/**
 * vim: set ts=4 :
 * =============================================================================
 * SourceMod Sample Extension
 * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
 * =============================================================================
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, version 3.0, as published by the
 * Free Software Foundation.
 *
 * This program 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 General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * As a special exception, AlliedModders LLC gives you permission to link the
 * code of this program (as well as its derivative works) to "Half-Life 2," the
 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
 * by the Valve Corporation.  You must obey the GNU General Public License in
 * all respects for all other code used.  Additionally, AlliedModders LLC grants
 * this exception to all derivative works.  AlliedModders LLC defines further
 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
 * or <http://www.sourcemod.net/license.php>.
 *
 * Version: $Id$
 */

#include "extension.h"
#include "gamemovement_hack.h"

FlashboostEnabler g_FlashboostEnabler;

SMEXT_LINK(&g_FlashboostEnabler );

typedef const Vector&(*GetPlayerViewVector_t)(CGameMovement*);

GetPlayerViewVector_t g_pGetPlayerMins = nullptr;
GetPlayerViewVector_t g_pGetPlayerMaxs = nullptr;


IEngineTrace* enginetrace = nullptr;
CGameMovement* g_pGameMovement = nullptr;

SH_DECL_MANUALHOOK3( MHook_TestPlayerPosition, 0, 0, 0, CBaseHandle, const Vector&, int, trace_t& );

bool FlashboostEnabler::SDK_OnLoad( char *error, size_t maxlen, bool late )
{
    g_pSM->LogMessage( myself, "Got interfaces: enginetrace=%p, g_pGameMovement=%p", enginetrace, g_pGameMovement );

    IGameConfig* cfg;

    char conf_error[255];
    if( !gameconfs->LoadGameConfigFile( "flashboost-enabler.games", &cfg, conf_error, sizeof( conf_error ) ) )
    {
        if( conf_error[0] )
            snprintf( error, maxlen, "Could not read config file flashboost-enabler.games.txt: %s", conf_error );

        return false;
    }

    int offset;

    if( cfg->GetOffset( "CGameMovement::TestPlayerPosition", &offset ) )
    {
        SH_MANUALHOOK_RECONFIGURE( MHook_TestPlayerPosition, offset, 0, 0 );
    }
    else
    {
        snprintf( error, maxlen, "Could not get offset for CGameMovement::TestPlayerPosition" );

        gameconfs->CloseGameConfigFile( cfg );
        return false;
    }

    if( cfg->GetOffset( "CGameMovement::GetPlayerMins", &offset ) )
    {
        int* pVtable = *reinterpret_cast<int**>( g_pGameMovement );
        g_pGetPlayerMins = reinterpret_cast<GetPlayerViewVector_t>( pVtable[offset] );
    }
    else
    {
        snprintf( error, maxlen, "Could not get offset for CGameMovement::GetPlayerMins" );

        gameconfs->CloseGameConfigFile( cfg );
        return false;
    }

    if( cfg->GetOffset( "CGameMovement::GetPlayerMaxs", &offset ) )
    {
        int* pVtable = *reinterpret_cast<int**>( g_pGameMovement );
        g_pGetPlayerMaxs = reinterpret_cast<GetPlayerViewVector_t>( pVtable[offset] );
    }
    else
    {
        snprintf( error, maxlen, "Could not get offset for CGameMovement::GetPlayerMaxs" );

        gameconfs->CloseGameConfigFile( cfg );
        return false;
    }

    cfg->GetAddress( "CTraceFilterSimple::ShouldHitEntity", reinterpret_cast<void**>( &g_pShouldHitEntity ) );
    if( g_pShouldHitEntity == nullptr )
    {
        snprintf( error, maxlen, "Failed to obtain CTraceFilterSimple::ShouldHitEntity from gamedata" );
        gameconfs->CloseGameConfigFile( cfg );
        return false;
    }

    gameconfs->CloseGameConfigFile( cfg );

    SH_ADD_MANUALHOOK( MHook_TestPlayerPosition, g_pGameMovement, SH_MEMBER( this, &FlashboostEnabler::Hook_TestPlayerPosition ), false );

    g_pSM->LogMessage( myself, "Successfully hooked/loaded" );

    return true;
}

void FlashboostEnabler::SDK_OnUnload()
{
    SH_REMOVE_MANUALHOOK( MHook_TestPlayerPosition, g_pGameMovement, SH_MEMBER( this, &FlashboostEnabler::Hook_TestPlayerPosition ), false );
}

bool FlashboostEnabler::SDK_OnMetamodLoad( ISmmAPI* ismm, char* error, size_t maxlen, bool late )
{
    GET_V_IFACE_ANY( GetEngineFactory, enginetrace, IEngineTrace, INTERFACEVERSION_ENGINETRACE_SERVER );
    GET_V_IFACE_ANY( GetServerFactory, g_pGameMovement, CGameMovement, INTERFACENAME_GAMEMOVEMENT );

    return true;
}

CBaseHandle FlashboostEnabler::Hook_TestPlayerPosition( const Vector& pos, int collisiongroup, trace_t& pm )
{
    g_pSM->LogMessage( myself, "Ran TestPlayerPosition" );
    Vector mins = g_pGetPlayerMins( g_pGameMovement );
    g_pSM->LogMessage( myself, "Got player mins: (%f, %f, %f)", mins.x, mins.y, mins.z );
    Vector maxs = g_pGetPlayerMaxs( g_pGameMovement );
    g_pSM->LogMessage( myself, "Got player maxs: (%f, %f, %f)", maxs.x, maxs.y, maxs.z );


    g_pSM->LogMessage( myself, "Creating ray ..." );
    Ray_t ray;
    ray.Init( pos, pos, mins, maxs );
    g_pSM->LogMessage( myself, "Ray created" );

    g_pSM->LogMessage( myself, "Creating trace filter ..." );
    IHandleEntity* playerhandle = reinterpret_cast<IHandleEntity*>( gamehelpers->GetHandleEntity( g_pGameMovement->mv->m_nPlayerHandle ) );
    CTraceFilterSimple traceFilter( playerhandle, collisiongroup );
    g_pSM->LogMessage( myself, "Trace filter created" );

    g_pSM->LogMessage( myself, "Doing trace ..." );
    enginetrace->TraceRay( ray, MASK_PLAYERSOLID, &tracefilter, &pm );
    g_pSM->LogMessage( myself, "Trace finished" );

    if( (pm.contents & MASK_PLAYERSOLID) && pm.m_pEnt )
    {
        g_pSM->LogMessage( myself, "END 1: standing on entity" );
        RETURN_META_VALUE( MRES_SUPERCEDE, reinterpret_cast<IHandleEntity*>(pm.m_pEnt)->GetRefEHandle() );
    }
    else
    {
        g_pSM->LogMessage( myself, "END 2: not standing on entity" );
        RETURN_META_VALUE( MRES_SUPERCEDE, INVALID_EHANDLE_INDEX );
    }
}