#include "StdAfx.h"
#include "ScriptParser.h"

CScriptParser::CScriptParser(void): 
	m_pScript(NULL),
	m_pScriptSection(NULL),
	m_pLastScriptSection(NULL),
	m_pToken(NULL) {
	ClearBuffer();
}

CScriptParser::~CScriptParser(void) {
	ClearBuffer();
}

void CScriptParser::ClearBuffer(void) {
	if(m_pScript) {
		delete[] m_pScript;
		m_pScript = NULL;
	}
	if(m_pToken) {
		delete[] m_pToken;
		m_pToken = NULL;
	}
	m_pScriptSection = NULL;
	m_pLastScriptSection = NULL;
	memset(m_breakChars, 0, sizeof(m_breakChars));
}

const char* CScriptParser::MakeToken(const char* pToken) {
	if(m_pToken) {
		delete[] m_pToken;
		m_pToken = NULL;
	}

	if(!pToken) {
		pToken = "";
	}

	int len = static_cast<int>(strlen(pToken));

	m_pToken = new char[len + 1];
	m_pToken[len] = '\0';
	strcpy(m_pToken, pToken);

	return m_pToken;
}

#define MAX_TOKEN_STRING 1024
// Should NEVER return NULL
const char* CScriptParser::GetToken(bool bAllowLinebreaks) {
	int c = 0, len;
	char token[MAX_TOKEN_STRING];
	bool bNewLines = false;

	m_pLastScriptSection = m_pScriptSection;

	len = 0;
	*token = '\0';

	if(!m_pScript || !m_pScriptSection) {
		return MakeToken(token);
	}

	while ( true ) {
		SkipWhitespace( &bNewLines );
		if ( !*m_pScriptSection ) {
			return MakeToken(token);
		}
		if ( bNewLines && !bAllowLinebreaks ) {
			return MakeToken(token);
		}

		c = *m_pScriptSection;
		
		if ( c == '/' && m_pScriptSection[1] == '/' ) { // C style comments
			m_pScriptSection += 2;
			while (*m_pScriptSection && *m_pScriptSection != '\n') {
				m_pScriptSection++;
			}
		} else if ( c=='/' && m_pScriptSection[1] == '*' ) { // C++ style comments
			m_pScriptSection += 2;
			while ( *m_pScriptSection && ( *m_pScriptSection != '*' || m_pScriptSection[1] != '/' ) ) {
				m_pScriptSection++;
			}
			if ( *m_pScriptSection ) {
				m_pScriptSection += 2;
			}
		} else {
			break;
		}
	}

	if (c == '\"') {
		m_pScriptSection++;
		while ( true ) {
			c = *m_pScriptSection++;
			if (c=='\"' || !c) {
				token[len] = 0;
				return MakeToken(token);
			}
			if (len < MAX_TOKEN_STRING) {
				token[len] = c;
				len++;
			}
		}
	}

	do {
		if(len > 0 && IsBreakChar(*m_pScriptSection)) {
			break;
		}

		if (len < MAX_TOKEN_STRING) {
			token[len] = c;
			len++;
		}
		m_pScriptSection++;

		if(IsBreakChar(c)) {
			break;
		}

		c = *m_pScriptSection;
	} while (c > 32);

	if (len == MAX_TOKEN_STRING) {
		len = 0;
	}
	token[len] = 0;

	return MakeToken(token);
}

void CScriptParser::SkipWhitespace(bool* pbNewLines) {
	int c;

	if(!m_pScript || !m_pScriptSection) {
		return;
	}

	while( (c = *m_pScriptSection) <= ' ') {
		if( !c ) {
			return;
		}
		if( c == '\n' ) {
			*pbNewLines = true;
		}
		m_pScriptSection++;
	}
}

void CScriptParser::SkipBracedSection(void) {
	const char		*token;
	int				depth;

	depth = 0;
	do {
		token = GetToken( true );
		if( token[1] == 0 ) {
			if( *token == '{' ) {
				depth++;
			} else if( *token == '}' ) {
				depth--;
			}
		}
	} while( depth && *m_pScriptSection );
}

void CScriptParser::SkipRestOfLine(void) {
	char	*p;
	int		c;

	p = m_pScriptSection;
	while ( (c = *p++) != 0 ) {
		if ( c == '\n' ) {
			break;
		}
	}
	m_pScriptSection = p;
}

void CScriptParser::UndoGetToken(void) {
	if(!m_pLastScriptSection) {
		return;
	}
	m_pScriptSection = m_pLastScriptSection;
	m_pLastScriptSection = NULL;
}

void CScriptParser::ResetParseSession(void) {
	if(!m_pScript) {
		return;
	}

	m_pScriptSection = m_pScript;
	m_pLastScriptSection = NULL;
}

char* CScriptParser::GetBufferCopy(void) {
	if(!m_pScript) {
		return NULL;
	}

	int len = static_cast<int>(strlen(m_pScript));
	char* pBuffer = new char[len + 1];
	strcpy(pBuffer, m_pScript);
	return pBuffer;
}

int CScriptParser::GetTokenOffset(void) {
	if(!m_pScript || !m_pScriptSection) {
		return 0;
	}

	return static_cast<int>(m_pScriptSection - m_pScript);
}

void CScriptParser::LoadScript(const char* pScript) {
	ClearBuffer();

	int len = static_cast<int>(strlen(pScript));
	if(len <= 0) {
		return;
	}

	m_pScript = new char[len + 1];
	m_pScript[len] = '\0';

	strcpy(m_pScript, pScript);
	m_pScriptSection = m_pScript;
}

void CScriptParser::AddBreakChar(char c) {
	for(int i = 0; i < SP_MAX_BREAKCHARS; i++) {
		if(!m_breakChars[i]) {
			m_breakChars[i] = c;
			return;
		}
	}

	// TODO: Error: max break chars hit
}

bool CScriptParser::IsBreakChar(char c) {
	for(int i = 0; i < SP_MAX_BREAKCHARS; i++) {
		if(!m_breakChars[i]) {
			return false;
		}
		if(m_breakChars[i] == c) {
			return true;
		}
	}
	return false;
}

void CScriptParser::SetScript(char* pScript) {
	ClearBuffer();

	int len = static_cast<int>(strlen(pScript));
	if(len <= 0) {
		return;
	}

	m_pScript = pScript;
	m_pScriptSection = m_pScript;
}