// Adapted from the owner's Escapists Intel reroll: snapshot the cohort/chance,
// wait for accepted native operations, and process a bounded amount each tick.
class ERR_IntelRerollEntry
{
	ref ERR_IntelInsertCallback Operation;
	IEntity Actor;
	IEntity Removing;
	int Attempts;
	string WaitingFor = "inventory";
	bool GiveIntel;
	bool Inserting;
	bool Accepted;
	bool Done;
}

class ERR_IntelReroll
{
	protected ERR_GameMode m_Mode;
	protected ERR_IntelService m_Service;
	protected ref array<ref ERR_IntelRerollEntry> m_Entries = {};
	protected int m_Percent;
	protected int m_Next;
	protected int m_Completed;
	protected int m_Failed;
	protected int m_Skipped;
	protected bool m_Cancelled;

	void ERR_IntelReroll(ERR_GameMode mode, ERR_IntelService service, int percent)
	{
		m_Mode = mode;
		m_Service = service;
		m_Percent = percent;
	}

	void Add(IEntity actor)
	{
		ERR_IntelRerollEntry entry = new ERR_IntelRerollEntry();
		entry.Actor = actor;
		entry.GiveIntel = Math.RandomInt(0, 100) < m_Percent;
		m_Entries.Insert(entry);
	}

	bool Running() { return !m_Cancelled && m_Completed < m_Entries.Count(); }

	void Tick()
	{
		if (!Replication.IsServer() || !Running()) return;
		// Round-robin visits keep delayed inventory operations from starving others.
		int budget = Math.Min(8, m_Entries.Count());
		while (budget-- > 0)
		{
			if (m_Next >= m_Entries.Count()) m_Next = 0;
			ERR_IntelRerollEntry entry = m_Entries[m_Next++];
			if (!entry.Done) Process(entry);
		}
	}

	protected void Finish(ERR_IntelRerollEntry entry, bool failed = false, bool skipped = false)
	{
		entry.Done = true;
		entry.Removing = null;
		m_Completed++;
		if (failed) m_Failed++;
		if (skipped) m_Skipped++;
	}

	protected void Fail(ERR_IntelRerollEntry entry, string reason)
	{
		Print(string.Format("Rereintroduced [intel]: reroll failed reason=%1 actor=%2 attempts=%3", reason, entry.Actor.GetID(), entry.Attempts), LogLevel.WARNING);
		Finish(entry, true);
	}

	protected void Process(ERR_IntelRerollEntry entry)
	{
		if (!ERR_Actors.Alive(entry.Actor) || ERR_Actors.Player(entry.Actor))
		{
			if (entry.Accepted) m_Service.Unsettled(entry.Actor);
			Finish(entry, false, true);
			return;
		}
		entry.Attempts++;
		if (entry.Attempts > 30)
		{
			// A timed-out accepted insertion can still finish inside the engine.
			// Keep its actor quarantined for the remainder of this round.
			if (entry.Accepted) m_Service.Unsettled(entry.Actor);
			Fail(entry, "timeout-" + entry.WaitingFor);
			return;
		}
		SCR_InventoryStorageManagerComponent inventory = SCR_InventoryStorageManagerComponent.Cast(entry.Actor.FindComponent(SCR_InventoryStorageManagerComponent));
		if (!inventory) { entry.WaitingFor = "inventory"; return; }
		array<IEntity> folders = {};
		ERR_DiscoveryService.Folders(inventory, folders);
		if (m_Service.HasPendingInsertion(entry.Actor)) { entry.WaitingFor = "original-insertion"; return; }
		if (!m_Service.Settled(entry.Actor)) { entry.WaitingFor = "quarantined-insertion"; return; }

		if (!entry.Inserting)
		{
			if (entry.Removing)
			{
				if (folders.Contains(entry.Removing)) { entry.WaitingFor = "native-removal"; return; }
				InventoryItemComponent item = InventoryItemComponent.Cast(entry.Removing.FindComponent(InventoryItemComponent));
				// It may have transferred to another inventory meanwhile. Preserve it
				// and decline the replacement rather than racing its new owner.
				if (!item || item.GetParentSlot() || entry.Removing.GetParent())
				{
					Finish(entry, false, true);
					return;
				}
				entry.Removing = null;
			}
			foreach (IEntity known : folders)
			{
				// Never reroll mission clue documents or recovered/spent folders.
				if (m_Mode.Discovery().IsSpent(known) || known.FindComponent(ERR_DocumentComponent))
				{
					Finish(entry, false, true);
					return;
				}
			}
			if (!folders.IsEmpty())
			{
				IEntity folder = folders[0];
				// Check capacity before mutation; rejected removal leaves usable intel.
				if (!m_Mode.Discovery().CanMarkSpent(folder)) { Fail(entry, "spent-capacity"); return; }
				// Busy native inventory may reject a request transiently. Retry within
				// the existing phase budget without spending or owning the folder.
				if (!inventory.TryRemoveItemFromInventory(folder)) { entry.WaitingFor = "removal-refused"; return; }
				m_Mode.Discovery().MarkSpent(folder);
				m_Mode.Own(folder);
				entry.Removing = folder;
				entry.WaitingFor = "native-removal";
				return;
			}
			entry.Inserting = true;
			entry.Attempts = 0;
			if (!entry.GiveIntel) { Finish(entry); return; }
		}
		if (entry.Accepted)
		{
			entry.WaitingFor = "native-insertion";
			if (entry.Operation && entry.Operation.Finished)
			{
				if (entry.Operation.Succeeded) Finish(entry);
				else Fail(entry, "insertion-callback");
			}
			return;
		}
		if (!folders.IsEmpty()) { Finish(entry); return; }
		entry.Operation = new ERR_IntelInsertCallback();
		entry.Accepted = inventory.TrySpawnPrefabToStorage(ERR_Resources.IntelFolder(), purpose: EStoragePurpose.PURPOSE_ANY, cb: entry.Operation);
		entry.WaitingFor = "insertion-refused";
		if (entry.Accepted) entry.WaitingFor = "native-insertion";
	}

	string Status()
	{
		string state = "complete";
		if (Running()) state = "running";
		if (m_Cancelled) state = "cancelled";
		return string.Format("Intel reroll %1 at %2 percent: %3/%4 AI processed, %5 failed, %6 skipped.", state, m_Percent, m_Completed, m_Entries.Count(), m_Failed, m_Skipped);
	}

	void Stop()
	{
		m_Cancelled = true;
		foreach (ERR_IntelRerollEntry entry : m_Entries)
		{
			entry.Actor = null;
			entry.Removing = null;
		}
	}
}