spacing with correct cooldowns and updates

src/include/main.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <vector>
+
+#include "parser.h"
+
+void update();
+void saveMdem();
+
+struct MdemBuffer {
+	std::vector<Question*>   questions     = std::vector<Question*>();
+	time_t                   trainedAt = 0;
+};
+

src/include/trainWindow.h

@@ -2,6 +2,7 @@
 
 #include <QMainWindow>
 
+#include "main.h"
 #include "parser.h"
 
 extern QMainWindow *trainWindow;
@@ -15,7 +16,6 @@ enum PracticeAlgorithm {
 void initTrainWindow();
 
 void initiatePractice(
-	std::vector<Question*> questions,
-	PracticeAlgorithm algorithm,
-	time_t *trainedAt
+	MdemBuffer        *mdemBuffer,
+	PracticeAlgorithm  algorithm
 );

src/qtapp/main.cpp

@@ -58,6 +58,7 @@
 #include <QPushButton>
 #include <QStandardPaths>
 
+#include "main.h"
 #include "api.h"
 #include "parser.h"
 #include "qscilexer.h"
@@ -86,11 +87,6 @@ struct Mdem {
 	Question        *question;
 };
 
-struct MdemBuffer {
-	std::vector<Question*>   questions     = std::vector<Question*>();
-	time_t                   trainedAt = 0;
-};
-
 struct ErrorView {
 	QWidget     box;
 	QVBoxLayout layout;
@@ -164,6 +160,8 @@ std::string outputMdem(std::vector<Question*> questions, time_t time = 0) {
 	std::stringstream ss;
 
 	if (time > 0) {
+		auto timezoneOffset = settings->value("timezone").toInt();
+		/*time = time + 3600 * timezoneOffset;*/
 		std::tm* tm = std::localtime(&time);
 		char buffer[100];
 		std::strftime(buffer, sizeof(buffer), "%d.%m.%Y %H\\:%M", tm);
@@ -242,8 +240,13 @@ void makePages() {
 
 void setupMdem(Mdem *mdem, Question *question) {
 	if (MultiElementQuestion* mw = dynamic_cast<MultiElementQuestion*>(question)) {
+		std::stringstream ss;
+		if (mw->Cooldown > 0) {
+			ss << std::format("[{:.2f}] ", question->Cooldown);
+		}
+		ss << mw->QuestionText;
 		mdem->wFrontText.setText(
-			QString::fromStdString(mw->QuestionText)	
+			QString::fromStdString(ss.str())	
 		);
 		auto choices = mw->Choices;
 		for (size_t k = 0; k < choices.size(); ++k) {
@@ -444,7 +447,35 @@ void CreateMdems(std::vector<Question*>& questions) {
 	hMdemScroll->addItem(mdemSpacer);
 }
 
+void updateMdemInfo(std::string filename, bool isChanged = false) {
+	if (filename.length() > 0) {
+		std::stringstream ss;
+		ss << std::format("mdem: {}", filename); 
+		if (isChanged) {
+			ss << "*";
+		}
+		if (mdemBuffer->trainedAt > 0) {
+			std::tm* tm = std::localtime(&mdemBuffer->trainedAt);
+			char buffer[100];
+			std::strftime(buffer, sizeof(buffer), "%d.%m.%Y %H:%M", tm);
+			ss << std::endl << "Last practiced: " << std::string(buffer);
+		}
+		deckListLabel->setText(QString::fromStdString(ss.str()));
+	} else {
+		deckListLabel->setText("");
+	}
+}
 
+std::string getFilename(std::string path) {
+	std::smatch matches;
+	auto filenameMatched = std::regex_search(path, matches, lastPathElementExp); 
+	return matches[2].str();
+}
+
+void update() {
+	SwitchPage(currentPage);
+	updateMdemInfo(getFilename(currentMdem));
+}
 
 void SwitchPage(int pageIdx) {
     currentPage = pageIdx;
@@ -560,29 +591,6 @@ void releaseError(ErrorView** item) {
 	std::cout << std::format("Released, current pool size: {}\n", errorPool.size());
 }
 
-std::string getFilename(std::string path) {
-	std::smatch matches;
-	auto filenameMatched = std::regex_search(path, matches, lastPathElementExp); 
-	return matches[2].str();
-}
-
-
-void updateMdemInfo(std::string filename) {
-	if (filename.length() > 0) {
-		std::stringstream ss;
-		ss << std::format("mdem: {}", filename); 
-		if (mdemBuffer->trainedAt > 0) {
-			std::tm* tm = std::localtime(&mdemBuffer->trainedAt);
-			char buffer[100];
-			std::strftime(buffer, sizeof(buffer), "%d.%m.%Y %H:%M", tm);
-			ss << std::endl << "Last practiced: " << std::string(buffer);
-		}
-		deckListLabel->setText(QString::fromStdString(ss.str()));
-	} else {
-		deckListLabel->setText("");
-	}
-}
-
 void reloadMdem() {
 	auto file = std::ifstream(currentMdem);
 	std::string content;
@@ -616,7 +624,7 @@ void reloadMdem() {
 				mdemBuffer->trainedAt = 0;
 			} else {
 				auto timezoneOffset = settings->value("timezone").toInt();
-				mdemBuffer->trainedAt = res.value.lastTrainedAt + 3600 * timezoneOffset;
+				mdemBuffer->trainedAt = res.value.lastTrainedAt - 3600 * timezoneOffset;
 			}
 			std::cout << std::format("Last trained at: {}", mdemBuffer->trainedAt) << std::endl;
 
@@ -705,13 +713,13 @@ void setupEditorSave(bool checked) {
 				for (int i = 0; i < mdemBuffer->questions.size(); ++i) {
 					if (mdemBuffer->questions[i] == oldQuestion) {
 						mdemBuffer->questions.erase(mdemBuffer->questions.begin() + i);
-						delete mdemBuffer->questions[i];
-						mdemBuffer->questions[i] = editMdem->question;
+						delete oldQuestion;
+						mdemBuffer->questions.insert(mdemBuffer->questions.begin() + i, res.value.questions[0]);
 						break;
 					}
 				}
-				/*setupMdem(editMdem, res.value.questions[0]);*/
-				/*showBacklabels(editMdem);*/
+				setupMdem(editMdem, res.value.questions[0]);
+				showBacklabels(editMdem);
 				editorWindow->hide();
 			} else {
 				QMessageBox::information(
@@ -741,6 +749,12 @@ void setupEditorSave(bool checked) {
 	}
 };
 
+void saveMdem() {
+	auto filename = getFilename(currentMdem);
+	std::ofstream out(currentMdem);
+	out << outputMdem(mdemBuffer->questions, mdemBuffer->trainedAt);
+}
+
 int main(int argc, char *argv[]) {
 	mdemBuffer = new MdemBuffer;
     QApplication app(argc, argv);
@@ -952,9 +966,9 @@ int main(int argc, char *argv[]) {
 	hlButtonsTop->addWidget(add);
 	hlButtonsTop->addWidget(save);
 	hlButtonsTop->addWidget(load);
-	cbAlgorithm->addItem("Primary", PRIMARY);
-	cbAlgorithm->addItem("Random",  RANDOM);
 	cbAlgorithm->addItem("Spaced",  SPACED);
+	cbAlgorithm->addItem("Random",  RANDOM);
+	cbAlgorithm->addItem("Primary", PRIMARY);
 	practice->setText("Practice");
 	hlButtonsBottom->addWidget(cbAlgorithm);
 	hlButtonsBottom->addWidget(practice);
@@ -972,9 +986,7 @@ int main(int argc, char *argv[]) {
 	});
 	QObject::connect(load, &QToolButton::clicked, &reloadMdem);
 	QObject::connect(save, &QToolButton::clicked, []() {
-		auto filename = getFilename(currentMdem);
-		std::ofstream out(currentMdem);
-		out << outputMdem(mdemBuffer->questions, mdemBuffer->trainedAt);
+		saveMdem();
 	});
 	QObject::connect(
 		practice,
@@ -983,9 +995,8 @@ int main(int argc, char *argv[]) {
 			trainWindow->show();
 			trainWindow->resize(600, 300);
 			initiatePractice(
-				mdemBuffer->questions,
-				static_cast<PracticeAlgorithm>(cbAlgorithm->currentData().toInt()),
-				&mdemBuffer->trainedAt
+				mdemBuffer,
+				static_cast<PracticeAlgorithm>(cbAlgorithm->currentData().toInt())
 			);
 		}
 	);

src/qtapp/trainWindow.cpp

@@ -2,14 +2,14 @@
 #include <QWidget>
 #include <QToolButton>
 #include <algorithm>
-#include <atomic>
 #include <cstdint>
+#include <ctime>
 #include <format>
 #include <cstdlib>
-#include <exception>
 #include <format>
 #include <qabstractitemview.h>
 #include <qboxlayout.h>
+#include <qchar.h>
 #include <qcoreevent.h>
 #include <qlabel.h>
 #include <qlayoutitem.h>
@@ -17,6 +17,7 @@
 #include <qnamespace.h>
 #include <qscrollarea.h>
 #include <qstandarditemmodel.h>
+#include <qstringalgorithms.h>
 #include <qstringlistmodel.h>
 #include <qtoolbutton.h>
 #include <Qt>
@@ -29,6 +30,7 @@
 #include <QStyledItemDelegate>
 #include <QPainter>
 
+#include "main.h"
 #include "trainWindow.h"
 #include "parser.h"
 
@@ -204,7 +206,6 @@ QLabel      *lQuestionText;
 QVBoxLayout *vButtonBox;
 QWidget     *actionButtons;
 QHBoxLayout *hButtons;
-QToolButton *btnPrev;
 QSpacerItem *leftSpacer;
 QToolButton *btnTriggerAnswer;
 QSpacerItem *rightSpacer;
@@ -229,10 +230,12 @@ QVBoxLayout                      *vGroups;
 std::vector<QStandardItemModel*>  groupModels;
 
 // Questions & State
-std::vector<Question*>  trainQuestions = std::vector<Question*>();
+MdemBuffer *currentBuffer;
+
 int32_t currentQuestionIndex = -1;
 std::vector<GroupView*> groupViews;
 PracticeAlgorithm practiceAlgoritm;
+time_t lastTrainedAt;
 
 std::default_random_engine  rng;
 std::vector<QStandardItem*> itemPool;
@@ -285,6 +288,11 @@ void hideQuestionElements() {
 	orderList->hide();
 	multiChoiceList->hide();
 	wGroupQuestion->hide();
+	btnNotRemembered->hide();
+	btnHard->hide();
+	btnMedium->hide();
+	btnEasy->hide();
+	btnTriggerAnswer->hide();
 }
 
 void setupAnswerQuestion(MultiElementQuestion *question) {
@@ -308,6 +316,10 @@ void setupAnswerQuestion(MultiElementQuestion *question) {
 		[](bool checked) {
 			answerText->show();
 			btnTriggerAnswer->hide();
+			btnNotRemembered->show();
+			btnHard->show();
+			btnMedium->show();
+			btnEasy->show();
 		}
 	);		
 	btnTriggerAnswer->show();
@@ -491,63 +503,132 @@ void setupQuestion(Question *question) {
 	hideQuestionElements();
 	releaseAllItems();
 	QObject::disconnect(btnTriggerAnswer, 0, 0, 0);		
-	if (auto *question = dynamic_cast<MultiElementQuestion*>(trainQuestions[currentQuestionIndex])) {
-		btnNotRemembered->hide();
-		btnHard->hide();
-		btnMedium->hide();
-		btnEasy->hide();
-		switch (question->type) {
+	if (auto *q = dynamic_cast<MultiElementQuestion*>(question)) {
+		switch (q->type) {
 			case MultiElementType::Order:
-				setupOrderQuestion(question);
+				setupOrderQuestion(q);
 				break;
 			case MultiElementType::MultiChoice:
-				setupMultiChoiceQuestion(question);
+				setupMultiChoiceQuestion(q);
 				break;
 			case MultiElementType::Regular:
-				setupAnswerQuestion(question);
+				setupAnswerQuestion(q);
 				break;
 		} 
-	} else if (auto *question = dynamic_cast<GroupQuestion*>(trainQuestions[currentQuestionIndex])) {
+	} else if (auto *question = dynamic_cast<GroupQuestion*>(
+	   currentBuffer->questions[currentQuestionIndex])
+	) {
 		setupGroupQuestion(question);
 	}
 }
 
 void updatePaginationVisibility() {
-	if (currentQuestionIndex == 0) {
-		btnPrev->hide();
-	} else {
-		btnPrev->show();
-	}
-	if (currentQuestionIndex == trainQuestions.size() - 1) {
+	if (currentQuestionIndex == currentBuffer->questions.size() - 1) {
 		btnNext->hide();
 	} else {
 		btnNext->show();
 	}
 }
 
-void initiatePractice(
-	std::vector<Question*> questions,
-	PracticeAlgorithm algorithm,
-	time_t *trainedAt
-) {
+template <typename T>
+int randomIndex(std::vector<T> *vec) {
+	srand(time(NULL));
+	return rand() % vec->size();
+}
+
+time_t getTime() {
 	auto now = std::chrono::system_clock::now();
-	time_t unix_timestamp = std::chrono::duration_cast<std::chrono::seconds>(
+	return std::chrono::duration_cast<std::chrono::seconds>(
 		now.time_since_epoch()
 	).count();
+}
 
-	trainQuestions = questions;
-	if (questions.size() <= 0) {
+void setupNextQuestion() {
+	if (currentBuffer->questions.size() <= 0) {
 		return;
 	}
-	currentQuestionIndex = 0;
+	switch (practiceAlgoritm) {
+		case PRIMARY: {
+				currentQuestionIndex++;
+				if (currentQuestionIndex < currentBuffer->questions.size()) {
+					setupQuestion(currentBuffer->questions[currentQuestionIndex]);
+				}
 				updatePaginationVisibility();
-	setupQuestion(trainQuestions[currentQuestionIndex]);
-	practiceAlgoritm = algorithm;
+			} break;
+		case RANDOM: {
+				auto questionCandidates = currentBuffer->questions;
+				if (currentQuestionIndex > -1) {
+					questionCandidates.erase(questionCandidates.begin() + currentQuestionIndex);
+				}
+				if (questionCandidates.size() > 0) {
+					auto i = randomIndex(&questionCandidates);
+					setupQuestion(questionCandidates[i]);
+					for (int k = 0; k < currentBuffer->questions.size(); ++k) {
+						if (currentBuffer->questions[k] == questionCandidates[i]) {
+							currentQuestionIndex = k;
+							break;
+						}
+					}
+				}
+			} break;
+		case SPACED: {
+				auto questionCandidates = std::vector<Question*>();
+				time_t time = getTime();
+				auto lastTrainedAt = currentBuffer->trainedAt;
+				currentBuffer->trainedAt = time;
+				for (int i = 0; i < currentBuffer->questions.size(); ++i) {
+					auto cooldownSeconds = currentBuffer->questions[i]->Cooldown * 3600;
+					auto cooldownEndsAt = lastTrainedAt + cooldownSeconds;
+					if (i != currentQuestionIndex && cooldownEndsAt <= time) {
+						questionCandidates.push_back(currentBuffer->questions[i]);
+					}
+					auto newCooldown = cooldownEndsAt - time;
+					if (newCooldown < 0) {
+						newCooldown = 0;
+					} 
+					currentBuffer->questions[i]->Cooldown = (double)newCooldown / 3600;
+				}
+				if (questionCandidates.size() > 0) {
+					auto i = randomIndex(&questionCandidates);
+					setupQuestion(questionCandidates[i]);
+					setupQuestion(
+						questionCandidates[randomIndex(&questionCandidates)]
+					);
+					for (int k = 0; k < currentBuffer->questions.size(); ++k) {
+						if (currentBuffer->questions[k] == questionCandidates[i]) {
+							currentQuestionIndex = k;
+							break;
+						}
+					}
+				}
+				update();
+			} break;
+	}
+}
 
-	btnNotRemembered->hide();
-	btnHard->hide();
-	btnMedium->hide();
-	btnEasy->hide();
+void initiatePractice(
+	MdemBuffer        *mdemBuffer,
+	PracticeAlgorithm algorithm
+) {
+	practiceAlgoritm = algorithm;
+	currentBuffer = mdemBuffer;
+
+	if (currentBuffer->questions.size() <= 0) {
+		return;
+	}
+
+	currentQuestionIndex = -1;
+	hideQuestionElements();
+	updatePaginationVisibility();
+	setupNextQuestion();
+}
+
+void setCooldownHours(int cooldown) {
+	time_t time = getTime();
+	currentBuffer->trainedAt = time;
+	auto question = currentBuffer->questions[currentQuestionIndex];
+	question->Cooldown = cooldown;
+	update();
 }
 
 void initTrainWindow() {
@@ -566,6 +647,25 @@ void initTrainWindow() {
 
 	itemDelegate = new CustomItemDelegate(multiChoiceList);
 
+	{ // Top button menu. 
+		auto hTopButtons         = new QHBoxLayout();
+		auto topButtons      = new QWidget();
+		topButtons->setLayout(hTopButtons);
+
+		auto topLeftSpacer = new QSpacerItem(50, 50, QSizePolicy::Expanding, QSizePolicy::Minimum);
+		auto btnSaveProgress = new QToolButton();
+		btnSaveProgress->setText("Save progress");
+
+		hTopButtons->addItem(topLeftSpacer);
+		hTopButtons->addWidget(btnSaveProgress);
+		vTrainWidget->addWidget(topButtons);
+
+		QObject::connect(btnSaveProgress, &QToolButton::clicked, []() {
+			saveMdem();
+		});
+	}
+
+
 	{ // Make the question box.
 		questionBox   = new QWidget();
 		vQuestionBox  = new QVBoxLayout();
@@ -639,16 +739,26 @@ void initTrainWindow() {
 		vButtonBox       = new QVBoxLayout();
 		actionButtons    = new QWidget();
 		hButtons         = new QHBoxLayout();
-		btnPrev          = new QToolButton();
+
 		leftSpacer       = new QSpacerItem(50, 50, QSizePolicy::Expanding, QSizePolicy::Minimum);
 
 		btnTriggerAnswer = new QToolButton();
-
 		btnNotRemembered = new QToolButton();
+		QObject::connect(btnNotRemembered, &QToolButton::clicked, []() {
+			setCooldownHours(0);
+		});
 		btnHard          = new QToolButton();
+		QObject::connect(btnHard, &QToolButton::clicked, []() {
+			setCooldownHours(12);
+		});
 		btnMedium        = new QToolButton();
+		QObject::connect(btnMedium, &QToolButton::clicked, []() {
+			setCooldownHours(48);
+		});
 		btnEasy          = new QToolButton();
-
+		QObject::connect(btnEasy, &QToolButton::clicked, []() {
+			setCooldownHours(72);
+		});
 		btnNotRemembered->setText("Not remembered");
 		btnHard->setText("Hard");
 		btnMedium->setText("Medium");
@@ -659,17 +769,10 @@ void initTrainWindow() {
 		rightSpacer      = new QSpacerItem(50, 50, QSizePolicy::Expanding, QSizePolicy::Minimum);
 		btnNext          = new QToolButton();
 
-		hButtons->addWidget(btnPrev);
 		hButtons->addItem(leftSpacer);
 		hButtons->addWidget(btnTriggerAnswer);
-
 		hButtons->addWidget(btnNotRemembered);
 		hButtons->addWidget(btnHard);
-		QObject::connect(btnHard, &QToolButton::clicked, []() {
-			const double hourCooldown = 25.0;
-			auto question = trainQuestions[currentQuestionIndex];
-			question->Cooldown = hourCooldown;
-		});
 		hButtons->addWidget(btnMedium);
 		hButtons->addWidget(btnEasy);
 
@@ -677,34 +780,13 @@ void initTrainWindow() {
 		hButtons->addWidget(btnNext);
 		vButtonBox->addWidget(actionButtons);
 		actionButtons->setLayout(hButtons);
-		btnPrev->setText("Previous");
-		QObject::connect(btnPrev, &QToolButton::clicked, []() {
-			currentQuestionIndex--;
-			if (currentQuestionIndex > -1) {
-				setupQuestion(trainQuestions[currentQuestionIndex]);
-			} 
-			updatePaginationVisibility();
-		});
 
 		btnTriggerAnswer->setText("Show answer");
+		btnTriggerAnswer->hide();
 
 		btnNext->setText("Next");
 		QObject::connect(btnNext, &QToolButton::clicked, []() {
-			switch (practiceAlgoritm) {
-				case PRIMARY:
-					currentQuestionIndex++;
-					if (currentQuestionIndex < trainQuestions.size()) {
-						setupQuestion(trainQuestions[currentQuestionIndex]);
-					}
-					updatePaginationVisibility();
-					break;
-				case RANDOM:
-					// TODO: implement
-					break;
-				case SPACED:
-					// TODO: implement
-					break;
-			}
+			setupNextQuestion();
 		});
 		questionBox->setObjectName("question-box");
 		actionButtons->setStyleSheet(QString(

src/transpiler/parser.cpp

@@ -141,6 +141,18 @@ Result<NoneType> ValidateGrammar(const std::vector<Token>& tokens) {
 	return {};
 }
 
+time_t parseToUTCTime(const std::string datetime, std::string format) {
+    std::tm tm = {};
+    std::istringstream ss(datetime);
+    ss >> std::get_time(&tm, format.c_str());
+    if (ss.fail()) {
+        throw std::runtime_error("Failed to parse datetime string");
+    }
+    std::time_t time = timegm(&tm);
+    return time;
+}
+
+
 Result<ParseInfo> parseQuestions(const std::vector<Token>& tokens) {
     auto questions = std::vector<Question*>();
 	time_t time = 0;
@@ -178,16 +190,14 @@ Result<ParseInfo> parseQuestions(const std::vector<Token>& tokens) {
 	};
 
 	if (isInBounds(i) && tokens[i].tokenType == TokenType::TextFragment) {
-		std::tm tm = {};
 		try {
-			strptime(tokens[i].content.c_str(), "%d.%m.%Y %H:%M", &tm);
+			time = parseToUTCTime(tokens[i].content.c_str(), "%d.%m.%Y %H:%M");
 		} catch (std::exception e) {
 			return makeResult(
 				std::format("cannot parse the time - {}", e.what()),
 				tokens[i]
 			);
 		}
-		time = mktime(&tm);
 		i++;
 	}