/*  Starshatter OpenSource Distribution
    Copyright (c) 1997-2004, Destroyer Studios LLC.
    All Rights Reserved.

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      this list of conditions and the following disclaimer.
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      this list of conditions and the following disclaimer in the documentation
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    * Neither the name "Destroyer Studios" nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.

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    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 COPYRIGHT HOLDER OR CONTRIBUTORS BE
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    POSSIBILITY OF SUCH DAMAGE.

    SUBSYSTEM:    Stars.exe
    FILE:         GroundAI.cpp
    AUTHOR:       John DiCamillo


    OVERVIEW
    ========
    Low-Level Artificial Intelligence class for Ground Units
*/

#include "MemDebug.h"
#include "GroundAI.h"
#include "SteerAI.h"
#include "System.h"
#include "Ship.h"
#include "ShipDesign.h"
#include "Shield.h"
#include "Sim.h"
#include "Player.h"
#include "CarrierAI.h"
#include "Contact.h"
#include "Weapon.h"
#include "WeaponGroup.h"

#include "Game.h"
#include "Physical.h"

// +----------------------------------------------------------------------+

GroundAI::GroundAI(SimObject* s)
: ship((Ship*) s), target(0), subtarget(0), exec_time(0), carrier_ai(0)
{
    Sim*  sim         = Sim::GetSim();
    Ship* pship       = sim->GetPlayerShip();
    int   player_team = 1;
    int   ai_level    = 1;

    if (pship)
    player_team = pship->GetIFF();

    Player* player = Player::GetCurrentPlayer();
    if (player) {
        if (ship && ship->GetIFF() && ship->GetIFF() != player_team) {
            ai_level = player->AILevel();
        }
        else if (player->AILevel() == 0) {
            ai_level = 1;
        }
    }

    // evil alien ships are *always* smart:
    if (ship && ship->GetIFF() > 1 && ship->Design()->auto_roll > 1) {
        ai_level = 2;
    }

    if (ship && ship->GetHangar() && ship->GetCommandAILevel() > 0)
    carrier_ai = new(__FILE__,__LINE__) CarrierAI(ship, ai_level);
}


// +--------------------------------------------------------------------+

GroundAI::~GroundAI()
{
    delete carrier_ai;
}

// +--------------------------------------------------------------------+

void
GroundAI::SetTarget(SimObject* targ, System* sub)
{
    if (target != targ) {
        target = targ;

        if (target)
        Observe(target);
    }

    subtarget = sub;
}

// +--------------------------------------------------------------------+

bool
GroundAI::Update(SimObject* obj)
{
    if (obj == target) {
        target = 0;
        subtarget = 0;
    }

    return SimObserver::Update(obj);
}

const char*
GroundAI::GetObserverName() const
{
    static char name[64];
    sprintf_s(name, "GroundAI(%s)", ship->Name());
    return name;
}

// +--------------------------------------------------------------------+

void
GroundAI::SelectTarget()
{
    SimObject* potential_target = 0;

    // pick the closest combatant ship with a different IFF code:
    double target_dist = 1.0e15;

    Ship* current_ship_target = 0;

    ListIter<Contact> c_iter = ship->ContactList();
    while (++c_iter) {
        Contact* contact = c_iter.value();
        int      c_iff   = contact->GetIFF(ship);
        Ship*    c_ship  = contact->GetShip();
        Shot*    c_shot  = contact->GetShot();
        bool     rogue   = false;

        if (c_ship)
        rogue = c_ship->IsRogue();

        if (rogue || c_iff > 0 && c_iff != ship->GetIFF() && c_iff < 1000) {
            if (c_ship && !c_ship->InTransition()) {
                // found an enemy, check distance:
                double dist = (ship->Location() - c_ship->Location()).length();

                if (!current_ship_target || (c_ship->Class() <= current_ship_target->Class() &&
                            dist < target_dist)) {
                    current_ship_target = c_ship;
                    target_dist = dist;
                }
            }
        }

        potential_target = current_ship_target;
    }

    SetTarget(potential_target);
}

// +--------------------------------------------------------------------+

int
GroundAI::Type() const
{
    return SteerAI::GROUND;
}

// +--------------------------------------------------------------------+

void
GroundAI::ExecFrame(double secs)
{
    const int exec_period = 1000;

    if ((int) Game::GameTime() - exec_time > exec_period) {
        exec_time = (int) Game::GameTime();
        SelectTarget();
    }

    if (ship) {
        Shield* shield = ship->GetShield();

        if (shield)
        shield->SetPowerLevel(100);

        ListIter<WeaponGroup> iter = ship->Weapons();
        while (++iter) {
            WeaponGroup* group = (WeaponGroup*) iter.value();

            if (group->NumWeapons() > 1 && group->CanTarget(Ship::DROPSHIPS))
            group->SetFiringOrders(Weapon::POINT_DEFENSE);
            else
            group->SetFiringOrders(Weapon::AUTO);

            group->SetTarget((Ship*) target, 0);
        }

        if (carrier_ai)
        carrier_ai->ExecFrame(secs);
    }
}