Add Article namespace for metadata parsing

Added a new namespace used for parsing article metadata embedded in
article Markdown files, and updated the Makefile accordingly.

Makefile

@@ -24,8 +24,8 @@ CXXFLAGS=-Wall -Wextra -g -O0 -std=c++17
 
 .PHONY: clean
 
-$(PROGRAM_NAME): build/ build/obj/ build/obj/main.o build/obj/ConfigUtils.o build/obj/WebsiteBuilder.o build/obj/SwgRuntime.o build/obj/MarkdownParser.o
+$(PROGRAM_NAME): build/ build/obj/ build/obj/main.o build/obj/ConfigUtils.o build/obj/WebsiteBuilder.o build/obj/SwgRuntime.o build/obj/MarkdownParser.o build/obj/Article.o
-	$(CXXC) -o $(PROGRAM_NAME) build/obj/main.o build/obj/ConfigUtils.o build/obj/WebsiteBuilder.o build/obj/SwgRuntime.o build/obj/MarkdownParser.o
+	$(CXXC) -o $(PROGRAM_NAME) build/obj/main.o build/obj/ConfigUtils.o build/obj/WebsiteBuilder.o build/obj/SwgRuntime.o build/obj/MarkdownParser.o build/obj/Article.o
 
 build/obj/main.o: src/main.cxx src/ConfigUtils.hxx src/SwgContext.hxx src/WebsiteBuilder.hxx src/Common.hxx
 	$(CXXC) $(CXXFLAGS) -o build/obj/main.o -c src/main.cxx
@@ -33,7 +33,7 @@ build/obj/main.o: src/main.cxx src/ConfigUtils.hxx src/SwgContext.hxx src/Websit
 build/obj/ConfigUtils.o: src/ConfigUtils.cxx src/SwgContext.hxx src/Common.hxx
 	$(CXXC) $(CXXFLAGS) -o build/obj/ConfigUtils.o -c src/ConfigUtils.cxx
 
-build/obj/WebsiteBuilder.o: src/WebsiteBuilder.hxx src/WebsiteBuilder.cxx src/SwgRuntime.hxx src/Common.hxx src/MarkdownParser.hxx
+build/obj/WebsiteBuilder.o: src/WebsiteBuilder.hxx src/WebsiteBuilder.cxx src/SwgRuntime.hxx src/Common.hxx src/MarkdownParser.hxx src/Article.hxx
 	$(CXXC) $(CXXFLAGS) -o build/obj/WebsiteBuilder.o -c src/WebsiteBuilder.cxx
 
 build/obj/SwgRuntime.o: src/SwgRuntime.hxx src/SwgRuntime.cxx
@@ -42,6 +42,9 @@ build/obj/SwgRuntime.o: src/SwgRuntime.hxx src/SwgRuntime.cxx
 build/obj/MarkdownParser.o: src/MarkdownParser.hxx src/MarkdownParser.cxx
 	$(CXXC) $(CXXFLAGS) -o build/obj/MarkdownParser.o -c src/MarkdownParser.cxx
 
+build/obj/Article.o: src/Article.hxx src/Article.cxx
+	$(CXXC) $(CXXFLAGS) -o build/obj/Article.o -c src/Article.cxx
+
 build/:
 	mkdir -p build/
 

src/Article.cxx

@@ -0,0 +1,135 @@
+/*
+ * 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 "Article.hxx"
+
+#include <iostream>
+#include <list>
+#include <string.h>
+
+#include "Common.hxx"
+
+enum IterationStage {
+	CHECKING_TITLE,
+	READING_TITLE,
+	CHECKING
+};
+
+namespace Article {
+	/*
+	 * FIXME: The article metadata declaration uses the same INI format as
+	 * swg.cfg.  Since they use the exact same format, we could unify the .cfg
+	 * parsing into one function.
+	 */
+	void get_metadata(std::string const &path, Metadata *m) {
+		memset(m, 0, sizeof(Metadata));
+		FILE *a = fopen(path.c_str(), "r");
+
+		int buflen = 16;
+		char buf[buflen];
+
+		const char *det_article = "<!--SwgArticle";
+		size_t det_article_pos = 0;
+		bool reading_metadata = false,
+			 done = false,
+			 skip = false;
+
+		std::list<std::string> cfg_lines = { "" };
+
+		while (fgets(buf, buflen, a) != NULL) {
+			// Ignore blank lines or lines starting with a comment.
+			if (buf[0] == '\n' || buf[0] == '#') continue;
+			int eol = -1;
+			for (int c = 0; c < buflen; c++) {
+				// Check if this loop has already done what it's supposed to do by checking if the title has been set.
+				if (done || buf[c] == '\0') break;
+				if (!reading_metadata) {
+				// FIXME: This code will not work if buflen < strlen(det_article).
+				if (buf[c] == det_article[det_article_pos]) {
+					det_article_pos++;
+				} else {
+					// TODO: Instead of exiting with an
+					// error code, prompt the end user
+					// whether the build should continue
+					// (while ignoring this article) or
+					// stop.
+					std::cerr << "error: invalid article: " << path << "\n";
+					exit(RETURN_FAILED_UNKNOWN_ERROR);
+				}
+				if (det_article_pos == strlen(det_article)) {
+					reading_metadata = true;
+					skip = true;
+				}
+				}
+				// Check end of HTML comment
+				if (buf[c] == '-' &&
+					buf[c+1] == '-' &&
+					buf[c+2] == '>') {
+					reading_metadata = false;
+					done = true;
+					break;
+				}
+				if (buf[c] == '\n')
+					eol = c;
+			}
+			if (skip) { skip = false; continue; }
+			if (done) break;
+			if (reading_metadata) {
+				if (eol > -1) {
+					buf[eol] = '\0';
+					*(--cfg_lines.end()) += buf;
+					cfg_lines.insert(cfg_lines.end(), "");
+				} else
+					*(--cfg_lines.end()) += buf;
+			}
+		}
+
+		bool reading_article_metadata = false;
+
+		for (std::string const &line : cfg_lines) {
+				std::cout << "[!] Line: " << line << "\n";
+				// Check namespace
+				if (reading_article_metadata) {
+						std::string k_title = "Title=",
+								    k_authors = "Authors=",
+									k_published = "Published=";
+						if (line.find(k_title) == 0)
+								strncpy(m->title, line.substr(k_title.length()).c_str(), sizeof(m->title));
+						else if (line.find(k_authors) == 0)
+								strncpy(m->authors, line.substr(k_authors.length()).c_str(), sizeof(m->authors));
+						else if (line.find(k_published) == 0)
+								m->publish_ts = atoi(line.substr(k_published.length()).c_str());
+						else
+								std::cerr << "warning: ignoring unknown key/value due to unknown key: " << line << std::endl;
+				} else if (line[0] == '[') {
+						if (line == "[ArticleMetadata]") {
+								reading_article_metadata = true;
+						} else {
+								std::cerr << "error: article properties has unknown namespace: " << line << std::endl;
+								exit(RETURN_FAILED_CONFIG_INVALID_SYNTAX);
+						}
+				}
+		}
+
+		fclose(a);
+	}
+};
+

src/Article.hxx

@@ -0,0 +1,50 @@
+/*
+ * 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>. 
+ */
+
+#pragma once
+
+#include <string>
+
+namespace Article {
+	struct Metadata {
+		char title[128];
+		char authors[128];		// Author (or authors) for this article
+
+		// Epoch timestamps
+		long original_ts;	// Original article timestamp (for "Originally written on [...]")
+		long publish_ts;	// (for "Published on [...]")
+		long update_ts;		// (for "Last updated on [...]")
+
+		// Article flags
+		bool partially_obsoleted,
+		     obsoleted,
+		     mature_content;
+
+		char partially_obsoleted_reason[256],
+		     obsoleted_reason[256],
+		     obsoletion_followup_article[128],
+
+		     mature_content_reason[256];
+	};
+
+	void get_metadata(std::string const &path, Metadata *m);
+}
+