Refactor ModConfiguration

src/content/mod_configuration.cpp

@@ -0,0 +1,255 @@
+/*
+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.
+*/
+
+#include "mod_configuration.h"
+#include "log.h"
+#include "settings.h"
+#include "filesys.h"
+
+void ModConfiguration::printUnsatisfiedModsError() const
+{
+	for (const ModSpec &mod : m_unsatisfied_mods) {
+		errorstream << "mod \"" << mod.name
+					<< "\" has unsatisfied dependencies: ";
+		for (const std::string &unsatisfied_depend : mod.unsatisfied_depends)
+			errorstream << " \"" << unsatisfied_depend << "\"";
+		errorstream << std::endl;
+	}
+}
+
+void ModConfiguration::addModsInPath(const std::string &path, const std::string &virtual_path)
+{
+	addMods(flattenMods(getModsInPath(path, virtual_path)));
+}
+
+void ModConfiguration::addMods(const std::vector<ModSpec> &new_mods)
+{
+	// Maintain a map of all existing m_unsatisfied_mods.
+	// Keys are mod names and values are indices into m_unsatisfied_mods.
+	std::map<std::string, u32> existing_mods;
+	for (u32 i = 0; i < m_unsatisfied_mods.size(); ++i) {
+		existing_mods[m_unsatisfied_mods[i].name] = i;
+	}
+
+	// Add new mods
+	for (int want_from_modpack = 1; want_from_modpack >= 0; --want_from_modpack) {
+		// First iteration:
+		// Add all the mods that come from modpacks
+		// Second iteration:
+		// Add all the mods that didn't come from modpacks
+
+		std::set<std::string> seen_this_iteration;
+
+		for (const ModSpec &mod : new_mods) {
+			if (mod.part_of_modpack != (bool)want_from_modpack)
+				continue;
+
+			if (existing_mods.count(mod.name) == 0) {
+				// GOOD CASE: completely new mod.
+				m_unsatisfied_mods.push_back(mod);
+				existing_mods[mod.name] = m_unsatisfied_mods.size() - 1;
+			} else if (seen_this_iteration.count(mod.name) == 0) {
+				// BAD CASE: name conflict in different levels.
+				u32 oldindex = existing_mods[mod.name];
+				const ModSpec &oldmod = m_unsatisfied_mods[oldindex];
+				warningstream << "Mod name conflict detected: \""
+						<< mod.name << "\"" << std::endl
+						<< "Will not load: " << oldmod.path
+						<< std::endl
+						<< "Overridden by: " << mod.path
+						<< std::endl;
+				m_unsatisfied_mods[oldindex] = mod;
+
+				// If there was a "VERY BAD CASE" name conflict
+				// in an earlier level, ignore it.
+				m_name_conflicts.erase(mod.name);
+			} else {
+				// VERY BAD CASE: name conflict in the same level.
+				u32 oldindex = existing_mods[mod.name];
+				const ModSpec &oldmod = m_unsatisfied_mods[oldindex];
+				warningstream << "Mod name conflict detected: \""
+						<< mod.name << "\"" << std::endl
+						<< "Will not load: " << oldmod.path
+						<< std::endl
+						<< "Will not load: " << mod.path
+						<< std::endl;
+				m_unsatisfied_mods[oldindex] = mod;
+				m_name_conflicts.insert(mod.name);
+			}
+
+			seen_this_iteration.insert(mod.name);
+		}
+	}
+}
+
+void ModConfiguration::addGameMods(const SubgameSpec &gamespec)
+{
+	std::string game_virtual_path;
+	game_virtual_path.append("games/").append(gamespec.id).append("/mods");
+	addModsInPath(gamespec.gamemods_path, game_virtual_path);
+}
+
+void ModConfiguration::addModsFromConfig(
+		const std::string &settings_path,
+		const std::unordered_map<std::string, std::string> &modPaths)
+{
+	Settings conf;
+	std::unordered_map<std::string, std::string> load_mod_names;
+
+	conf.readConfigFile(settings_path.c_str());
+	std::vector<std::string> names = conf.getNames();
+	for (const std::string &name : names) {
+		const auto &value = conf.get(name);
+		if (name.compare(0, 9, "load_mod_") == 0 && value != "false" &&
+				value != "nil")
+			load_mod_names[name.substr(9)] = value;
+	}
+
+	// List of enabled non-game non-world mods
+	std::vector<ModSpec> addon_mods;
+
+	// Map of modname to a list candidate mod paths. Used to list
+	// alternatives if a particular mod cannot be found.
+	std::unordered_map<std::string, std::vector<std::string>> candidates;
+
+	/*
+	 * Iterate through all installed mods except game mods and world mods
+	 *
+	 * If the mod is enabled, add it to `addon_mods`. *
+	 *
+	 * Alternative candidates for a modname are stored in `candidates`,
+	 * and used in an error message later.
+	 *
+	 * If not enabled, add `load_mod_modname = false` to world.mt
+	 */
+	for (const auto &modPath : modPaths) {
+		std::vector<ModSpec> addon_mods_in_path = flattenMods(getModsInPath(modPath.second, modPath.first));
+		for (const auto &mod : addon_mods_in_path) {
+			const auto &pair = load_mod_names.find(mod.name);
+			if (pair != load_mod_names.end()) {
+				if (is_yes(pair->second) || pair->second == mod.virtual_path) {
+					addon_mods.push_back(mod);
+				} else {
+					candidates[pair->first].emplace_back(mod.virtual_path);
+				}
+			} else {
+				conf.setBool("load_mod_" + mod.name, false);
+			}
+		}
+	}
+	conf.updateConfigFile(settings_path.c_str());
+
+	addMods(addon_mods);
+
+	// Remove all loaded mods from `load_mod_names`
+	// NB: as deps have not yet been resolved, `m_unsatisfied_mods` will contain all mods.
+	for (const ModSpec &mod : m_unsatisfied_mods)
+		load_mod_names.erase(mod.name);
+
+	// Complain about mods declared to be loaded, but not found
+	if (!load_mod_names.empty()) {
+		errorstream << "The following mods could not be found:";
+		for (const auto &pair : load_mod_names)
+			errorstream << " \"" << pair.first << "\"";
+		errorstream << std::endl;
+
+		for (const auto &pair : load_mod_names) {
+			const auto &candidate = candidates.find(pair.first);
+			if (candidate != candidates.end()) {
+				errorstream << "Unable to load " << pair.first << " as the specified path "
+							<< pair.second << " could not be found. "
+							<< "However, it is available in the following locations:"
+							<< std::endl;
+				for (const auto &path : candidate->second) {
+					errorstream << " - " << path << std::endl;
+				}
+			}
+		}
+	}
+}
+
+void ModConfiguration::checkConflictsAndDeps()
+{
+	// report on name conflicts
+	if (!m_name_conflicts.empty()) {
+		std::string s = "Unresolved name conflicts for mods ";
+
+		bool add_comma = false;
+		for (const auto& it : m_name_conflicts) {
+			if (add_comma)
+				s.append(", ");
+			s.append("\"").append(it).append("\"");
+			add_comma = true;
+		}
+		s.append(".");
+
+		throw ModError(s);
+	}
+
+	// get the mods in order
+	resolveDependencies();
+}
+
+void ModConfiguration::resolveDependencies()
+{
+	// Step 1: Compile a list of the mod names we're working with
+	std::set<std::string> modnames;
+	for (const ModSpec &mod : m_unsatisfied_mods) {
+		modnames.insert(mod.name);
+	}
+
+	// Step 2: get dependencies (including optional dependencies)
+	// of each mod, split mods into satisfied and unsatisfied
+	std::list<ModSpec> satisfied;
+	std::list<ModSpec> unsatisfied;
+	for (ModSpec mod : m_unsatisfied_mods) {
+		mod.unsatisfied_depends = mod.depends;
+		// check which optional dependencies actually exist
+		for (const std::string &optdep : mod.optdepends) {
+			if (modnames.count(optdep) != 0)
+				mod.unsatisfied_depends.insert(optdep);
+		}
+		// if a mod has no depends it is initially satisfied
+		if (mod.unsatisfied_depends.empty())
+			satisfied.push_back(mod);
+		else
+			unsatisfied.push_back(mod);
+	}
+
+	// Step 3: mods without unmet dependencies can be appended to
+	// the sorted list.
+	while (!satisfied.empty()) {
+		ModSpec mod = satisfied.back();
+		m_sorted_mods.push_back(mod);
+		satisfied.pop_back();
+		for (auto it = unsatisfied.begin(); it != unsatisfied.end();) {
+			ModSpec &mod2 = *it;
+			mod2.unsatisfied_depends.erase(mod.name);
+			if (mod2.unsatisfied_depends.empty()) {
+				satisfied.push_back(mod2);
+				it = unsatisfied.erase(it);
+			} else {
+				++it;
+			}
+		}
+	}
+
+	// Step 4: write back list of unsatisfied mods
+	m_unsatisfied_mods.assign(unsatisfied.begin(), unsatisfied.end());
+}