// Keyword Interpreter Code Generator
//
// by Nikolai Golovchenko March 31, 2000 - April 2, 2000;
// April 21, 2000 - added to form list of whitespaces and delimiters
//					and more comments
// http://techref.massmind.org/member/NG--944
// golovchenko@mail.ru
//
// 10-July
//     Banner removed
//     Added command line support
//     Broke source in several files by classes for easier maintainability
// 11-July
//     Fixed bug when called without query string
//     from MS IIS 4.0 server
// 14-July
//   1) Embedded the minimal form in code to display it if the external page doesn't exist
//	  2) Implemented shared access to the log file

#include <stdio.h>
#include <io.h>
#include <share.h>
#include <string.h>
#include <time.h>
#include <ctype.h>

extern "C"
{
	#include <cgi-lib.h>
	#include <html-lib.h>
	char** CommandLineArguments;
}

#include "listnode.h"
#include "listtree.h"
#include "form.h"

#include "keyword.h"
#include "keyword.inc"

bool isCGI;


bool Insense = false;
bool Whole = false;	//options
TextFormEntry Whitespaces; //lists of characters from form
TextFormEntry Delimiters; //lists of characters from form

int
main(int argc, char *argv[], char **envp)
{
	llist entries = {NULL}; //clear list
	char Text[TextSize];		//list of keywords
	int Error = 0;

	//make pointer to command line global
	CommandLineArguments = argv;

	/********* DEBUG *****************
	_putenv("SERVER_SOFTWARE=Microsoft-IIS/4.0");
	_putenv("SERVER_NAME=www.piclist.com");
	_putenv("GATEWAY_INTERFACE=CGI/1.1");
	_putenv("SERVER_PROTOCOL=HTTP/1.1");
	_putenv("SERVER_PORT=80");
	_putenv("REQUEST_METHOD=GET");
	_putenv("PATH_TRANSLATED=C:\\Inetpub\\wwwroot");
	_putenv("SCRIPT_NAME=/cgi-bin/test.exe");
	_putenv("REMOTE_HOST=204.210.50.240");
	_putenv("REMOTE_ADDR=204.210.50.240");
	_putenv("CONTENT_LENGTH=0");
	***********************************/

	//what kind of request
	isCGI = getenv("REQUEST_METHOD") != NULL;

	/* Read form values */ 
	read_cgi_input(&entries);

	if(isCGI)
	{
		//log request if this routine is called from server
		logRequest();
		//check if form is empty
		if( !is_field_exists(entries, "Keywords") 
		|| !is_field_exists(entries, "Whitespaces") 
		|| !is_field_exists(entries, "Delimiters") )
		{
			//CGI form should have query string and these fields
			helpScreen();
			list_clear(&entries);
			exit(0);
		}
		//Generate header and title
		html_header();
		html_begin("Code Generator Results");
	}
	else if(argc == 1 || !is_field_exists(entries, "Keywords"))
	{
		//command line mode and no required parameters
		helpScreen();
		list_clear(&entries);
		exit(0);
	}

	if(is_field_exists(entries, "Keywords"))
	{
		char *x;
		int len;
		x = cgi_val(entries, "Keywords");
		len = strlen(x);
			
		if(len == 0)
		{
			Error = 1;
		}
		else
		{
			if(len <= TextSize)
			{
				strcpy(Text, x);
			}
			else
			{
				Error = 2;
			}
		}
	}
	if(is_field_exists(entries, "CaseInsensitive"))
	{
		if(_stricmp(cgi_val(entries, "CaseInsensitive"), "yes") == 0)
		{
			Insense = true;
		}
	}
	if(is_field_exists(entries, "Whole"))
	{
		if(_stricmp(cgi_val(entries, "Whole"), "yes") == 0)
		{
			Whole = true;
		}
	}
	if(is_field_exists(entries, "Whitespaces"))
	{
		strcpy(Whitespaces.text, cgi_val(entries, "Whitespaces"));
		Whitespaces.ParseCharsList();
	}
	if(is_field_exists(entries, "Delimiters"))
	{
		strcpy(Delimiters.text, cgi_val(entries, "Delimiters"));
		Delimiters.ParseCharsList();
	}
	if(Error == 0)
	{
		/* Open preformatted block */ 
		if(isCGI)
		{
			printf("<PRE>\n");
		}
		/* Call code generation */
		Error = generate(Text, Insense, Whole);
		/* Close preformatted block */
		if(!Error)
		{
			if(isCGI)
			{
				printf("</PRE>\n");
				TimeStamp();
				Banner();
			}
		}
		else
		{
			ReportError(Error);
		}
	}
	else
	{
		/* Report error */
		ReportError(Error);
	}
	
	if(isCGI)
	{
		html_end();
	}
	list_clear(&entries);
	return 0;
}

void
ReportError(char Err)
{
	if(isCGI)
	{
		printf("<H2>");
	}
	printf("Error %d: ", Err);
	switch(Err)
	{
	case 1:
		printf("Text area empty\n");
		break;
	case 2:
		printf("Text area size exceeded %d characters\n", TextSize);
		break;
	case 3:
		printf("No keywords\n");
		break;
	case 4:
		printf("Too much states to fit in an 8bit variable\n");
		break;
	case 5:
		printf("Two keywords with the same name detected\n");
		break;
	default:
		break;
	}
	if(isCGI)
	{
		printf("</H2>");
	}
	printf("\n");
}

void
logRequest()
{
	FILE* log = NULL;
	time_t ltime;
	time_t final;
	time_t nowTime;
   struct tm* now;
	char* buf;
	char* query;

	time(&final);
	nowTime = ltime = final;
	final += 3; //3 seconds for retries
	while(log == NULL && nowTime < final)
	{
		if(ltime == nowTime)
		{
			ltime++;
			log = _fsopen( "keyword_log.csv", "a", _SH_DENYWR);	//create or open file in append mode
			//writing is disabled for other processes
		}
		time(&nowTime);
	}

	if(log != NULL)
	{
		//file opened ok

		//if file is empty, create header
		if(_filelength(_fileno(log)) == 0)
		{
			fprintf(log, "Date,Time,Address,Client,Method,Query\n");
		}

		//Date and time
		time(&ltime);
		now = localtime(&ltime);
		fprintf(log,
			"%d/%d/%d,",
			1900 + now->tm_year,
			now->tm_mon,
			now->tm_mday);
		fprintf(log,
			"%d:%d:%d,",
			now->tm_hour,
			now->tm_min,
			now->tm_sec);

		//Address,Client,Method
		logPrint(log, "REMOTE_ADDR");
		logPrint(log, "HTTP_USER_AGENT");
		logPrint(log, "REQUEST_METHOD");

		//Query
		query = getenv("QUERY_STRING");
		if(query != NULL)
		{
			buf = new char[strlen(query) + 1];
			strcpy(buf, query);
			//unescape_url(buf);	//remove escape sequencies
			fprintf(log, "%s", buf); //without comma at the end of line
			delete(buf);
		}

		fprintf(log, "\n");
		fclose(log);
	}
}

//print env variable if not empty
void
logPrint(FILE* log, char* envName)
{
	char *var; 
	
	var = getenv(envName);
	if(var != NULL)
	{
		fprintf(log, "%s", var); 
	}
	fprintf(log, ","); //comma separation
}

void
TimeStamp()
{
	time_t ltime;
    struct tm *gmt;
    
	/* Display UTC. */
	time(&ltime);
	gmt = gmtime(&ltime);
   printf("; Generated by <A HREF=\"/cgi-bin/keyword.exe\">www.piclist.com/cgi-bin/keyword.exe</A> (%s version)<BR>\n", VERSIONDATE);
	printf("; %s GMT<BR>\n", asctime(gmt));
}

void Banner()
{
#ifdef SHOW_BANNER
	printf("<TABLE ALIGN=\"CENTER\"  BORDER=\"1\"  CELLPADDING=\"8\">\n");
	printf("	<TR>\n");
	printf("		<TD WIDTH=90%s BGCOLOR=\"#FFFF00\" >\n", "%");
	printf("		<FONT COLOR=\"#000080\"><CENTER>\n");
	printf("I hope my little code generator helps you. Would you like to help \n");
	printf("me find a job in the U.S.?<BR>\n");
	printf("<A HREF=\"http://techref.massmind.org/member/NG--944\">Nikolai Golovchenko</A>\n");
	printf("		</CENTER></FONT></TD>\n");
	printf("	</TR>\n");
	printf("</TABLE>\n");
#endif
}

void
helpScreen()
{
	FILE* form;
	char ch;

	if(isCGI)
	{
		html_header();
		//try to open form
		form = fopen("keyword.htm", "r");
		if(form == NULL)
		{
			html_begin("Keyword Interpreter Code Generator");
			h1("Keyword Interpreter Code Generator");
			printf("<!-- Can't open \"keyword.htm\" -->\n");
			//print built-in form
			printf("<FORM action=\"/cgi-bin/keyword.exe\" method=\"GET\">\n");
			printf("<TABLE  border=\"2\" cellpadding=\"5\" bgcolor=\"#E0E0E0\">\n");
			printf("<TR><TD valign=\"TOP\"><H2>Keywords List</H2>\n");
			printf("<TEXTAREA name=\"Keywords\" rows=\"20\" cols=\"32\">send\n");
			printf("write\n");
			printf("read\n");
			printf("on\n");
			printf("off\n");
			printf("0\n");
			printf("1\n");
			printf("help\n");
			printf("test\n");
			printf("getEE\n");
			printf("putEE</TEXTAREA><BR>\n");
			printf("Whitespaces:<BR><INPUT type=\"text\" name=\"Whitespaces\" size=\"36\" maxlength=\"255\" value=\"' ', '\\t', 0x0D, 0x0A\"><BR>\n");
			printf("Delimeters:<BR><INPUT type=\"text\" name=\"Delimiters\" size=\"36\" maxlength=\"255\" value=\"' ', '\\t', 0x0D, 0x0A\"><BR>\n");
			printf("<input type=\"checkbox\" name=\"CaseInsensitive\" value=\"yes\">Case	insensitive<BR>\n");
			printf("<input type=\"checkbox\" name=\"Whole\" value=\"yes\">Whole words match<BR><BR><BR>\n");
			printf("<CENTER><INPUT type=\"submit\" value=\"Generate Now!\"></CENTER></TD></TR>\n");
			printf("</TABLE>	</FORM>\n");
			html_end();
		}
		else
		{
			//print external form
			while(!feof(form))
			{
				fread(&ch, 1, 1, form);
				putchar(ch);
			}
			fclose(form);
		}
	}
	else
	{
		printf("--------------------------------------------------------------------\n");
		printf("KEYWORD INTERPRETER CODE GENERATION IN PIC ASSEMBLY\n");
		printf("http://www.piclist.com/codegen/\n");
		printf("--------------------------------------------------------------------\n");
		printf("Command line: keyword.exe {option=value} {> OutputFile}\n");
		printf("Options:\n\tKeywords - list of space separated keywords\n");
		printf("\tCaseInsensitive - yes/no (default: no)\n");
		printf("\tWhole - whole words match, yes/no (default: no)\n");
		printf("\tWhitespaces - characters that are ignored before a word (no default)\n");
		printf("\tDelimiters - characters indicating end of word  (no default)\n");
		printf("\nNote:\n");
		printf("  If a value contains spaces, insert quotes around the value,\n  e.g. Keywords=\"send write read\"\n");
		printf("\nExample:\n");
		printf("  keyword.exe keywords=\"send write read\" whitespaces=\"' ', '\\t'\" delimiters=\"' ','\\t',0x0D,0x0A\" > result.asm\n");
	}
}

int
generate(char *Text, bool Insense, bool Whole)
{
	int Err, keycode;
	char code[MAXCODESIZE];
	listtree *parsetree;
	char *p;
	
	code[0] = 0;
	parsetree = new listtree(Insense, Whole);

	//convert to lowercase if caseinsensitive
	if(Insense)
	{
		p = Text;
		while(*p != '\0')
		{
			*p = tolower(*p);
			p++;
		}
	}
	//build the parser tree
	p = Text;
	while(*p != '\0')
	{
		//skip whitespace
		if(isspace(*p))
		{
			p++;
		}
		else
		{
			if(*p != '\0')
			{
				//start of a keyword
				p = parsetree->addkeyword(p);
				if(parsetree->Error)
				{
					return parsetree->Error;
				}
			}
		}
	}
	
	if(parsetree->keywords == 0)
	{
		Err = 3;	//error - no keywords
	}
	else
	{
		if((parsetree->keywords + parsetree->totalstates()) > 254)
		{
			Err = 4;	//error - too much states to fit in an 8bit variable
		}
		else
		{
			//print #define and cblock
			printf("#define parse_state_offset %#.2x\n\n", parsetree->keywords + 1);
			printf("\tcblock\n");
			printf("\tparse_state, parse_char\n");
			printf("\tendc\n");
			//generates keyword symbol table
			printf(";-------------- keywords list ---------------------\n");
			if(Insense)
			{
				printf("; Case Insensitive\n");
			}
			else
			{
				printf("; Case Sensitive\n");
			}
			if(Whole)
			{
				printf("; Whole words match\n");
			}
			else
			{
				printf("; Incomplete words match\n");
			}
			Whitespaces.printList();
			printf("; Whitespaces: %s\n", Whitespaces.textBuf);
			Delimiters.printList();
			printf("; Delimiters: %s\n", Delimiters.textBuf);

			printf(";\n; Keywords codes:\n");
			p = Text;
			keycode = 1;
			while(*p != '\0')
			{
				if(!isspace(*p))
				{
					printf("; %#.2x: ", keycode++);
					while((*p != '\0') && (!isspace(*p)))
					{
						printf("%.1s", p++);
					}
					printf("\n");
				}
				else
				{
					p++;
				}
			}
			printf("\n");
			//print file keywordasm1
			printf("%s", keywordasm1);
			if(Insense)
			{
				//if case insensitive, add conversion to lower case
				printf(";convert to lower case\n");
				printf("\taddlw\t-'A'\n");
				printf("\tsublw\t'Z' - 'A' + 1\n");
				printf("\tskpnc\n");
				printf("\t bsf parse_char, 5\n");
 				//print the rest of keyword.asm
			}
			//print whitespace skiping code
			if(Whitespaces.CharsList != NULL)
			{
				printf("\tmovfw parse_state       ;check if current state is zero\n");
				printf("\tskpz\n");
				printf("\t goto parse2\n");
				printf("\tmovfw parse_char        ;then skip whitespaces\n");
				Whitespaces.printfCode();
				printf("parse2\n");
			}
			//print file keywordasm2
			printf("%s", keywordasm2);
			//print delimiters skiping code
			printf("parse_state_delimiter\n");
			printf(";called from state table to check for end of name\n");
			printf("\tmovwf parse_state\n");
			if(Delimiters.CharsList != NULL)
			{
				printf("\tmovfw parse_char\n");
				Delimiters.printfCode();
				printf("\tretlw 0xFF\t\t;Not a delimiter - error\n");
			}
			else
			{
				printf("\tretlw 0\n");
			}

			//generate jumptable
			printf("\nparse_table_start\n");
			parsetree->jumptable(code); 
			printf(";---------------- jump table start ----------------\n");
			printf("%s", code);
			printf(";---------------- jump table end ------------------\n\n");
			//generate statetable
			code[0]='\0';
			parsetree->statetable(code);
			printf(";--------------- state table start ----------------\n");
			printf("%s", code);
			printf(";--------------- state table end ------------------\n\n");
			Err = 0;
		}
	}

	delete parsetree;
	return Err;
}