/*
** p_switch.cpp
** Switch and button maintenance and animation
**
**---------------------------------------------------------------------------
** Copyright 1998-2006 Randy Heit
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' 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 AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/

#include "templates.h"
#include "i_system.h"
#include "doomdef.h"
#include "p_local.h"
#include "p_lnspec.h"
#include "p_3dmidtex.h"
#include "m_random.h"
#include "g_game.h"
#include "s_sound.h"
#include "doomstat.h"
#include "r_state.h"
#include "w_wad.h"
#include "tarray.h"
#include "cmdlib.h"
#include "sc_man.h"

#include "gi.h"

#define MAX_FRAMES 128

static FRandom pr_switchanim ("AnimSwitch");

class DActiveButton : public DThinker
{
	DECLARE_CLASS (DActiveButton, DThinker)
public:
	DActiveButton ();
	DActiveButton (side_t *, int, WORD switchnum, fixed_t x, fixed_t y, bool flippable);

	void Serialize (FArchive &arc);
	void Tick ();

	side_t	*m_Side;
	SBYTE	m_Part;
	WORD	m_SwitchDef;
	WORD	m_Frame;
	WORD	m_Timer;
	bool	bFlippable;
	fixed_t	m_X, m_Y;	// Location of timer sound

protected:
	bool AdvanceFrame ();
};

struct FSwitchDef
{
	FTextureID PreTexture;		// texture to switch from
	WORD PairIndex;		// switch def to use to return to PreTexture
	WORD NumFrames;		// # of animation frames
	FSoundID Sound;		// sound to play at start of animation
	bool QuestPanel;	// Special texture for Strife mission
	struct frame		// Array of times followed by array of textures
	{					//   actual length of each array is <NumFrames>
		DWORD Time;
		FTextureID Texture;
	} u[1];
};

static int STACK_ARGS SortSwitchDefs (const void *a, const void *b);
static FSwitchDef *ParseSwitchDef (FScanner &sc, bool ignoreBad);
static WORD AddSwitchDef (FSwitchDef *def);

//
// CHANGE THE TEXTURE OF A WALL SWITCH TO ITS OPPOSITE
//

class DeletingSwitchArray : public TArray<FSwitchDef *>
{
public:
	~DeletingSwitchArray()
	{
		for(unsigned i=0;i<Size();i++)
		{
			if ((*this)[i] != NULL)
			{
				M_Free((*this)[i]);
				(*this)[i] = NULL;
			}
		}
	}
};
static DeletingSwitchArray SwitchList;

//
// P_InitSwitchList
// Only called at game initialization.
//
// [RH] Rewritten to use a BOOM-style SWITCHES lump and remove the
//		MAXSWITCHES limit.
void P_InitSwitchList ()
{
	const BITFIELD texflags = FTextureManager::TEXMAN_Overridable | FTextureManager::TEXMAN_TryAny;
	int lump = Wads.CheckNumForName ("SWITCHES");
	FSwitchDef **origMap;
	int i, j;

	if (lump != -1)
	{
		FMemLump lumpdata = Wads.ReadLump (lump);
		const char *alphSwitchList = (const char *)lumpdata.GetMem();
		const char *list_p;
		FSwitchDef *def1, *def2;

		for (list_p = alphSwitchList; list_p[18] || list_p[19]; list_p += 20)
		{
			// [RH] Check for switches that aren't really switches
			if (stricmp (list_p, list_p+9) == 0)
			{
				Printf ("Switch %s in SWITCHES has the same 'on' state\n", list_p);
				continue;
			}
			// [RH] Skip this switch if its textures can't be found.
			if (TexMan.CheckForTexture (list_p /* .name1 */, FTexture::TEX_Wall, texflags).Exists() &&
				TexMan.CheckForTexture (list_p + 9 /* .name2 */, FTexture::TEX_Wall, texflags).Exists())
			{
				def1 = (FSwitchDef *)M_Malloc (sizeof(FSwitchDef));
				def2 = (FSwitchDef *)M_Malloc (sizeof(FSwitchDef));
				def1->PreTexture = def2->u[0].Texture = TexMan.CheckForTexture (list_p /* .name1 */, FTexture::TEX_Wall, texflags);
				def2->PreTexture = def1->u[0].Texture = TexMan.CheckForTexture (list_p + 9, FTexture::TEX_Wall, texflags);
				def1->Sound = def2->Sound = 0;
				def1->NumFrames = def2->NumFrames = 1;
				def1->u[0].Time = def2->u[0].Time = 0;
				def2->PairIndex = AddSwitchDef (def1);
				def1->PairIndex = AddSwitchDef (def2);
			}
		}
	}

	SwitchList.ShrinkToFit ();

	// Sort SwitchList for quick searching
	origMap = new FSwitchDef *[SwitchList.Size ()];
	for (i = 0; i < (int)SwitchList.Size (); i++)
	{
		origMap[i] = SwitchList[i];
	}

	qsort (&SwitchList[0], i, sizeof(FSwitchDef *), SortSwitchDefs);

	// Correct the PairIndex of each switch def, since the sorting broke them
	for (i = (int)(SwitchList.Size () - 1); i >= 0; i--)
	{
		FSwitchDef *def = SwitchList[i];
		if (def->PairIndex != 65535)
		{
			for (j = (int)(SwitchList.Size () - 1); j >= 0; j--)
			{
				if (SwitchList[j] == origMap[def->PairIndex])
				{
					def->PairIndex = (WORD)j;
					break;
				}
			}
		}
	}

	delete[] origMap;
}

static int STACK_ARGS SortSwitchDefs (const void *a, const void *b)
{
	return (*(FSwitchDef **)a)->PreTexture - (*(FSwitchDef **)b)->PreTexture;
}

// Parse a switch block in ANIMDEFS and add the definitions to SwitchList
void P_ProcessSwitchDef (FScanner &sc)
{
	const BITFIELD texflags = FTextureManager::TEXMAN_Overridable | FTextureManager::TEXMAN_TryAny;
	FString picname;
	FSwitchDef *def1, *def2;
	FTextureID picnum;
	int gametype;
	bool quest = false;

	def1 = def2 = NULL;
	sc.MustGetString ();
	if (sc.Compare ("doom"))
	{
		gametype = GAME_DoomChex;
		sc.CheckNumber();	// skip the gamemission filter
	}
	else if (sc.Compare ("heretic"))
	{
		gametype = GAME_Heretic;
	}
	else if (sc.Compare ("hexen"))
	{
		gametype = GAME_Hexen;
	}
	else if (sc.Compare ("strife"))
	{
		gametype = GAME_Strife;
	}
	else if (sc.Compare ("any"))
	{
		gametype = GAME_Any;
	}
	else
	{
		// There is no game specified; just treat as any
		//max = 240;
		gametype = GAME_Any;
		sc.UnGet ();
	}

	sc.MustGetString ();
	picnum = TexMan.CheckForTexture (sc.String, FTexture::TEX_Wall, texflags);
	picname = sc.String;
	while (sc.GetString ())
	{
		if (sc.Compare ("quest"))
		{
			quest = true;
		}
		else if (sc.Compare ("on"))
		{
			if (def1 != NULL)
			{
				sc.ScriptError ("Switch already has an on state");
			}
			def1 = ParseSwitchDef (sc, !picnum.Exists());
		}
		else if (sc.Compare ("off"))
		{
			if (def2 != NULL)
			{
				sc.ScriptError ("Switch already has an off state");
			}
			def2 = ParseSwitchDef (sc, !picnum.Exists());
		}
		else
		{
			sc.UnGet ();
			break;
		}
	}

	if (def1 == NULL || !picnum.Exists() ||
		(gametype != GAME_Any && !(gametype & gameinfo.gametype)))
	{
		if (def2 != NULL)
		{
			free (def2);
		}
		if (def1 != NULL)
		{
			free (def1);
		}
		return;
	}

	// If the switch did not have an off state, create one that just returns
	// it to the original texture without doing anything interesting
	if (def2 == NULL)
	{
		def2 = (FSwitchDef *)M_Malloc (sizeof(FSwitchDef));
		def2->Sound = def1->Sound;
		def2->NumFrames = 1;
		def2->u[0].Time = 0;
		def2->u[0].Texture = picnum;
	}

	def1->PreTexture = picnum;
	def2->PreTexture = def1->u[def1->NumFrames-1].Texture;
	if (def1->PreTexture == def2->PreTexture)
	{
		sc.ScriptError ("The on state for switch %s must end with a texture other than %s", picname.GetChars(), picname.GetChars());
	}
	def2->PairIndex = AddSwitchDef (def1);
	def1->PairIndex = AddSwitchDef (def2);
	def1->QuestPanel = def2->QuestPanel = quest;
}

FSwitchDef *ParseSwitchDef (FScanner &sc, bool ignoreBad)
{
	const BITFIELD texflags = FTextureManager::TEXMAN_Overridable | FTextureManager::TEXMAN_TryAny;
	FSwitchDef *def;
	TArray<FSwitchDef::frame> frames;
	FSwitchDef::frame thisframe;
	FTextureID picnum;
	bool bad;
	FSoundID sound;

	bad = false;

	while (sc.GetString ())
	{
		if (sc.Compare ("sound"))
		{
			if (sound != 0)
			{
				sc.ScriptError ("Switch state already has a sound");
			}
			sc.MustGetString ();
			sound = sc.String;
		}
		else if (sc.Compare ("pic"))
		{
			sc.MustGetString ();
			picnum = TexMan.CheckForTexture (sc.String, FTexture::TEX_Wall, texflags);
			if (!picnum.Exists() && !ignoreBad)
			{
				//Printf ("Unknown switch texture %s\n", sc.String);
				bad = true;
			}
			thisframe.Texture = picnum;
			sc.MustGetString ();
			if (sc.Compare ("tics"))
			{
				sc.MustGetNumber ();
				thisframe.Time = sc.Number & 65535;
			}
			else if (sc.Compare ("rand"))
			{
				int min, max;

				sc.MustGetNumber ();
				min = sc.Number & 65535;
				sc.MustGetNumber ();
				max = sc.Number & 65535;
				if (min > max)
				{
					swap (min, max);
				}
				thisframe.Time = ((max - min + 1) << 16) | min;
			}
			else
			{
			    thisframe.Time = 0;     // Shush, GCC.
				sc.ScriptError ("Must specify a duration for switch frame");
			}
			frames.Push(thisframe);
		}
		else
		{
			sc.UnGet ();
			break;
		}
	}
	if (frames.Size() == 0)
	{
		sc.ScriptError ("Switch state needs at least one frame");
	}
	if (bad)
	{
		return NULL;
	}

	def = (FSwitchDef *)M_Malloc (myoffsetof (FSwitchDef, u[0]) + frames.Size()*sizeof(frames[0]));
	def->Sound = sound;
	def->NumFrames = frames.Size();
	memcpy (&def->u[0], &frames[0], frames.Size() * sizeof(frames[0]));
	def->PairIndex = 65535;
	return def;
}

static WORD AddSwitchDef (FSwitchDef *def)
{
	unsigned int i;

	for (i = SwitchList.Size (); i-- > 0; )
	{
		if (SwitchList[i]->PreTexture == def->PreTexture)
		{
			free (SwitchList[i]);
			SwitchList[i] = def;
			return (WORD)i;
		}
	}
	return (WORD)SwitchList.Push (def);
}

//
// Start a button counting down till it turns off.
// [RH] Rewritten to remove MAXBUTTONS limit.
//
static bool P_StartButton (side_t *side, int Where, int switchnum,
						   fixed_t x, fixed_t y, bool useagain)
{
	DActiveButton *button;
	TThinkerIterator<DActiveButton> iterator;
	
	// See if button is already pressed
	while ( (button = iterator.Next ()) )
	{
		if (button->m_Side == side)
		{
			button->m_Timer=1;	// force advancing to the next frame
			return false;
		}
	}

	new DActiveButton (side, Where, switchnum, x, y, useagain);
	return true;
}

static int TryFindSwitch (side_t *side, int Where)
{
	int mid, low, high;

	FTextureID texture = side->GetTexture(Where);
	high = (int)(SwitchList.Size () - 1);
	if (high >= 0)
	{
		low = 0;
		do
		{
			mid = (high + low) / 2;
			if (SwitchList[mid]->PreTexture == texture)
			{
				return mid;
			}
			else if (texture < SwitchList[mid]->PreTexture)
			{
				high = mid - 1;
			}
			else
			{
				low = mid + 1;
			}
		} while (low <= high);
	}
	return -1;
}

//
// Checks whether a switch is reachable
// This is optional because old maps can rely on being able to 
// use non-reachable switches.
//
bool P_CheckSwitchRange(AActor *user, line_t *line, int sideno)
{
	// if this line is one sided this function must always return success.
	if (line->sidenum[0] == NO_SIDE || line->sidenum[1] == NO_SIDE) return true;

	fixed_t checktop;
	fixed_t checkbot;
	side_t *side = &sides[line->sidenum[sideno]];
	sector_t *front = sides[line->sidenum[sideno]].sector;
	sector_t *back = sides[line->sidenum[1-sideno]].sector;
	FLineOpening open;

	// 3DMIDTEX forces CHECKSWITCHRANGE because otherwise it might cause problems.
	if (!(line->flags & (ML_3DMIDTEX|ML_CHECKSWITCHRANGE))) return true;

	// calculate the point where the user would touch the wall.
	divline_t dll, dlu;
	fixed_t inter, checkx, checky;

	P_MakeDivline (line, &dll);

	dlu.x = user->x;
	dlu.y = user->y;
	dlu.dx = finecosine[user->angle >> ANGLETOFINESHIFT];
	dlu.dy = finesine[user->angle >> ANGLETOFINESHIFT];
	inter = P_InterceptVector(&dll, &dlu);

	checkx = dll.x + FixedMul(dll.dx, inter);
	checky = dll.y + FixedMul(dll.dy, inter);

	// Now get the information from the line.
	P_LineOpening(open, NULL, line, checkx, checky, user->x, user->y);
	if (open.range <= 0) return true;

	if ((TryFindSwitch (side, side_t::top)) != -1)
	{
		return (user->z + user->height >= open.top);
	}
	else if ((TryFindSwitch (side, side_t::bottom)) != -1)
	{
		return (user->z <= open.bottom);
	}
	else if ((line->flags & (ML_3DMIDTEX)) || (TryFindSwitch (side, side_t::mid)) != -1)
	{
		// 3DMIDTEX lines will force a mid texture check if no switch is found on this line
		// to keep compatibility with Eternity's implementation.
		if (!P_GetMidTexturePosition(line, sideno, &checktop, &checkbot)) return false;
		return user->z < checktop || user->z + user->height > checkbot;
	}
	else
	{
		// no switch found. Check whether the player can touch either top or bottom texture
		return (user->z + user->height >= open.top) || (user->z <= open.bottom);
	}
}

//
// Function that changes wall texture.
// Tell it if switch is ok to use again (1=yes, it's a button).
//
bool P_ChangeSwitchTexture (side_t *side, int useAgain, BYTE special, bool *quest)
{
	int texture;
	int i, sound;

	if ((i = TryFindSwitch (side, side_t::top)) != -1)
	{
		texture = side_t::top;
	}
	else if ((i = TryFindSwitch (side, side_t::bottom)) != -1)
	{
		texture = side_t::bottom;
	}
	else if ((i = TryFindSwitch (side, side_t::mid)) != -1)
	{
		texture = side_t::mid;
	}
	else
	{
		if (quest != NULL)
		{
			*quest = false;
		}
		return false;
	}

	// EXIT SWITCH?
	if (SwitchList[i]->Sound != 0)
	{
		sound = SwitchList[i]->Sound;
	}
	else
	{
		sound = S_FindSound (
			special == Exit_Normal ||
			special == Exit_Secret ||
			special == Teleport_NewMap ||
			special == Teleport_EndGame
		   ? "switches/exitbutn" : "switches/normbutn");
	}

	// [RH] The original code played the sound at buttonlist->soundorg,
	//		which wasn't necessarily anywhere near the switch if it was
	//		facing a big sector (and which wasn't necessarily for the
	//		button just activated, either).
	fixed_t pt[2];
	line_t *line = &lines[side->linenum];
	bool playsound;

	pt[0] = line->v1->x + (line->dx >> 1);
	pt[1] = line->v1->y + (line->dy >> 1);
	side->SetTexture(texture, SwitchList[i]->u[0].Texture);
	if (useAgain || SwitchList[i]->NumFrames > 1)
		playsound = P_StartButton (side, texture, i, pt[0], pt[1], !!useAgain);
	else 
		playsound = true;
	if (playsound)
		S_Sound (pt[0], pt[1], 0, CHAN_VOICE|CHAN_LISTENERZ, sound, 1, ATTN_STATIC);
	if (quest != NULL)
	{
		*quest = SwitchList[i]->QuestPanel;
	}
	return true;
}

IMPLEMENT_CLASS (DActiveButton)

DActiveButton::DActiveButton ()
{
	m_Side = NULL;
	m_Part = -1;
	m_SwitchDef = 0;
	m_Timer = 0;
	m_X = 0;
	m_Y = 0;
	bFlippable = false;
}

DActiveButton::DActiveButton (side_t *side, int Where, WORD switchnum,
							  fixed_t x, fixed_t y, bool useagain)
{
	m_Side = side;
	m_Part = SBYTE(Where);
	m_X = x;
	m_Y = y;
	bFlippable = useagain;

	m_SwitchDef = switchnum;
	m_Frame = 65535;
	AdvanceFrame ();
}

void DActiveButton::Serialize (FArchive &arc)
{
	SDWORD sidenum;

	Super::Serialize (arc);
	if (arc.IsStoring ())
	{
		sidenum = m_Side ? m_Side - sides : -1;
	}
	arc << sidenum << m_Part << m_SwitchDef << m_Frame << m_Timer << bFlippable << m_X << m_Y;
	if (arc.IsLoading ())
	{
		m_Side = sidenum >= 0 ? sides + sidenum : NULL;
	}
}

void DActiveButton::Tick ()
{
	if (--m_Timer == 0)
	{
		FSwitchDef *def = SwitchList[m_SwitchDef];
		if (m_Frame == def->NumFrames - 1)
		{
			m_SwitchDef = def->PairIndex;
			if (m_SwitchDef != 65535)
			{
				def = SwitchList[def->PairIndex];
				m_Frame = 65535;
				S_Sound (m_X, m_Y, 0, CHAN_VOICE|CHAN_LISTENERZ,
					def->Sound != 0 ? def->Sound : FSoundID("switches/normbutn"),
					1, ATTN_STATIC);
				bFlippable = false;
			}
			else
			{
				Destroy ();
				return;
			}
		}
		bool killme = AdvanceFrame ();

		m_Side->SetTexture(m_Part, def->u[m_Frame].Texture);

		if (killme)
		{
			Destroy ();
		}
	}
}

bool DActiveButton::AdvanceFrame ()
{
	bool ret = false;
	FSwitchDef *def = SwitchList[m_SwitchDef];

	if (++m_Frame == def->NumFrames - 1)
	{
		if (bFlippable == true)
		{
			m_Timer = BUTTONTIME;
		}
		else
		{
			ret = true;
		}
	}
	else
	{
		if (def->u[m_Frame].Time & 0xffff0000)
		{
			int t = pr_switchanim();

			m_Timer = (WORD)((((t | (pr_switchanim() << 8))
				% def->u[m_Frame].Time) >> 16)
				+ (def->u[m_Frame].Time & 0xffff));
		}
		else
		{
			m_Timer = (WORD)def->u[m_Frame].Time;
		}
	}
	return ret;
}