Generate blog catalog

WebsiteBuilder now generates a blog catalog containing each article from
every blog.  Articles are sorted by published date and are grouped based
on their month and year.

src/Article.cxx

@@ -131,7 +131,7 @@ namespace Article {
 		fclose(a);
 	}
 	bool Comparator::comp(Metadata *a, Metadata *b) {
-			return a->publish_ts < b->publish_ts;
+			return a->publish_ts > b->publish_ts;
 	}
 	bool Comparator::equiv(Metadata *a, Metadata *b) {
 			return a->publish_ts == b->publish_ts;

src/Article.hxx

@@ -27,6 +27,7 @@ namespace Article {
 	struct Metadata {
 		char title[128];
 		char authors[128];		// Author (or authors) for this article
+		char path[256];			// Path to this article
 
 		// Epoch timestamps
 		long original_ts;	// Original article timestamp (for "Originally written on [...]")

src/WebsiteBuilder.cxx

@@ -153,7 +153,6 @@ void build_blog_structure(std::string const &path, std::string const &prefix, st
 		Article::get_metadata(a, articleMetadata);
 		std::cout << "Parsed metadata for article \"" << articleMetadata->title << "\"\n\tPublished on "
 				<< ctime(&(articleMetadata->publish_ts)) << "\n";
-		am.push_back(articleMetadata);
 
 		// TODO: This code could be optimized by removing directory
 		// checks for every single article.  Instead, add
@@ -162,18 +161,25 @@ void build_blog_structure(std::string const &path, std::string const &prefix, st
 		// directories later as needed.
 		try {
 			// Create directory for the year of this article if it doesn't exist.
-			std::filesystem::path oad = obp; // Output Article Directory
+			std::filesystem::path oad = obp, // Output Article Directory
+								  rap;		 // Relative Article Path
 			oad /= year;
+			rap /= year;
 			if (!std::filesystem::exists(oad)) std::filesystem::create_directory(oad);
 
 			// Do the same for the article month.
 			oad /= month;
+			rap /= month;
 			if (!std::filesystem::exists(oad)) std::filesystem::create_directory(oad);
 
 			// Now create the article file.
-			oad /= getFilename(a, false);
-			oad += ".html";
+			std::string new_article_filename = getFilename(a, false);
+			new_article_filename += ".html";
+			oad /= new_article_filename;
+			rap /= new_article_filename;
 			compile_markdown(path, a, oad);
+			strncpy(articleMetadata->path, rap.c_str(), sizeof(articleMetadata->path));
+			am.push_back(articleMetadata);
 		} catch (std::filesystem::filesystem_error const &e) {
 			std::cerr << "error: failed to create directory for an article from blog \""
 				<< blog->name << "\": " << e.what() << std::endl;
@@ -182,6 +188,47 @@ void build_blog_structure(std::string const &path, std::string const &prefix, st
 	}
 	// Sort am list.
 	am.sort(Article::Comparator::comp);
+	// Generate blog catalog.
+	std::string blog_html_catalog = "<ul>",
+			last_date = "";
+	std::string hr_month[] = {
+		"January",
+		"February",
+		"March",
+		"April",
+		"May",
+		"June",
+		"July",
+		"August",
+		"September",
+		"October",
+		"November",
+		"December"
+	};
+
+	for (Article::Metadata *m : am) {
+		struct tm *article_time = gmtime(&(m->publish_ts));
+		std::string hr_date = hr_month[article_time->tm_mon];
+		hr_date += " ";
+		hr_date += std::to_string(article_time->tm_year + 1900);
+		// Check if this article belongs to the same "month + year" group as
+		// the last article.  If it doesn't, add a new group to the catalog.
+		if (hr_date != last_date) {
+			last_date = hr_date;
+			blog_html_catalog += "<span><b>";
+			blog_html_catalog += hr_date;
+			blog_html_catalog += "</b></span>";
+		}
+
+		blog_html_catalog += "<li><a href=\"./";
+		blog_html_catalog += m->path;
+		blog_html_catalog += "\">";
+		blog_html_catalog += m->title;
+		blog_html_catalog += "</a></li>";
+		// Free memory as it's no longer needed.
+		free(m);
+	}
+	blog_html_catalog += "</ul>";
 }
 
 /**