/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections;
using System.Collections.Generic;
using System.Threading;
using System.Diagnostics;
using OpenMetaverse;
using log4net;
using OpenSim.Framework;
using OpenSim.Region.Framework.Scenes;
using OpenSim.Region.ScriptEngine.Shared;
using OpenSim.Region.ScriptEngine.Interfaces;

namespace OpenSim.Region.ScriptEngine.Interfaces
{
    public enum StateSource
    {
        RegionStart = 0,
        NewRez = 1,
        PrimCrossing = 2,
        ScriptedRez = 3,
        AttachedRez = 4,
        Teleporting = 5
    }

    public interface IScriptWorkItem
    {
        bool Cancel();
        bool Abort();

        /// <summary>
        /// Wait for the work item to complete.
        /// </summary>
        /// <param name='t'>The number of milliseconds to wait.  Must be >= -1 (Timeout.Infinite).</param>
        bool Wait(int t);
    }

    /// <summary>
    /// Interface for interaction with a particular script instance
    /// </summary>
    public interface IScriptInstance
    {
        /// <summary>
        /// Debug level for this script instance.
        /// </summary>
        /// <remarks>
        /// Level == 0, no extra data is logged.
        /// Level >= 1, state changes are logged.
        /// Level >= 2, event firing is logged.
        /// <value>
        /// The debug level.
        /// </value>
        int DebugLevel { get; set; }

        /// <summary>
        /// Is the script currently running?
        /// </summary>
        bool Running { get; set; }

        /// <summary>
        /// Is the script suspended?
        /// </summary>
        bool Suspended { get; set; }

        /// <summary>
        /// Is the script shutting down?
        /// </summary>
        bool ShuttingDown { get; set; }

        /// <summary>
        /// When stopping the script: should it remain stopped permanently (i.e., save !Running in its state)?
        /// </summary>
        bool StayStopped { get; set; }

        /// <summary>
        /// Script state
        /// </summary>
        string State { get; set; }

        /// <summary>
        /// If true then the engine is responsible for persisted state.  If false then some other component may
        /// persist state (e.g. attachments persisting in assets).
        /// </summary>
        bool StatePersistedHere { get; }

        /// <summary>
        /// Time the script was last started
        /// </summary>
        DateTime TimeStarted { get; }

        /// <summary>
        /// Collects information about how long the script was executed.
        /// </summary>
        MetricsCollectorTime ExecutionTime { get; }

        /// <summary>
        /// Scene part in which this script instance is contained.
        /// </summary>
        SceneObjectPart Part { get; }

        IScriptEngine Engine { get; }
        UUID AppDomain { get; set; }
        string PrimName { get; }
        string ScriptName { get; }
        UUID ItemID { get; }
        UUID ObjectID { get; }

        /// <summary>
        /// UUID of the root object for the linkset that the script is in.
        /// </summary>
        UUID RootObjectID { get; }

        /// <summary>
        /// Local id of the root object for the linkset that the script is in.
        /// </summary>
        uint RootLocalID { get; }

        uint LocalID { get; }
        UUID AssetID { get; }

        /// <summary>
        /// Inventory item containing the script used.
        /// </summary>
        TaskInventoryItem ScriptTask { get; }

        Queue EventQueue { get; }

        /// <summary>
        /// Number of events queued for processing.
        /// </summary>
        long EventsQueued { get; }

        /// <summary>
        /// Number of events processed by this script instance.
        /// </summary>
        long EventsProcessed { get; }

        void ClearQueue();
        int StartParam { get; set; }

        WaitHandle CoopWaitHandle { get; }
        Stopwatch ExecutionTimer { get; }

        void RemoveState();

        void Init();
        void Start();

        /// <summary>
        /// Stop the script instance.
        /// </summary>
        /// <remarks>
        /// This must not be called by a thread that is in the process of handling an event for this script.  Otherwise
        /// there is a danger that it will self-abort and not complete the reset.
        /// </remarks>
        /// <param name="timeout"></param>
        /// How many milliseconds we will wait for an existing script event to finish before
        /// forcibly aborting that event.
        /// <param name="clearEventQueue">If true then the event queue is also cleared</param>
        /// <returns>true if the script was successfully stopped, false otherwise</returns>
        bool Stop(int timeout, bool clearEventQueue = false);

        void SetState(string state);

        /// <summary>
        /// Post an event to this script instance.
        /// </summary>
        /// <param name="data"></param>
        void PostEvent(EventParams data);

        void Suspend();
        void Resume();

        /// <summary>
        /// Process the next event queued for this script instance.
        /// </summary>
        /// <returns></returns>
        object EventProcessor();

        int EventTime();

        /// <summary>
        /// Reset the script.
        /// </summary>
        /// <remarks>
        /// This must not be called by a thread that is in the process of handling an event for this script.  Otherwise
        /// there is a danger that it will self-abort and not complete the reset.  Such a thread must call
        /// ApiResetScript() instead.
        /// </remarks>
        /// <param name='timeout'>
        /// How many milliseconds we will wait for an existing script event to finish before
        /// forcibly aborting that event prior to script reset.
        /// </param>
        void ResetScript(int timeout);

        /// <summary>
        /// Reset the script.
        /// </summary>
        /// <remarks>
        /// This must not be called by any thread other than the one executing the scripts current event.  This is
        /// because there is no wait or abort logic if another thread is in the middle of processing a script event.
        /// Such an external thread should use ResetScript() instead.
        /// </remarks>
        void ApiResetScript();

        Dictionary<string, object> GetVars();
        void SetVars(Dictionary<string, object> vars);
        DetectParams GetDetectParams(int idx);
        UUID GetDetectID(int idx);
        void SaveState();
        void DestroyScriptInstance();

        IScriptApi GetApi(string name);

        Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>> LineMap
                { get; set; }

        string GetAssemblyName();
        string GetXMLState();
        double MinEventDelay { set; }
        UUID RegionID { get; }
    }
}
