Implement world cache to monitor expeditions

This implements a small cache in world to track expedition states.

This fixes expired expeditions being left in zone caches unless the
expedition's dz instance was running to detect it (or unless an
expedition was deleted via a client using /kickplayers). This was also
leaving clients in a ghost expedition that no longer actually existed

world/expedition.h

@@ -21,12 +21,27 @@
 #ifndef WORLD_EXPEDITION_H
 #define WORLD_EXPEDITION_H
 
+#include "../common/rulesys.h"
+#include "../common/timer.h"
+#include <chrono>
+#include <vector>
+
+extern class ExpeditionCache expedition_cache;
+
+class Expedition;
 class ServerPacket;
 
-namespace Expedition
+namespace ExpeditionDatabase
 {
 	void PurgeExpiredExpeditions();
 	void PurgeExpiredCharacterLockouts();
+	std::vector<Expedition> LoadExpeditions();
+	Expedition LoadExpedition(uint32_t expedition_id);
+	void DeleteExpeditions(const std::vector<uint32_t>& expedition_ids);
+};
+
+namespace ExpeditionMessage
+{
 	void HandleZoneMessage(ServerPacket* pack);
 	void AddPlayer(ServerPacket* pack);
 	void MakeLeader(ServerPacket* pack);
@@ -35,4 +50,38 @@ namespace Expedition
 	void RequestInvite(ServerPacket* pack);
 };
 
+class ExpeditionCache
+{
+public:
+	void AddExpedition(uint32_t expedition_id);
+	void RemoveExpedition(uint32_t expedition_id);
+	void LoadActiveExpeditions();
+	void Process();
+
+private:
+	std::vector<Expedition> m_expeditions;
+	Timer m_process_throttle_timer{static_cast<uint32_t>(RuleI(Expedition, WorldExpeditionProcessRateMS))};
+};
+
+class Expedition
+{
+public:
+	Expedition() = default;
+	Expedition(
+		uint32_t expedition_id, uint32_t instance_id, uint32_t dz_zone_id,
+		uint32_t expire_time, uint32_t duration);
+
+	uint32_t GetID() const { return m_expedition_id; }
+	bool IsExpired() const { return m_expire_time < std::chrono::system_clock::now(); }
+	void SendZonesExpeditionExpired();
+
+private:
+	uint32_t m_expedition_id  = 0;
+	uint32_t m_dz_instance_id = 0;
+	uint32_t m_dz_zone_id     = 0;
+	uint32_t m_start_time     = 0;
+	uint32_t m_duration       = 0;
+	std::chrono::time_point<std::chrono::system_clock> m_expire_time;
+};
+
 #endif