package net.crystalyx.bukkit.simplyperms;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import net.crystalyx.bukkit.simplyperms.io.ConfigFile;
import net.crystalyx.bukkit.simplyperms.io.ConfigSQL;
import net.crystalyx.bukkit.simplyperms.io.PermsConfig;

import org.bukkit.configuration.ConfigurationSection;
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.configuration.file.YamlConfiguration;
import org.bukkit.entity.Player;
import org.bukkit.permissions.Permission;
import org.bukkit.permissions.PermissionAttachment;
import org.bukkit.plugin.java.JavaPlugin;

public class SimplyPlugin extends JavaPlugin {

	protected PermsConfig config;
	private SimplyPlayer playerListener = new SimplyPlayer(this);
	private SimplyCommands commandExecutor = new SimplyCommands(this);
	private HashMap<String, PermissionAttachment> permissions = new HashMap<String, PermissionAttachment>();

	private File configFile;
	private YamlConfiguration YamlConfig;

	// -- Basic stuff
	@Override
	public void onEnable() {
		// Unregister existing PermissionsBukkit nodes
		if (getServer().getPluginManager().isPluginEnabled("PermissionsBukkit")) {
			for (Permission perm : getServer().getPluginManager().getPlugin("PermissionsBukkit").getDescription().getPermissions()) {
				getServer().getPluginManager().removePermission(perm);
			}
		}

		// Take care of configuration
		configFile = new File(getDataFolder(), "config.yml");
		if (!configFile.exists()) {
			saveDefaultConfig();
		}
		reloadConfig();

		// Register stuff
		getCommand("permissions").setExecutor(commandExecutor);
		getServer().getPluginManager().registerEvents(playerListener, this);
		registerEvents();

		// Register everyone online right now
		for (Player p : getServer().getOnlinePlayers()) {
			registerPlayer(p);
		}

		// How are you gentlemen
		getLogger().info("Enabled successfully, " + getServer().getOnlinePlayers().length + " players registered");
	}

	@Override
	public FileConfiguration getConfig() {
		return YamlConfig;
	}

	@Override
	public void reloadConfig() {
		YamlConfig = new YamlConfiguration();
		YamlConfig.options().pathSeparator('/');
		try {
			YamlConfig.load(configFile);
		} catch (Exception e) {
			getLogger().severe("Unable to load configuration!");
		}

		// Init DB
		initDatabase();
	}

	@Override
	public void onDisable() {
		// Unregister everyone
		for (Player p : getServer().getOnlinePlayers()) {
			unregisterPlayer(p);
		}

		// Good day to you! I said good day!
		getLogger().info("Disabled successfully, " + getServer().getOnlinePlayers().length + " players unregistered");
	}

	private void initDatabase() {
		if (getConfig().getString("db/type") != null
				&& !getConfig().getString("db/type").equals("file")) {
			ConfigSQL configsql = new ConfigSQL(this);
			if (configsql.checkDatabase()) {
				config = configsql;
			} else {
				debug("Fail to connect to database !");
				config = new ConfigFile(this);
			}
		}
		else {
			config = new ConfigFile(this);
		}
	}

	public SimplyAPI getAPI() {
		return new SimplyAPI(this);
	}

	public List<String> getKeys(YamlConfiguration config, String node) {
		if (config.isConfigurationSection(node)) {
			return new ArrayList<String>(config.getConfigurationSection(node).getKeys(false));
		}
		else {
			return new ArrayList<String>();
		}
	}

	// -- Plugin stuff

	protected void registerPlayer(Player player) {
		if (permissions.containsKey(player.getName())) {
			debug("Registering " + player.getName() + ": was already registered");
			unregisterPlayer(player);
		}
		PermissionAttachment attachment = player.addAttachment(this);
		permissions.put(player.getName(), attachment);
		calculateAttachment(player);
	}

	protected void unregisterPlayer(Player player) {
		if (permissions.containsKey(player.getName())) {
			try {
				player.removeAttachment(permissions.get(player.getName()));
			}
			catch (IllegalArgumentException ex) {
				debug("Unregistering " + player.getName() + ": player did not have attachment");
			}
			permissions.remove(player.getName());
		} else {
			debug("Unregistering " + player.getName() + ": was not registered");
		}
	}

	protected void refreshPermissions() {
		try {
			getConfig().save(configFile);
			reloadConfig();
		} catch (IOException e) {
			getLogger().warning("Failed to write changed config.yml: " + e.getMessage());
		}
		for (String player : permissions.keySet()) {
			PermissionAttachment attachment = permissions.get(player);
			for (String key : attachment.getPermissions().keySet()) {
				attachment.unsetPermission(key);
			}

			calculateAttachment(getServer().getPlayer(player));
		}
	}

	public ConfigurationSection getNode(String node) {
		for (String entry : getConfig().getKeys(true)) {
			if (node.equalsIgnoreCase(entry) && getConfig().isConfigurationSection(entry)) {
				return getConfig().getConfigurationSection(entry);
			}
		}
		return null;
	}

	public void debug(String message) {
		if (getConfig().getBoolean("debug", false)) {
			getLogger().info("Debug: " + message);
		}
	}

	protected void calculateAttachment(Player player) {
		if (player == null) {
			return;
		}
		PermissionAttachment attachment = permissions.get(player.getName());
		if (attachment == null) {
			debug("Calculating permissions on " + player.getName() + ": attachment was null");
			return;
		}

		for (String key : attachment.getPermissions().keySet()) {
			attachment.unsetPermission(key);
		}

		for (Map.Entry<String, Boolean> entry : calculatePlayerPermissions(player.getName().toLowerCase(), player.getWorld().getName()).entrySet()) {
			attachment.setPermission(entry.getKey(), entry.getValue());
		}

		player.recalculatePermissions();
	}

	// -- Private stuff

	private Map<String, Boolean> calculatePlayerPermissions(String player, String world) {
		String default_group = getConfig().getString("default", "default");
		if (!config.isPlayerInDB(player)) {
			return calculateGroupPermissions(default_group, world);
		}

		Map<String, Boolean> perms = new HashMap<String, Boolean>();
		List<String> groups = config.getPlayerGroups(player);
		if (groups.isEmpty()) groups.add(default_group);
		perms.putAll(config.getPlayerPermissions(player));
		// No containskey; world overrides non-world
		perms.putAll(config.getPlayerPermissions(player, world));

		for (String group : groups) {
			for (Map.Entry<String, Boolean> entry : calculateGroupPermissions(group, world).entrySet()) {
				if (!perms.containsKey(entry.getKey())) { // User overrides group
					perms.put(entry.getKey(), entry.getValue());
				}
			}
		}

		return perms;
	}

	private Map<String, Boolean> calculateGroupPermissions(String group, String world) {
		if (getNode("groups/" + group) == null) {
			return new HashMap<String, Boolean>();
		}

		Map<String, Boolean> perms = config.getGroupPermissions(group);
		// No containskey; world overrides non-world
		perms.putAll(config.getGroupPermissions(group, world));

		for (String parent : config.getGroupInheritance(group)) {
			for (Map.Entry<String, Boolean> entry : calculateGroupPermissions(parent, world).entrySet()) {
				if (!perms.containsKey(entry.getKey())) { // Children override permissions
					perms.put(entry.getKey(), entry.getValue());
				}
			}
		}

		return perms;
	}

	private void registerEvents() {
		String path = getDescription().getMain().substring(0, getDescription().getMain().lastIndexOf('.'));
		for (String prevent : SimplyPrevents.preventions) {
			try {
				getServer().getPluginManager().registerEvents((SimplyPrevents) Class.forName(path + ".preventions." + prevent).getDeclaredConstructor(SimplyPlugin.class).newInstance(this), this);
			} catch (Exception e) {
				debug(e.getMessage());
			}
		}
	}

}