--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/core/anime_db.cc	Mon Oct 23 12:07:27 2023 -0400
@@ -0,0 +1,108 @@
+#include "core/anime_db.h"
+#include "core/anime.h"
+#include "core/strings.h"
+#include <QDebug>
+
+namespace Anime {
+
+int Database::GetTotalAnimeAmount() {
+	int total = 0;
+	for (const auto& a : items) {
+		if (a.second.IsInUserList())
+			total++;
+	}
+	return total;
+}
+
+int Database::GetListsAnimeAmount(ListStatus status) {
+	if (status == ListStatus::NOT_IN_LIST)
+		return 0;
+	int total = 0;
+	for (const auto& a : items) {
+		if (a.second.IsInUserList() && a.second.GetUserStatus() == status)
+			total++;
+	}
+	return total;
+}
+
+int Database::GetTotalEpisodeAmount() {
+	int total = 0;
+	for (const auto& a : items) {
+		if (a.second.IsInUserList()) {
+			total += a.second.GetUserRewatchedTimes() * a.second.GetEpisodes();
+			total += a.second.GetUserProgress();
+		}
+	}
+	return total;
+}
+
+/* Returns the total watched amount in minutes. */
+int Database::GetTotalWatchedAmount() {
+	int total = 0;
+	for (const auto& a : items) {
+		if (a.second.IsInUserList()) {
+			total += a.second.GetDuration() * a.second.GetUserProgress();
+			total += a.second.GetEpisodes() * a.second.GetDuration() * a.second.GetUserRewatchedTimes();
+		}
+	}
+	return total;
+}
+
+/* Returns the total planned amount in minutes.
+   Note that we should probably limit progress to the
+   amount of episodes, as AniList will let you
+   set episode counts up to 32768. But that should
+   rather be handled elsewhere. */
+int Database::GetTotalPlannedAmount() {
+	int total = 0;
+	for (const auto& a : items) {
+		if (a.second.IsInUserList())
+			total += a.second.GetDuration() * (a.second.GetEpisodes() - a.second.GetUserProgress());
+	}
+	return total;
+}
+
+/* I'm sure many will appreciate this being called an
+   "average" instead of a "mean" */
+double Database::GetAverageScore() {
+	double avg = 0;
+	int amt = 0;
+	for (const auto& a : items) {
+		if (a.second.IsInUserList() && a.second.GetUserScore()) {
+			avg += a.second.GetUserScore();
+			amt++;
+		}
+	}
+	return avg / amt;
+}
+
+double Database::GetScoreDeviation() {
+	double squares_sum = 0, avg = GetAverageScore();
+	int amt = 0;
+	for (const auto& a : items) {
+		if (a.second.IsInUserList() && a.second.GetUserScore()) {
+			squares_sum += std::pow(static_cast<double>(a.second.GetUserScore()) - avg, 2);
+			amt++;
+		}
+	}
+	return (amt > 0) ? std::sqrt(squares_sum / amt) : 0;
+}
+
+int Database::GetAnimeFromTitle(std::string title) {
+	if (title.empty())
+		return 0;
+	for (const auto& a : items) {
+		if (a.second.GetUserPreferredTitle().find(title) != std::string::npos)
+			return a.second.GetId();
+		for (const auto& t : a.second.GetTitleSynonyms()) {
+			if (t.find(title) != std::string::npos) {
+				return a.second.GetId();
+			}
+		}
+	}
+	return 0;
+}
+
+Database db;
+
+} // namespace Anime
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