package me.ghost.API;

import java.lang.reflect.Field;
import java.util.List;

import org.bukkit.Bukkit;
import org.bukkit.command.CommandSender;
import org.bukkit.command.ConsoleCommandSender;
import org.bukkit.entity.Player;
import org.bukkit.permissions.Permissible;
import org.bukkit.permissions.PermissibleBase;

public class PermissionsInjector {
	@SuppressWarnings({ "unchecked", "rawtypes" })
	public static org.bukkit.permissions.Permissible inject(CommandSender sender, org.bukkit.permissions.Permissible newpermissible) {
		try {
			Field perm = getPermField(sender);
			if (perm == null) {
				return null;
			}
			perm.setAccessible(true);
			org.bukkit.permissions.Permissible oldpermissible = (org.bukkit.permissions.Permissible) perm.get(sender);
			if (newpermissible instanceof PermissibleBase) {
				// copy attachments
				Field attachments = PermissibleBase.class.getDeclaredField("attachments");
				attachments.setAccessible(true);
				((List) attachments.get(newpermissible)).addAll((List) attachments.get(oldpermissible));
			}

			// inject permissible
			perm.set(sender, newpermissible);
			return oldpermissible;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	public static org.bukkit.permissions.Permissible uninject(CommandSender sender) {
		try {
			Field perm = getPermField(sender);
			if (perm == null) {
				return null;
			}
			perm.setAccessible(true);
			org.bukkit.permissions.Permissible permissible = (org.bukkit.permissions.Permissible) perm.get(sender);
			if (permissible instanceof Permissible) {
				perm.set(sender, ((Permissible) permissible));
				return (Permissible) permissible;
			}

			return null;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	public static org.bukkit.permissions.PermissibleBase getPermissible(CommandSender sender) {
		try {
			Field perm = getPermField(sender);
			if (perm == null) {
				return null;
			}
			perm.setAccessible(true);
			PermissibleBase permissible = (PermissibleBase) perm.get(sender);

			return permissible;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	private static Field getPermField(CommandSender sender) {
		Field perm = null;
		try {
			if (sender instanceof Player) {
				perm = Class.forName(getVersionedClassName("entity.CraftHumanEntity")).getDeclaredField("perm");
			} else if (sender instanceof ConsoleCommandSender) {
				perm = Class.forName(getVersionedClassName("command.ServerCommandSender")).getDeclaredField("perm");
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return perm;
	}

	private static String getVersionedClassName(String classname) {
		String version;

		@SuppressWarnings("rawtypes")
		Class serverClass = Bukkit.getServer().getClass();
		if (!serverClass.getSimpleName().equals("CraftServer")) {
			return null;
		} else if (serverClass.getName().equals("org.bukkit.craftbukkit.CraftServer")) {
			version = ".";
		} else {
			version = serverClass.getName().substring("org.bukkit.craftbukkit".length());
			version = version.substring(0, version.length() - "CraftServer".length());
		}

		return "org.bukkit.craftbukkit" + version + classname;
	}
}