Implement incoming links

README.md

@@ -12,7 +12,7 @@ over explain every line of code.
 
 ## Features
 - [x] Rendering wikilinks
-- [ ] Ability to keep track of incoming links
+- [x] Ability to keep track of incoming links
 - [ ] Named wikilinks (i.e. `[[link title|actual page]]`)
 
 ## installation

calathea.c

@@ -11,6 +11,7 @@ struct Page {
   char title[80];
   char *permalink;
   struct Page *next;
+  struct PageList *incoming;
   char *content;
 };
 
@@ -93,6 +94,44 @@ struct Page * map_get(struct Page **map, int mapSize, char title[]) {
   return page;
 }
 
+/*** Dynamic Array Implementation ***/
+struct PageList {
+  struct Page **pages;
+  int length;
+  int capacity;
+};
+
+struct PageList * page_list(int capacity) {
+  struct PageList *pageList = malloc(sizeof(struct PageList));
+  pageList->pages = malloc(sizeof(struct Page *) * capacity);
+  pageList->capacity = capacity;
+  pageList->length = 0;
+
+  return pageList;
+}
+
+void page_list_insert(struct PageList *list, struct Page *page) {
+  // If the page is already present in the list, we don't bother adding it again
+  for (int i = 0; i < list->length; i++) {
+    if (page == list->pages[i]) {
+      return;
+    }
+  }
+
+  // Increase the length of the array if necessary
+  if (list->length >= list->capacity) {
+    list->pages = realloc(list->pages, (list->capacity + 1)*sizeof(struct Page *));
+  }
+
+  list->pages[list->length] = page;
+  list->length++;
+}
+
+void page_list_free(struct PageList *list) {
+  free(list->pages);
+  free(list);
+}
+
 /*** Templating ***/
 char * substitute_string(char dest[], char sub[], char *start, char *end) {
   int startIndex = start - dest;
@@ -100,7 +139,7 @@ char * substitute_string(char dest[], char sub[], char *start, char *end) {
   int newLength = strlen(dest) - (end - start) + strlen(sub) + 1;
 
   char *compiled = malloc(newLength * sizeof(char));
-  compiled[0] = 0;
+  memset(compiled, 0, newLength * sizeof(char));
   strncpy(compiled, dest, startIndex);
   strcat(compiled, sub);
   strcat(compiled, end);
@@ -111,6 +150,7 @@ char * substitute_string(char dest[], char sub[], char *start, char *end) {
 int main(int argc, char *argv[]) {
   char pagesLocation[256] = "./pages";
   int mapSize = 1000;
+  int initialInboundCapacity = 2;
   char templateFileName[256] = "./template.html";
   char outputDirectoryName[256] = "./build";
 
@@ -137,6 +177,11 @@ int main(int argc, char *argv[]) {
         i++;
         strcpy(outputDirectoryName, argv[i]);
       }
+    } else if (strcmp(argv[i], "--incoming-cap") == 0) {
+      if (i + 1 < argc) {
+        i++;
+        initialInboundCapacity = atoi(argv[i]);
+      }
     } else {
       printf("Unknown argument: %s\n", argv[i]);
     }
@@ -194,6 +239,8 @@ int main(int argc, char *argv[]) {
       }
     }
 
+    currentPage->incoming = page_list(initialInboundCapacity);
+
     // Build the page's permalink
     currentPage->permalink = malloc(strlen(fileBasename) + 6);
 
@@ -274,7 +321,7 @@ int main(int argc, char *argv[]) {
 
   free(createOutputDir);
 
-  /*** Page Processing ***/
+  /*** Link Processing ***/
   currentPage = firstPage;
   while (currentPage != NULL) {
     // Scan the file for links
@@ -298,6 +345,7 @@ int main(int argc, char *argv[]) {
       title[linkLength - 2] = 0;
 
       struct Page *linkedPage = map_get(pageMap, mapSize, title);
+
       char *compiledLink;
 
       if (linkedPage == NULL) {
@@ -307,6 +355,7 @@ int main(int argc, char *argv[]) {
         strcat(compiledLink, title);
         strcat(compiledLink, "</a>\0");
       } else {
+        page_list_insert(linkedPage->incoming, currentPage);
         compiledLink = malloc(strlen(title) + strlen(linkedPage->permalink) + 5);
         strcpy(compiledLink, "[");
         strcat(compiledLink, title);
@@ -331,6 +380,12 @@ int main(int argc, char *argv[]) {
       nextLinkStart = strstr(currentPage->content, "[[");
     }
 
+    currentPage = currentPage->next;
+  }
+
+  /*** Rendering ***/
+  currentPage = firstPage;
+  while (currentPage != NULL) {
     // Compile the markdown
     currentPage->content = cmark_markdown_to_html(
         currentPage->content,
@@ -338,14 +393,53 @@ int main(int argc, char *argv[]) {
         (1 << 17) // Disables safe mode, allowing raw HTML
     );
 
+    // Insert the content into the template
+    char *renderedPage = NULL;
     char *templateTagStart = strstr(templateContent, "{{content}}");
-    char *renderedPageContent = substitute_string(
+    char *renderedWithContent = substitute_string(
       templateContent,
       currentPage->content,
       templateTagStart,
       templateTagStart + 11
     );
 
+    renderedPage = renderedWithContent;
+
+    char *incomingTagStart = strstr(renderedPage, "{{incoming}}");
+    if (incomingTagStart != NULL) {
+      // Build the incoming links list
+      int incomingListSize = 37;   // <ul class="calathea-incoming">\n</ul>\n
+      for (int i = 0; i < currentPage->incoming->length; i++) {
+        // `  <li><a href=\"[permalink]\">[title]</a></li>\n`
+        struct Page *page = currentPage->incoming->pages[i];
+        incomingListSize += 27 + strlen(page->title) + strlen(page->permalink);
+      }
+
+      char *incomingLinksList = malloc((incomingListSize + 1) * sizeof(char));
+      memset(incomingLinksList, 0, (incomingListSize + 1) * sizeof(char));
+
+      strcpy(incomingLinksList, "<ul class=\"calathea-incoming\">\n");
+      for (int i = 0; i < currentPage->incoming->length; i++) {
+        struct Page *page = currentPage->incoming->pages[i];
+        strcat(incomingLinksList, "  <li><a href=\"");
+        strcat(incomingLinksList, page->permalink);
+        strcat(incomingLinksList, "\">");
+        strcat(incomingLinksList, page->title);
+        strcat(incomingLinksList, "</a></li>\n");
+      }
+      strcat(incomingLinksList, "</ul>\n");
+
+      char *renderedWithInbound = substitute_string(
+        renderedPage,
+        incomingLinksList,
+        incomingTagStart,
+        incomingTagStart + 12
+      );
+
+      renderedPage = renderedWithInbound;
+      free(renderedWithContent);
+    }
+
     // Output the page to the file
     char *outputFileName = malloc(
       (strlen(outputDirectoryName)
@@ -358,23 +452,25 @@ int main(int argc, char *argv[]) {
     FILE *outputFile = fopen(outputFileName, "w");
 
     if (outputFile != NULL) {
-      fputs(renderedPageContent, outputFile);
+      fputs(renderedPage, outputFile);
       fclose(outputFile);
     } else {
       printf("Warning: failed to create %s\n", outputFileName);
     }
 
     free(outputFileName);
-    free(renderedPageContent);
+    free(renderedPage);
 
     currentPage = currentPage->next;
   }
 
+
   /*** Deallocation and whatnot ***/
   currentPage = firstPage;
   while (currentPage != NULL) {
     free(currentPage->content);
     free(currentPage->permalink);
+    page_list_free(currentPage->incoming);
     struct Page *next = currentPage->next;
     free(currentPage);
     currentPage = next;