1 files changed, 110 insertions, 0 deletions
diff --git a/src/openvic-simulation/history/HistoryMap.hpp b/src/openvic-simulation/history/HistoryMap.hpp
new file mode 100644
index 0000000..64d886d
--- /dev/null
+++ b/src/openvic-simulation/history/HistoryMap.hpp
@@ -0,0 +1,110 @@
+#pragma once
+
+#include <map>
+#include <memory>
+
+#include "openvic-simulation/dataloader/NodeTools.hpp"
+#include "openvic-simulation/types/Date.hpp"
+
+namespace OpenVic {
+
+	struct HistoryEntry {
+	private:
+		Date PROPERTY(date);
+
+	protected:
+		HistoryEntry(Date new_date);
+	};
+
+	struct GameManager;
+
+	/* Helper functions to avoid cyclic dependency issues */
+	Date _get_start_date(GameManager const& game_manager);
+	Date _get_end_date(GameManager const& game_manager);
+
+	template<std::derived_from<HistoryEntry> _Entry, typename... Args>
+	struct HistoryMap {
+		using entry_type = _Entry;
+
+	private:
+		std::map<Date, std::unique_ptr<entry_type>> PROPERTY(entries);
+
+		bool _try_load_history_entry(GameManager const& game_manager, Args... args, Date date, ast::NodeCPtr root) {
+			typename decltype(entries)::iterator it = entries.find(date);
+			if (it == entries.end()) {
+				const std::pair<typename decltype(entries)::iterator, bool> result = entries.emplace(date, _make_entry(date));
+				if (result.second) {
+					it = result.first;
+				} else {
+					Logger::error("Failed to create history entry at date ", date);
+					return false;
+				}
+			}
+			return _load_history_entry(game_manager, args..., *it->second, root);
+		}
+
+	protected:
+		HistoryMap() = default;
+
+		virtual std::unique_ptr<entry_type> _make_entry(Date date) const = 0;
+
+		virtual bool _load_history_entry(
+			GameManager const& game_manager, Args... args, entry_type& entry, ast::NodeCPtr root
+		) = 0;
+
+		bool _load_history_file(GameManager const& game_manager, Args... args, ast::NodeCPtr root) {
+			return _try_load_history_entry(game_manager, args..., _get_start_date(game_manager), root);
+		}
+
+		bool _load_history_sub_entry_callback(
+			GameManager const& game_manager, Args... args, Date date, ast::NodeCPtr root, std::string_view key,
+			ast::NodeCPtr value, NodeTools::key_value_callback_t default_callback = NodeTools::key_value_invalid_callback
+		) {
+			/* Date blocks (loaded into the corresponding HistoryEntry) */
+			bool is_date = false;
+			const Date sub_date { Date::from_string(key, &is_date, true) };
+			if (is_date) {
+				if (sub_date <= date) {
+					Logger::error("History entry ", sub_date, " defined before parent entry date ", date);
+					return false;
+				}
+				const Date end_date = _get_end_date(game_manager);
+				if (sub_date > end_date) {
+					Logger::error("History entry ", sub_date, " defined after end date ", end_date);
+					return false;
+				}
+				if (_try_load_history_entry(game_manager, args..., sub_date, value)) {
+					return true;
+				} else {
+					Logger::error("Failed to load history entry at date ", sub_date);
+					return false;
+				}
+			}
+
+			return default_callback(key, value);
+		}
+
+	public:
+		/* Returns history entry at specific date, if date doesn't have an entry returns nullptr. */
+		entry_type const* get_entry(Date date) const {
+			typename decltype(entries)::const_iterator it = entries.find(date);
+			if (it != entries.end()) {
+				return it->second.get();
+			}
+			return nullptr;
+		}
+		/* Returns history entries up to date as an ordered list of entries. */
+		std::vector<entry_type const*> get_entries(Date end) const {
+			std::vector<entry_type const*> ret;
+			for (typename decltype(entries)::value_type const& entry : entries) {
+				if (entry.first <= end) {
+					ret.push_back(entry.second.get());
+				}
+			}
+			std::sort(ret.begin(), ret.end(), [](entry_type const* lhs, entry_type const* rhs) -> bool {
+				return lhs->get_date() < rhs->get_date();
+			});
+			return ret;
+		}
+	};
+}