// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.


// PatchEngine
// Supports simple memory patches, and has a partial Action Replay implementation
// in ActionReplay.cpp/h.

// TODO: Still even needed?  Zelda WW now works with improved DSP code.
// Zelda item hang fixes:
// [Tue Aug 21 2007] [18:30:40] <Knuckles->    0x802904b4 in US released
// [Tue Aug 21 2007] [18:30:53] <Knuckles->    0x80294d54 in EUR Demo version
// [Tue Aug 21 2007] [18:31:10] <Knuckles->    we just patch a blr on it (0x4E800020)
// [OnLoad]
// 0x80020394=dword,0x4e800020

#include <algorithm>
#include <map>
#include <set>
#include <string>
#include <vector>

#include "Common/CommonPaths.h"
#include "Common/FileUtil.h"
#include "Common/IniFile.h"
#include "Common/StringUtil.h"

#include "Core/ActionReplay.h"
#include "Core/ConfigManager.h"
#include "Core/GeckoCode.h"
#include "Core/GeckoCodeConfig.h"
#include "Core/PatchEngine.h"
#include "Core/PowerPC/PowerPC.h"

using namespace Common;

namespace PatchEngine
{

const char *PatchTypeStrings[] =
{
	"byte",
	"word",
	"dword",
};

static std::vector<Patch> onFrame;
static std::map<u32, int> speedHacks;

void LoadPatchSection(const std::string& section, std::vector<Patch>& patches, IniFile& globalIni, IniFile& localIni)
{
	// Load the name of all enabled patches
	std::string enabledSectionName = section + "_Enabled";
	std::vector<std::string> enabledLines;
	std::set<std::string> enabledNames;
	localIni.GetLines(enabledSectionName, &enabledLines);
	for (const std::string& line : enabledLines)
	{
		if (line.size() != 0 && line[0] == '$')
		{
			std::string name = line.substr(1, line.size() - 1);
			enabledNames.insert(name);
		}
	}

	const IniFile* inis[2] = {&globalIni, &localIni};

	for (const IniFile* ini : inis)
	{
		std::vector<std::string> lines;
		Patch currentPatch;
		ini->GetLines(section, &lines);

		for (std::string& line : lines)
		{
			if (line.size() == 0)
				continue;

			if (line[0] == '$')
			{
				// Take care of the previous code
				if (currentPatch.name.size())
				{
					patches.push_back(currentPatch);
				}
				currentPatch.entries.clear();

				// Set active and name
				currentPatch.name = line.substr(1, line.size() - 1);
				currentPatch.active = enabledNames.find(currentPatch.name) != enabledNames.end();
				currentPatch.user_defined = (ini == &localIni);
			}
			else
			{
				std::string::size_type loc = line.find('=');

				if (loc != std::string::npos)
				{
					line[loc] = ':';
				}

				std::vector<std::string> items;
				SplitString(line, ':', items);

				if (items.size() >= 3)
				{
					PatchEntry pE;
					bool success = true;
					success &= TryParse(items[0], &pE.address);
					success &= TryParse(items[2], &pE.value);

					pE.type = PatchType(std::find(PatchTypeStrings, PatchTypeStrings + 3, items[1]) - PatchTypeStrings);
					success &= (pE.type != (PatchType)3);
					if (success)
					{
						currentPatch.entries.push_back(pE);
					}
				}
			}
		}

		if (currentPatch.name.size() && currentPatch.entries.size())
		{
			patches.push_back(currentPatch);
		}
	}
}

static void LoadSpeedhacks(const std::string& section, IniFile& ini)
{
	std::vector<std::string> keys;
	ini.GetKeys(section, &keys);
	for (const std::string& key : keys)
	{
		std::string value;
		ini.GetOrCreateSection(section)->Get(key, &value, "BOGUS");
		if (value != "BOGUS")
		{
			u32 address;
			u32 cycles;
			bool success = true;
			success &= TryParse(key, &address);
			success &= TryParse(value, &cycles);
			if (success)
			{
				speedHacks[address] = (int)cycles;
			}
		}
	}
}

int GetSpeedhackCycles(const u32 addr)
{
	std::map<u32, int>::const_iterator iter = speedHacks.find(addr);
	if (iter == speedHacks.end())
		return 0;
	else
		return iter->second;
}

void LoadPatches()
{
	IniFile merged = SConfig::GetInstance().LoadGameIni();
	IniFile globalIni = SConfig::GetInstance().LoadDefaultGameIni();
	IniFile localIni = SConfig::GetInstance().LoadLocalGameIni();

	LoadPatchSection("OnFrame", onFrame, globalIni, localIni);
	ActionReplay::LoadAndApplyCodes(globalIni, localIni);

	// lil silly
	std::vector<Gecko::GeckoCode> gcodes;
	Gecko::LoadCodes(globalIni, localIni, gcodes);
	Gecko::SetActiveCodes(gcodes);

	LoadSpeedhacks("Speedhacks", merged);
}

static void ApplyPatches(const std::vector<Patch> &patches)
{
	for (const Patch& patch : patches)
	{
		if (patch.active)
		{
			for (const PatchEntry& entry : patch.entries)
			{
				u32 addr = entry.address;
				u32 value = entry.value;
				switch (entry.type)
				{
				case PATCH_8BIT:
					PowerPC::HostWrite_U8((u8)value, addr);
					break;
				case PATCH_16BIT:
					PowerPC::HostWrite_U16((u16)value, addr);
					break;
				case PATCH_32BIT:
					PowerPC::HostWrite_U32(value, addr);
					break;
				default:
					//unknown patchtype
					break;
				}
			}
		}
	}
}

void ApplyFramePatches()
{
	// TODO: Messing with MSR this way is really, really, evil; we should
	// probably be using some sort of Gecko OS-style hooking mechanism
	// so the emulated CPU is in a predictable state when we process cheats.
	u32 oldMSR = MSR;
	UReg_MSR newMSR = oldMSR;
	newMSR.IR = 1;
	newMSR.DR = 1;
	MSR = newMSR.Hex;
	ApplyPatches(onFrame);

	// Run the Gecko code handler
	Gecko::RunCodeHandler();
	ActionReplay::RunAllActive();
	MSR = oldMSR;
}

void Shutdown()
{
	onFrame.clear();
}

}  // namespace
