//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// 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
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Handle Sector base lighting effects.
//	Muzzle flash?
//

#include "doomdef.h"
#include "m_random.h"
#include "p_local.h"
#include "z_zone.h"

// State.
#include "r_state.h"

//
// FIRELIGHT FLICKER
//

//
// T_FireFlicker
//
void T_FireFlicker(fireflicker_t* flick) {
    int amount;

    if (--flick->count)
        return;

    amount = (P_Random() & 3) * 16;

    if (flick->sector->lightlevel - amount < flick->minlight)
        flick->sector->lightlevel = flick->minlight;
    else
        flick->sector->lightlevel = flick->maxlight - amount;

    flick->count = 4;
}

//
// P_SpawnFireFlicker
//
void P_SpawnFireFlicker(sector_t* sector) {
    fireflicker_t* flick;

    // Note that we are resetting sector attributes.
    // Nothing special about it during gameplay.
    sector->special = 0;

    flick = Z_Malloc(sizeof(*flick), PU_LEVSPEC, 0);

    P_AddThinker(&flick->thinker);

    flick->thinker.function.acp1 = (actionf_p1) T_FireFlicker;
    flick->sector = sector;
    flick->maxlight = sector->lightlevel;
    flick->minlight = P_FindMinSurroundingLight(sector, sector->lightlevel) + 16;
    flick->count = 4;
}

//
// BROKEN LIGHT FLASHING
//

//
// T_LightFlash
// Do flashing lights.
//
void T_LightFlash(lightflash_t* flash) {
    if (--flash->count)
        return;

    if (flash->sector->lightlevel == flash->maxlight) {
        flash->sector->lightlevel = flash->minlight;
        flash->count = (P_Random() & flash->mintime) + 1;
    } else {
        flash->sector->lightlevel = flash->maxlight;
        flash->count = (P_Random() & flash->maxtime) + 1;
    }
}

//
// P_SpawnLightFlash
// After the map has been loaded, scan each sector
// for specials that spawn thinkers
//
void P_SpawnLightFlash(sector_t* sector) {
    lightflash_t* flash;

    // nothing special about it during gameplay
    sector->special = 0;

    flash = Z_Malloc(sizeof(*flash), PU_LEVSPEC, 0);

    P_AddThinker(&flash->thinker);

    flash->thinker.function.acp1 = (actionf_p1) T_LightFlash;
    flash->sector = sector;
    flash->maxlight = sector->lightlevel;

    flash->minlight = P_FindMinSurroundingLight(sector, sector->lightlevel);
    flash->maxtime = 64;
    flash->mintime = 7;
    flash->count = (P_Random() & flash->maxtime) + 1;
}

//
// STROBE LIGHT FLASHING
//

//
// T_StrobeFlash
//
void T_StrobeFlash(strobe_t* flash) {
    if (--flash->count)
        return;

    if (flash->sector->lightlevel == flash->minlight) {
        flash->sector->lightlevel = flash->maxlight;
        flash->count = flash->brighttime;
    } else {
        flash->sector->lightlevel = flash->minlight;
        flash->count = flash->darktime;
    }
}

//
// P_SpawnStrobeFlash
// After the map has been loaded, scan each sector
// for specials that spawn thinkers
//
void P_SpawnStrobeFlash(sector_t* sector, int fastOrSlow, int inSync) {
    strobe_t* flash;

    flash = Z_Malloc(sizeof(*flash), PU_LEVSPEC, 0);

    P_AddThinker(&flash->thinker);

    flash->sector = sector;
    flash->darktime = fastOrSlow;
    flash->brighttime = STROBEBRIGHT;
    flash->thinker.function.acp1 = (actionf_p1) T_StrobeFlash;
    flash->maxlight = sector->lightlevel;
    flash->minlight = P_FindMinSurroundingLight(sector, sector->lightlevel);

    if (flash->minlight == flash->maxlight)
        flash->minlight = 0;

    // nothing special about it during gameplay
    sector->special = 0;

    if (!inSync)
        flash->count = (P_Random() & 7) + 1;
    else
        flash->count = 1;
}

//
// Start strobing lights (usually from a trigger)
//
void EV_StartLightStrobing(line_t* line) {
    int secnum;
    sector_t* sec;

    secnum = -1;
    while ((secnum = P_FindSectorFromLineTag(line, secnum)) >= 0) {
        sec = &sectors[secnum];
        if (sec->specialdata)
            continue;

        P_SpawnStrobeFlash(sec, SLOWDARK, 0);
    }
}

//
// TURN LINE'S TAG LIGHTS OFF
//
void EV_TurnTagLightsOff(line_t* line) {
    int i;
    int j;
    int min;
    sector_t* sector;
    sector_t* tsec;
    line_t* templine;

    sector = sectors;

    for (j = 0; j < numsectors; j++, sector++) {
        if (sector->tag == line->tag) {
            min = sector->lightlevel;
            for (i = 0; i < sector->linecount; i++) {
                templine = sector->lines[i];
                tsec = getNextSector(templine, sector);
                if (!tsec)
                    continue;
                if (tsec->lightlevel < min)
                    min = tsec->lightlevel;
            }
            sector->lightlevel = min;
        }
    }
}

//
// TURN LINE'S TAG LIGHTS ON
//
void EV_LightTurnOn(line_t* line, int bright) {
    int i;
    int j;
    sector_t* sector;
    sector_t* temp;
    line_t* templine;

    sector = sectors;

    for (i = 0; i < numsectors; i++, sector++) {
        if (sector->tag == line->tag) {
            // bright = 0 means to search
            // for highest light level
            // surrounding sector
            if (!bright) {
                for (j = 0; j < sector->linecount; j++) {
                    templine = sector->lines[j];
                    temp = getNextSector(templine, sector);

                    if (!temp)
                        continue;

                    if (temp->lightlevel > bright)
                        bright = temp->lightlevel;
                }
            }
            sector->lightlevel = bright;
        }
    }
}

//
// Spawn glowing light
//

void T_Glow(glow_t* g) {
    switch (g->direction) {
    case -1:
        // DOWN
        g->sector->lightlevel -= GLOWSPEED;
        if (g->sector->lightlevel <= g->minlight) {
            g->sector->lightlevel += GLOWSPEED;
            g->direction = 1;
        }
        break;

    case 1:
        // UP
        g->sector->lightlevel += GLOWSPEED;
        if (g->sector->lightlevel >= g->maxlight) {
            g->sector->lightlevel -= GLOWSPEED;
            g->direction = -1;
        }
        break;
    }
}

void P_SpawnGlowingLight(sector_t* sector) {
    glow_t* g;

    g = Z_Malloc(sizeof(*g), PU_LEVSPEC, 0);

    P_AddThinker(&g->thinker);

    g->sector = sector;
    g->minlight = P_FindMinSurroundingLight(sector, sector->lightlevel);
    g->maxlight = sector->lightlevel;
    g->thinker.function.acp1 = (actionf_p1) T_Glow;
    g->direction = -1;

    sector->special = 0;
}
