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#include "Wikipedia.h"
#include <curl/curl.h>
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct WikiMemoryStruct {
char *memory;
size_t size;
};
static void shorten_summary(char **extract_ptr, int max_chars) {
if (!extract_ptr || !*extract_ptr) return;
char *text = *extract_ptr;
int len = strlen(text);
if (len <= max_chars) return;
int end_pos = max_chars;
for (int i = max_chars; i > (max_chars / 2); i--) {
if (text[i] == '.' || text[i] == '!' || text[i] == '?') {
end_pos = i + 1;
break;
}
}
char *new_text = (char *)malloc(end_pos + 4);
if (new_text) {
strncpy(new_text, text, end_pos);
new_text[end_pos] = '\0';
strcat(new_text, "...");
free(*extract_ptr);
*extract_ptr = new_text;
}
}
static size_t WikiWriteMemoryCallback(void *contents, size_t size, size_t nmemb,
void *userp) {
size_t realsize = size * nmemb;
struct WikiMemoryStruct *mem = (struct WikiMemoryStruct *)userp;
char *ptr = realloc(mem->memory, mem->size + realsize + 1);
if (ptr == NULL) {
fprintf(stderr, "Not enough memory (realloc returned NULL)\n");
return 0;
}
mem->memory = ptr;
memcpy(&(mem->memory[mem->size]), contents, realsize);
mem->size += realsize;
mem->memory[mem->size] = 0;
return realsize;
}
static void extract_wiki_info(xmlNode *node, InfoBox *info) {
xmlNode *cur_node = NULL;
for (cur_node = node; cur_node; cur_node = cur_node->next) {
if (cur_node->type == XML_ELEMENT_NODE) {
if (strcmp((const char *)cur_node->name, "page") == 0) {
xmlChar *title = xmlGetProp(cur_node, (const xmlChar *)"title");
if (title) {
info->title = strdup((const char *)title);
const char *base_article_url = "https://en.wikipedia.org/wiki/";
char *formatted_title = strdup((const char *)title);
for (int i = 0; formatted_title[i]; i++) {
if (formatted_title[i] == ' ') formatted_title[i] = '_';
}
info->url =
malloc(strlen(base_article_url) + strlen(formatted_title) + 1);
if (info->url) {
strcpy(info->url, base_article_url);
strcat(info->url, formatted_title);
}
free(formatted_title);
xmlFree(title);
}
}
if (strcmp((const char *)cur_node->name, "thumbnail") == 0) {
xmlChar *source = xmlGetProp(cur_node, (const xmlChar *)"source");
if (source) {
info->thumbnail_url = strdup((const char *)source);
xmlFree(source);
}
}
if (strcmp((const char *)cur_node->name, "extract") == 0) {
xmlChar *content = xmlNodeGetContent(cur_node);
if (content) {
info->extract = strdup((const char *)content);
shorten_summary(&(info->extract), 300);
xmlFree(content);
}
}
}
extract_wiki_info(cur_node->children, info);
}
}
InfoBox fetch_wiki_data(char *api_url) {
CURL *curl_handle;
CURLcode res;
struct WikiMemoryStruct chunk;
InfoBox info = {NULL, NULL, NULL, NULL};
chunk.memory = malloc(1);
chunk.size = 0;
curl_handle = curl_easy_init();
if (curl_handle) {
curl_easy_setopt(curl_handle, CURLOPT_URL, api_url);
curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION,
WikiWriteMemoryCallback);
curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);
curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");
res = curl_easy_perform(curl_handle);
if (res == CURLE_OK) {
xmlDocPtr doc =
xmlReadMemory(chunk.memory, chunk.size, "noname.xml", NULL, 0);
if (doc != NULL) {
xmlNode *root_element = xmlDocGetRootElement(doc);
extract_wiki_info(root_element, &info);
xmlFreeDoc(doc);
}
}
curl_easy_cleanup(curl_handle);
free(chunk.memory);
}
return info;
}
char *construct_wiki_url(const char *search_term) {
CURL *curl = curl_easy_init();
if (!curl) return NULL;
char *escaped_term = curl_easy_escape(curl, search_term, 0);
const char *base =
"https://en.wikipedia.org/w/"
"api.php?action=query&prop=extracts|pageimages&exintro&"
"explaintext&pithumbsize=400&format=xml&origin=*&titles=";
char *full_url = malloc(strlen(base) + strlen(escaped_term) + 1);
if (full_url) {
strcpy(full_url, base);
strcat(full_url, escaped_term);
}
curl_free(escaped_term);
curl_easy_cleanup(curl);
return full_url;
}
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