/**
 * @file llrun.cpp
 * @author Phoenix
 * @date 2006-02-16
 * @brief Implementation of the LLRunner and related classes
 *
 * $LicenseInfo:firstyear=2006&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library 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;
 * version 2.1 of the License only.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"
#include "llrun.h"

#include "llframetimer.h"

static const LLRunner::run_handle_t INVALID_RUN_HANDLE = 0;

/**
 * LLRunner
 */
LLRunner::LLRunner() :
    mNextHandle(1)
{
}

LLRunner::~LLRunner()
{
    mRunOnce.clear();
    mRunEvery.clear();
}

size_t LLRunner::run()
{
    // We collect all of the runnables which should be run. Since the
    // runnables are allowed to adjust the run list, we need to copy
    // them into a temporary structure which then iterates over them
    // to call out of this method into the runnables.
    F64 now = LLFrameTimer::getTotalSeconds();
    run_list_t run_now;

    // Collect the run once. We erase the matching ones now because
    // it's easier. If we find a reason to keep them around for a
    // while, we can restructure this method.
    LLRunner::run_list_t::iterator iter = mRunOnce.begin();
    for( ; iter != mRunOnce.end(); )
    {
        if(now > (*iter).mNextRunAt)
        {
            run_now.push_back(*iter);
            iter = mRunOnce.erase(iter);
        }
        else
        {
            ++iter;
        }
    }

    // Collect the ones that repeat.
    iter = mRunEvery.begin();
    LLRunner::run_list_t::iterator end = mRunEvery.end();
    for( ; iter != end; ++iter )
    {
        if(now > (*iter).mNextRunAt)
        {
            (*iter).mNextRunAt = now + (*iter).mIncrement;
            run_now.push_back(*iter);
        }
    }

    // Now, run them.
    iter = run_now.begin();
    end = run_now.end();
    for( ; iter != end; ++iter )
    {
        (*iter).mRunnable->run(this, (*iter).mHandle);
    }
    return run_now.size();
}

LLRunner::run_handle_t LLRunner::addRunnable(
    run_ptr_t runnable,
    ERunSchedule schedule,
    F64 seconds)
{
    if(!runnable) return INVALID_RUN_HANDLE;
    run_handle_t handle = mNextHandle++;
    F64 next_run = LLFrameTimer::getTotalSeconds() + seconds;
    LLRunInfo info(handle, runnable, schedule, next_run, seconds);
    switch(schedule)
    {
    case RUN_IN:
        // We could optimize this a bit by sorting this on entry.
        mRunOnce.push_back(info);
        break;
    case RUN_EVERY:
        mRunEvery.push_back(info);
        break;
    default:
        handle = INVALID_RUN_HANDLE;
        break;
    }
    return handle;
}

LLRunner::run_ptr_t LLRunner::removeRunnable(LLRunner::run_handle_t handle)
{
    LLRunner::run_ptr_t rv;
    LLRunner::run_list_t::iterator iter = mRunOnce.begin();
    LLRunner::run_list_t::iterator end = mRunOnce.end();
    for( ; iter != end; ++iter)
    {
        if((*iter).mHandle == handle)
        {
            rv = (*iter).mRunnable;
            mRunOnce.erase(iter);
            return rv;
        }
    }

    iter = mRunEvery.begin();
    end = mRunEvery.end();
    for( ; iter != end; ++iter)
    {
        if((*iter).mHandle == handle)
        {
            rv = (*iter).mRunnable;
            mRunEvery.erase(iter);
            return rv;
        }
    }
    return rv;
}

/**
 * LLRunner::LLRunInfo
 */
LLRunner::LLRunInfo::LLRunInfo(
    run_handle_t handle,
    run_ptr_t runnable,
    ERunSchedule schedule,
    F64 next_run_after,
    F64 increment) :
    mHandle(handle),
    mRunnable(runnable),
    mSchedule(schedule),
    mNextRunAt(next_run_after),
    mIncrement(increment)
{
}

LLRunnable::LLRunnable()
{ }

// virtual
LLRunnable::~LLRunnable()
{ }