# HG changeset patch
# User František Kučera <franta-hg@frantovo.cz>
# Date 1546984161 -3600
# Node ID 82f86dc4833957a0e2c4472627967def07d5ae13
# Parent  97967db4b95b0ec61188e2c7c1d2f5b104d9a7ed
first working version

diff -r 97967db4b95b -r 82f86dc48339 src/CSVHandler.h
--- a/src/CSVHandler.h	Tue Jan 08 18:40:15 2019 +0100
+++ b/src/CSVHandler.h	Tue Jan 08 22:49:21 2019 +0100
@@ -30,6 +30,8 @@
 #include <relpipe/reader/handlers/RelationalReaderStringHandler.h>
 #include <relpipe/reader/handlers/AttributeMetadata.h>
 
+#include "RelpipeCSVWriterException.h"
+
 namespace relpipe {
 namespace out {
 namespace csv {
@@ -41,19 +43,43 @@
 class CSVHandler : public RelationalReaderStringHadler {
 private:
 	std::ostream& output;
-	std::wstring_convert<std::codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.
+	const char QUOTE = '"';
+	std::wstring_convert<std::codecvt_utf8<wchar_t>> convertor; // TODO: local system encoding or generate CSV always in UTF-8 like XML?
+	std::vector<AttributeMetadata> firstAttributes;
+	integer_t valueCount = 0;
 public:
 
 	CSVHandler(std::ostream& output) : output(output) {
 	}
 
 	void startRelation(string_t name, std::vector<AttributeMetadata> attributes) override {
-
+		if (firstAttributes.empty()) {
+			firstAttributes = attributes;
+			for (auto attr : attributes) attribute(attr.getAttributeName());
+		} else {
+			// TODO: UNION ALL if data types and attribute count matches
+			throw RelpipeCSVWriterException(L"Only a single relation can be converted to the CSV format.");
+		}
 	}
 
 	void attribute(const string_t& value) override {
-		output << convertor.to_bytes(value).c_str();
-		output.put(0);
+		valueCount++;
+
+		if (value.size() > 0) {
+			output << QUOTE;
+			for (auto ch : convertor.to_bytes(value)) {
+				if (ch == QUOTE) output << QUOTE << QUOTE;
+				else output << ch;
+			}
+			output << QUOTE;
+		}
+
+		if (valueCount % firstAttributes.size()) {
+			output << ",";
+		} else {
+			output << std::endl;
+			valueCount = 0;
+		}
 	}
 
 	void endOfPipe() {
diff -r 97967db4b95b -r 82f86dc48339 src/RelpipeCSVWriterException.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/RelpipeCSVWriterException.h	Tue Jan 08 22:49:21 2019 +0100
@@ -0,0 +1,44 @@
+/**
+ * Relational pipes
+ * Copyright © 2018 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 <string>
+
+using namespace std;
+
+namespace relpipe {
+namespace out {
+namespace csv {
+
+class RelpipeCSVWriterException {
+private:
+	wstring message;
+public:
+
+	RelpipeCSVWriterException(wstring message) : message(message) {
+	}
+
+	wstring getMessge() {
+		return message;
+	}
+
+};
+
+}
+}
+}
\ No newline at end of file
diff -r 97967db4b95b -r 82f86dc48339 src/relpipe-out-csv.cpp
--- a/src/relpipe-out-csv.cpp	Tue Jan 08 18:40:15 2019 +0100
+++ b/src/relpipe-out-csv.cpp	Tue Jan 08 22:49:21 2019 +0100
@@ -27,6 +27,7 @@
 #include <relpipe/reader/RelpipeReaderException.h>
 
 #include "CSVHandler.h"
+#include "RelpipeCSVWriterException.h"
 
 using namespace relpipe::cli;
 using namespace relpipe::reader;
@@ -53,6 +54,9 @@
 		fwprintf(stderr, L"Caught Reader exception: %ls\n", e.getMessge().c_str());
 		fwprintf(stderr, L"Debug: Input stream: eof=%ls, lastRead=%d\n", (cin.eof() ? L"true" : L"false"), cin.gcount());
 		resultCode = CLI::EXIT_CODE_DATA_ERROR;
+	} catch (RelpipeCSVWriterException e) {
+		fwprintf(stderr, L"Error while generating CSV: %ls\n", e.getMessge().c_str());
+		resultCode = CLI::EXIT_CODE_DATA_ERROR;
 	}
 
 	return resultCode;