// Copyright (C) 2007 EQ2EMulator Development Team - GPL v3 License

#pragma once

#include <map>
#include <vector>
#include <deque>
#include <thread>
#include <mutex>
#include <condition_variable>

#include "database_core.hpp"
#include "query.hpp"
#include "../stream/eq_stream.hpp"
#include "../packet/packet_functions.hpp"
#include "../opcodes/emu_opcodes.hpp"
#include "../eq_emu_error.hpp"
#include "../packet/packet_dump.hpp"

#ifdef WORLD
	#include "../../WorldServer/WorldDatabase.h"
#endif
#ifdef LOGIN
	#include "../../LoginServer/login_database.hpp"
#endif
#ifdef PARSER
	#include "../PacketParser/ParserDatabase.h"
#endif
#ifdef PATCHER
	#include "../PatchServer/PatcherDatabase.h"
#endif


using namespace std;

// Forward declaration
class Query;

// Structure for async database operations
typedef struct
{
	int32 queryid;
} DBStruct;

// Advanced database class with async processing and game-specific functionality
class Database : public DatabaseCore
{
public:
	// Constructor - initializes database variables
	Database()
	{
#ifdef WORLD
		continueAsync = false;
#endif
	}

	// Destructor - cleans up resources and async queries
	~Database()
	{
#ifdef WORLD
		DBQueryMutex.writelock(__FUNCTION__, __LINE__);
		activeQuerySessions.clear();
		DBQueryMutex.releasewritelock(__FUNCTION__, __LINE__);

		DBAsyncMutex.writelock();
		continueAsync = false;
		for (auto& itr : asyncQueries) {
			asyncQueriesMutex[itr.first]->writelock();
			auto& queries = itr.second;
			while (queries.size() > 0) {
				Query* cur = queries.front();
				queries.pop_front();
				safe_delete(cur);
			}
			asyncQueriesMutex[itr.first]->releasewritelock();
			Mutex* mutex = asyncQueriesMutex[itr.first];
			asyncQueriesMutex.erase(itr.first);
			safe_delete(mutex);
		}
		asyncQueries.clear();
		asyncQueriesMutex.clear();
		DBAsyncMutex.releasewritelock();

		PurgeDBInstances();
#endif
	}

	// Initialize database connection with optional silent loading
	bool Init(bool silentLoad = false)
	{
		return Connect();
	}

	// Comprehensive query execution method - inherits from DatabaseCore but ensures Database access
	using DatabaseCore::RunQuery;

	// Retrieve opcode mappings for specified client version
	map<string, uint16> GetOpcodes(int16 version)
	{
		map<string, uint16> opcodes;
		DatabaseResult result;
		if (Select(&result, "select name, opcode from opcodes where %i between version_range1 and version_range2 order by version_range1, id", version)) {
			while (result.Next()) {
				opcodes[result.GetStringStr("name")] = result.GetInt16Str("opcode");
			}
		}
		return opcodes;
	}

	// Get available client version ranges
	map<int16, int16> GetVersions()
	{
		map<int16, int16> versions;
		DatabaseResult result;
		if (Select(&result, "select distinct version_range1, version_range2 from opcodes")) {
			while (result.Next()) {
				versions[result.GetInt16Str("version_range1")] = result.GetInt16Str("version_range2");
			}
		}
		return versions;
	}

	// Authenticate web user credentials and return user ID
	int32 AuthenticateWebUser(char* userName, char* passwd, int32* status = 0)
	{
		if (status) {
			*status = 0;
		}
		int32 id = 0;
		DatabaseResult result;
		if (Select(&result, "select id, status from web_users where username='%s' and passwd = sha2('%s', 512)", EscapeStr(userName).c_str(), EscapeStr(passwd).c_str())) {
			if (result.Next()) {
				id = result.GetInt32Str("id");
				if (status) {
					*status = result.GetInt32Str("status");
				}
			}
		}
		return id;
	}

	// Check if route requires authentication
	int32 NoAuthRoute(char* route)
	{
		int32 status = 0xFFFFFFFF;
		DatabaseResult result;
		if (Select(&result, "select status from web_routes where route='%s'", EscapeStr(route).c_str())) {
			if (result.Next()) {
				status = result.GetInt32Str("status");
			}
		}
		return status;
	}

	// Handle MySQL error codes with appropriate logging
	void HandleMysqlError(int32 errnum)
	{
		switch (errnum) {
		case 0:
			break;
		case 1045: // Access Denied
		case 2001: {
			AddEQEMuError(EQEMuError_Mysql_1405, true);
			break;
		}
		case 2003: { // Unable to connect
			AddEQEMuError(EQEMuError_Mysql_2003, true);
			break;
		}
		case 2005: { // Unable to connect
			AddEQEMuError(EQEMuError_Mysql_2005, true);
			break;
		}
		case 2007: { // Unable to connect
			AddEQEMuError(EQEMuError_Mysql_2007, true);
			break;
		}
		}
	}

#ifdef WORLD
	// Add query to async processing queue
	void AddAsyncQuery(Query* query)
	{
		DBAsyncMutex.writelock();
		map<int32, Mutex*>::iterator mutexItr = asyncQueriesMutex.find(query->GetQueryID());
		if (mutexItr == asyncQueriesMutex.end()) {
			Mutex* queryMutex = new Mutex();
			queryMutex->SetName("AsyncQuery" + query->GetQueryID());
			asyncQueriesMutex.insert(make_pair(query->GetQueryID(), queryMutex));
		}
		map<int32, deque<Query*>>::iterator itr = asyncQueries.find(query->GetQueryID());
		asyncQueriesMutex[query->GetQueryID()]->writelock();

		if (itr != asyncQueries.end())
			itr->second.push_back(query);
		else {
			deque<Query*> queue;
			queue.push_back(query);
			asyncQueries.insert(make_pair(query->GetQueryID(), queue));
		}

		AddActiveQuery(query);

		asyncQueriesMutex[query->GetQueryID()]->releasewritelock();
		DBAsyncMutex.releasewritelock();

		bool isActive = IsActiveQuery(query->GetQueryID(), query);
		if (!isActive) {
			continueAsync = true;
			DBStruct* tmp = new DBStruct;
			tmp->queryid = query->GetQueryID();

			thread asyncThread(DBAsyncQueries, (void*)tmp);
			asyncThread.detach();
		}
	}

	// Process all async queries for specified query ID
	void RunAsyncQueries(int32 queryid)
	{
		Database* asyncdb = FindFreeInstance();
		DBAsyncMutex.writelock();
		map<int32, deque<Query*>>::iterator itr = asyncQueries.find(queryid);
		if (itr == asyncQueries.end()) {
			DBAsyncMutex.releasewritelock();
			return;
		}

		asyncQueriesMutex[queryid]->writelock();
		deque<Query*> queries;
		while (itr->second.size()) {
			Query* cur = itr->second.front();
			queries.push_back(cur);
			itr->second.pop_front();
		}
		itr->second.clear();
		asyncQueries.erase(itr);
		DBAsyncMutex.releasewritelock();
		asyncQueriesMutex[queryid]->releasewritelock();

		while (queries.size() > 0) {
			Query* cur = queries.front();
			cur->RunQueryAsync(asyncdb);
			this->RemoveActiveQuery(cur);
			queries.pop_front();
			safe_delete(cur);
		}
		FreeDBInstance(asyncdb);

		bool isActive = IsActiveQuery(queryid);
		if (isActive) {
			continueAsync = true;
			DBStruct* tmp = new DBStruct;
			tmp->queryid = queryid;

			thread asyncThread(DBAsyncQueries, (void*)tmp);
			asyncThread.detach();
		}
	}

	// Find available database instance from pool
	Database* FindFreeInstance()
	{
		Database* db_inst = 0;
		map<Database*, bool>::iterator itr;
		DBInstanceMutex.writelock(__FUNCTION__, __LINE__);
		for (itr = dbInstances.begin(); itr != dbInstances.end(); itr++) {
			if (!itr->second) {
				db_inst = itr->first;
				itr->second = true;
				break;
			}
		}

		if (!db_inst) {
			WorldDatabase* tmp = new WorldDatabase();
			db_inst = (Database*)tmp;
			tmp->Init();
			tmp->ConnectNewDatabase();
			dbInstances.insert(make_pair(db_inst, true));
		}
		DBInstanceMutex.releasewritelock(__FUNCTION__, __LINE__);

		return db_inst;
	}

	// Remove query from active session tracking
	void RemoveActiveQuery(Query* query)
	{
		DBQueryMutex.writelock(__FUNCTION__, __LINE__);

		vector<Query*>::iterator itr;
		for (itr = activeQuerySessions.begin(); itr != activeQuerySessions.end(); itr++) {
			Query* curQuery = *itr;
			if (query == curQuery) {
				activeQuerySessions.erase(itr);
				break;
			}
		}
		DBQueryMutex.releasewritelock(__FUNCTION__, __LINE__);
	}

	// Add query to active session tracking
	void AddActiveQuery(Query* query)
	{
		DBQueryMutex.writelock(__FUNCTION__, __LINE__);
		activeQuerySessions.push_back(query);
		DBQueryMutex.releasewritelock(__FUNCTION__, __LINE__);
	}

	// Check if query ID has active operations
	bool IsActiveQuery(int32 id, Query* skip = 0)
	{
		bool isActive = false;

		DBQueryMutex.readlock(__FUNCTION__, __LINE__);
		vector<Query*>::iterator itr;
		for (itr = activeQuerySessions.begin(); itr != activeQuerySessions.end(); itr++) {
			Query* query = *itr;
			if (query == skip)
				continue;

			if (query->GetQueryID() == id) {
				isActive = true;
				break;
			}
		}
		DBQueryMutex.releasereadlock(__FUNCTION__, __LINE__);

		return isActive;
	}

	// Ping all async database connections
	void PingAsyncDatabase()
	{
		map<Database*, bool>::iterator itr;
		DBInstanceMutex.readlock(__FUNCTION__, __LINE__);
		for (itr = dbInstances.begin(); itr != dbInstances.end(); itr++) {
			Database* tmpInst = itr->first;
			tmpInst->Ping();
		}
		DBInstanceMutex.releasereadlock(__FUNCTION__, __LINE__);
	}

private:
	// Clean up all database instances in pool
	void PurgeDBInstances()
	{
		map<Database*, bool>::iterator itr;
		DBInstanceMutex.writelock(__FUNCTION__, __LINE__);
		for (itr = dbInstances.begin(); itr != dbInstances.end(); itr++) {
			WorldDatabase* tmpInst = (WorldDatabase*)itr->first;
			safe_delete(tmpInst);
		}
		dbInstances.clear();
		DBInstanceMutex.releasewritelock(__FUNCTION__, __LINE__);
	}

	// Return database instance to available pool
	void FreeDBInstance(Database* cur)
	{
		DBInstanceMutex.writelock(__FUNCTION__, __LINE__);
		dbInstances[cur] = false;
		DBInstanceMutex.releasewritelock(__FUNCTION__, __LINE__);
	}

	bool continueAsync;								// Flag to continue async processing
	map<int32, deque<Query*>> asyncQueries;			// Queue of async queries by ID
	map<int32, Mutex*> asyncQueriesMutex;			// Mutex per query ID for thread safety
	map<Database*, bool> dbInstances;				// Pool of database instances
	vector<Query*> activeQuerySessions;			// Currently active query sessions
	Mutex DBAsyncMutex;								// Mutex for async operations
	Mutex DBInstanceMutex;							// Mutex for instance pool management
	Mutex DBQueryMutex;								// Mutex for query session tracking
#endif
};

#ifdef WORLD
// Global database instance declaration - would be defined elsewhere
extern Database database;

// Thread function for processing async database queries
ThreadReturnType DBAsyncQueries(void* str)
{
	this_thread::sleep_for(chrono::milliseconds(10));
	DBStruct* data = (DBStruct*)str;
	database.RunAsyncQueries(data->queryid);
	delete data;
	THREAD_RETURN(NULL);
}
#endif