/*
 * Tiny Embedded JavaScript parser
 *
 * Copyright 2003, Broadcom Corporation
 * All Rights Reserved.                
 *                                     
 * This is UNPUBLISHED PROPRIETARY SOURCE CODE of Broadcom Corporation;   
 * the contents of this file may not be disclosed to third parties, copied
 * or duplicated in any form, in whole or in part, without the prior      
 * written permission of Broadcom Corporation.                            
 *
 * $Id: ej.c,v 1.2 2009/02/12 09:09:24 james26_jang Exp $
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>

#include <httpd.h>
#include "bcmnvram.h"


static char * get_arg(char *args, char **next);
static void call(char *func, FILE *stream);

/* Look for unquoted character within a string */
static char *
unqstrstr(char *haystack, char *needle)
{
	char *cur;
	int q;

	for (cur = haystack, q = 0;
	     cur < &haystack[strlen(haystack)] && !(!q && !strncmp(needle, cur, strlen(needle)));
	     cur++) {
		if (*cur == '"')
			q ? q-- : q++;
	}
	return (cur < &haystack[strlen(haystack)]) ? cur : NULL;
}

static char *
get_arg(char *args, char **next)
{
	char *arg, *end;

	/* Parse out arg, ... */
	if (!(end = unqstrstr(args, ","))) {
		end = args + strlen(args);
		*next = NULL;
	} else
		*next = end + 1;

	/* Skip whitespace and quotation marks on either end of arg */
	for (arg = args; isspace((int)*arg) || *arg == '"'; arg++);
	for (*end-- = '\0'; isspace((int)*end) || *end == '"'; end--)
		*end = '\0';

	return arg;
}

static void
call(char *func, FILE *stream)
{
	char *args, *end, *next;
	int argc;
	char * argv[16];
	struct ej_handler *handler;

	/* Parse out ( args ) */
	if (!(args = strchr(func, '(')))
		return;
	if (!(end = unqstrstr(func, ")")))
		return;
	*args++ = *end = '\0';

	/* Set up argv list */
	for (argc = 0; argc < 16 && args && *args; argc++, args = next) {
		if (!(argv[argc] = get_arg(args, &next)))
			break;
	}

	/* Call handler */
	for (handler = &ej_handlers[0]; handler->pattern; handler++) {
		if (strncmp(handler->pattern, func, strlen(handler->pattern)) == 0){
			handler->output(0, stream, argc, argv);
			
			return;
		}
	}
}

static const char *asp_mark1 = "<%", *asp_mark2 = "%>", *kw_mark1 = "<#", *kw_mark2 = "#>";

// Call this function if and only if we can read whole <%....%> pattern.
static char *
process_asp (char *s, char *e, FILE *f)
{
        char *func = NULL, *end = NULL;

        if (s == NULL || e == NULL || f == NULL || s >= e)      {
                return NULL;
        }

        for (func = s; func < e; func = end) {
                /* Skip initial whitespace */
                for (; isspace((int)*func); func++);
                if (!(end = unqstrstr(func, ";")))
                        break;
                *end++ = '\0';

                /* Call function */
                call(func, f);

                // skip asp_mark2
                end = e + strlen (asp_mark2);
                break;
        }

        return end;
}

#ifdef TRANSLATE_ON_FLY
// Call this function if and only if we can read whole <#....#> pattern.
static char *
translate_lang (char *s, char *e, FILE *f, kw_t *pkw)
{
        char *end = NULL, *name = NULL, *desc = NULL;

        if (s == NULL || e == NULL || f == NULL || pkw == NULL || s >= e)       {
                return NULL;
        }

        for (name = s; name < e; name = end) {
                /* Skip initial whitespace */
                for (; isspace((int)*name); name++);
                if (!(end = strstr(name, kw_mark2)))
                        break;
                *end++ = '=';           // '#' --> '=', search_desc() need '='
                *end++ = '\0';          // '>' --> '\0'

                desc = search_desc (pkw, name);
                if (desc != NULL)       {
                        fprintf (f, "%s", desc);
                }

                // skip kw_mark2
                end = e + strlen (kw_mark2);
                break;
        }

        return end;
}
#endif // TRANSLATE_ON_FLY

// This translation engine can not process <%...%> interlace with <#...#>
void
do_ej(char *path, FILE *stream)
{
#define PATTERN_LENGTH	1024
#define FRAG_SIZE	128
#define RESERVE_SIZE	4
        int frag_size = FRAG_SIZE;
        int pattern_size = PATTERN_LENGTH - RESERVE_SIZE;
        char pat_buf[PATTERN_LENGTH];
        char *pattern = pat_buf, *asp = NULL, *asp_end = NULL, *key = NULL, *key_end = NULL;
        char *start_pat, *end_pat, *lang;
        FILE *fp;
        int conn_break = 0;
        size_t ret, read_len, len;
#ifdef TRANSLATE_ON_FLY
        int no_translate = 1;
        static kw_t kw = {0, 0, NULL, NULL};
#endif // TRANSLATE_ON_FLY

        if (!(fp = fopen(path, "r")))
                return;

#ifdef TRANSLATE_ON_FLY
        // Load dictionary file

        // If the router is restored to default, using browser's language setting to display ALL pages
        if (is_firsttime () && Accept_Language[0] != '\0')      {
                lang = Accept_Language;
        } else {
                lang = nvram_safe_get ("preferred_lang");
        }

        if (load_dictionary (lang, &kw))        {
                no_translate = 0;
        }
#endif  //defined TRANSLATE_ON_FLY

        start_pat = end_pat = pattern;
        memset (pattern + pattern_size, 0, 4);
        while (conn_break == 0)
        {
                int special;

                // Arrange pattern[] if available buffer length (end_pat~pattern[pattern_size]) is smaller than frag_size
                if (((pattern + pattern_size) - end_pat) < frag_size)
                {
                        len = end_pat - start_pat;
                        memcpy (pattern, start_pat, len);
                        start_pat = pattern;
                        end_pat = start_pat + len;
                        *end_pat = '\0';
                }

                read_len = (pattern + pattern_size) - end_pat;
                len = fread (end_pat, 1, read_len, fp);
                if (len == 0)   {
                        if (start_pat < end_pat)        {
                                fwrite (start_pat, 1, (size_t) (end_pat - start_pat), stream);
                        }
                        break;
                }
                end_pat += len;
                *end_pat = '\0';


                asp = strstr (start_pat, asp_mark1);

                key = NULL;
#ifdef TRANSLATE_ON_FLY
                if (no_translate == 0)  {
                        key = strstr (start_pat, kw_mark1);
                }
#endif // TRANSLATE_ON_FLY
                special = 0;

                while ((start_pat < end_pat) && special == 0)
                {
                        int postproc = 0;       /* 0: need more data; 1: translate; 2: execute asp; 3: write only; */
                        char *s, *e, *p;

                        /*                                 asp      asp_end
                         *                                 ^        ^
                         *  +------------------------------<%.......%>-------------------------------+
                         *  |         XXXXXXXXXXXXXXXXXXXXX<#.......#>YYYYYYYYYYYYYYYYYY0            |0000
                         *  +------------------------------------------------------------------------+
                         *  ^         ^                    ^        ^ ^                 ^             ^
                         *  |         |                    |        | p                 |             |
                         *  pattern   start_pat,s          key,e(2) key_end             end_pat,e(1)  pattern + pattern_size
                         *                                     ^                                |
                         *                                     +--------------------------------+
                         *
                         */

                        // If <%...%> and <#...#> do not exist in pattern[], write whole pattern[].
                        s = start_pat;
                        e = end_pat;

#ifdef TRANSLATE_ON_FLY
                        if (key != NULL && asp == NULL) {
                                e = key;                                                // Write start_pat ~ (key - 1)
                                key_end = strstr (key, kw_mark2);
                                if (key_end != NULL)    {               // We do have <#...#> in pattern[].
                                        postproc = 1;
                                }
                        } else
#endif // TRANSLATE_ON_FLY
                        if (key != NULL && asp != NULL)  {
                                // We have <%...%> and <#...#> in pattern[], process first occurrence
                                if (asp < key)  {
                                        e = asp;                                        // Write start_pat ~ (asp - 1)
                                        asp_end = strstr (asp, asp_mark2);
                                        if (asp_end != NULL)    {       // We do have whole <%...%>.
                                                postproc = 2;
                                        }
                                }
#ifdef TRANSLATE_ON_FLY
                                else {
                                        e = key;                                        // Write start_pat ~ (key - 1)
                                        key_end = strstr (key, kw_mark2);
                                        if (key_end != NULL)    {       // We do have whole <#...#>.
                                                postproc = 1;
                                        }
                                }
#endif // TRANSLATE_ON_FLY
                        } else if (key == NULL && asp != NULL)  {
                                e = asp;                                                // Write start_pat ~ (asp - 1)
                                asp_end = strstr (asp, asp_mark2);
                                if (asp_end != NULL)    {               // We do have whole <%...%>.
                                        postproc = 2;
                                }
                        } else {
                                // Special case. If last character is '<'
                                // DO NOT write this character due to next one may be % or #.
                                if (*(e-1) == *asp_mark1 || *(e-1) == *kw_mark1)        {
                                        special = 1;
                                        e--;
                                }

                                postproc = 3;
                        }

                        // process text preceeding <# or <%
                        if (e > s)      {
                                ret = fwrite (s, 1, (size_t) (e - s), stream);
                                if (ret == 0 || ret < (e - s))  {
                                        /* the connection had been damaged. DO NOT process another data. */
                                        /* (reduce response time of httpd) */
//                                      cprintf ("fwrite() ret %d, s %p e %p len %d, break do_ej()'s while loop\n", ret, s, e, e-s);
                                        conn_break = 1;
                                        break;
                                } else {
                                        start_pat = e;
                                }
                        }
                        // post process
                        p = NULL;
#ifdef TRANSLATE_ON_FLY
                        if (postproc == 1) {                            // translate
                                p = translate_lang (key + strlen (kw_mark1), key_end, stream, &kw);
                                if (no_translate == 0 && p != NULL)     {
                                        key = strstr (p, kw_mark1);
                                }
                        } else
#endif // TRANSLATE_ON_FLY
                        if (postproc == 2)       {               // execute asp
                                p = process_asp (asp + strlen (asp_mark1), asp_end, stream);
                                if (p != NULL)  {
                                        asp = strstr (p, asp_mark1);
                                }
                        } else if (postproc == 3)       {               // no <%...%> or <#...#>
                                p = e;
                        } else if (postproc == 0)       {               // read more data
                                break;
                        }

                        if (p != NULL)  {
                                start_pat = p;
                        }

                }       /* while ((start_pat < end_pat) && special == 0) */
        }               /* while (conn_break == 0) */


        fflush (stream);
        fclose(fp);

        if (pattern != pat_buf) {
                free (pattern);
        }
}

int
ejArgs(int argc, char **argv, char *fmt, ...)
{
	va_list	ap;
	int arg;
	char *c;

	if (!argv)
		return 0;

	va_start(ap, fmt);
	for (arg = 0, c = fmt; c && *c && arg < argc;) {
		if (*c++ != '%')
			continue;
		switch (*c) {
		case 'd':
			*(va_arg(ap, int *)) = atoi(argv[arg]);
			break;
		case 's':
			*(va_arg(ap, char **)) = argv[arg];
			break;
		}
		arg++;
	}
	va_end(ap);

	return arg;
}