//===========================================================================//
// File:	mislanch.cpp                                                        //
// Project: BattleTech           Brick: Mech weapons                          //
// Contents: MissileLauncher -- a projectile weapon that fires missile salvos //
//---------------------------------------------------------------------------//
// Copyright (C) 1995, Virtual World Entertainment, Inc.                     //
// All Rights reserved worldwide                                             //
// This unpublished sourcecode is PROPRIETARY and CONFIDENTIAL               //
//===========================================================================//

#include <bt.hpp>
#pragma hdrstop

#if !defined(MISLANCH_HPP)
#	include <mislanch.hpp>
#endif

#if !defined(MECH_HPP)
#	include <mech.hpp>
#endif

#if !defined(MISSILE_HPP)
#	include <missile.hpp>
#endif

#if !defined(APP_HPP)
#	include <app.hpp>
#endif

#if !defined(HOSTMGR_HPP)
#	include <hostmgr.hpp>
#endif

//
// STAGED launch speed (the binary derives it from the authored
// MuzzleVelocity vector -- the muzzle wave).
//
static const Scalar kMissileLaunchSpeed = 150.0f;	// u/s

Derivation
	MissileLauncher::ClassDerivations(
		ProjectileWeapon::ClassDerivations,
		"MissileLauncher"
	);

MissileLauncher::SharedData
	MissileLauncher::DefaultData(
		MissileLauncher::ClassDerivations,
		Subsystem::MessageHandlers,
		Subsystem::AttributeIndex,
		Subsystem::StateCount
	);

MissileLauncher::MissileLauncher(
	Mech				*owner,
	int					subsystem_ID,
	SubsystemResource	*subsystem_resource,
	SharedData			&default_data
):
	ProjectileWeapon(owner, subsystem_ID, subsystem_resource, default_data)
{
	Check(owner);
	Check_Pointer(subsystem_resource);

	missileCount = subsystem_resource->missileCount;

	//
	// A salvo delivers missileCount missiles; split the per-shot damage across
	// the salvo.  (The per-missile launch mechanics live in FireWeapon, staged.)
	//
	if (missileCount > 0)
	{
		damageData.burstCount	= missileCount;
		damageData.damageAmount	= damageData.damageAmount / (Scalar)missileCount;
	}

	Check_Fpu();
}

MissileLauncher::~MissileLauncher()
{
}

Logical
	MissileLauncher::TestInstance() const
{
	return IsDerivedFrom(ClassDerivations);
}

//
//#############################################################################
// Damage / death.
//#############################################################################
//
void
	MissileLauncher::TakeDamage(Damage &damage)
{
	Check(this);
	ProjectileWeapon::TakeDamage(damage);
}

void
	MissileLauncher::DeathReset(Logical /*full_reset*/)
{
	Check(this);
}

//
// The missile-salvo discharge.  Not yet reconstructed.
//
void
	MissileLauncher::FireWeapon()
{
	Check(this);

	//
	// PARTIAL (binary @004bcc60): the authentic body launches missileCount
	// Missile entities toward the owner's target (each carrying the salvo-split
	// damageData) and dumps the firing heat.  The Missile entity spawn needs
	// the entity-spawn + targeting waves; the view/target gate, ammo pull and
	// recoil all live in the CALLER (ProjectileWeaponSimulation's Loaded case).
	//
	// Ballistic heatCostToFire is stored 1e7-unit-NATIVE in the stream (SRM6
	// reads 5.06e7 = +641K on its own sink -- the same design magnitude as the
	// PPC's +632K); dump it raw, under the heat-model experience gate (novice /
	// standard fire generates no heat -- authentic).  (The EMITTER's authored
	// value is small and its 1e7 comes from the energy algebra.)
	if (HeatModelActive())
	{
		AddPendingHeat(heatCostToFire);
	}

	//
	// The salvo launch (binary @004bcc60): ONE cluster Missile entity per
	// trigger, spawned through the Mover make machinery -- the MakeMessage's
	// resourceID is this weapon's projectile GameModel (explosionResourceID
	// @0x3e4), so the Mover base streams the authored mass/drag.  The round
	// carries the salvo-split cluster damage record (burstCount =
	// missileCount rides into the gyro bounce + splash) and homes via its
	// Seeker; the proximity fuse delivers the damage ONCE (the arcade
	// economy, BT411 task #62).  Muzzle = the mech origin STAGED (the
	// authored MuzzleVelocity arc through the MOUNT segment frame is the
	// muzzle wave).  If the projectile model resource is absent the launch
	// falls back to the 5.3.16 instant-hit delivery.
	//
	if (targetWithinRange && owner != NULL
		&& owner->GetTargetEntity() != NULL
		&& getenv("BT_MISSILE_FLIGHT") == NULL)
	{
		//
		// DEFAULT delivery (the 5.3.18a arcade economy): the instant-hit
		// cluster message.  The flying-Missile path below is complete and
		// live-verified through DETONATE, but its DEATH-ROW TEARDOWN still
		// page-faults (the 5.3.18 frontier, MISSILE.NOTES.md) -- opt in
		// with BT_MISSILE_FLIGHT=1 until the dtor chain is closed.
		//
		SendDamage(owner->GetTargetEntity(), damageData);
	}
	else if (targetWithinRange && owner != NULL
		&& owner->GetTargetEntity() != NULL)
	{
		//
		// The MakeMessage's resourceID must be a resource FAMILY id -- the
		// Mover base ctor runs its own SearchList(resourceID, GameModel),
		// and SearchList CRASHES (engine @0x414938) when the id isn't in
		// the top-level directory (member resources resolve only through
		// their family head).  The streamed explosionModelFile is a small
		// INDEX (SRM6 reads 17) into a model list -- decoding it into the
		// real projectile family is the projectile-model brick.  Until
		// then the round spawns on the OWNER's family (its GameModel
		// member provably streams every boot -- the mech model params);
		// our staged flight integration reads none of the Mover mass/drag.
		//
		{
			HostManager *host_manager = application->GetHostManager();
			Check(host_manager);

			Origin muzzle = owner->localOrigin;
			Mover::MakeMessage
				spawn_round(
					Entity::MakeMessageID,
					sizeof(Mover::MakeMessage),
					EntityID(host_manager->GetLocalHostID()),
					(Entity::ClassID)MissileClassID,
					EntityID::Null,
					owner->GetResourceID(),
					Entity::DefaultFlags,
					muzzle,
					Motion::Identity,
					Motion::Identity
				);
			Missile *round = new Missile(&spawn_round);
			Register_Object(round);
			round->Launch(
				owner,
				owner->GetTargetEntity(),
				damageData,
				kMissileLaunchSpeed
			);
		}
	}

	if (getenv("BT_MECH_LOG"))
	{
		DEBUG_STREAM << "[fire] '" << GetName()
			<< "' FIRED (salvo of " << missileCount
			<< ", recharge=" << rechargeRate
			<< "s heat+=" << heatCostToFire << ")" << endl << flush;
	}
}

//
// Model-load-time construction.  Not yet reconstructed.
//
Logical
	MissileLauncher::CreateStreamedSubsystem(
		ResourceFile				*,
		NotationFile				*,
		const char					*,
		const char					*,
		SubsystemResource			*,
		NotationFile				*,
		const ResourceDirectories	*,
		int
	)
{
	Fail("MissileLauncher::CreateStreamedSubsystem -- mislanch.cpp not yet reconstructed");
	return False;
}