Minor code refactoring

Moved certain functions to proper locations and added new source files
for minor refactoring.

src/BlogBuilder.cxx

@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2022 luca0N!
+ *
+ * This file is part of Static Website Generator (swg).
+ *
+ * Static Website Generator (swg) is free software: you can redistribute it
+ * and/or modify it under the terms of the version 3 of the GNU Lesser General
+ * Public License as published by the Free Software Foundation.
+ *
+ * Static Website Generator (swg) is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Static Website Generator (swg). If not, see
+ * <https://www.gnu.org/licenses/>.
+ *
+ * Contact luca0N! by e-mail: <luca0n [at] luca0n [dot] com>. 
+ */
+
+#include "BlogBuilder.hxx"
+
+#include <regex>
+#include <iostream>
+
+#include "Article.hxx"
+#include "WebsiteBuilder.hxx"
+
+std::string blog_relative_path(std::string const &pathPrefix, std::string const &path) {
+	return path.substr(pathPrefix.length() - 1);
+}
+
+bool is_valid_article(std::string const &pathPrefix, std::string const &path) {
+	return std::regex_search(blog_relative_path(pathPrefix, path), std::regex("^/\\d{4}/\\d{2}/.*\\.md"));
+}
+void build_blog_structure(std::string const &path, std::string const &prefix, std::list<std::string> const &articles, Blog *blog) {
+	std::filesystem::path obp = get_output_path(path); // Output Blog Path
+	obp /= "blog";
+	obp /= blog->dir;
+	try {
+		// Create blog directory
+		if (!std::filesystem::exists(obp)) std::filesystem::create_directories(obp);
+	} catch (std::filesystem::filesystem_error const &e) {
+		std::cerr << "error: failed to create directory for blog \"" << blog->name << "\": " << e.what() << std::endl;
+		exit(RETURN_FAILED_UNKNOWN_ERROR);
+	}
+
+	std::list<Article::Metadata*> am;
+	//std::map<std::string, std::list<std::string>> sorted_articles;
+
+	for (std::string const &a : articles) {
+		std::string articlePath = blog_relative_path(prefix, a);
+		std::regex yearMonth("(\\d+)");
+		auto match = std::sregex_iterator(articlePath.begin(), articlePath.end(), yearMonth);
+
+		std::string year = match->str(),
+			month = (++match)->str();
+
+		// Go ahead and parse article metadata.
+		Article::Metadata *articleMetadata = (Article::Metadata*) malloc(sizeof(Article::Metadata));
+		Article::get_metadata(a, articleMetadata);
+		std::cout << "Parsed metadata for article \"" << articleMetadata->title << "\"\n\tPublished on "
+				<< ctime(&(articleMetadata->publish_ts)) << "\n";
+
+		// TODO: This code could be optimized by removing directory
+		// checks for every single article.  Instead, add
+		// directory-checks for years and months to a queue (skipping
+		// existing ones) and then checking and creating the
+		// 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
+								  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.
+			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, articleMetadata);
+			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;
+			exit(RETURN_FAILED_UNKNOWN_ERROR);
+		}
+	}
+	// Sort am list.
+	am.sort(Article::Comparator::comp);
+	// Generate blog catalog.
+	std::string blog_html_catalog,
+		last_date = "";
+	blog_html_catalog += "<h2>";
+	blog_html_catalog += blog->name;
+	blog_html_catalog += " - Catalog</h2>\n<ul>";
+
+	for (Article::Metadata *m : am) {
+		struct tm *article_time = gmtime(&(m->publish_ts));
+		std::string hr_date = get_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 += "\n\t<span><b>";
+			blog_html_catalog += hr_date;
+			blog_html_catalog += "</b></span>\n";
+		}
+		blog_html_catalog += "\t<li><a href=\"./";
+		blog_html_catalog += m->path;
+		blog_html_catalog += "\">";
+		blog_html_catalog += m->title;
+		blog_html_catalog += "</a></li>\n";
+		// Free memory as it's no longer needed.
+		free(m);
+	}
+	blog_html_catalog += "</ul>";
+	// Put catalog HTML into template and save it to the blog directory.
+	std::filesystem::path catalog_output_path = obp;
+	catalog_output_path /= "index.html";
+
+	std::string html_template = get_template(path);
+	std::regex content_placeholder("<!--\\[_SWG: \\$CONTENT\\]-->");
+	std::string catalog_html_contents = std::regex_replace(html_template, content_placeholder, blog_html_catalog);
+
+	FILE *catalog_output_file = fopen(catalog_output_path.c_str(), "w");
+	fputs(catalog_html_contents.c_str(), catalog_output_file);
+	fclose(catalog_output_file);
+}
+