/*
Minetest
Copyright (C) 2010-2013 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 "irrlichttypes_bloated.h"
#include "light.h"
#include <string>
#include <vector>

class NodeDefManager;
class Map;

/*
	Naming scheme:
	- Material = irrlicht's Material class
	- Content = (content_t) content of a node
	- Tile = TileSpec at some side of a node of some content type
*/
typedef u16 content_t;

/*
	The maximum node ID that can be registered by mods. This must
	be significantly lower than the maximum content_t value, so that
	there is enough room for dummy node IDs, which are created when
	a MapBlock containing unknown node names is loaded from disk.
*/
#define MAX_REGISTERED_CONTENT 0x7fffU

/*
	A solid walkable node with the texture unknown_node.png.

	For example, used on the client to display unregistered node IDs
	(instead of expanding the vector of node definitions each time
	such a node is received).
*/
#define CONTENT_UNKNOWN 125

/*
	The common material through which the player can walk and which
	is transparent to light
*/
#define CONTENT_AIR 126

/*
	Ignored node.

	Unloaded chunks are considered to consist of this. Several other
	methods return this when an error occurs. Also, during
	map generation this means the node has not been set yet.

	Doesn't create faces with anything and is considered being
	out-of-map in the game map.
*/
#define CONTENT_IGNORE 127

enum LightBank
{
	LIGHTBANK_DAY,
	LIGHTBANK_NIGHT
};

/*
	Simple rotation enum.
*/
enum Rotation {
	ROTATE_0,
	ROTATE_90,
	ROTATE_180,
	ROTATE_270,
	ROTATE_RAND,
};

/*
	Masks for MapNode.param2 of flowing liquids
 */
#define LIQUID_LEVEL_MASK 0x07
#define LIQUID_FLOW_DOWN_MASK 0x08

//#define LIQUID_LEVEL_MASK 0x3f // better finite water
//#define LIQUID_FLOW_DOWN_MASK 0x40 // not used when finite water

/* maximum amount of liquid in a block */
#define LIQUID_LEVEL_MAX LIQUID_LEVEL_MASK
#define LIQUID_LEVEL_SOURCE (LIQUID_LEVEL_MAX+1)

#define LIQUID_INFINITY_MASK 0x80 //0b10000000

// mask for leveled nodebox param2
#define LEVELED_MASK 0x7F
#define LEVELED_MAX LEVELED_MASK


struct ContentFeatures;

/*
	This is the stuff what the whole world consists of.
*/


struct MapNode
{
	/*
		Main content/*
Minetest
Copyright (C) 2013 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 <cctype>
#include <fstream>
#include <json/json.h>
#include <algorithm>
#include "content/mods.h"
#include "filesys.h"
#include "log.h"
#include "content/subgames.h"
#include "settings.h"
#include "porting.h"
#include "convert_json.h"

bool parseDependsString(std::string &dep, std::unordered_set<char> &symbols)
{
	dep = trim(dep);
	symbols.clear();
	size_t pos = dep.size();
	while (pos > 0 &&
			!string_allowed(dep.substr(pos - 1, 1), MODNAME_ALLOWED_CHARS)) {
		// last character is a symbol, not part of the modname
		symbols.insert(dep[pos - 1]);
		--pos;
	}
	dep = trim(dep.substr(0, pos));
	return !dep.empty();
}

void parseModContents(ModSpec &spec)
{
	// NOTE: this function works in mutual recursion with getModsInPath
	Settings info;
	info.readConfigFile((spec.path + DIR_DELIM + "mod.conf").c_str());

	if (info.exists("name"))
		spec.name = info.get("name");

	if (info.exists("author"))
		spec.author = info.get("author");

	if (info.exists("release"))
		spec.release = info.getS32("release");

	spec.depends.clear();
	spec.optdepends.clear();
	spec.is_modpack = false;
	spec.modpack_content.clear();

	// Handle modpacks (defined by containing modpack.txt)
	std::ifstream modpack_is((spec.path + DIR_DELIM + "modpack.txt").c_str());
	std::ifstream modpack2_is((spec.path + DIR_DELIM + "modpack.conf").c_str());
	if (modpack_is.good() || modpack2_is.good()) {
		if (modpack_is.good())
			modpack_is.close();

		if (modpack2_is.good())
			modpack2_is.close();

		spec.is_modpack = true;
		spec.modpack_content = getModsInPath(spec.path, true);

	} else {
		// Attempt to load dependencies from mod.conf
		bool mod_conf_has_depends = false;
		if (info.exists("depends")) {
			mod_conf_has_depends = true;
			std::string dep = info.get("depends");
			// clang-format off
			dep.erase(std::remove_if(dep.begin(), dep.end(),
					static_cast<int (*)(int)>(&std::isspace)), dep.end());
			// clang-format on
			for (const auto &dependency : str_split(dep, ',')) {
				spec.depends.insert(dependency);
			}
		}

		if (info.exists("optional_depends")) {
			mod_conf_has_depends = true;
			std::string dep = info.get("optional_depends");
			// clang-format off
			dep.erase(std::remove_if(dep.begin(), dep.end(),
					static_cast<int (*)(int)>(&std::isspace)), dep.end());
			// clang-format on
			for (const auto &dependency : str_split(dep, ',')) {
				spec.optdepends.insert(dependency);
			}
		}

		// Fallback to depends.txt
		if (!mod_conf_has_depends) {
			std::vector<std::string> dependencies;

			std::ifstream is((spec.path + DIR_DELIM + "depends.txt").c_str());
			while (is.good()) {
				std::string dep;
				std::getline(is, dep);
				dependencies.push_back(dep);
			}

			for (auto &dependency : dependencies) {
				std::unordered_set<char> symbols;
				if (parseDependsString(dependency, symbols)) {
					if (symbols.count('?') != 0) {
						spec.optdepends.insert(dependency);
					} else {
						spec.depends.insert(dependency);
					}
				}
			}
		}

		if (info.exists("description")) {
			spec.desc = info.get("description");
		} else {
			std::ifstream is((spec.path + DIR_DELIM + "description.txt")
							 .c_str());
			spec.desc = std::string((std::istreambuf_iterator<char>(is)),
					std::istreambuf_iterator<char>());
		}
	}
}

std::map<std::string, ModSpec> getModsInPath(
		const std::string &path, bool part_of_modpack)
{
	// NOTE: this function works in mutual recursion with parseModContents

	std::map<std::string, ModSpec> result;
	std::vector<fs::DirListNode> dirlist = fs::GetDirListing(path);
	std::string modpath;

	for (const fs::DirListNode &dln : dirlist) {
		if (!dln.dir)
			continue;

		const std::string &modname = dln.name;
		// Ignore all directories beginning with a ".", especially
		// VCS directories like ".git" or ".svn"
		if (modname[0] == '.')
			continue;

		modpath.clear();
		modpath.append(path).append(DIR_DELIM).append(modname);

		ModSpec spec(modname, modpath, part_of_modpack);
		parseModContents(spec);
		result.insert(std::make_pair(modname, spec));
	}
	return result;
}

std::vector<ModSpec> flattenMods(std::map<std::string, ModSpec> mods)
{
	std::vector<ModSpec> result;
	for (const auto &it : mods) {
		const ModSpec &mod = it.second;
		if (mod.is_modpack) {
			std::vector<ModSpec> content = flattenMods(mod.modpack_content);
			result.reserve(result.size() + content.size());
			result.insert(result.end(), content.begin(), content.end());

		} else // not a modpack
		{
			result.push_back(mod);
		}
	}
	return result;
}

ModConfiguration::ModConfiguration(const std::string &worldpath)
{
}

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)
{
	addMods(flattenMods(getModsInPath(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::addModsFromConfig(
		const std::string &settings_path, const std::set<std::string> &mods)
{
	Settings conf;
	std::set<std::string> load_mod_names;

	conf.readConfigFile(settings_path.c_str());
	std::vector<std::string> names = conf.getNames();
	for (const std::string &name : names) {
		if (name.compare(0, 9, "load_mod_") == 0 && conf.get(name) != "false" &&
				conf.get(name) != "nil")
			load_mod_names.insert(name.substr(9));
	}

	std::vector<ModSpec> addon_mods;
	for (const std::string &i : mods) {
		std::vector<ModSpec> addon_mods_in_path = flattenMods(getModsInPath(i));
		for (std::vector<ModSpec>::const_iterator it = addon_mods_in_path.begin();
				it != addon_mods_in_path.end(); ++it) {
			const ModSpec &mod = *it;
			if (load_mod_names.count(mod.name) != 0)
				addon_mods.push_back(mod);
			else
				conf.setBool("load_mod_" + mod.name, false);
		}
	}
	conf.updateConfigFile(settings_path.c_str());

	addMods(addon_mods);
	checkConflictsAndDeps();

	// complain about mods declared to be loaded, but not found
	for (const ModSpec &addon_mod : addon_mods)
		load_mod_names.erase(addon_mod.name);

	std::vector<ModSpec> unsatisfiedMods = getUnsatisfiedMods();

	for (const ModSpec &unsatisfiedMod : unsatisfiedMods)
		load_mod_names.erase(unsatisfiedMod.name);

	if (!load_mod_names.empty()) {
		errorstream << "The following mods could not be found:";
		for (const std::string &mod : load_mod_names)
			errorstream << " \"" << mod << "\"";
		errorstream << std::endl;
	}
}

void ModConfiguration::checkConflictsAndDeps()
{
	// report on name conflicts
	if (!m_name_conflicts.empty()) {
		std::string s = "Unresolved name conflicts for mods ";
		for (std::unordered_set<std::string>::const_iterator it =
						m_name_conflicts.begin();
				it != m_name_conflicts.end(); ++it) {
			if (it != m_name_conflicts.begin())
				s += ", ";
			s += std::string("\"") + (*it) + "\"";
		}
		s += ".";
		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());
}

#ifndef SERVER
ClientModConfiguration::ClientModConfiguration(const std::string &path) :
		ModConfiguration(path)
{
	std::set<std::string> paths;
	std::string path_user = porting::path_user + DIR_DELIM + "clientmods";
	paths.insert(path);
	paths.insert(path_user);

	std::string settings_path = path_user + DIR_DELIM + "mods.conf";
	addModsFromConfig(settings_path, paths);
}
#endif

ModMetadata::ModMetadata(const std::string &mod_name) : m_mod_name(mod_name)
{
}

void ModMetadata::clear()
{
	Metadata::clear();
	m_modified = true;
}

bool ModMetadata::save(const std::string &root_path)
{
	Json::Value json;
	for (StringMap::const_iterator it = m_stringvars.begin();
			it != m_stringvars.end(); ++it) {
		json[it->first] = it->second;
	}

	if (!fs::PathExists(root_path)) {
		if (!fs::CreateAllDirs(root_path)) {
			errorstream << "ModMetadata[" << m_mod_name
				    << "]: Unable to save. '" << root_path
				    << "' tree cannot be created." << std::endl;
			return false;
		}
	} else if (!fs::IsDir(root_path)) {
		errorstream << "ModMetadata[" << m_mod_name << "]: Unable to save. '"
			    << root_path << "' is not a directory." << std::endl;
		return false;
	}

	bool w_ok = fs::safeWriteToFile(
			root_path + DIR_DELIM + m_mod_name, fastWriteJson(json));

	if (w_ok) {
		m_modified = false;
	} else {
		errorstream << "ModMetadata[" << m_mod_name << "]: failed write file."
			    << std::endl;
	}
	return w_ok;
}

bool ModMetadata::load(const std::string &root_path)
{
	m_stringvars.clear();

	std::ifstream is((root_path + DIR_DELIM + m_mod_name).c_str(),
			std::ios_base::binary);
	if (!is.good()) {
		return false;
	}

	Json::Value root;
	Json::CharReaderBuilder builder;
	builder.settings_["collectComments"] = false;
	std::string errs;

	if (!Json::parseFromStream(builder, is, &root, &errs)) {
		errorstream << "ModMetadata[" << m_mod_name
			    << "]: failed read data "
			       "(Json decoding failure). Message: "
			    << errs << std::endl;
		return false;
	}

	const Json::Value::Members attr_list = root.getMemberNames();
	for (const auto &it : attr_list) {
		Json::Value attr_value = root[it];
		m_stringvars[it] = attr_value.asString();
	}

	return true;
}

bool ModMetadata::setString(const std::string &name, const std::string &var)
{
	m_modified = Metadata::setString(name, var);
	return m_modified;
}