#include "proto.h"

#include "EterBase/StdAfx.h"
#include "EterBase/lzo.h"
#include "GameLib/StdAfx.h"
#include "GameLib/ItemData.h"
#include "../platform/UserInterface/UserInterface.h"

#include <cstring>
#include <fstream>

namespace mtproto {

namespace {

// CPythonNonPlayer::SMobTable (UserInterface/PythonNonPlayer.h), the 40250 ILP32 layout. The mirror of that header
// needs UserInterface/StdAfx.h, which includes the Python headers (after batch 2P); until then the table is here.
#pragma pack(push, 1)
struct SMobSkillLevel {
	DWORD dwVnum;
	BYTE bLevel;
};

struct SMobTable {
	DWORD dwVnum;
	char szName[24 + 1]; // CHARACTER_NAME_MAX_LEN (UserInterface/StdAfx.h)
	char szLocaleName[24 + 1];

	BYTE bType;
	BYTE bRank;
	BYTE bBattleType;
	BYTE bLevel;
	BYTE bSize;

	DWORD dwGoldMin;
	DWORD dwGoldMax;
	DWORD dwExp;
	DWORD dwMaxHP;
	BYTE bRegenCycle;
	BYTE bRegenPercent;
	WORD wDef;

	DWORD dwAIFlag;
	DWORD dwRaceFlag;
	DWORD dwImmuneFlag;

	BYTE bStr, bDex, bCon, bInt;
	DWORD dwDamageRange[2];

	short sAttackSpeed;
	short sMovingSpeed;
	BYTE bAggresiveHPPct;
	WORD wAggressiveSight;
	WORD wAttackRange;

	char cEnchants[6]; // MOB_ENCHANTS_MAX_NUM
	char cResists[11]; // MOB_RESISTS_MAX_NUM

	DWORD dwResurrectionVnum;
	DWORD dwDropItemVnum;

	BYTE bMountCapacity;
	BYTE bOnClickType;

	BYTE bEmpire;
	char szFolder[64 + 1];
	float fDamMultiply;
	DWORD dwSummonVnum;
	DWORD dwDrainSP;
	DWORD dwMonsterColor;
	DWORD dwPolymorphItemVnum;

	SMobSkillLevel Skills[5]; // MOB_SKILL_MAX_NUM

	BYTE bBerserkPoint;
	BYTE bStoneSkinPoint;
	BYTE bGodSpeedPoint;
	BYTE bDeathBlowPoint;
	BYTE bRevivePoint;
};
#pragma pack(pop)
static_assert(sizeof(SMobTable) == 255, "mob_proto record");

using TItemTable = CItemData::TItemTable;

uint32_t rd_u32(const uint8_t *p) {
	uint32_t v;
	std::memcpy(&v, p, 4);
	return v;
}

std::string cstr(const char *p, size_t maxn) {
	size_t n = 0;
	while (n < maxn && p[n]) {
		++n;
	}
	return std::string(p, n);
}

} // namespace

bool load_proto(const std::string &path, const std::array<uint32_t, 4> &key, Proto &out,
		std::string *err) {
	std::ifstream f(path, std::ios::binary);
	if (!f) {
		if (err) *err = "cannot open " + path;
		return false;
	}
	std::vector<uint8_t> file((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
	return load_proto_bytes(file, key, out, err);
}

// The header checks of CItemManager::LoadItemTable / CPythonNonPlayer::LoadNonPlayerData, then CLZO::Decompress.
bool load_proto_bytes(const std::vector<uint8_t> &file, const std::array<uint32_t, 4> &key,
		Proto &out, std::string *err) {
	out = Proto{};
	if (file.size() < 12) {
		if (err) *err = "file too small";
		return false;
	}

	size_t pos = 0;
	auto read_u32 = [&](uint32_t &v) {
		if (pos + 4 > file.size()) {
			return false;
		}
		v = rd_u32(file.data() + pos);
		pos += 4;
		return true;
	};

	read_u32(out.fourcc);
	if (out.fourcc == MAKEFOURCC('M', 'I', 'P', 'X')) {
		if (!read_u32(out.version) || !read_u32(out.stride)) {
			if (err) *err = "truncated MIPX header";
			return false;
		}
		if (out.version != 1) {
			if (err) *err = "invalid item_proto VERSION " + std::to_string(out.version);
			return false;
		}
		if (out.stride != sizeof(TItemTable)) {
			if (err) *err = "invalid item_proto STRIDE " + std::to_string(out.stride) + " != sizeof(SItemTable)";
			return false;
		}
	} else if (out.fourcc == MAKEFOURCC('M', 'I', 'P', 'T')) {
		out.stride = sizeof(TItemTable);
	} else if (out.fourcc == MAKEFOURCC('M', 'M', 'P', 'T')) {
		out.stride = sizeof(SMobTable);
	} else {
		if (err) *err = "invalid proto type";
		return false;
	}

	uint32_t data_size = 0;
	if (!read_u32(out.elements) || !read_u32(data_size)) {
		if (err) *err = "truncated proto header";
		return false;
	}
	// 40250 reads dwDataSize bytes without checking; CLZO then reads its own header lengths.
	if (pos + data_size > file.size() || data_size < sizeof(CLZObject::THeader)) {
		if (err) *err = "declared data_size past end of file";
		return false;
	}

	PackSingletons(); // CLZO, as 40250 Main() creates it
	DWORD dwKey[4] = {key[0], key[1], key[2], key[3]};
	CLZObject zObj;
	if (!CLZO::Instance().Decompress(zObj, file.data() + pos, dwKey)) {
		if (err) *err = "CLZO::Decompress failed (wrong key or corrupt data)";
		return false;
	}

	if (out.fourcc == MAKEFOURCC('M', 'M', 'P', 'T') && (zObj.GetSize() % sizeof(SMobTable)) != 0) {
		if (err) *err = "invalid mob_proto size " + std::to_string(zObj.GetSize()) + ", check data format";
		return false;
	}
	// 40250 walks dwElements records from the buffer without comparing against its size.
	if (static_cast<uint64_t>(out.stride) * out.elements > zObj.GetSize()) {
		if (err) *err = "elements * stride past decompressed size";
		return false;
	}
	const BYTE *buf = zObj.GetBuffer();
	out.blob.assign(buf, buf + static_cast<size_t>(out.stride) * out.elements);
	return true;
}

ItemRecord parse_item(const uint8_t *r, uint32_t stride) {
	ItemRecord it;
	if (!r || stride != sizeof(TItemTable)) {
		return it;
	}
	TItemTable t;
	std::memcpy(&t, r, sizeof(t));
	it.vnum = t.dwVnum;
	it.vnum_range = t.dwVnumRange;
	it.name = cstr(t.szName, sizeof(t.szName));
	it.locale_name = cstr(t.szLocaleName, sizeof(t.szLocaleName));
	it.type = t.bType;
	it.sub_type = t.bSubType;
	it.weight = t.bWeight;
	it.size = t.bSize;
	it.anti_flags = t.dwAntiFlags;
	it.flags = t.dwFlags;
	it.wear_flags = t.dwWearFlags;
	it.immune_flag = t.dwImmuneFlag;
	it.buy_price = t.dwIBuyItemPrice;
	it.sell_price = t.dwISellItemPrice;
	for (int i = 0; i < CItemData::ITEM_LIMIT_MAX_NUM; ++i) {
		it.limits[i] = {t.aLimits[i].bType, t.aLimits[i].lValue};
	}
	for (int i = 0; i < CItemData::ITEM_APPLY_MAX_NUM; ++i) {
		it.applies[i] = {t.aApplies[i].bType, t.aApplies[i].lValue};
	}
	for (int i = 0; i < CItemData::ITEM_VALUES_MAX_NUM; ++i) {
		it.values[i] = t.alValues[i];
	}
	for (int i = 0; i < CItemData::ITEM_SOCKET_MAX_NUM; ++i) {
		it.sockets[i] = t.alSockets[i];
	}
	it.refined_vnum = t.dwRefinedVnum;
	it.refine_set = t.wRefineSet;
	it.alter_to_magic_pct = t.bAlterToMagicItemPct;
	it.specular = t.bSpecular;
	it.gain_socket_pct = t.bGainSocketPct;
	return it;
}

MobRecord parse_mob(const uint8_t *r, uint32_t stride) {
	MobRecord m;
	if (!r || stride != sizeof(SMobTable)) {
		return m;
	}
	SMobTable t;
	std::memcpy(&t, r, sizeof(t));
	m.vnum = t.dwVnum;
	m.name = cstr(t.szName, sizeof(t.szName));
	m.locale_name = cstr(t.szLocaleName, sizeof(t.szLocaleName));
	m.type = t.bType;
	m.rank = t.bRank;
	m.battle_type = t.bBattleType;
	m.level = t.bLevel;
	m.size = t.bSize;
	m.attack_speed = t.sAttackSpeed;
	m.moving_speed = t.sMovingSpeed;
	m.on_click_type = t.bOnClickType;
	m.empire = t.bEmpire;
	m.folder = cstr(t.szFolder, sizeof(t.szFolder));
	m.monster_color = t.dwMonsterColor;
	return m;
}

} // namespace mtproto