Adding support for partial dates (only year or month), fixes #477

src/libs/core/include/core/PartialDateTime.hpp

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2025 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS 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.
+ *
+ * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <string_view>
+
+namespace lms::core
+{
+    class PartialDateTime
+    {
+    public:
+        constexpr PartialDateTime() = default;
+        PartialDateTime(int year);
+        PartialDateTime(int year, unsigned month);
+        PartialDateTime(int year, unsigned month, unsigned day);
+        PartialDateTime(int year, unsigned month, unsigned day, unsigned hour, unsigned min, unsigned sec);
+
+        static PartialDateTime fromString(std::string_view str);
+        std::string toISO8601String() const;
+
+        bool isValid() const { return _precision != Precision::Invalid; }
+
+        constexpr std::optional<int> getYear() const { return (_precision >= Precision::Year ? std::make_optional(_year) : std::nullopt); }
+        constexpr std::optional<int> getMonth() const { return (_precision >= Precision::Month ? std::make_optional(_month) : std::nullopt); }
+        constexpr std::optional<int> getDay() const { return (_precision >= Precision::Day ? std::make_optional(_day) : std::nullopt); }
+
+        constexpr auto operator<=>(const PartialDateTime& other) const = default;
+
+    private:
+        std::int16_t _year{};
+        std::uint8_t _month{}; // 1 to 12
+        std::uint8_t _day{};   // 1 to 31
+        std::uint8_t _hour{};  // 0 to 23
+        std::uint8_t _min{};   // 0 to 59
+        std::uint8_t _sec{};   // 0 to 59
+        enum class Precision : std::uint8_t
+        {
+            Invalid,
+            Year,
+            Month,
+            Day,
+            Hour,
+            Min,
+            Sec,
+        };
+        Precision _precision{ Precision::Invalid };
+    };
+} // namespace lms::core