From 78e553b7249cbf683183e29eefaee7997137407e Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Tue, 2 May 2023 17:31:56 +0300
Subject: [PATCH] Added usage of segment tree in Data class for statistics.

---
 Telegram/SourceFiles/data/data_statistics.cpp | 141 ++++++++++++++++++
 Telegram/SourceFiles/data/data_statistics.h   |  49 ++++++
 2 files changed, 190 insertions(+)

diff --git a/Telegram/SourceFiles/data/data_statistics.cpp b/Telegram/SourceFiles/data/data_statistics.cpp
index 604797551e..d663530267 100644
--- a/Telegram/SourceFiles/data/data_statistics.cpp
+++ b/Telegram/SourceFiles/data/data_statistics.cpp
@@ -11,4 +11,145 @@ namespace Data {
 namespace {
 } // namespace
 
+void StatisticalChart::measure() {
+	if (x.empty()) {
+		return;
+	}
+	const auto n = x.size();
+	const auto start = x.front();
+	const auto end = x.back();
+
+	xPercentage.clear();
+	xPercentage.resize(n);
+	if (n == 1) {
+		xPercentage[0] = 1;
+	} else {
+		for (auto i = 0; i < n; i++) {
+			xPercentage[i] = (x[i] - start) / float64(end - start);
+		}
+	}
+
+	for (auto i = 0; i < lines.size(); i++) {
+		if (lines[i].maxValue > maxValue) {
+			maxValue = lines[i].maxValue;
+		}
+		if (lines[i].minValue < minValue) {
+			minValue = lines[i].minValue;
+		}
+		lines[i].segmentTree = Statistic::SegmentTree(lines[i].y);
+	}
+
+	daysLookup.clear();
+	const auto dateCount = int((end - start) / timeStep) + 10;
+	daysLookup.reserve(dateCount);
+	constexpr auto kOneDay = 3600 * 24 * 1000;
+	const auto formatter = u"MMM d"_q;
+	for (auto i = 0; i < dateCount; i++) {
+		const auto r = (start + (i * timeStep)) / 1000;
+		const auto dateTime = QDateTime::fromSecsSinceEpoch(r);
+		if (timeStep == 1) {
+			daysLookup.push_back(
+				QString(((i < 10) ? u"0%1:00"_q : u"%1:00"_q).arg(i)));
+		} else if (timeStep < kOneDay) {
+			daysLookup.push_back(u"%1:%2"_q
+				.arg(dateTime.time().hour(), 2, 10, QChar('0'))
+				.arg(dateTime.time().minute(), 2, 10, QChar('0')));
+		} else {
+			const auto date = dateTime.date();
+			daysLookup.push_back(QLocale().toString(date, formatter));
+		}
+	}
+
+	oneDayPercentage = timeStep / float64(end - start);
+}
+
+QString StatisticalChart::getDayString(int i) const {
+	return daysLookup[int((x[i] - x[0]) / timeStep)];
+}
+
+int StatisticalChart::findStartIndex(float v) const {
+	if (v == 0) {
+		return 0;
+	}
+	const auto n = int(xPercentage.size());
+
+	if (n < 2) {
+		return 0;
+	}
+	auto left = 0;
+	auto right = n - 1;
+
+	while (left <= right) {
+		const auto middle = (right + left) >> 1;
+		if (v < xPercentage[middle]
+			&& (middle == 0 || v > xPercentage[middle - 1])) {
+			return middle;
+		}
+		if (v == xPercentage[middle]) {
+			return middle;
+		}
+		if (v < xPercentage[middle]) {
+			right = middle - 1;
+		} else if (v > xPercentage[middle]) {
+			left = middle + 1;
+		}
+	}
+	return left;
+}
+
+int StatisticalChart::findEndIndex(int left, float v) const {
+	const auto n = int(xPercentage.size());
+	if (v == 1.) {
+		return n - 1;
+	}
+	auto right = n - 1;
+
+	while (left <= right) {
+		const auto middle = (right + left) >> 1;
+		if (v > xPercentage[middle]
+			&& (middle == n - 1 || v < xPercentage[middle + 1])) {
+			return middle;
+		}
+		if (v == xPercentage[middle]) {
+			return middle;
+		}
+		if (v < xPercentage[middle]) {
+			right = middle - 1;
+		} else if (v > xPercentage[middle]) {
+			left = middle + 1;
+		}
+	}
+	return right;
+}
+
+
+int StatisticalChart::findIndex(int left, int right, float v) const {
+	const auto n = int(xPercentage.size());
+
+	if (v <= xPercentage[left]) {
+		return left;
+	}
+	if (v >= xPercentage[right]) {
+		return right;
+	}
+
+	while (left <= right) {
+		const auto middle = (right + left) >> 1;
+		if (v > xPercentage[middle]
+			&& (middle == n - 1 || v < xPercentage[middle + 1])) {
+			return middle;
+		}
+
+		if (v == xPercentage[middle]) {
+			return middle;
+		}
+		if (v < xPercentage[middle]) {
+			right = middle - 1;
+		} else if (v > xPercentage[middle]) {
+			left = middle + 1;
+		}
+	}
+	return right;
+}
+
 } // namespace Data
diff --git a/Telegram/SourceFiles/data/data_statistics.h b/Telegram/SourceFiles/data/data_statistics.h
index dd0c640719..fbfe0f9139 100644
--- a/Telegram/SourceFiles/data/data_statistics.h
+++ b/Telegram/SourceFiles/data/data_statistics.h
@@ -7,6 +7,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
+#include "statistics/segment_tree.h"
+
 namespace Data {
 
 struct StatisticsMessageInteractionInfo final {
@@ -33,7 +35,54 @@ struct StatisticsInviterInfo final {
 	int addedMemberCount = 0;
 };
 
+struct StatisticalChart {
+	StatisticalChart() = default;
+
+	[[nodiscard]] bool empty() const {
+		return lines.empty();
+	}
+	[[nodiscard]] explicit operator bool() const {
+		return !empty();
+	}
+
+	void measure();
+
+	[[nodiscard]] QString getDayString(int i) const;
+
+	[[nodiscard]] int findStartIndex(float v) const;
+	[[nodiscard]] int findEndIndex(int left, float v) const;
+	[[nodiscard]] int findIndex(int left, int right, float v) const;
+
+	struct Line final {
+		std::vector<int> y;
+
+		Statistic::SegmentTree segmentTree;
+		QString id;
+		QString name;
+		int maxValue = 0;
+		int minValue = std::numeric_limits<int>::max();
+		int colorKey = 0;
+		QColor color;
+		QColor colorDark;
+	};
+
+	std::vector<float64> x;
+	std::vector<float64> xPercentage;
+	std::vector<QString> daysLookup;
+
+	std::vector<Line> lines;
+
+	int maxValue = 0;
+	int minValue = std::numeric_limits<int>::max();
+
+	float64 oneDayPercentage = 0.;
+
+	float64 timeStep = 0.;
+
+};
+
 struct StatisticalGraph final {
+	StatisticalChart chart;
 };
 
 struct StatisticalValue final {