/*
Copyright (C) 1996-1997 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

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 included (GNU.txt) 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, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
/* ZOID
 *
 * Player camera tracking in Spectator mode
 *
 * This takes over player controls for spectator automatic camera.
 * Player moves as a spectator, but the camera tracks and enemy player
 */

#include "quakedef.h"
#include "pmove.h"
#include "sbar.h"
#include "teamplay.h"	
#include "utils.h"

static vec3_t desired_position; // where the camera wants to be
static qboolean locked = false;
static int oldbuttons;

cvar_t cl_chasecam = {"cl_chasecam", "1"};		// "through the eyes" view

vec3_t cam_viewangles;
double cam_lastviewtime;

int spec_track = 0; // player# of who we are tracking
int autocam = CAM_NONE;


int		ideal_track = 0;
float	last_lock = 0;


void CL_Track_f(void);	

void vectoangles(vec3_t vec, vec3_t ang) {
	float forward, yaw, pitch;
	
	if (vec[1] == 0 && vec[0] == 0) {
		yaw = 0;
		pitch = (vec[2] > 0) ? 90 : 270;
	} else {
		yaw = (int) (atan2(vec[1], vec[0]) * 180 / M_PI);
		if (yaw < 0)
			yaw += 360;

		forward = sqrt (vec[0]*vec[0] + vec[1]*vec[1]);
		pitch = (int) (atan2(vec[2], forward) * 180 / M_PI);
		if (pitch < 0)
			pitch += 360;
	}

	ang[0] = pitch;
	ang[1] = yaw;
	ang[2] = 0;
}

void Cam_SetViewPlayer (void) {
	if (cl.spectator && autocam && locked && cl_chasecam.value)
		cl.viewplayernum = spec_track;
	else
		cl.viewplayernum = cl.playernum;
}

// returns true if weapon model should be drawn in camera mode
qboolean Cam_DrawViewModel(void) {
	if (!cl.spectator)
		return true;

	if (autocam && locked && cl_chasecam.value)
		return true;
	return false;
}

// returns true if we should draw this player, we don't if we are chase camming
qboolean Cam_DrawPlayer(int playernum) {
	if (cl.spectator && autocam && locked && cl_chasecam.value && 
		spec_track == playernum)
		return false;
	return true;
}

void Cam_Unlock(void) {
	if (!autocam)
		return;

	MSG_WriteByte (&cls.netchan.message, clc_stringcmd);
	MSG_WriteString (&cls.netchan.message, "ptrack");
	autocam = CAM_NONE;
	locked = false;
	Sbar_Changed();

	if (TP_NeedRefreshSkins())
		TP_RefreshSkins();
}

void Cam_Lock(int playernum) {
	char st[40];

	sprintf(st, "ptrack %i", playernum);

	if (cls.mvdplayback) {
		memcpy(cl.stats, cl.players[playernum].stats, sizeof(cl.stats));
		ideal_track = playernum;
	}	
	last_lock = cls.realtime;

	MSG_WriteByte (&cls.netchan.message, clc_stringcmd);
	MSG_WriteString (&cls.netchan.message, st);
	spec_track = playernum;
	locked = false;
	Sbar_Changed();

	if (TP_NeedRefreshSkins())
		TP_RefreshSkins();
}

pmtrace_t Cam_DoTrace(vec3_t vec1, vec3_t vec2) {
	VectorCopy (vec1, pmove.origin);
	return PM_PlayerTrace(pmove.origin, vec2);
}
	
// Returns distance or 9999 if invalid for some reason
static float Cam_TryFlyby(player_state_t *self, player_state_t *player, vec3_t vec, qboolean checkvis) {
	vec3_t v;
	pmtrace_t trace;
	float len;

	vectoangles(vec, v);
	VectorCopy (v, pmove.angles);
	VectorNormalizeFast(vec);
	VectorMA(player->origin, 800, vec, v);
	// v is endpos
	// fake a player move
	trace = Cam_DoTrace(player->origin, v);
	if (trace.inwater)
		return 9999;
	VectorCopy(trace.endpos, vec);
	VectorSubtract(trace.endpos, player->origin, v);
	len = VectorLength(v);
	if (len < 32 || len > 800)
		return 9999;
	if (checkvis) {
		VectorSubtract(trace.endpos, self->origin, v);
		len = VectorLength(v);

		trace = Cam_DoTrace(self->origin, vec);
		if (trace.fraction != 1 || trace.inwater)
			return 9999;
	}
	return len;
}

// Is player visible?
static qboolean Cam_IsVisible(player_state_t *player, vec3_t vec) {
	pmtrace_t trace;
	vec3_t v;

	trace = Cam_DoTrace(player->origin, vec);
	if (trace.fraction != 1 || /*trace.inopen ||*/ trace.inwater)
		return false;
	// check distance, don't let the player get too far away or too close
	VectorSubtract(player->origin, vec, v);

	return ((v[0]*v[0]+v[1]*v[1]+v[2]*v[2]) >= 256);
}

static qboolean InitFlyby(player_state_t *self, player_state_t *player, int checkvis) {
    float f, max;
    vec3_t vec, vec2;
	vec3_t forward, right, up;

	VectorCopy(player->viewangles, vec);
    vec[0] = 0;
	AngleVectors (vec, forward, right, up);

    max = 1000;
	VectorAdd(forward, up, vec2);
	VectorAdd(vec2, right, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorAdd(forward, up, vec2);
	VectorSubtract(vec2, right, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorAdd(forward, right, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorSubtract(forward, right, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorAdd(forward, up, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorSubtract(forward, up, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorAdd(up, right, vec2);
	VectorSubtract(vec2, forward, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorSubtract(up, right, vec2);
	VectorSubtract(vec2, forward, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	// invert
	VectorSubtract(vec3_origin, forward, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorCopy(forward, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	// invert
	VectorSubtract(vec3_origin, right, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }
	VectorCopy(right, vec2);
    if ((f = Cam_TryFlyby(self, player, vec2, checkvis)) < max) {
        max = f;
		VectorCopy(vec2, vec);
    }

	// ack, can't find him
    if (max >= 1000)
		return false;
	locked = true;
	VectorCopy(vec, desired_position); 
	return true;
}

// Take over the user controls and track a player.
// We find a nice position to watch the player and move there
void Cam_Track(usercmd_t *cmd) {
	player_state_t *player, *self;
	frame_t *frame;
	vec3_t vec;

	if (!cl.spectator)
		return;
	
	if (!autocam || cls.state != ca_active)
		return;

	if (locked && (!cl.players[spec_track].name[0] || cl.players[spec_track].spectator)) {
		locked = false;
		Cam_Unlock();
		return;
	}

	frame = &cl.frames[cl.validsequence & UPDATE_MASK];


	if (autocam && cls.mvdplayback)	{
		if (ideal_track != spec_track && cls.realtime - last_lock > 0.1 && 
			frame->playerstate[ideal_track].messagenum == cl.parsecount)
			Cam_Lock(ideal_track);

		if (frame->playerstate[spec_track].messagenum != cl.parsecount)	{
			int i;

			for (i = 0; i < MAX_CLIENTS; i++) {
				if (frame->playerstate[i].messagenum == cl.parsecount)
					break;
			}
			if (i < MAX_CLIENTS)
				Cam_Lock(i);
		}
	}


	player = frame->playerstate + spec_track;
	self = frame->playerstate + cl.playernum;

	if (!locked || !Cam_IsVisible(player, desired_position)) {
		if (!locked || cls.realtime - cam_lastviewtime > 0.1) {
			if (!InitFlyby(self, player, true))
				InitFlyby(self, player, false);
			cam_lastviewtime = cls.realtime;
		}
	} else {
		cam_lastviewtime = cls.realtime;
	}
	
	// couldn't track for some reason
	if (!locked || !autocam)
		return;

	if (cl_chasecam.value) {
		cmd->forwardmove = cmd->sidemove = cmd->upmove = 0;

		VectorCopy(player->viewangles, cl.viewangles);
		VectorCopy(player->origin, desired_position);
		if (memcmp(&desired_position, &self->origin, sizeof(desired_position)) != 0) {
			MSG_WriteByte (&cls.netchan.message, clc_tmove);
			MSG_WriteCoord (&cls.netchan.message, desired_position[0]);
			MSG_WriteCoord (&cls.netchan.message, desired_position[1]);
			MSG_WriteCoord (&cls.netchan.message, desired_position[2]);
			// move there locally immediately
			VectorCopy(desired_position, self->origin);
		}
	} else {
		// Ok, move to our desired position and set our angles to view
		// the player
		VectorSubtract(desired_position, self->origin, vec);
		cmd->forwardmove = cmd->sidemove = cmd->upmove = 0;
		if (VectorLength(vec) > 16) { // close enough?
			MSG_WriteByte (&cls.netchan.message, clc_tmove);
			MSG_WriteCoord (&cls.netchan.message, desired_position[0]);
			MSG_WriteCoord (&cls.netchan.message, desired_position[1]);
			MSG_WriteCoord (&cls.netchan.message, desired_position[2]);
		}

		// move there locally immediately
		VectorCopy(desired_position, self->origin);
										 
		VectorSubtract(player->origin, desired_position, vec);
		vectoangles(vec, cl.viewangles);
		cl.viewangles[0] = -cl.viewangles[0];
	}
}

void Cam_FinishMove(usercmd_t *cmd) {
	int i, end;
	player_info_t *s;

	if (cls.state != ca_active)
		return;

	if (!cl.spectator) // only in spectator mode
		return;

	if (cmd->buttons & BUTTON_ATTACK) {
		if (!(oldbuttons & BUTTON_ATTACK)) {

			oldbuttons |= BUTTON_ATTACK;
			autocam++;

			if (autocam > CAM_TRACK) {
				Cam_Unlock();
				VectorCopy(cl.viewangles, cmd->angles);
				return;
			}
		} else
			return;
	} else {
		oldbuttons &= ~BUTTON_ATTACK;
		if (!autocam)
			return;
	}

	if (locked) {
		if ((cmd->buttons & BUTTON_JUMP) && (oldbuttons & BUTTON_JUMP))
			return;		// don't pogo stick

		if (!(cmd->buttons & BUTTON_JUMP)) {
			oldbuttons &= ~BUTTON_JUMP;
			return;
		}
		oldbuttons |= BUTTON_JUMP;	// don't jump again until released
	}

	
	if (locked && autocam)
		end = (ideal_track + 1) % MAX_CLIENTS;
	else
		end = ideal_track;

	i = end;
	do {
		s = &cl.players[i];
		if (s->name[0] && !s->spectator) {
			Cam_Lock(i);
			ideal_track = i;    
			return;
		}
		i = (i + 1) % MAX_CLIENTS;
	} while (i != end);
	// stay on same guy?	

	i = ideal_track;	
	s = &cl.players[i];
	if (s->name[0] && !s->spectator) {
		Cam_Lock(i);
		return;
	}
	Com_Printf ("No target found ...\n");
	autocam = locked = false;
}

void Cam_Reset(void) {
	autocam = CAM_NONE;
	spec_track = 0;
	ideal_track = 0;    
}

//Fixes spectator chasecam demos
void Cam_TryLock (void) {
	int i, j, old_autocam, old_spec_track;
	player_state_t *state;
	static float cam_lastlocktime;

	if (!cl.validsequence)
		return;

	if (!autocam)
		cam_lastlocktime = 0;

	old_autocam = autocam;
	old_spec_track = spec_track;

	state = cl.frames[cl.validsequence & UPDATE_MASK].playerstate;
	for (i = 0; i < MAX_CLIENTS; i++) {
		if (!cl.players[i].name[0] || cl.players[i].spectator ||
			state[i].messagenum != cl.parsecount)
			continue;
		if (fabs(state[i].command.angles[0] - cl.viewangles[0]) < 2 && fabs(state[i].command.angles[1] - cl.viewangles[1]) < 2) {
			for (j = 0; j < 3; j++)
				if (fabs(state[i].origin[j] - state[cl.playernum].origin[j]) > 200)
					break;	// too far
			if (j < 3)
				continue;
			autocam = CAM_TRACK;
			spec_track = i;
			locked = true;
			cam_lastlocktime = cls.realtime;
			break;
		}
	}

	if (cls.realtime - cam_lastlocktime > 0.3) {
		// Couldn't lock to any player for 0.3 seconds, so assume
		// the spectator switched to free spectator mode
		autocam = CAM_NONE;
		spec_track = 0;
		locked = false;
	}

	if (autocam != old_autocam || spec_track != old_spec_track) {
		Sbar_Changed ();

		if (TP_NeedRefreshSkins())
			TP_RefreshSkins();
	}
}

void CL_InitCam(void) {
	Cvar_SetCurrentGroup(CVAR_GROUP_SPECTATOR);
	Cvar_Register (&cl_chasecam);

	Cvar_ResetCurrentGroup();
	Cmd_AddCommand ("track", CL_Track_f);		
}

void CL_Track_f(void) {	
	int slot;
	char *arg;

	if (cls.state < ca_connected) {
		Com_Printf("You must be connected to track\n", Cmd_Argv(0));
		return;
	}
	if (!cl.spectator) {
		Com_Printf("You can only track in spectator mode\n", Cmd_Argv(0));
		return;
	}
	if (Cmd_Argc() != 2) {
		Com_Printf("Usage: %s <name | userid>\n", Cmd_Argv(0));
		return;
	}

	slot = Player_GetSlot(arg = Cmd_Argv(1));

	if (slot == PLAYER_NAME_NOMATCH) {
		Com_Printf("%s : no such player %s\n", Cmd_Argv(0), arg);
		return;
	} else if (slot == PLAYER_ID_NOMATCH) {
		Com_Printf("%s : no player with userid %d\n", Cmd_Argv(0), Q_atoi(arg));
		return;
	} else if (slot < 0 || slot >= MAX_CLIENTS) {	//PLAYER_NUM_MISMATCH covered by this
		Com_Printf("%s : no such player\n", Cmd_Argv(0));
		return;
	}

	if (cl.players[slot].spectator) {
		Com_Printf("You cannot track a spectator\n", Cmd_Argv(0));
	} else if (Cam_TrackNum() != slot) {
		autocam = CAM_TRACK;
		Cam_Lock(slot);
		ideal_track = slot;
		locked = true;
	}
}



int Cam_TrackNum(void) {
	if (!autocam)
		return -1;
	return spec_track;
}