7 files changed, 134 insertions, 29 deletions

diff --git a/debian/changelog b/debian/changelog
index 4de38b7..14d93f6 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+sear.c (0.0.26-1) stable; urgency=low
+
+  * support for suggested queries and query redirects
+
+ -- Anton Luka Šijanec <anton@sijanec.eu>  Fri, 01 Jan 2024 16:42:42 +0100
+
 sear.c (0.0.25-1) stable; urgency=low
 
   * updated git hostname
diff --git a/src/api.c b/src/api.c
index a652e3a..b0ef96d 100644
--- a/src/api.c
+++ b/src/api.c
@@ -127,6 +127,7 @@ int sc_fix_url (char ** h) { /* fixes a (result) URL in-place (removes tracking
 enum sc_return sc_query_google (const char * s, /* breaking change: changed return type */
 		struct sc_cache * c,
 		struct sc_query * q,
+		char ** redirect, /* variable redirect will be set to a heap allocated string that must be freed by the caller if the upstream returned results for a different query. in that case the returned query object will be for a different search string! -- if NULL, request that upstream does not enable "results for" feature */
 		SC_OPT_TYPE opt) { /* check4cachedB4 */
 	/* query is in most cases NULL. then it will be allocated and put into sc_cache. otherwise response will be put into passed q. */
 	/* if query is not NULL, it MUST be initialized */
@@ -155,6 +156,9 @@ enum sc_return sc_query_google (const char * s, /* breaking change: changed retu
 	htmlDocPtr xmldoc = NULL;
 	char * txtdoc = NULL;
 	int qwasgiven = 0;
+	SC_LOG(SC_LOG_DEBUG, c, "%s called, redirect is %p", __func__, redirect);
+	if (redirect)
+		*redirect = NULL;
 	if (!s || !c) {
 		rs = SC_BADCALL;
 		goto rc;
@@ -166,7 +170,7 @@ enum sc_return sc_query_google (const char * s, /* breaking change: changed retu
 		qwasgiven++;
 	char * us = malloc(sizeof(char)*strlen(s)*3+1);
 	urlencode(us, s);
-	txtdoc = SC_CAPI(c, NULL, NULL, "http://wap.google.com/search?q=%s&num=100&ie=UTF-8%s", us, (opt&SC_OPT_IMAGE) ? "&tbm=isch" : "");
+	txtdoc = SC_CAPI(c, NULL, NULL, "http://wap.google.com/search?q=%s&num=100&ie=UTF-8%s%s", us, (opt&SC_OPT_IMAGE) ? "&tbm=isch" : "", redirect ? "" : "&nfpr=1");
 	// fprintf(stdout, "%s\n", txtdoc);
 	free(us);
 	if (!txtdoc) {
@@ -178,6 +182,7 @@ enum sc_return sc_query_google (const char * s, /* breaking change: changed retu
 		rs = SC_CAPTCHA;
 		goto rc;
 	}
+	char * resultsforclass = sc_find_class(txtdoc, "{color:#1967d2}");
 	if (opt & SC_OPT_IMAGE) {
 		imageclass = sc_find_class(txtdoc, "{font-family:Roboto,Helvetica,Arial,sans-serif}");
 		if (!imageclass) {
@@ -292,11 +297,42 @@ enum sc_return sc_query_google (const char * s, /* breaking change: changed retu
 			SC_CUE(c, c->queries_lock);
 		goto rc;
 	}
+	q->string = realloc(q->string, sl+1);
+	strcpy(q->string, s);
+	char * xpathsugg = NULL;
+	if (resultsforclass) {
+		xpathsugg = malloc(512+strlen(resultsforclass));
+		sprintf(xpathsugg, "//a[contains(@class, '%s')]", resultsforclass);
+		xmlNodePtr suggnode = nthNodeX(xmldoc, xpathsugg, 0);
+		if (suggnode && xmlHasProp(suggnode, BAD_CAST "href")) {
+			char * href = (char *) xmlGetProp(suggnode, BAD_CAST "href");
+			char * content = (char *) xmlNodeGetContent(suggnode);
+			if (href && strstr(href, "&spell=1&"))
+				strcpy((q->suggested = realloc(q->suggested, strlen(content)+1)), content);
+			xmlFree(href);
+			xmlFree(content);
+		} else {
+			free(q->suggested);
+			q->suggested = NULL;
+		}
+	} else {
+		free(q->suggested);
+		q->suggested = NULL;
+	}
+	xmlNodePtr first = nthNodeX(xmldoc, xpathsugg, 1);
+	if (redirect && xpathsugg && q->suggested && xmlHasProp(first, BAD_CAST "href")) {
+		char * href = (char *) xmlGetProp(first, BAD_CAST "href");
+		if (href && strstr(href, "&nfpr=1&")) {
+			*redirect = q->suggested;
+			q->suggested = NULL;
+			q->string = realloc(q->string, strlen(*redirect)+1);
+			strcpy(q->string, *redirect);
+		}
+		xmlFree(href);
+	}
 	q->cache = c;
 	q->lookup_time = time(NULL);
-	q->string = realloc(q->string, sl+1);
 	q->opt |= opt | SC_ENGINE_GOOGLE;
-	strcpy(q->string, s);
 	if (!qwasgiven) {
 		SC_CWLE(c, c->queries_lock);
 #ifdef SC_OLD_STORAGE
@@ -318,6 +354,8 @@ rc:
 	free(titleclass);
 	free(descclass);
 	free(imageclass);
+	free(resultsforclass);
 	free(xpath);
+	free(xpathsugg);
 	return rs;
 }
diff --git a/src/httpd.c b/src/httpd.c
index 0171a11..c200fc6 100644
--- a/src/httpd.c
+++ b/src/httpd.c
@@ -3,7 +3,7 @@ char * sc_https2http (char * i) {
 		memmove(i+4, i+5, strlen(i)-3);
 	return i;
 }
-char * sc_queryhtml (const struct sc_query * q, const char * add_form, size_t l) { /* remember to free returned string in the caller */ /* caller takes care of freeing */
+char * sc_queryhtml (const struct sc_query * q, const char * add_form, size_t l, const char * r) { /* remember to free returned string in the caller */ /* caller takes care of freeing */
 	size_t resultshtml_written = 0;
 	size_t resultshtml_sizeof = SC_ALLOC_CHUNK;
 	char * resultshtml = malloc(resultshtml_sizeof);
@@ -39,16 +39,48 @@ char * sc_queryhtml (const struct sc_query * q, const char * add_form, size_t l)
 		free(safebody);
 		free(safeurl);
 	}
-#define SC_HRS SC_I18N_NUMBER_OF_RESULTS ": %zu | " SC_I18N_QUERY_TIME ": %s"
 	char formatted_time[128];
 	struct tm tm;
 	localtime_r(&q->lookup_time, &tm);
 	strftime(formatted_time, 128, SC_I18N_DATETIME_FORMAT, &tm);
-	char queryinfo[256];
-	snprintf(queryinfo, 256, SC_HRS, q->results_length, formatted_time);
+	char * safesuggested = NULL;
+	if (q->suggested && strlen(q->suggested) < 4096) {
+		safesuggested = alloca(strlen(q->suggested)*3+256);
+		strcpy(safesuggested, "?q=");
+		urlencode(safesuggested+3, q->suggested);
+	}
+	if (!q->suggested && r && strlen(r) < 4096) {
+		safesuggested = alloca(strlen(r)*3+256);
+		strcpy(safesuggested, "?q=");
+		urlencode(safesuggested+3, r);
+	}
+	char * htmlsuggested = htmlspecialchars(q->suggested);
+	if (!htmlsuggested)
+		htmlsuggested = htmlspecialchars(r);
+	if (safesuggested) {
+		if (strstr(add_form, "name=h"))
+			strcat(safesuggested, "&h=h");
+		if (strstr(add_form, "name=l"))
+			sprintf(safesuggested+strlen(safesuggested), "&l=%d", atoi(strstr(add_form, "name=l")+8));
+		if (strstr(add_form, "name=h"))
+			strcat(safesuggested, "&h=h");
+		if (strstr(add_form, "name=e") || r)
+			strcat(safesuggested, "&e=e");
+	}
+	char * suggested = NULL;
+	if (htmlsuggested && safesuggested)
+		suggested = malloc(1+strlen(SC_I18N_DID_YOU_REALLY_MEAN)+strlen(SC_I18N_DID_YOU_MEAN)+strlen(safesuggested)+strlen(htmlsuggested));
+	if (suggested)
+		sprintf(suggested, "%s <a href='%s'>%s</a>", q->suggested ? SC_I18N_DID_YOU_MEAN : SC_I18N_DID_YOU_REALLY_MEAN, safesuggested, htmlsuggested);
+	char * queryinfo = malloc(256+strlen(suggested ? suggested : ""));
+	snprintf(queryinfo, 256, "%s%s" SC_I18N_NUMBER_OF_RESULTS ": %zu | " SC_I18N_QUERY_TIME ": %s"
+, suggested ? suggested : "", suggested ? " | " : "", q->results_length, formatted_time);
 	char * safequery = htmlspecialchars(q->string);
 	char * response = malloc(strlen((char *) sc_hp)+2*strlen(safequery)+strlen(queryinfo)+strlen(resultshtml)+strlen(add_form));
 	sprintf(response, (char *) sc_hp, safequery, safequery, add_form, queryinfo, resultshtml);
+	free(queryinfo);
+	free(suggested);
+	free(htmlsuggested);
 	free(safequery);
 	free(resultshtml);
 	return response;
@@ -130,6 +162,8 @@ enum MHD_Result sc_httpd (void * cls,
 	const char * l = MHD_lookup_connection_value(connection, MHD_GET_ARGUMENT_KIND, "l");
 	const char * h = MHD_lookup_connection_value(connection, MHD_GET_ARGUMENT_KIND, "h");
 	const char * f = MHD_lookup_connection_value(connection, MHD_GET_ARGUMENT_KIND, "f");
+	const char * e = MHD_lookup_connection_value(connection, MHD_GET_ARGUMENT_KIND, "e");
+	const char * r = MHD_lookup_connection_value(connection, MHD_GET_ARGUMENT_KIND, "r");
 	snprintf(add_form, 128, "%s%s%d%s", h ? "<input type=hidden name=h value=h />" : "",
 		l ? "<input type=hidden name=l value=" : "<!-- Odgovor na dokončno vprašanje o Življenju, Vesolju in sploh Vsem je ",
 		l ? atoi(l) : 42,
@@ -212,11 +246,29 @@ retry:
 					sc_https2http(LOCHORSE);
 				location = out;
 			} else
-				response = sc_queryhtml(q, add_form, atoi(l ? l : "0")); /* MHD_create_response_from_buffer will free response (; */
+				response = sc_queryhtml(q, add_form, atoi(l ? l : "0"), r); /* MHD_create_response_from_buffer will free response (; */
 			SC_CUE(c, c->queries_lock);
 		} else {
 			SC_CUE(c, c->queries_lock);
-			enum sc_return r = sc_query_google(query, c, NULL, opt);
+			char * redirect = NULL;
+			enum sc_return r = sc_query_google(query, c, NULL, e ? NULL : &redirect, opt);
+			if (redirect && strlen(query) < 4096 && strlen(redirect) < 4096) {
+				status_code = 307;
+				location = alloca(256+strlen(query)*3+strlen(redirect)*3);
+				sprintf(location, "?l=%d%s%s%s%s&q=", atoi(l ? l : ""), (opt & SC_OPT_IMAGE) ? "&i=i" : "", h ? "&h=h" : "", f ? "&f=f" : "", e ? "&e=e" : "");
+				urlencode(location+strlen(location), redirect);
+				free(redirect);
+				redirect = NULL;
+				strcat(location, "&r=");
+				urlencode(location+strlen(location), query);
+				content_type = "text/plain";
+				char * safeurl = htmlspecialchars(location);
+				free(response);
+				response = malloc(strlen(safeurl)*3+512);
+				sprintf(response, "<meta http-equiv=refresh content='0;URL=%s'><a id=a href='%s'>%s</a><script>a.click();</script>", safeurl, safeurl, safeurl);
+				free(safeurl);
+				goto sendresp;
+			}
 			if (already_retried++ || r == SC_CAPTCHA) {
 				status_code = 570+ABS(r);
 				if (r == SC_CAPTCHA && strlen(query) < 4096) {
@@ -224,15 +276,8 @@ retry:
 						status_code = 307;
 						location = alloca(strlen(getenv("SC_FALLBACK"))
 								+ 256 + strlen(query)*3);
-						sprintf(location, "%sl=%d&q=", getenv("SC_FALLBACK"),
-								atoi(l ? l : ""));
+						sprintf(location, "%sl=%d%s%s%s%s&q=", getenv("SC_FALLBACK"), atoi(l ? l : ""), (opt & SC_OPT_IMAGE) ? "&i=i" : "", h ? "&h=h" : "", f ? "&f=f" : "", e ? "&e=e" : "");
 						urlencode(location+strlen(location), query);
-						if (opt & SC_OPT_IMAGE)
-							strcat(location, "&i=i");
-						if (h)
-							strcat(location, "&h=h");
-						if (f)
-							strcat(location, "&f=f");
 					}
 					char * safequery = htmlspecialchars(query);
 					response = malloc(strlen((char*) sc_hp)
@@ -258,6 +303,7 @@ retry:
 			} else goto retry;
 		}
 	}
+	sendresp:
 	httpd_response = MHD_create_response_from_buffer (response_len ? response_len : strlen(response), (void *) response, mhdrmm);
 	MHD_add_response_header(httpd_response, "Content-Type", content_type);
 	if (status_code >= 300 && status_code <= 399)
diff --git a/src/i18n.h b/src/i18n.h
index d06e4f0..86d7b21 100644
--- a/src/i18n.h
+++ b/src/i18n.h
@@ -35,3 +35,5 @@
 #define SC_I18N_SEARCH "išči"
 #define SC_I18N_HORSESHOE "hitro"
 #define SC_I18N_IMAGES "slike"
+#define SC_I18N_DID_YOU_REALLY_MEAN "preusmeril sem vas iz:"
+#define SC_I18N_DID_YOU_MEAN "predlagam iskanje:"
diff --git a/src/lib.c b/src/lib.c
index 2377ec9..62ddf84 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -46,18 +46,23 @@ void eachNodeX (htmlDocPtr doc, const char * xpath, node_function_t f, void * da
 	eachNode(nodes, f, data);
 	xmlXPathFreeObject(nodes);
 }
-xmlNodePtr nthNodeXN (xmlNodePtr node, const char * xpath, int n) {
-	xmlXPathObjectPtr nodes = findNodesN(node, xpath);
-	if (!nodes)
-		return NULL;
-	xmlNodeSetPtr nodeset = nodes->nodesetval;
-	int size = nodeset->nodeNr;
-	if (size <= n)
-		return NULL;
-	xmlNodePtr toreturn = (xmlNodePtr) nodeset->nodeTab[n];
-	xmlXPathFreeObject(nodes);
-	return toreturn;
+#define nthNodeFunctionGenerator(type, x) \
+xmlNodePtr nthNodeX##x (type node, const char * xpath, int n) { \
+	xmlXPathObjectPtr nodes = findNodes##x(node, xpath); \
+	if (!nodes) \
+		return NULL; \
+	xmlNodeSetPtr nodeset = nodes->nodesetval; \
+	int size = nodeset->nodeNr; \
+	if (size <= n) { \
+		xmlXPathFreeObject(nodes); \
+		return NULL; \
+	} \
+	xmlNodePtr toreturn = (xmlNodePtr) nodeset->nodeTab[n]; \
+	xmlXPathFreeObject(nodes); \
+	return toreturn; \
 }
+nthNodeFunctionGenerator(htmlDocPtr,) // this one gets doc
+nthNodeFunctionGenerator(xmlNodePtr, N)
 #define EACHNODE(node, nodes) /* you can instead use eachNodeX with anonymous function - no need to free and findnodes separatl */ \
 	for (int EACHNODE_i = 0; \
 			nodes ? nodes->nodesetval ? \
@@ -110,6 +115,9 @@ char * htmlspecialchars (const char * i) { /* remember to free the output */
 			case '"':
 				w += sprintf(o+w, "&quot;");
 				break;
+			case '\'':
+				w += sprintf(o+w, "&apos;");
+				break;
 			default:
 				o[w++] = *i;
 				break;
diff --git a/src/main.c b/src/main.c
index fdab429..a9857b6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,4 +1,5 @@
 #define _GNU_SOURCE
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/src/structs.c b/src/structs.c
index 6deea3e..f23e52f 100644
--- a/src/structs.c
+++ b/src/structs.c
@@ -84,6 +84,8 @@ struct sc_query {
 	SC_IN_STRUCT_ARRAY(struct sc_result, results); /* yesfree */
 	char * string; /* yesfree - query string, stripped of any excess characters that should be excluded from indexing */
 	time_t lookup_time; /* time of last lookup */
+	char * suggested; /* yesfree - suggested search query (did you mean) */
+	bool redirect; /* true if client is encouraged to be redirected to suggested (showing results for) */
 	SC_OPT_TYPE opt; /* some options including engines */
 };
 struct sc_query * sc_query_init () {
@@ -95,6 +97,7 @@ struct sc_query * sc_query_init () {
 		q->results[i]->query = q;
 	}
 	q->string = NULL;
+	q->suggested = NULL;
 	q->opt = SC_OPT_INIT;
 	return q;
 }
@@ -122,8 +125,9 @@ sc_query_free (
 #endif
 			;
 	if (q->cache)
-		SC_LOG(SC_LOG_DEBUG, q->cache, "sc_query_free: %s", q->string ? q->string : "NULL");
+		SC_LOG(SC_LOG_DEBUG, q->cache, "sc_query_free: %s (sugg: %s)", q->string ? q->string : "NULL", q->suggested ? q->suggested : "NULL");
 	free(q->string); /* if they were not alloced, they are NULL, if they were free'd somewhere else, they are also set to NULL */
+	free(q->suggested);
 	for (size_t i = 0; i < q->results_sizeof; i++)
 		sc_result_free(q->results[i]);
 	free(q->results);