#include "stdafx.h"
#include "SectionRegionCache.h"
#include "AecDbObjXDataMap.h"
#include "SectionPerfCounter.h"

#include <windows.h>
#include <stdlib.h>
#include <string>
#include <map>
#include <list>

namespace
{
	// 每个通道的条目上限。实测大图纸唯一 SAT 文本约 2600 条，2048 会把热条目挤掉，
	// 所以默认给 4096；可用 AEC_SECTION_CACHE_MAX 覆盖（内存吃紧时调小）。
	const size_t kDefaultMaxEntries = 4096;
	size_t GetMaxEntries()
	{
		static size_t s_nMax = 0;
		if (s_nMax == 0)
		{
			const char* psz = ::getenv("AEC_SECTION_CACHE_MAX");
			s_nMax = (psz != NULL) ? (size_t)atoi(psz) : 0;
			if (s_nMax < 16)
				s_nMax = kDefaultMaxEntries;
		}
		return s_nMax;
	}

	static const char* kChannelName[] = { "text", "attr", "param" };

	struct ChannelData
	{
		ChannelData() : nHits(0), nMisses(0), nEvicted(0) {}

		std::map<unsigned long long, AcDbRegion*> map;
		std::list<unsigned long long>             fifo;
		unsigned long long nHits;
		unsigned long long nMisses;
		unsigned long long nEvicted;

		void ReleaseAll()
		{
			for (std::map<unsigned long long, AcDbRegion*>::iterator it = map.begin(); it != map.end(); ++it)
			{
				AcDbRegion* p = it->second;
				if (p != NULL)
					delete p;
			}
			map.clear();
			fifo.clear();
			nEvicted = 0;
		}
	};

	struct State
	{
		State() : bInited(false), bEnabled(true) {}

		bool              bInited;
		bool              bEnabled;
		ChannelData       channels[SectionRegionCache::kChannelCount];
		CRITICAL_SECTION  cs;
	};

	// 函数内 static：CoreLibrary 是静态库且只被 CoreCommand 链接，
	// 所以 CoreCommand.arx 内只有这一份缓存。
	// 注意：不在析构里 delete 母体（DLL 卸载时 modeler 可能已先关，
	// 析构顺序不安全）；由 ClearAll() 在 kUnloadAppMsg 里显式释放。
	State& GetState()
	{
		static State s_state;
		if (!s_state.bInited)
		{
			::InitializeCriticalSection(&s_state.cs);
			const char* psz = ::getenv("AEC_SECTION_CACHE");
			s_state.bEnabled = !(psz != NULL && psz[0] == '0');
			s_state.bInited = true;
		}
		return s_state;
	}

	struct AutoLock
	{
		explicit AutoLock(CRITICAL_SECTION* pcs) : m_pcs(pcs) { ::EnterCriticalSection(m_pcs); }
		~AutoLock() { ::LeaveCriticalSection(m_pcs); }
		CRITICAL_SECTION* m_pcs;
	};

	unsigned long long HashAdd(unsigned long long h, const void* pData, size_t nLen)
	{
		if (pData == NULL || nLen == 0)
			return h;
		const unsigned char* p = (const unsigned char*)pData;
		for (size_t i = 0; i < nLen; ++i)
		{
			h ^= (unsigned long long)p[i];
			h *= 1099511628211ULL;
		}
		return h;
	}
}

namespace {
	// 诊断用：AEC_SAT_SAMPLE=n 时把前 n 个"未命中的 SAT 文本"导出，便于比对差异来源
	void DumpSample(const void* pData, size_t nLen)
	{
		static int s_nRemain = -1;
		if (s_nRemain < 0)
		{
			const char* psz = ::getenv("AEC_SAT_SAMPLE");
			s_nRemain = (psz != NULL) ? atoi(psz) : 0;
		}
		if (s_nRemain <= 0)
			return;
		--s_nRemain;

		char szTmp[MAX_PATH + 1];
		::memset(szTmp, 0, sizeof(szTmp));
		if (::GetTempPathA(MAX_PATH, szTmp) == 0)
			return;
		std::string sPath(szTmp);
		sPath += "aec_sat_samples.txt";

		FILE* fp = NULL;
		if (fopen_s(&fp, sPath.c_str(), "ab") == 0 && fp != NULL)
		{
			fprintf(fp, "===== SAMPLE len=%llu =====\n", (unsigned long long)nLen);
			fwrite(pData, 1, nLen, fp);
			fprintf(fp, "\n===== END =====\n");
			fclose(fp);
		}
	}
}
namespace SectionRegionCache
{
	bool Enabled()
	{
		return GetState().bEnabled;
	}

	unsigned long long HashBytes(const void* pData, size_t nLen)
	{
		return HashAdd(1469598103934665603ULL, pData, nLen);
	}

	unsigned long long HashSatText(const void* pData, size_t nLen)
	{
		if (pData == NULL || nLen == 0)
			return 1469598103934665603ULL;

		const char* p = (const char*)pData;
		const char* pEnd = p + nLen;

		// 找第 2 行（SAT 的 16 号记录：Autodesk 版本 + 存盘时间戳）
		const char* pNL1 = (const char*)memchr(p, '\n', nLen);
		if (pNL1 != NULL && pNL1 + 1 < pEnd)
		{
			const char* pLine2 = pNL1 + 1;
			const char* pNL2 = (const char*)memchr(pLine2, '\n', (size_t)(pEnd - pLine2));
			if (pNL2 != NULL)
			{
				// 只在第 2 行确实是 Autodesk 头时才跳过，避免误伤别的格式
				bool bHeader = false;
				for (const char* q = pLine2; q + 9 <= pNL2; ++q)
				{
					if (_strnicmp(q, "Autodesk", 8) == 0)
					{
						bHeader = true;
						break;
					}
				}
				if (bHeader)
				{
					unsigned long long h = HashBytes(p, (size_t)(pNL1 - p));
					return HashAdd(h, pNL2 + 1, (size_t)(pEnd - (pNL2 + 1)));
				}
			}
		}

		return HashBytes(pData, nLen);
	}

	unsigned long long BuildSpecAttrHash(const AecDbObjXDataMap& map, const TCHAR* pszClass)
	{
		unsigned long long h = 1469598103934665603ULL;

		// 类名参与：不同实体类即使数据相同也绝不能共用截面
		CStringA sCls(pszClass != NULL ? pszClass : _T("?"));
		h = HashAdd(h, (LPCSTR)sCls, strlen((LPCSTR)sCls));

		// std::map 按 key 排序，遍历顺序稳定
		for (AecDbObjXDataMap::It it = const_cast<AecDbObjXDataMap&>(map).Begin();
			it != const_cast<AecDbObjXDataMap&>(map).End(); ++it)
		{
			const CString& sKey = it->first;
			const AecXData& xd = it->second;

			// 编号每根管子唯一，必须排除
			if (sKey.CompareNoCase(_T("No.")) == 0)
				continue;

			h = HashAdd(h, sKey.GetString(), (size_t)sKey.GetLength() * sizeof(TCHAR));
			h = HashAdd(h, &xd.nVt, sizeof(xd.nVt));

			switch (xd.nVt)
			{
			case AecXData::kTypeShort:
				h = HashAdd(h, &xd.iVal, sizeof(xd.iVal));
				break;
			case AecXData::kTypeInt:
			case AecXData::kTypeInt64:
				h = HashAdd(h, &xd.nVal, sizeof(xd.nVal));
				break;
			case AecXData::kTypeDouble:
				h = HashAdd(h, &xd.dVal[0], sizeof(double));
				break;
			case AecXData::kTypeString:
				if (xd.pszVal != NULL)
					h = HashAdd(h, xd.pszVal, _tcslen(xd.pszVal) * sizeof(TCHAR));
				break;
			default:
				// Id / 点 / 向量 / 矩阵 / 二进制：与截面无关或随实体变化，跳过
				break;
			}
		}
		return h;
	}

	AcDbRegion* Acquire(Channel ch, unsigned long long nKey, const void* pSampleData, size_t nSampleLen)
	{
		State& s = GetState();
		if (!s.bEnabled || ch < 0 || ch >= kChannelCount)
			return NULL;

		AutoLock lock(&s.cs);
		ChannelData& cd = s.channels[ch];

		std::map<unsigned long long, AcDbRegion*>::iterator it = cd.map.find(nKey);
		if (it == cd.map.end() || it->second == NULL)
		{
			++cd.nMisses;
			if (ch == SectionRegionCache::kText && pSampleData != NULL)
				DumpSample(pSampleData, nSampleLen);
			return NULL;
		}

		++cd.nHits;
		SectionPerf::Scope hitScope("cache.hit.clone");
		return (AcDbRegion*)it->second->clone();
	}

	AcDbRegion* Put(Channel ch, unsigned long long nKey, AcDbRegion* pMaster)
	{
		State& s = GetState();
		if (pMaster == NULL)
			return NULL;
		if (!s.bEnabled || ch < 0 || ch >= kChannelCount)
			return pMaster;   // 关闭时原样返回，调用方照旧拥有

		AcDbRegion* pForCaller = NULL;
	{
		SectionPerf::Scope putScope("cache.miss.clone");
		pForCaller = (AcDbRegion*)pMaster->clone();
	}

		AutoLock lock(&s.cs);
		ChannelData& cd = s.channels[ch];

		std::map<unsigned long long, AcDbRegion*>::iterator it = cd.map.find(nKey);
		if (it != cd.map.end())
		{
			// 已有同 key（并发或重复入库）：丢弃新的母体
			delete pMaster;
			return pForCaller;
		}

		// 超出上限先淘汰最旧的
		while (cd.map.size() >= GetMaxEntries() && !cd.fifo.empty())
		{
			const unsigned long long nOld = cd.fifo.front();
			cd.fifo.pop_front();
			std::map<unsigned long long, AcDbRegion*>::iterator itOld = cd.map.find(nOld);
			if (itOld != cd.map.end())
			{
				AcDbRegion* pOld = itOld->second;
				cd.map.erase(itOld);
				delete pOld;
				++cd.nEvicted;
			}
		}

		cd.map[nKey] = pMaster;
		cd.fifo.push_back(nKey);
		return pForCaller;
	}

	void Dump()
	{
		State& s = GetState();
		std::string out;
		char szLine[512];

		out += "\n---- section region cache ----\n";
		out += "  channel   entries   hits    misses  hit_rate  evicted\n";
		for (int i = 0; i < (int)kChannelCount; ++i)
		{
			const ChannelData& cd = s.channels[i];
			const unsigned long long nTotal = cd.nHits + cd.nMisses;
			const double rate = nTotal ? (100.0 * (double)cd.nHits / (double)nTotal) : 0.0;
			sprintf_s(szLine, sizeof(szLine), "  %-9s %-9llu %-7llu %-7llu %7.1f%%  %llu\n",
				kChannelName[i], (unsigned long long)cd.map.size(),
				cd.nHits, cd.nMisses, rate, cd.nEvicted);
			out += szLine;
		}

		const char* psz = out.c_str();
		while (*psz != '\0')
		{
			const char* pszEnd = strchr(psz, '\n');
			const size_t nSeg = (pszEnd != NULL) ? (size_t)(pszEnd - psz) : strlen(psz);
			if (nSeg > 0 && nSeg < sizeof(szLine))
			{
				memcpy(szLine, psz, nSeg);
				szLine[nSeg] = '\0';
				acutPrintf(_T("\n%hs"), szLine);
			}
			if (pszEnd == NULL)
				break;
			psz = pszEnd + 1;
		}

		// 同时写进与 SectionPerf 相同的报告文件，便于脚本回收
		SectionPerf::AppendReport(out.c_str());
	}

	void ClearAll()
	{
		State& s = GetState();
		AutoLock lock(&s.cs);
		for (int i = 0; i < (int)kChannelCount; ++i)
			s.channels[i].ReleaseAll();
	}
}