oopsies

2 files changed, 517 insertions, 0 deletions

diff --git a/src/Scraping/Scraping.c b/src/Scraping/Scraping.c
new file mode 100644
index 0000000..42e05d6
--- /dev/null
+++ b/src/Scraping/Scraping.c
@@ -0,0 +1,459 @@
+#include "Scraping.h"
+#include "../Utility/Unescape.h"
+#include <curl/curl.h>
+#include <libxml/HTMLparser.h>
+#include <libxml/xpath.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+static size_t WriteMemoryCallback(void *contents, size_t size, size_t nmemb,
+                                  void *userp) {
+  size_t realsize = size * nmemb;
+  MemoryBuffer *mem = (MemoryBuffer *)userp;
+
+  if (mem->size + realsize + 1 > mem->capacity) {
+
+    size_t new_cap = mem->capacity == 0 ? 16384 : mem->capacity * 2;
+    while (new_cap < mem->size + realsize + 1) new_cap *= 2;
+
+    char *ptr = (char *)realloc(mem->memory, new_cap);
+    if (!ptr) {
+      return 0;
+    }
+    mem->memory = ptr;
+    mem->capacity = new_cap;
+  }
+
+  memcpy(&(mem->memory[mem->size]), contents, realsize);
+  mem->size += realsize;
+  mem->memory[mem->size] = 0;
+
+  return realsize;
+}
+
+static const char *get_random_user_agent() {
+  static const char *agents[] = {
+      "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, "
+      "like Gecko) Chrome/120.0.0.0 Safari/537.36",
+      "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 "
+      "(KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36",
+      "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like "
+      "Gecko) "
+      "Chrome/120.0.0.0` Safari/537.36",
+      "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 "
+      "Firefox/121.0",
+      "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 "
+      "(KHTML, like Gecko) Version/17.2 Safari/605.1.15"};
+  return agents[rand() % 5];
+}
+
+static int parse_ddg_lite(const char *engine_name, xmlDocPtr doc,
+                          SearchResult **out_results, int max_results) {
+  (void)engine_name;
+  int found_count = 0;
+  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
+  if (!xpathCtx) {
+    return 0;
+  }
+
+  const char *link_xpath = "//tr[not(contains(@class, 'result-sponsored'))]//a[@class='result-link']";
+  xmlXPathObjectPtr xpathObj =
+      xmlXPathEvalExpression((xmlChar *)link_xpath, xpathCtx);
+
+  if (!xpathObj || !xpathObj->nodesetval || xpathObj->nodesetval->nodeNr == 0) {
+    if (xpathObj) xmlXPathFreeObject(xpathObj);
+    xmlXPathFreeContext(xpathCtx);
+    return 0;
+  }
+
+  int num_links = xpathObj->nodesetval->nodeNr;
+
+  int actual_alloc = (num_links < max_results) ? num_links : max_results;
+  *out_results = (SearchResult *)calloc(actual_alloc, sizeof(SearchResult));
+  if (!*out_results) {
+    xmlXPathFreeObject(xpathObj);
+    xmlXPathFreeContext(xpathCtx);
+    return 0;
+  }
+
+  for (int i = 0; i < num_links && found_count < max_results; i++) {
+    xmlNodePtr linkNode = xpathObj->nodesetval->nodeTab[i];
+    char *title = (char *)xmlNodeGetContent(linkNode);
+    char *url = (char *)xmlGetProp(linkNode, (xmlChar *)"href");
+    char *snippet_text = NULL;
+
+    xmlNodePtr current = linkNode->parent;
+    while (current && xmlStrcasecmp(current->name, (const xmlChar *)"tr") != 0)
+      current = current->parent;
+
+    if (current && current->next) {
+      xmlNodePtr snippetRow = current->next;
+      while (snippetRow &&
+             xmlStrcasecmp(snippetRow->name, (const xmlChar *)"tr") != 0)
+        snippetRow = snippetRow->next;
+      if (snippetRow) {
+
+        xpathCtx->node = snippetRow;
+        xmlXPathObjectPtr sObj = xmlXPathEvalExpression(
+            (xmlChar *)".//td[@class='result-snippet']", xpathCtx);
+        if (sObj && sObj->nodesetval && sObj->nodesetval->nodeNr > 0) {
+          snippet_text = (char *)xmlNodeGetContent(sObj->nodesetval->nodeTab[0]);
+        }
+        if (sObj) xmlXPathFreeObject(sObj);
+        xpathCtx->node = NULL; 
+
+      }
+    }
+
+    (*out_results)[found_count].url = unescape_search_url(url);
+    (*out_results)[found_count].title = strdup(title ? title : "No Title");
+    (*out_results)[found_count].snippet = strdup(snippet_text ? snippet_text : "");
+
+    found_count++;
+
+    if (title) xmlFree(title);
+    if (url) xmlFree(url);
+    if (snippet_text) xmlFree(snippet_text);
+  }
+
+  xmlXPathFreeObject(xpathObj);
+  xmlXPathFreeContext(xpathCtx);
+  return found_count;
+}
+
+static int parse_startpage(const char *engine_name, xmlDocPtr doc,
+                           SearchResult **out_results, int max_results) {
+  (void)engine_name;
+  int found_count = 0;
+  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
+  if (!xpathCtx) {
+    return 0;
+  }
+
+  const char *container_xpath = "//div[contains(@class, 'result')]";
+  xmlXPathObjectPtr xpathObj =
+      xmlXPathEvalExpression((xmlChar *)container_xpath, xpathCtx);
+
+  if (!xpathObj || !xpathObj->nodesetval || xpathObj->nodesetval->nodeNr == 0) {
+    if (xpathObj) xmlXPathFreeObject(xpathObj);
+    xmlXPathFreeContext(xpathCtx);
+    return 0;
+  }
+
+  int num_results = xpathObj->nodesetval->nodeNr;
+
+  int actual_alloc = (num_results < max_results) ? num_results : max_results;
+  *out_results = (SearchResult *)calloc(actual_alloc, sizeof(SearchResult));
+  if (!*out_results) {
+    xmlXPathFreeObject(xpathObj);
+    xmlXPathFreeContext(xpathCtx);
+    return 0;
+  }
+
+  for (int i = 0; i < num_results && found_count < max_results; i++) {
+    xmlNodePtr resultNode = xpathObj->nodesetval->nodeTab[i];
+    xpathCtx->node = resultNode;
+
+    xmlXPathObjectPtr linkObj = xmlXPathEvalExpression(
+        (xmlChar *)".//a[contains(@class, 'result-link')]", xpathCtx);
+    char *url =
+        (linkObj && linkObj->nodesetval && linkObj->nodesetval->nodeNr > 0)
+            ? (char *)xmlGetProp(linkObj->nodesetval->nodeTab[0],
+                                 (xmlChar *)"href")
+            : NULL;
+
+    xmlXPathObjectPtr titleObj = xmlXPathEvalExpression(
+        (xmlChar *)".//h2[contains(@class, 'wgl-title')]", xpathCtx);
+    char *title =
+        (titleObj && titleObj->nodesetval && titleObj->nodesetval->nodeNr > 0)
+            ? (char *)xmlNodeGetContent(titleObj->nodesetval->nodeTab[0])
+            : NULL;
+
+    xmlXPathObjectPtr snippetObj = xmlXPathEvalExpression(
+        (xmlChar *)".//p[contains(@class, 'description')]", xpathCtx);
+    char *snippet_text =
+        (snippetObj && snippetObj->nodesetval &&
+         snippetObj->nodesetval->nodeNr > 0)
+            ? (char *)xmlNodeGetContent(snippetObj->nodesetval->nodeTab[0])
+            : NULL;
+
+    if (url && title) {
+      (*out_results)[found_count].url = strdup(url);
+      (*out_results)[found_count].title = strdup(title);
+      (*out_results)[found_count].snippet =
+          strdup(snippet_text ? snippet_text : "");
+      found_count++;
+    }
+
+    if (title) xmlFree(title);
+    if (url) xmlFree(url);
+    if (snippet_text) xmlFree(snippet_text);
+    if (linkObj) xmlXPathFreeObject(linkObj);
+    if (titleObj) xmlXPathFreeObject(titleObj);
+    if (snippetObj) xmlXPathFreeObject(snippetObj);
+  }
+
+  xpathCtx->node = NULL; 
+
+  xmlXPathFreeObject(xpathObj);
+  xmlXPathFreeContext(xpathCtx);
+  return found_count;
+}
+
+static int parse_yahoo(const char *engine_name, xmlDocPtr doc,
+                       SearchResult **out_results, int max_results) {
+  (void)engine_name;
+  int found_count = 0;
+  xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
+  if (!xpathCtx) {
+    return 0;
+  }
+
+  const char *container_xpath = "//div[contains(@class, 'algo-sr')]";
+  xmlXPathObjectPtr xpathObj =
+      xmlXPathEvalExpression((xmlChar *)container_xpath, xpathCtx);
+
+  if (!xpathObj || !xpathObj->nodesetval || xpathObj->nodesetval->nodeNr == 0) {
+    if (xpathObj) xmlXPathFreeObject(xpathObj);
+    xmlXPathFreeContext(xpathCtx);
+    return 0;
+  }
+
+  int num_results = xpathObj->nodesetval->nodeNr;
+
+  int actual_alloc = (num_results < max_results) ? num_results : max_results;
+  *out_results = (SearchResult *)calloc(actual_alloc, sizeof(SearchResult));
+  if (!*out_results) {
+    xmlXPathFreeObject(xpathObj);
+    xmlXPathFreeContext(xpathCtx);
+    return 0;
+  }
+
+  for (int i = 0; i < num_results && found_count < max_results; i++) {
+    xmlNodePtr resultNode = xpathObj->nodesetval->nodeTab[i];
+    xpathCtx->node = resultNode;
+
+    xmlXPathObjectPtr linkObj = xmlXPathEvalExpression(
+        (xmlChar *)".//div[contains(@class, 'compTitle')]//a[@target='_blank']",
+        xpathCtx);
+    char *url =
+        (linkObj && linkObj->nodesetval && linkObj->nodesetval->nodeNr > 0)
+            ? (char *)xmlGetProp(linkObj->nodesetval->nodeTab[0],
+                                 (xmlChar *)"href")
+            : NULL;
+
+    xmlXPathObjectPtr titleObj = xmlXPathEvalExpression(
+        (xmlChar *)".//h3[contains(@class, 'title')]", xpathCtx);
+    char *title =
+        (titleObj && titleObj->nodesetval && titleObj->nodesetval->nodeNr > 0)
+            ? (char *)xmlNodeGetContent(titleObj->nodesetval->nodeTab[0])
+            : NULL;
+
+    xmlXPathObjectPtr snippetObj = xmlXPathEvalExpression(
+        (xmlChar *)".//div[contains(@class, 'compText')]//p", xpathCtx);
+    char *snippet_text =
+        (snippetObj && snippetObj->nodesetval &&
+         snippetObj->nodesetval->nodeNr > 0)
+            ? (char *)xmlNodeGetContent(snippetObj->nodesetval->nodeTab[0])
+            : NULL;
+
+    if (url && title) {
+      (*out_results)[found_count].url = unescape_search_url(url);
+      (*out_results)[found_count].title = strdup(title);
+      (*out_results)[found_count].snippet =
+          strdup(snippet_text ? snippet_text : "");
+      found_count++;
+    }
+
+    if (title) xmlFree(title);
+    if (url) xmlFree(url);
+    if (snippet_text) xmlFree(snippet_text);
+    if (linkObj) xmlXPathFreeObject(linkObj);
+    if (titleObj) xmlXPathFreeObject(titleObj);
+    if (snippetObj) xmlXPathFreeObject(snippetObj);
+  }
+
+  xpathCtx->node = NULL;
+  xmlXPathFreeObject(xpathObj);
+  xmlXPathFreeContext(xpathCtx);
+  return found_count;
+}
+
+const SearchEngine ENGINE_REGISTRY[] = {
+    {.name = "DuckDuckGo Lite",
+     .base_url = "https://lite.duckduckgo.com/lite/?q=",
+     .host_header = "lite.duckduckgo.com",
+     .referer = "https://lite.duckduckgo.com/",
+     .page_param = "s",
+     .page_multiplier = 30,
+     .page_base = 0,
+     .parser = parse_ddg_lite},
+    {.name = "Startpage",
+     .base_url = "https://www.startpage.com/sp/search?q=",
+     .host_header = "www.startpage.com",
+     .referer = "https://www.startpage.com/",
+     .page_param = "page",
+     .page_multiplier = 1,
+     .page_base = 1,   
+     .parser = parse_startpage},
+    {.name = "Yahoo",
+     .base_url = "https://search.yahoo.com/search?p=",
+     .host_header = "search.yahoo.com",
+     .referer = "https://search.yahoo.com/",
+     .page_param = "b",
+     .page_multiplier = 10,
+     .page_base = 1,   
+     .parser = parse_yahoo}};
+
+const int ENGINE_COUNT = sizeof(ENGINE_REGISTRY) / sizeof(SearchEngine);
+
+static void configure_curl_handle(CURL *curl, const char *full_url, 
+                                   MemoryBuffer *chunk,
+                                   struct curl_slist *headers) {
+  curl_easy_setopt(curl, CURLOPT_URL, full_url);
+  curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
+  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
+  curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)chunk);
+  curl_easy_setopt(curl, CURLOPT_USERAGENT, get_random_user_agent());
+
+  curl_easy_setopt(curl, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
+
+  curl_easy_setopt(curl, CURLOPT_ACCEPT_ENCODING, "");
+
+  curl_easy_setopt(curl, CURLOPT_DNS_CACHE_TIMEOUT, 300L);
+
+  curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+  curl_easy_setopt(curl, CURLOPT_TIMEOUT, 15L);
+  curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
+  curl_easy_setopt(curl, CURLOPT_COOKIEFILE, "");
+}
+
+int scrape_engines_parallel(ScrapeJob *jobs, int num_jobs) {
+  CURLM *multi_handle = curl_multi_init();
+  if (!multi_handle) {
+    return -1;
+  }
+
+  for (int i = 0; i < num_jobs; i++) {
+    ScrapeJob *job = &jobs[i];
+    job->handle = curl_easy_init();
+    if (!job->handle) {
+      continue;
+    }
+
+    job->response.memory = (char *)malloc(16384);
+    job->response.size = 0;
+    job->response.capacity = 16384;
+
+    char full_url[1024];
+    char *encoded_query = curl_easy_escape(job->handle, job->query, 0);
+    if (!encoded_query) {
+      curl_easy_cleanup(job->handle);
+      job->handle = NULL;
+      continue;
+    }
+
+    int page = (job->page < 1) ? 1 : job->page;
+    int page_value = (page - 1) * job->engine->page_multiplier + job->engine->page_base;
+
+    snprintf(full_url, sizeof(full_url), "%s%s&%s=%d",
+             job->engine->base_url,
+             encoded_query,
+             job->engine->page_param,
+             page_value);
+    curl_free(encoded_query);
+
+    struct curl_slist *headers = NULL;
+    char host_buf[256], ref_buf[256];
+    snprintf(host_buf, sizeof(host_buf), "Host: %s", job->engine->host_header);
+    snprintf(ref_buf, sizeof(ref_buf), "Referer: %s", job->engine->referer);
+    headers = curl_slist_append(headers, host_buf);
+    headers = curl_slist_append(headers, ref_buf);
+    headers = curl_slist_append(headers, "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
+    headers = curl_slist_append(headers, "Accept-Language: en-US,en;q=0.5");
+    headers = curl_slist_append(headers, "DNT: 1");
+
+    configure_curl_handle(job->handle, full_url, &job->response, headers);
+
+    curl_easy_setopt(job->handle, CURLOPT_PRIVATE, headers);
+
+    curl_multi_add_handle(multi_handle, job->handle);
+  }
+
+  usleep(100000 + (rand() % 100000)); 
+
+  int still_running = 0;
+  curl_multi_perform(multi_handle, &still_running);
+
+  do {
+    int numfds = 0;
+    CURLMcode mc = curl_multi_wait(multi_handle, NULL, 0, 1000, &numfds);
+
+    if (mc != CURLM_OK) {
+      break;
+    }
+
+    curl_multi_perform(multi_handle, &still_running);
+  } while (still_running);
+
+  CURLMsg *msg;
+  int msgs_left;
+  while ((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
+    if (msg->msg == CURLMSG_DONE) {
+      CURL *handle = msg->easy_handle;
+
+      for (int i = 0; i < num_jobs; i++) {
+        if (jobs[i].handle == handle) {
+          ScrapeJob *job = &jobs[i];
+
+          long response_code;
+          curl_easy_getinfo(handle, CURLINFO_RESPONSE_CODE, &response_code);
+
+          if (msg->data.result == CURLE_OK && job->response.size > 0) {
+            xmlDocPtr doc = htmlReadMemory(
+                job->response.memory, job->response.size, NULL, NULL,
+                HTML_PARSE_RECOVER | HTML_PARSE_NOERROR | HTML_PARSE_NOWARNING);
+
+            if (doc) {
+              job->results_count = job->engine->parser(
+                  job->engine->name, doc, job->out_results, job->max_results);
+              xmlFreeDoc(doc);
+            }
+          } else {
+            job->results_count = 0;
+          }
+
+          struct curl_slist *headers;
+          curl_easy_getinfo(handle, CURLINFO_PRIVATE, &headers);
+          if (headers) curl_slist_free_all(headers);
+
+          free(job->response.memory);
+          curl_multi_remove_handle(multi_handle, handle);
+          curl_easy_cleanup(handle);
+          break;
+        }
+      }
+    }
+  }
+
+  curl_multi_cleanup(multi_handle);
+  return 0;
+}
+
+int scrape_engine(const SearchEngine *engine, const char *query,
+                  SearchResult **out_results, int max_results) {
+  ScrapeJob job = {
+      .engine = engine,
+      .query = (char *)query,
+      .out_results = out_results,
+      .max_results = max_results,
+      .results_count = 0,
+      .page = 1
+  };
+
+  scrape_engines_parallel(&job, 1);
+  return job.results_count;
+}
\ No newline at end of file
diff --git a/src/Scraping/Scraping.h b/src/Scraping/Scraping.h
new file mode 100644
index 0000000..d8a3b13
--- /dev/null
+++ b/src/Scraping/Scraping.h
@@ -0,0 +1,58 @@
+#ifndef SCRAPING_H
+#define SCRAPING_H
+
+#include <libxml/HTMLparser.h>
+#include <curl/curl.h>
+
+#define LOG_INFO(msg, ...) fprintf(stderr, "[INFO] " msg "\n", ##__VA_ARGS__)
+#define LOG_WARN(msg, ...) fprintf(stderr, "[WARN] " msg "\n", ##__VA_ARGS__)
+#define LOG_DEBUG(msg, ...) fprintf(stderr, "[DEBUG] " msg "\n", ##__VA_ARGS__)
+#define LOG_ERROR(msg, ...) fprintf(stderr, "[ERROR] " msg "\n", ##__VA_ARGS__)
+
+typedef struct {
+  char *url;
+  char *title;
+  char *snippet;
+} SearchResult;
+
+typedef int (*ParserFunc)(const char *engine_name, xmlDocPtr doc,
+                          SearchResult **out_results, int max_results);
+
+typedef struct {
+  const char *name;
+  const char *base_url;
+  const char *host_header;
+  const char *referer;
+
+  const char *page_param;
+  int         page_multiplier;
+  int         page_base;
+  ParserFunc parser;
+} SearchEngine;
+
+typedef struct {
+  char *memory;
+  size_t size;
+  size_t capacity;
+} MemoryBuffer;
+
+typedef struct {
+  const SearchEngine *engine;
+  char *query;
+  SearchResult **out_results;
+  int max_results;
+  int page;          
+  CURL *handle;
+  MemoryBuffer response;
+  int results_count;
+} ScrapeJob;
+
+extern const SearchEngine ENGINE_REGISTRY[];
+extern const int ENGINE_COUNT;
+
+int scrape_engine(const SearchEngine *engine, const char *query,
+                  SearchResult **out_results, int max_results);
+
+int scrape_engines_parallel(ScrapeJob *jobs, int num_jobs);
+
+#endif
\ No newline at end of file