package org.bukkit.permissions;

import org.bukkit.plugin.Plugin;

import java.util.LinkedHashMap;
import java.util.Map;

/**
 * Holds information about a permission attachment on a {@link Permissible}
 * object
 */
public class PermissionAttachment
{
	private PermissionRemovedExecutor removed;
	private final Map<String, Boolean> permissions = new LinkedHashMap<String, Boolean>();
	private final Permissible permissible;
	private final Plugin plugin;

	public PermissionAttachment(Plugin plugin, Permissible Permissible)
	{
		if(plugin == null)
		{
			throw new IllegalArgumentException("Plugin cannot be null");
		}
		else if(!plugin.isEnabled())
		{
			throw new IllegalArgumentException("Plugin " + plugin.getDescription().getFullName() + " is disabled");
		}

		this.permissible = Permissible;
		this.plugin = plugin;
	}

	/**
	 * Gets the plugin responsible for this attachment
	 *
	 * @return Plugin responsible for this permission attachment
	 */
	public Plugin getPlugin()
	{
		return plugin;
	}

	/**
	 * Sets an object to be called for when this attachment is removed from a
	 * {@link Permissible}. May be null.
	 *
	 * @param ex Object to be called when this is removed
	 */
	public void setRemovalCallback(PermissionRemovedExecutor ex)
	{
		removed = ex;
	}

	/**
	 * Gets the class that was previously set to be called when this
	 * attachment was removed from a {@link Permissible}. May be null.
	 *
	 * @return Object to be called when this is removed
	 */
	public PermissionRemovedExecutor getRemovalCallback()
	{
		return removed;
	}

	/**
	 * Gets the Permissible that this is attached to
	 *
	 * @return Permissible containing this attachment
	 */
	public Permissible getPermissible()
	{
		return permissible;
	}

	/**
	 * Gets a copy of all set permissions and values contained within this
	 * attachment.
	 * <p>
	 * This map may be modified but will not affect the attachment, as it is a
	 * copy.
	 *
	 * @return Copy of all permissions and values expressed by this attachment
	 */
	public Map<String, Boolean> getPermissions()
	{
		return new LinkedHashMap<String, Boolean>(permissions);
	}

	/**
	 * Sets a permission to the given value, by its fully qualified name
	 *
	 * @param name  Name of the permission
	 * @param value New value of the permission
	 */
	public void setPermission(String name, boolean value)
	{
		permissions.put(name.toLowerCase(), value);
		permissible.recalculatePermissions();
	}

	/**
	 * Sets a permission to the given value
	 *
	 * @param perm  Permission to set
	 * @param value New value of the permission
	 */
	public void setPermission(Permission perm, boolean value)
	{
		setPermission(perm.getName(), value);
	}

	/**
	 * Removes the specified permission from this attachment.
	 * <p>
	 * If the permission does not exist in this attachment, nothing will
	 * happen.
	 *
	 * @param name Name of the permission to remove
	 */
	public void unsetPermission(String name)
	{
		permissions.remove(name.toLowerCase());
		permissible.recalculatePermissions();
	}

	/**
	 * Removes the specified permission from this attachment.
	 * <p>
	 * If the permission does not exist in this attachment, nothing will
	 * happen.
	 *
	 * @param perm Permission to remove
	 */
	public void unsetPermission(Permission perm)
	{
		unsetPermission(perm.getName());
	}

	/**
	 * Removes this attachment from its registered {@link Permissible}
	 *
	 * @return true if the permissible was removed successfully, false if it
	 * did not exist
	 */
	public boolean remove()
	{
		try
		{
			permissible.removeAttachment(this);
			return true;
		} catch(IllegalArgumentException ex)
		{
			return false;
		}
	}
}