/*

WhatsAppWeb plugin for Miranda NG
Copyright © 2019-22 George Hazan

*/

#define DICT_VERSION 2

#define LIST_EMPTY   0
#define STREAM_END   2
#define DICTIONARY_0 236
#define DICTIONARY_1 237
#define DICTIONARY_2 238
#define DICTIONARY_3 239
#define AD_JID       247
#define LIST_8       248
#define LIST_16      249
#define JID_PAIR     250
#define HEX_8        251
#define BINARY_8     252
#define BINARY_20    253
#define BINARY_32    254
#define NIBBLE_8     255

class WANode // kinda XML
{
	friend class WAReader;
	friend class WAWriter;

	WANode *pParent = nullptr;
	OBJLIST<struct Attr> attrs;
	OBJLIST<WANode> children;

public:
	WANode();
	WANode(const char *pszTitle);
	~WANode();

	void addAttr(const char *pszName, const char *pszValue);
	void addAttr(const char *pszName, int iValue);
	const char* getAttr(const char *pszName) const;

	CMStringA getBody() const;

	WANode* addChild(const char *pszName);
	WANode* getChild(const char *pszName) const;
	WANode* getFirstChild(void) const;

	void print(CMStringA &dest, int level = 0) const;

	CMStringA title;
	MBinBuffer content;
};

__forceinline WANode& operator<<(WANode &node, const CHAR_PARAM &param)
{
	node.addAttr(param.szName, param.szValue);
	return node;
}

class WAReader
{
	const BYTE *m_buf, *m_limit;

	uint32_t readIntN(int i);
	CMStringA readStringFromChars(int size);

	bool      readAttributes(WANode *node, int count);
	uint32_t  readInt20();
	bool      readList(WANode *pParent, int tag);
	int       readListSize(int tag);
	CMStringA readPacked(int tag);
	CMStringA readString(int tag);

public:
	WAReader(const void *buf, size_t cbLen) :
		m_buf((BYTE*)buf),
		m_limit((BYTE*)buf + cbLen)
	{}

	WANode* readNode();

	__forceinline uint32_t readInt8() { return readIntN(1); }
	__forceinline uint32_t readInt16() { return readIntN(2); }
	__forceinline uint32_t readInt32() { return readIntN(4); }
};

class WAWriter
{
	__forceinline void writeInt8(int value) { writeIntN(value, 1); }
	__forceinline void writeInt16(int value) { writeIntN(value, 2); }
	__forceinline void writeInt32(int value) { writeIntN(value, 4); }

	void writeByte(uint8_t b);
	void writeIntN(int value, int i);
	void writeInt20(int value);
	void writeLength(int value);
	void writeListSize(int tag);
	void writePacked(const CMStringA &str, int tag);
	void writeString(const char *str);
	bool writeToken(const char *str);

public:
	void writeNode(const WANode *pNode);

	MBinBuffer body;
};

/////////////////////////////////////////////////////////////////////////////////////////

struct WAJid
{
	int device, agent;
	CMStringA user, server;

	WAJid(const char *pszJid);
	WAJid(const char *pszUser, const char *pszServer, int device = 0, int agent = 0);

	CMStringA toString() const;
};

/////////////////////////////////////////////////////////////////////////////////////////

std::string encodeBigEndian(uint32_t num, size_t len = sizeof(uint32_t));
void generateIV(uint8_t *iv, int &pVar);

unsigned char* HKDF(const EVP_MD *evp_md,
	const unsigned char *salt, size_t salt_len,
	const unsigned char *key, size_t key_len,
	const unsigned char *info, size_t info_len,
	unsigned char *okm, size_t okm_len);