Refactor ModConfiguration

1 files changed, 111 insertions, 0 deletions

diff --git a/src/content/mod_configuration.h b/src/content/mod_configuration.h
new file mode 100644
index 000000000..1595d1ca3
--- /dev/null
+++ b/src/content/mod_configuration.h
@@ -0,0 +1,111 @@
+/*
+Minetest
+Copyright (C) 2013-22 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "mods.h"
+
+
+/**
+ * ModConfiguration is a subset of installed mods. This class
+ * is used to resolve dependencies and return a sorted list of mods.
+ *
+ * This class should not be extended from, but instead used as a
+ * component in other classes.
+ */
+class ModConfiguration
+{
+public:
+	/**
+	 * @returns true if all dependencies are fullfilled.
+	 */
+	inline bool isConsistent() const { return m_unsatisfied_mods.empty(); }
+
+	inline const std::vector<ModSpec> &getUnsatisfiedMods() const
+	{
+		return m_unsatisfied_mods;
+	}
+
+	/**
+	 * List of mods sorted such that they can be loaded in the
+	 * given order with all dependencies being fulfilled.
+	 *
+	 * I.e: every mod in this list has only dependencies on mods which
+	 * appear earlier in the vector.
+	 */
+	const std::vector<ModSpec> &getMods() const { return m_sorted_mods; }
+
+	void printUnsatisfiedModsError() const;
+
+	/**
+	 * Adds all mods in the given path. used for games, modpacks
+	 * and world-specific mods (worldmods-folders)
+	 *
+	 * @param path To search, should be absolute
+	 * @param virtual_path Virtual path for this directory, see comment in ModSpec
+	 */
+	void addModsInPath(const std::string &path, const std::string &virtual_path);
+
+	/**
+	 * Adds all mods in `new_mods`
+	 */
+	void addMods(const std::vector<ModSpec> &new_mods);
+
+	/**
+	 * Adds game mods
+	 */
+	void addGameMods(const SubgameSpec &gamespec);
+
+	/**
+	 * Adds mods specifed by a world.mt config
+	 *
+	 * @param settings_path Path to world.mt
+	 * @param modPaths Map from virtual name to mod path
+	 */
+	void addModsFromConfig(const std::string &settings_path,
+			const std::unordered_map<std::string, std::string> &modPaths);
+
+	/**
+	 * Call this function once all mods have been added
+	 */
+	void checkConflictsAndDeps();
+
+private:
+	std::vector<ModSpec> m_sorted_mods;
+
+	/**
+	 * move mods from m_unsatisfied_mods to m_sorted_mods
+	 * in an order that satisfies dependencies
+	 */
+	void resolveDependencies();
+
+	// mods with unmet dependencies. Before dependencies are resolved,
+	// this is where all mods are stored. Afterwards this contains
+	// only the ones with really unsatisfied dependencies.
+	std::vector<ModSpec> m_unsatisfied_mods;
+
+	// set of mod names for which an unresolved name conflict
+	// exists. A name conflict happens when two or more mods
+	// at the same level have the same name but different paths.
+	// Levels (mods in higher levels override mods in lower levels):
+	// 1. game mod in modpack; 2. game mod;
+	// 3. world mod in modpack; 4. world mod;
+	// 5. addon mod in modpack; 6. addon mod.
+	std::unordered_set<std::string> m_name_conflicts;
+};