// Copyright (C) 1999-2000 Id Software, Inc.
//

/*
 *  Portions Copyright (C) 2000-2001 Tim Angus
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the OSML - Open Source Modification License v1.0 as
 *  described in the file COPYING which is distributed with this source
 *  code.
 *
 *  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.
 */

#include "g_local.h"

#define MISSILE_PRESTEP_TIME  50

/*
================
G_BounceMissile

================
*/
void G_BounceMissile( gentity_t *ent, trace_t *trace )
{
  vec3_t  velocity;
  float dot;
  int   hitTime;

  // reflect the velocity on the trace plane
  hitTime = level.previousTime + ( level.time - level.previousTime ) * trace->fraction;
  BG_EvaluateTrajectoryDelta( &ent->s.pos, hitTime, velocity );
  dot = DotProduct( velocity, trace->plane.normal );
  VectorMA( velocity, -2 * dot, trace->plane.normal, ent->s.pos.trDelta );

  if( ent->s.eFlags & EF_BOUNCE_HALF )
  {
    VectorScale( ent->s.pos.trDelta, 0.65, ent->s.pos.trDelta );
    // check for stop
    if( trace->plane.normal[ 2 ] > 0.2 && VectorLength( ent->s.pos.trDelta ) < 40 )
    {
      G_SetOrigin( ent, trace->endpos );
      return;
    }
  }

  VectorAdd( ent->r.currentOrigin, trace->plane.normal, ent->r.currentOrigin );
  VectorCopy( ent->r.currentOrigin, ent->s.pos.trBase );
  ent->s.pos.trTime = level.time;
}


/*
================
G_ExplodeMissile

Explode a missile without an impact
================
*/
void G_ExplodeMissile( gentity_t *ent )
{
  vec3_t    dir;
  vec3_t    origin;

  BG_EvaluateTrajectory( &ent->s.pos, level.time, origin );
  SnapVector( origin );
  G_SetOrigin( ent, origin );

  // we don't have a valid direction, so just point straight up
  dir[ 0 ] = dir[ 1 ] = 0;
  dir[ 2 ] = 1;

  ent->s.eType = ET_GENERAL;

  //TA: tired... can't be fucked... hack
  if( ent->s.weapon != WP_LOCKBLOB_LAUNCHER && ent->s.weapon != WP_FLAMER )
    G_AddEvent( ent, EV_MISSILE_MISS, DirToByte( dir ) );

  ent->freeAfterEvent = qtrue;

  // splash damage
  if( ent->splashDamage )
    G_RadiusDamage( ent->r.currentOrigin, ent->parent, ent->splashDamage,
                    ent->splashRadius, ent, ent->splashMethodOfDeath );

  trap_LinkEntity( ent );
}


/*
================
G_MissileImpact

================
*/
void G_MissileImpact( gentity_t *ent, trace_t *trace )
{
  gentity_t   *other;
  qboolean    hitClient = qfalse;

  other = &g_entities[ trace->entityNum ];

  // check for bounce
  if( !other->takedamage &&
      ( ent->s.eFlags & ( EF_BOUNCE | EF_BOUNCE_HALF ) ) )
  {
    G_BounceMissile( ent, trace );
    G_AddEvent( ent, EV_GRENADE_BOUNCE, 0 );
    return;
  }

  // impact damage
  if( other->takedamage )
  {
    // FIXME: wrong damage direction?
    if( ent->damage )
    {
      vec3_t  velocity;

      BG_EvaluateTrajectoryDelta( &ent->s.pos, level.time, velocity );
      if( VectorLength( velocity ) == 0 )
        velocity[ 2 ] = 1;  // stepped on a grenade
      
      G_Damage( other, ent, &g_entities[ ent->r.ownerNum ], velocity,
        ent->s.origin, ent->damage, 
        0, ent->methodOfDeath );
    }
  }

  if( !strcmp( ent->classname, "lockblob" ) )
  {
    if( other->client && other->client->ps.stats[ STAT_PTEAM ] == PTE_HUMANS )
    {
      other->client->ps.stats[ STAT_STATE ] |= SS_BLOBLOCKED;
      other->client->lastLockTime = level.time;
      VectorCopy( other->client->ps.viewangles, other->client->ps.grapplePoint );
    }
  }
  else if( !strcmp( ent->classname, "slowblob" ) )
  {
    if( other->client && other->client->ps.stats[ STAT_PTEAM ] == PTE_HUMANS )
    {
      other->client->ps.stats[ STAT_STATE ] |= SS_SLOWLOCKED;
      other->client->lastSlowTime = level.time;
      VectorCopy( other->client->ps.viewangles, other->client->ps.grapplePoint );
    }
  }
  
  // is it cheaper in bandwidth to just remove this ent and create a new
  // one, rather than changing the missile into the explosion?

  if( other->takedamage && other->client )
  {
    G_AddEvent( ent, EV_MISSILE_HIT, DirToByte( trace->plane.normal ) );
    ent->s.otherEntityNum = other->s.number;
  }
  else if( trace->surfaceFlags & SURF_METALSTEPS )
    G_AddEvent( ent, EV_MISSILE_MISS_METAL, DirToByte( trace->plane.normal ) );
  else
    G_AddEvent( ent, EV_MISSILE_MISS, DirToByte( trace->plane.normal ) );

  ent->freeAfterEvent = qtrue;

  // change over to a normal entity right at the point of impact
  ent->s.eType = ET_GENERAL;

  SnapVectorTowards( trace->endpos, ent->s.pos.trBase );  // save net bandwidth

  G_SetOrigin( ent, trace->endpos );

  // splash damage (doesn't apply to person directly hit)
  if( ent->splashDamage )
    G_RadiusDamage( trace->endpos, ent->parent, ent->splashDamage, ent->splashRadius, 
                    other, ent->splashMethodOfDeath );

  trap_LinkEntity( ent );
}


/*
================
G_RunMissile

================
*/
void G_RunMissile( gentity_t *ent )
{
  vec3_t    origin;
  trace_t   tr;
  int     passent;

  // get current position
  BG_EvaluateTrajectory( &ent->s.pos, level.time, origin );

  // if this missile bounced off an invulnerability sphere
  if ( ent->target_ent )
  {
    passent = ent->target_ent->s.number;
  }
  else
  {
    // ignore interactions with the missile owner
    passent = ent->r.ownerNum;
  }
  // trace a line from the previous position to the current position
  trap_Trace( &tr, ent->r.currentOrigin, ent->r.mins, ent->r.maxs, origin, passent, ent->clipmask );

  if( tr.startsolid || tr.allsolid )
  {
    // make sure the tr.entityNum is set to the entity we're stuck in
    trap_Trace( &tr, ent->r.currentOrigin, ent->r.mins, ent->r.maxs, ent->r.currentOrigin, passent, ent->clipmask );
    tr.fraction = 0;
  }
  else
    VectorCopy( tr.endpos, ent->r.currentOrigin );

  trap_LinkEntity( ent );

  if( tr.fraction != 1 )
  {
    // never explode or bounce on sky
    if( tr.surfaceFlags & SURF_NOIMPACT )
    {
      // If grapple, reset owner
      if( ent->parent && ent->parent->client && ent->parent->client->hook == ent )
        ent->parent->client->hook = NULL;
        
      G_FreeEntity( ent );
      return;
    }

    G_MissileImpact( ent, &tr );
    if ( ent->s.eType != ET_MISSILE )
      return;   // exploded
  }

  // check think function after bouncing
  G_RunThink( ent );
}


//=============================================================================

/*
=================
fire_flamer

=================
*/
gentity_t *fire_flamer( gentity_t *self, vec3_t start, vec3_t dir )
{
  gentity_t *bolt;
  vec3_t    pvel;

  VectorNormalize (dir);

  bolt = G_Spawn();
  bolt->classname = "flame";
  bolt->nextthink = level.time + FLAMER_LIFETIME;
  bolt->think = G_ExplodeMissile;
  bolt->s.eType = ET_MISSILE;
  bolt->r.svFlags = SVF_USE_CURRENT_ORIGIN;
  bolt->s.weapon = WP_FLAMER;
  bolt->r.ownerNum = self->s.number;
  bolt->parent = self;
  bolt->damage = FLAMER_DMG;
  bolt->splashDamage = FLAMER_DMG;
  bolt->splashRadius = FLAMER_RADIUS;
  bolt->methodOfDeath = MOD_FLAMER;
  bolt->splashMethodOfDeath = MOD_FLAMER_SPLASH;
  bolt->clipmask = MASK_SHOT;
  bolt->target_ent = NULL;

  bolt->s.pos.trType = TR_LINEAR;
  bolt->s.pos.trTime = level.time - MISSILE_PRESTEP_TIME;   // move a bit on the very first frame
  VectorCopy( start, bolt->s.pos.trBase );
  VectorScale( self->client->ps.velocity, FLAMER_LAG, pvel );
  VectorMA( pvel, FLAMER_SPEED, dir, bolt->s.pos.trDelta );
  SnapVector( bolt->s.pos.trDelta );      // save net bandwidth

  VectorCopy( start, bolt->r.currentOrigin );

  return bolt;
} 

//=============================================================================

/*
=================
fire_pulseRifle

=================
*/
gentity_t *fire_pulseRifle( gentity_t *self, vec3_t start, vec3_t dir )
{
  gentity_t *bolt;

  VectorNormalize (dir);

  bolt = G_Spawn();
  bolt->classname = "pulse";
  bolt->nextthink = level.time + 10000;
  bolt->think = G_ExplodeMissile;
  bolt->s.eType = ET_MISSILE;
  bolt->r.svFlags = SVF_USE_CURRENT_ORIGIN;
  bolt->s.weapon = WP_PULSE_RIFLE;
  bolt->r.ownerNum = self->s.number;
  bolt->parent = self;
  bolt->damage = PRIFLE_DMG;
  bolt->splashDamage = 0;
  bolt->splashRadius = 0;
  //bolt->methodOfDeath = MOD_FLAMER;
  //bolt->splashMethodOfDeath = MOD_FLAMER_SPLASH;
  bolt->clipmask = MASK_SHOT;
  bolt->target_ent = NULL;

  bolt->s.pos.trType = TR_LINEAR;
  bolt->s.pos.trTime = level.time - MISSILE_PRESTEP_TIME;   // move a bit on the very first frame
  VectorCopy( start, bolt->s.pos.trBase );
  VectorScale( dir, PRIFLE_SPEED, bolt->s.pos.trDelta );
  SnapVector( bolt->s.pos.trDelta );      // save net bandwidth

  VectorCopy( start, bolt->r.currentOrigin );

  return bolt;
}

//=============================================================================

/*
=================
fire_luciferCanon

=================
*/
gentity_t *fire_luciferCanon( gentity_t *self, vec3_t start, vec3_t dir, int damage )
{
  gentity_t *bolt;
  int localDamage = (int)( ceil( ( (float)damage /
                                   (float)LCANON_TOTAL_CHARGE ) * (float)LCANON_DAMAGE ) );

  VectorNormalize( dir );

  bolt = G_Spawn( );
  bolt->classname = "lcanon";
  bolt->nextthink = level.time + 10000;
  bolt->think = G_ExplodeMissile;
  bolt->s.eType = ET_MISSILE;
  bolt->r.svFlags = SVF_USE_CURRENT_ORIGIN;
  bolt->s.weapon = WP_LUCIFER_CANON;
  bolt->r.ownerNum = self->s.number;
  bolt->parent = self;
  bolt->damage = localDamage;
  bolt->splashDamage = localDamage / 2;
  bolt->splashRadius = localDamage;
  bolt->s.generic1 = damage;
  //bolt->methodOfDeath = MOD_FLAMER;
  //bolt->splashMethodOfDeath = MOD_FLAMER_SPLASH;
  bolt->clipmask = MASK_SHOT;
  bolt->target_ent = NULL;

  bolt->s.pos.trType = TR_LINEAR;
  bolt->s.pos.trTime = level.time - MISSILE_PRESTEP_TIME;   // move a bit on the very first frame
  VectorCopy( start, bolt->s.pos.trBase );
  VectorScale( dir, LCANON_SPEED, bolt->s.pos.trDelta );
  SnapVector( bolt->s.pos.trDelta );      // save net bandwidth

  VectorCopy( start, bolt->r.currentOrigin );

  return bolt;
}

//=============================================================================

/*
=================
fire_lockblob
=================
*/
gentity_t *fire_lockblob( gentity_t *self, vec3_t start, vec3_t dir )
{
  gentity_t *bolt;

  VectorNormalize ( dir );

  bolt = G_Spawn( );
  bolt->classname = "lockblob";
  bolt->nextthink = level.time + 15000;
  bolt->think = G_ExplodeMissile;
  bolt->s.eType = ET_MISSILE;
  bolt->r.svFlags = SVF_USE_CURRENT_ORIGIN;
  bolt->s.weapon = WP_LOCKBLOB_LAUNCHER;
  bolt->r.ownerNum = self->s.number;
  bolt->parent = self;
  bolt->damage = 0;
  bolt->splashDamage = 0;
  bolt->splashRadius = 0;
  bolt->methodOfDeath = MOD_ROCKET;
  bolt->splashMethodOfDeath = MOD_ROCKET_SPLASH;
  bolt->clipmask = MASK_SHOT;
  bolt->target_ent = NULL;

  bolt->s.pos.trType = TR_LINEAR;
  bolt->s.pos.trTime = level.time - MISSILE_PRESTEP_TIME;   // move a bit on the very first frame
  VectorCopy( start, bolt->s.pos.trBase );
  VectorScale( dir, 500, bolt->s.pos.trDelta );
  SnapVector( bolt->s.pos.trDelta );      // save net bandwidth
  VectorCopy( start, bolt->r.currentOrigin );

  return bolt;
}

/*
=================
fire_SlowBlob
=================
*/
gentity_t *fire_slowBlob( gentity_t *self, vec3_t start, vec3_t dir )
{
  gentity_t *bolt;

  VectorNormalize ( dir );

  bolt = G_Spawn( );
  bolt->classname = "slowblob";
  bolt->nextthink = level.time + 15000;
  bolt->think = G_ExplodeMissile;
  bolt->s.eType = ET_MISSILE;
  bolt->r.svFlags = SVF_USE_CURRENT_ORIGIN;
  bolt->s.weapon = WP_POUNCE_UPG;
  bolt->r.ownerNum = self->s.number;
  bolt->parent = self;
  bolt->damage = DRAGOON_SLOWBLOB_DMG;
  bolt->splashDamage = 0;
  bolt->splashRadius = 0;
  bolt->methodOfDeath = MOD_ROCKET;
  bolt->splashMethodOfDeath = MOD_ROCKET_SPLASH;
  bolt->clipmask = MASK_SHOT;
  bolt->target_ent = NULL;

  bolt->s.pos.trType = TR_GRAVITY;
  bolt->s.pos.trTime = level.time - MISSILE_PRESTEP_TIME;   // move a bit on the very first frame
  VectorCopy( start, bolt->s.pos.trBase );
  VectorScale( dir, DRAGOON_SLOWBLOB_SPEED, bolt->s.pos.trDelta );
  SnapVector( bolt->s.pos.trDelta );      // save net bandwidth
  VectorCopy( start, bolt->r.currentOrigin );

  return bolt;
}

/*
=================
fire_paraLockBlob
=================
*/
gentity_t *fire_paraLockBlob( gentity_t *self, vec3_t start, vec3_t dir )
{
  gentity_t *bolt;

  VectorNormalize ( dir );

  bolt = G_Spawn( );
  bolt->classname = "lockblob";
  bolt->nextthink = level.time + 15000;
  bolt->think = G_ExplodeMissile;
  bolt->s.eType = ET_MISSILE;
  bolt->r.svFlags = SVF_USE_CURRENT_ORIGIN;
  bolt->s.weapon = WP_LOCKBLOB_LAUNCHER;
  bolt->r.ownerNum = self->s.number;
  bolt->parent = self;
  bolt->damage = 0;
  bolt->splashDamage = 0;
  bolt->splashRadius = 0;
  bolt->methodOfDeath = MOD_ROCKET;
  bolt->splashMethodOfDeath = MOD_ROCKET_SPLASH;
  bolt->clipmask = MASK_SHOT;
  bolt->target_ent = NULL;

  bolt->s.pos.trType = TR_GRAVITY;
  bolt->s.pos.trTime = level.time - MISSILE_PRESTEP_TIME;   // move a bit on the very first frame
  VectorCopy( start, bolt->s.pos.trBase );
  VectorScale( dir, LOCKBLOB_SPEED, bolt->s.pos.trDelta );
  SnapVector( bolt->s.pos.trDelta );      // save net bandwidth
  VectorCopy( start, bolt->r.currentOrigin );

  return bolt;
}