/**

  * vim: set ts=4 :

  * ================================================================

  * SourceMod

  * Copyright (C) 2004-2007 AlliedModders LLC.  All rights reserved.

  * ================================================================

  *

  * This program is free software; you can redistribute it and/or 

  * modify it under the terms of the GNU General Public License, 

  * version 3.0, as published by the Free Software Foundation.

  * 

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program.  If not, see <http://www.gnu.org/licenses/>.

  *

  * As a special exception, AlliedModders LLC gives you permission to 

  * link the code of this program (as well as its derivative works) to 

  * "Half-Life 2," the "Source Engine," the "SourcePawn JIT," and any 

  * Game MODs that run on software by the Valve Corporation.  You must 

  * obey the GNU General Public License in all respects for all other 

  * code used. Additionally, AlliedModders LLC grants this exception 

  * to all derivative works. AlliedModders LLC defines further 

  * exceptions, found in LICENSE.txt (as of this writing, version 

  * JULY-31-2007), or <http://www.sourcemod.net/license.php>.

  *

  * Version: $Id$

  */

 #include <stdio.h>

 #include <ctype.h>

 #include <wctype.h>

 #include <string.h>

 #include <stdlib.h>

 #include <assert.h>

 #include "TextParsers.h"

 #include "ShareSys.h"

 TextParsers g_TextParser;

 static int g_ini_chartable1[255] = {0};

 static int g_ws_chartable[255] = {0};

 bool IsWhitespace(const char *stream)

 {

 	return g_ws_chartable[(unsigned)*stream] == 1;

 }

 TextParsers::TextParsers()

 {

 	g_ini_chartable1[(unsigned)'_'] = 1;

 	g_ini_chartable1[(unsigned)'-'] = 1;

 	g_ini_chartable1[(unsigned)','] = 1;

 	g_ini_chartable1[(unsigned)'+'] = 1;

 	g_ini_chartable1[(unsigned)'.'] = 1;

 	g_ini_chartable1[(unsigned)'$'] = 1;

 	g_ini_chartable1[(unsigned)'?'] = 1;

 	g_ini_chartable1[(unsigned)'/'] = 1;

 	g_ws_chartable[(unsigned)'\n'] = 1;

 	g_ws_chartable[(unsigned)'\v'] = 1;

 	g_ws_chartable[(unsigned)'\r'] = 1;

 	g_ws_chartable[(unsigned)'\t'] = 1;

 	g_ws_chartable[(unsigned)'\f'] = 1;

 	g_ws_chartable[(unsigned)' '] = 1;

 }

 void TextParsers::OnSourceModAllInitialized()

 {

 	g_ShareSys.AddInterface(NULL, this);

 }

 unsigned int TextParsers::GetUTF8CharBytes(const char *stream)

 {

 	return _GetUTF8CharBytes(stream);

 }

 /**

  * Character streams

  */

 struct CharStream

 {

 	const char *curpos;

 };

 bool CharStreamReader(void *stream, char *buffer, size_t maxlength, unsigned int *read)

 {

 	CharStream *srdr = (CharStream *)stream;

 	const char *ptr = srdr->curpos;

 	for (size_t i=0; i<maxlength; i++)

 	{

 		if (*ptr == '\0')

 		{

 			break;

 		}

 		*buffer++ = *ptr++;

 	}

 	*read = ptr - srdr->curpos;

 	srdr->curpos = ptr;

 	return true;

 }

 SMCParseError TextParsers::ParseString_SMC(const char *stream, 

 					 ITextListener_SMC *smc,

 					 unsigned int *line,

 					 unsigned int *col)

 {

 	CharStream srdr = { stream };

 	return ParseStream_SMC(&srdr, CharStreamReader, smc, line, col);

 }

 /**

  * File streams

  */

 bool FileStreamReader(void *stream, char *buffer, size_t maxlength, unsigned int *read)

 {

 	size_t num = fread(buffer, 1, maxlength, (FILE *)stream);

 	*read = static_cast<unsigned int>(num);

 	if (num == 0 && feof((FILE *)stream))

 	{

 		return true;

 	}

 	return (ferror((FILE *)stream) == 0);

 }

 SMCParseError TextParsers::ParseFile_SMC(const char *file, ITextListener_SMC *smc, unsigned int *line, unsigned int *col)

 {

 	FILE *fp = fopen(file, "rt");

 	if (!fp)

 	{

 		return SMCParse_StreamOpen;

 	}

 	SMCParseError result = ParseStream_SMC(fp, FileStreamReader, smc, line, col);

 	fclose(fp);

 	return result;

 }

 /** 

  * Raw parsing of streams with helper functions

  */

 struct StringInfo

 {

 	StringInfo() : quoted(false), ptr(NULL), end(NULL), special(false) { }

 	bool quoted;

 	char *ptr;

 	char *end;

 	bool special;

 };

 const char *FixupString(StringInfo &data)

 {

 	if (!data.ptr)

 	{

 		return NULL;

 	}

 	if (data.quoted)

 	{

 		data.ptr++;

 	}

 #if defined _DEBUG

 	else {

 		/* A string will never have beginning whitespace because we ignore it in the stream.

 		 * Furthermore, if there is trailing whitespace, the end ptr will point to it, so it is valid

 		 * to overwrite!  Lastly, the last character must be whitespace or a comment/invalid character.

 		 */

  	}

 #endif

 	/* Do some extra work on strings that have special quoted characters. */

 	if (data.special)

 	{

 		char *outptr = data.ptr;

 		size_t len = data.end - data.ptr;

 		if (len >= 2)

 		{

 			for (size_t i=0; i<len; i++)

 			{

 				if (data.ptr[i] == '\\' && i < len - 1)

 				{

 					/* Resolve the next character. */

 					i++;

 					if (data.ptr[i] == 'n')

 					{

 						data.ptr[i] = '\n';

 					} else if (data.ptr[i] == 't') {

 						data.ptr[i] = '\t';

 					} else if (data.ptr[i] == 'r') {

 						data.ptr[i] = '\r';

 					} else if (data.ptr[i] != '\\'

 						&& data.ptr[i] != '"') {

 						/* This character is invalid, so go back one */

 						i--;

 					}

 				}

 				*outptr++ = data.ptr[i];

 			}

 			*outptr = '\0';

 		}

 	}

 	*(data.end) = '\0';

 	return data.ptr;

 }

 const char *rotate(StringInfo info[3])

 {

 	if (info[2].ptr != NULL)

 	{

 		return info[2].ptr;

 	}

 	if (info[0].ptr != NULL)

 	{

 		info[2] = info[1];

 		info[1] = info[0];

 		info[0] = StringInfo();

 	}

 	return NULL;

 }

 void scrap(StringInfo info[3])

 {

 	info[2] = StringInfo();

 	info[1] = StringInfo();

 	info[0] = StringInfo();

 }

 void reloc(StringInfo &data, unsigned int bytes)

 {

 	if (data.ptr)

 	{

 		data.ptr -= bytes;

 	}

 	if (data.end)

 	{

 		data.end -= bytes;

 	}

 }

 char *lowstring(StringInfo info[3])

 {

 	for (int i=2; i>=0; i--)

 	{

 		if (info[i].ptr)

 		{

 			return info[i].ptr;

 		}

 	}

 	return NULL;

 }

 SMCParseError TextParsers::ParseStream_SMC(void *stream, 

 								   STREAMREADER srdr, 

 								   ITextListener_SMC *smc, 

 								   unsigned int *line, 

 								   unsigned int *col)

 {

 	char in_buf[4096];

 	char *reparse_point = NULL;

 	char *parse_point = in_buf;

 	char *line_begin = in_buf;

 	unsigned int read;

 	unsigned int curline = 1;

 	unsigned int curtok = 0;

 	unsigned int curlevel = 0;

 	bool in_quote = false;

 	bool ignoring = false;

 	bool eol_comment = false;

 	bool ml_comment = false;

 	unsigned int i;

 	SMCParseError err = SMCParse_Okay;

 	SMCParseResult res;

 	char c;

 	StringInfo strings[3];

 	StringInfo emptystring;

 	smc->ReadSMC_ParseStart();

 	while (srdr(stream, parse_point, sizeof(in_buf) - (parse_point - line_begin) - 1, &read))

 	{

 		if (!read)

 		{

 			break;

 		}

 		/* :TODO: do this outside of the main loop somehow

 		 * This checks for BOM markings

 		 */

 		if (curline == 1 && 

 			in_buf[0] == (char)0xEF && 

 			in_buf[1] == (char)0xBB && 

 			in_buf[2] == (char)0xBF)

 		{

 			/* Move EVERYTHING down :\ */

 			memmove(in_buf, &in_buf[3], read - 3);

 			read -= 3;

 		}

 		if (reparse_point)

 		{

 			read += (parse_point - reparse_point);

 			parse_point = reparse_point;

 			reparse_point = NULL;

 		}

 		for (i=0; i<read; i++)

 		{

 			c = parse_point[i];

 			if (c == '\n')

 			{

 				/* If we got a newline, there's a lot of things that could have happened in the interim.

 				 * First, let's make sure the staged strings are rotated.

 				 */

 				if (strings[0].ptr)

 				{

 					strings[0].end = &parse_point[i];

 					if (rotate(strings) != NULL)

 					{

 						err = SMCParse_InvalidTokens;

 						goto failed;

 					}

 				}

 				/* Next, let's clear some line-based values that may no longer have meaning */

 				eol_comment = false;

 				in_quote = false;

 				if (ignoring && !ml_comment)

 				{

 					ignoring = false;

 				}

 				/* Pass the raw line onto the listener */

 				if ((res=smc->ReadSMC_RawLine(line_begin, curline)) != SMCParse_Continue)

 				{

 					err = (res == SMCParse_HaltFail) ? SMCParse_Custom : SMCParse_Okay;

 					goto failed;

 				}

 				/* Now we check the sanity of our staged strings! */

 				if (strings[2].ptr)

 				{

 					if (!curlevel)

 					{

 						err = SMCParse_InvalidProperty1;

 						goto failed;

 					}

 					/* Assume the next string is a property and pass the info on. */

 					if ((res=smc->ReadSMC_KeyValue(

 						FixupString(strings[2]),

 						FixupString(strings[1]),

 						strings[2].quoted,

 						strings[1].quoted)) != SMCParse_Continue)

 					{

 						err = (res == SMCParse_HaltFail) ? SMCParse_Custom : SMCParse_Okay;

 						goto failed;

 					}

 					scrap(strings);

 				}

 				/* Change the states for the next line */

 				curtok = 0;

 				curline++;

 				line_begin = &parse_point[i+1];		//Note: safe because this gets relocated later

 			} else if (ignoring) {

 				if (in_quote)

 				{

 					/* If i was 0, this case is impossible due to reparsing */

 					if ((i != 0) && c == '"' && parse_point[i-1] != '\\')

 					{

 						/* If we reached a quote in an ignore phase,

 						 * we're staging a string and we must rotate it out.

 						 */

 						in_quote = false;

 						ignoring = false;

 						/* Set our info */

 						strings[0].end = &parse_point[i];

 						strings[0].quoted = true;

 						if (rotate(strings) != NULL)

 						{

 							/* If we rotated too many strings, there was too much crap on one line */

 							err = SMCParse_InvalidTokens;

 							goto failed;

 						}

 					} else if (c == '\\') {

 						strings[0].special = true;

 						if (i == (read - 1))

 						{

 							reparse_point = &parse_point[i];

 							break;

 						}

 					}

 				} else if (ml_comment) {

 					if (c == '*')

 					{

 						/* Check if we need to get more input first */

 						if (i == read - 1)

 						{

 							reparse_point = &parse_point[i];

 							break;

 						}

 						if (parse_point[i+1] == '/')

 						{

 							ml_comment = false;

 							ignoring = false;

 							/* We should not be staging anything right now. */

 							assert(strings[0].ptr == NULL);

 							/* Advance the input stream so we don't choke on this token */

 							i++;

 							curtok++;

 						}

 					}

 				}

 			} else {

 				/* Check if we're whitespace or not */

 				if (!g_ws_chartable[(unsigned)c])

 				{

 					bool restage = false;

 					/* Check various special tokens:

 					 * ;

 					 * //

 					 * / *

 					 * {

 					 * }

 					 */

 					if (c == ';' || c == '/')

 					{

 						/* If it's a line-based comment (that is, ; or //)

 						 * we will need to scrap everything until the end of the line.

 						 */

 						if (c == '/')

 						{

 							if (i == read - 1)

 							{

 								/* If we reached the end of the look-ahead, we need to re-check our input.

 								 * Breaking out will force this to be the new reparse point!

 								 */

 								reparse_point = &parse_point[i];

 								break;

 							}

 							if (parse_point[i + 1] == '/')

 							{

 								/* standard comment */

 								ignoring = true;

 								eol_comment = true;

 								restage = true;

 							} else if (parse_point[i+1] == '*') {

 								/* inline comment - start ignoring */

 								ignoring = true;

 								ml_comment = true;

 								/* yes, we restage, meaning that:

 								 * STR/ *stuff* /ING  (space because ml comments don't nest in C++)

 								 * will not generate 'STRING', but rather 'STR' and 'ING'.

 								 * This should be a rare occurrence and is done here for convenience.

 								 */

 								restage = true;

 							}

 						} else {

 							ignoring = true;

 							eol_comment = true;

 							restage = true;

 						}

 					} else if (c == '{') {

 						/* If we are staging a string, we must rotate here */

 						if (strings[0].ptr)

 						{

 							/* We have unacceptable tokens on this line */

 							if (rotate(strings) != NULL)

 							{

 								err = SMCParse_InvalidSection1;

 								goto failed;

 							}

 						}

 						/* Sections must always be alone */

 						if (strings[2].ptr != NULL)

 						{

 							err = SMCParse_InvalidSection1;

 							goto failed;

 						} else if (strings[1].ptr == NULL) {

 							err = SMCParse_InvalidSection2;

 							goto failed;

 						}

 						if ((res=smc->ReadSMC_NewSection(FixupString(strings[1]), strings[1].quoted))

 							!= SMCParse_Continue)

 						{

 							err = (res == SMCParse_HaltFail) ? SMCParse_Custom : SMCParse_Okay;

 							goto failed;

 						}

 						strings[1] = emptystring;

 						curlevel++;

 					} else if (c == '}') {

 						/* Unlike our matching friend, this can be on the same line as something prior */

 						if (rotate(strings) != NULL)

 						{

 							err = SMCParse_InvalidSection3;

 							goto failed;

 						}

 						if (strings[2].ptr)

 						{

 							if (!curlevel)

 							{

 								err = SMCParse_InvalidProperty1;

 								goto failed;

 							}

 							if ((res=smc->ReadSMC_KeyValue(

 											FixupString(strings[2]),

 											FixupString(strings[1]),

 											strings[2].quoted,

 											strings[1].quoted))

 								!= SMCParse_Continue)

 							{

 								err = (res == SMCParse_HaltFail) ? SMCParse_Custom : SMCParse_Okay;

 								goto failed;

 							}

 						} else if (strings[1].ptr) {

 							err = SMCParse_InvalidSection3;

 							goto failed;

 						} else if (!curlevel) {

 							err = SMCParse_InvalidSection4;

 							goto failed;

 						}

 						/* Now it's safe to leave the section */

 						scrap(strings);

 						if ((res=smc->ReadSMC_LeavingSection()) != SMCParse_Continue)

 						{

 							err = (res == SMCParse_HaltFail) ? SMCParse_Custom : SMCParse_Okay;

 							goto failed;

 						}

 						curlevel--;

 					} else if (c == '"') {

 						/* If we get a quote mark, we always restage, but we need to do it beforehand */

 						if (strings[0].ptr)

 						{

 							strings[0].end = &parse_point[i];

 							if (rotate(strings) != NULL)

 							{

 								err = SMCParse_InvalidTokens;

 								goto failed;

 							}

 						}

 						strings[0].ptr = &parse_point[i];

 						in_quote = true;

 						ignoring = true;

 					} else if (!strings[0].ptr) {

 						/* If we have no string, we must start one */

 						strings[0].ptr = &parse_point[i];

 					}

 					if (restage && strings[0].ptr)

 					{

 						strings[0].end = &parse_point[i];

 						if (rotate(strings) != NULL)

 						{

 							err = SMCParse_InvalidTokens;

 							goto failed;

 						}

 					}

 				} else {

 					/* If we're eating a string and get whitespace, we need to restage.

 					 * (Note that if we are quoted, this is being ignored)

 					 */

 					if (strings[0].ptr)

 					{

 						/*

 						 * The specification says the second string in a pair does not need to be quoted.

 						 * Thus, we check if there's already a string on the stack.

 						 * If there's a newline, we always rotate so the newline has an empty starter.

 						 */

 						if (!strings[1].ptr)

 						{

 							/* There's no string, so we must move this one down and eat up another */

 							strings[0].end = &parse_point[i];

 							rotate(strings);

 						} else if (!strings[1].quoted) {

 							err = SMCParse_InvalidTokens;

 							goto failed;

 						}

 					}

 				}

 			}

 			/* Advance which token we're on */

 			curtok++;

 		}

 		if (line_begin != in_buf)

 		{

 			/* The line buffer has advanced, so it's safe to copy N bytes back to the beginning.

 			 * What's N?  N is the lowest point we're currently relying on.

 			 */

 			char *stage = lowstring(strings);

 			if (!stage || stage > line_begin)

 			{

 				stage = line_begin;

 			}

 			unsigned int bytes = read - (stage - parse_point);

 			/* It is now safe to delete everything before the staged point */

 			memmove(in_buf, stage, bytes);

 			/* Calculate the number of bytes in the new buffer */

 			bytes = stage - in_buf;

 			/* Relocate all the cached pointers to our new base */

 			line_begin -= bytes;

 			reloc(strings[0], bytes);

 			reloc(strings[1], bytes);

 			reloc(strings[2], bytes);

 			if (reparse_point)

 			{

 				reparse_point -= bytes;

 			}

 			if (parse_point)

 			{

 				parse_point = &parse_point[read];

 				parse_point -= bytes;

 			}

 		} else if (read == sizeof(in_buf) - 1) {

 			err = SMCParse_TokenOverflow;

 			goto failed;

 		}

 	}

 	/* If we're done parsing and there are tokens left over... */

 	if (curlevel)

 	{

 		err = SMCParse_InvalidSection5;

 		goto failed;

 	} else if (strings[0].ptr || strings[1].ptr) {

 		err = SMCParse_InvalidTokens;

 		goto failed;

 	}

 	smc->ReadSMC_ParseEnd(false, false);

 	return SMCParse_Okay;

 failed:

 	if (line)

 	{

 		*line = curline;

 	}

 	smc->ReadSMC_ParseEnd(true, (err == SMCParse_Custom));

 	if (col)

 	{

 		*col = curtok;

 	}

 	return err;

 }

 /**

  * INI parser 

  */

 bool TextParsers::ParseFile_INI(const char *file, ITextListener_INI *ini_listener, unsigned int *line, unsigned int *col)

 {

 	FILE *fp = fopen(file, "rt");

 	unsigned int curline = 0;

 	unsigned int curtok;

 	size_t len;

 	if (!fp)

 	{

 		if (line)

 		{

 			*line = 0;

 		}

 		return false;

 	}

 	char buffer[2048];

 	char *ptr, *save_ptr;

 	bool in_quote;

 	while (!feof(fp))

 	{

 		curline++;

 		curtok = 0;

 		buffer[0] = '\0';

 		if (fgets(buffer, sizeof(buffer), fp) == NULL)

 		{

 			break;

 		}

 		//:TODO: this will only run once, so find a nice way to move it out of the while loop

 		/* If this is the first line, check the first three bytes for BOM */

 		if (curline == 1 && 

 			buffer[0] == (char)0xEF && 

 			buffer[1] == (char)0xBB && 

 			buffer[2] == (char)0xBF)

 		{

 			/* We have a UTF-8 marked file... skip these bytes */

 			ptr = &buffer[3];

 		} else {

 			ptr = buffer;

 		}

 		/***************************************************

 		 * We preprocess the string before parsing tokens! *

 		 ***************************************************/

 		/* First strip beginning whitespace */

 		while (*ptr != '\0' && g_ws_chartable[(unsigned)*ptr] != 0)

 		{

 			ptr++;

 		}

 		len = strlen(ptr);

 		if (!len)

 		{

 			continue;

 		}

 		/* Now search for comment characters */

 		in_quote = false;

 		save_ptr = ptr;

 		for (size_t i=0; i<len; i++,ptr++)

 		{

 			if (!in_quote)

 			{

 				switch (*ptr)

 				{

 				case '"':

 					{

 						in_quote = true;

 						break;

 					}

 				case ';':

 					{

 						/* Stop the loop */

 						len = i;

 						/* Terminate the string here */

 						*ptr = '\0';

 						break;

 					}

 				}

 			} else {

 				if (*ptr == '"')

 				{

 					in_quote = false;

 				}

 			}

 		}

 		if (!len)

 		{

 			continue;

 		}

 		ptr = save_ptr;

 		/* Lastly, strip ending whitespace off */

 		for (size_t i=len-1; i>=0 && i<len; i--)

 		{

 			if (g_ws_chartable[(unsigned)ptr[i]])

 			{

 				ptr[i] = '\0';

 				len--;

 			} else {

 				break;

 			}

 		}

 		if (!len)

 		{

 			continue;

 		}

 		if (!ini_listener->ReadINI_RawLine(ptr, &curtok))

 		{

 			goto event_failed;

 		}

 		if (*ptr == '[')

 		{

 			bool invalid_tokens = false;

 			bool got_bracket = false;

 			bool extra_tokens = false;

 			char c;

 			bool alnum;

 			wchar_t wc;

 			for (size_t i=1; i<len; i++)

 			{

 				c = ptr[i];

 				alnum = false;

 				if (c & (1<<7))

 				{

 					if (mbtowc(&wc, &ptr[i], len-i) != -1)

 					{

 						alnum = (iswalnum(wc) != 0);

 						i += _GetUTF8CharBytes(&ptr[i]) - 1;

 					}

 				} else {

 					alnum = (isalnum(c) != 0) || (g_ini_chartable1[(unsigned)c] != 0);

 				}

 				if (!alnum)

 				{

 					/* First check - is this a bracket? */

 					if (c == ']')

 					{

 						/* Yes! */

 						got_bracket = true;

 						/* If this isn't the last character... */

 						if (i != len - 1)

 						{

 							extra_tokens = true;

 						}

 						/* terminate */

 						ptr[i] = '\0';

 						break;

 					} else {

 						/* n...No! Continue copying. */

 						invalid_tokens = true;

 					}

 				}

 			}

 			/* Tell the handler */

 			if (!ini_listener->ReadINI_NewSection(&ptr[1], invalid_tokens, got_bracket, extra_tokens, &curtok))

 			{

 				goto event_failed;

 			}

 		} else {

 			char *key_ptr = ptr;

 			char *val_ptr = NULL;

 			char c;

 			size_t first_space = 0;

 			bool invalid_tokens = false;

 			bool equal_token = false;

 			bool quotes = false;

 			bool alnum;

 			wchar_t wc;

 			for (size_t i=0; i<len; i++)

 			{

 				c = ptr[i];

 				alnum = false;

 				/* is this an invalid char? */

 				if (c & (1<<7))

 				{

 					if (mbtowc(&wc, &ptr[i], len-i) != -1)

 					{

 						alnum = (iswalnum(wc) != 0);

 						i += _GetUTF8CharBytes(&ptr[i]) - 1;

 					}

 				} else {

 					alnum = (isalnum(c) != 0) || (g_ini_chartable1[(unsigned)c] != 0);

 				}

 				if (!alnum)

 				{

 					if (g_ws_chartable[(unsigned)c])

 					{

 						/* if it's a space, keep track of the first occurring space */

 						if (!first_space)

 						{

 							first_space = i;

 						}

 					} else {

 						if (c == '=')

 						{

 							/* if it's an equal sign, we're done with the key */

 							if (first_space)

 							{

 								/* remove excess whitespace */

 								key_ptr[first_space] = '\0';

 							} else {

 								/* remove the equal sign */

 								key_ptr[i] = '\0';

 							}

 							if (ptr[++i] != '\0')

 							{

 								/* If this isn't the end, set next pointer */

 								val_ptr = &ptr[i];

 							}

 							equal_token = true;

 							break;

 						} else {

 							/* Mark that we got something invalid! */

 							invalid_tokens = true;

 							first_space = 0;

 						}

 					}

 				}

 			}

 			/* Now we need to parse the value, if any */

 			if (val_ptr)

 			{

 				/* eat up spaces! there shouldn't be any h*/