get() != ' ') input.unget();
} else {
input.unget();
state = ParserState::START;
emitLogicalLine(type, name, value);
}
break;
case ParserState::COMMENT:
if (ch == '\n') {
state = ParserState::START;
emitLogicalLine(type, name, value);
} else {
value << ch;
}
break;
default:
throw RelpipeWriterException(L"Unknown ParserState: " + std::to_wstring((int) state) + L" in RecfileParser."); // TODO: better exception
}
}
emitLogicalLine(type, name, value);
}
};
public:
void process(std::istream& input, std::ostream& output) {
unique_ptr<RelationalWriter> writer(Factory::create(output));
RecfileHandler handler(writer.get());
RecfileParser parser(handler);
parser.parse(input);
}
};
}
}
}