-- definitions of BUILD and game types for the Lunatic Interpreter
-- INTERNAL!

local ffi = require("ffi")

---- sector, wall, sprite, ... ----
ffi.cdef[[
#pragma pack(push,1)
typedef struct
{
    const int16_t wallptr, wallnum;
    int32_t ceilingz, floorz;
    int16_t ceilingstat, floorstat;
    int16_t ceilingpicnum, ceilingheinum;
    int8_t ceilingshade;
    uint8_t ceilingpal, ceilingxpanning, ceilingypanning;
    int16_t floorpicnum, floorheinum;
    int8_t floorshade;
    uint8_t floorpal, floorxpanning, floorypanning;
    uint8_t visibility, filler;
    int16_t lotag, hitag, extra;
} sectortype;

typedef struct
{
    int32_t x, y;
    const int16_t point2, nextwall, nextsector; int16_t cstat;
    int16_t picnum, overpicnum;
    int8_t shade;
    uint8_t pal, xrepeat, yrepeat, xpanning, ypanning;
    int16_t lotag, hitag, extra;
} walltype;

typedef struct
{
    int32_t x, y, z;
    int16_t cstat, picnum;
    int8_t shade;
    uint8_t pal, clipdist, filler;
    uint8_t xrepeat, yrepeat;
    int8_t xoffset, yoffset;
    const int16_t sectnum, statnum;
    int16_t ang, owner, xvel, yvel, zvel;
    int16_t lotag, hitag, extra;
} spritetype;

typedef struct {
    const uint32_t mdanimtims;
    const int16_t mdanimcur;
    int16_t angoff, pitch, roll;
    int32_t xoff, yoff, zoff;
    uint8_t flags;
    uint8_t xpanning, ypanning;
    const uint8_t filler;
    float alpha;
    const int32_t _do_not_use1;
    const int32_t _do_not_use2;
} spriteext_t;

typedef struct {
    int32_t x, y, z;
} vec3_t;
#pragma pack(pop)
]]

assert(ffi.sizeof('sectortype')==40)
assert(ffi.sizeof('walltype')==32)
assert(ffi.sizeof('spritetype')==44)

-- game structs
ffi.cdef[[
#pragma pack(push,1)
// ACTOR_T, might still need to make some fields read-only
typedef struct
{
    const int32_t t_data[10];  // 40b sometimes used to hold offsets to con code
    int16_t picnum,ang,extra,owner; //8b
    int16_t movflag,tempang,timetosleep; //6b

    int32_t flags, bposx,bposy,bposz; //16b
    int32_t floorz,ceilingz,lastvx,lastvy; //16b
    int32_t lasttransport; //4b

    const int16_t lightId, lightcount, lightmaxrange, cgg; //8b
    int16_t actorstayput, dispicnum, shootzvel; // 6b

    const int8_t _do_not_use[24];
} actor_t;
#pragma pack(pop)

//#define MAXMOUSEBUTTONS 10
//#define MAXMOUSEAXES 2
//#define MAXJOYBUTTONS (32+4)  // XXX
//#define MAXJOYAXES 8
//#define NUMGAMEFUNCTIONS 56

typedef struct {
    vec3_t camera;
    int32_t const_visibility,uw_framerate;
    int32_t camera_time,folfvel,folavel,folx,foly,fola;
    int32_t reccnt,crosshairscale;

    int32_t runkey_mode,statusbarscale,mouseaiming,weaponswitch,drawweapon;   // JBF 20031125
    int32_t democams,color,msgdisptime,statusbarmode;
    int32_t m_noexits,noexits,autovote,automsg,idplayers;
    int32_t team, viewbob, weaponsway, althud, weaponscale, textscale;

    int32_t entered_name,screen_tilting,shadows,fta_on,executions,auto_run;
    int32_t coords,tickrate,levelstats,m_coop,coop,screen_size,lockout,crosshair;
    int32_t playerai,angleinterpolation,obituaries;

    int32_t respawn_monsters,respawn_items,respawn_inventory,recstat,monsters_off,brightness;
    int32_t m_respawn_items,m_respawn_monsters,m_respawn_inventory,m_recstat,m_monsters_off,detail;
    int32_t m_ffire,ffire,m_player_skill,m_level_number,m_volume_number,multimode;
    int32_t player_skill,level_number,volume_number,m_marker,marker,mouseflip;

    int32_t configversion;

    int16_t cameraang, camerasect, camerahoriz;
    int16_t pause_on,from_bonus;
    int16_t camerasprite,last_camsprite;
    int16_t last_level,secretlevel, bgstretch;

    struct {
        int32_t UseJoystick;
        int32_t UseMouse;
        int32_t AutoAim;
        int32_t ShowOpponentWeapons;
        int32_t MouseDeadZone,MouseBias;
        int32_t SmoothInput;

        // JBF 20031211: Store the input settings because
        // (currently) jmact can't regurgitate them
        int32_t MouseFunctions[10][2];  // MAXMOUSEBUTTONS
        int32_t MouseDigitalFunctions[2][2];  // MAXMOUSEAXES
        int32_t MouseAnalogueAxes[2];  // MAXMOUSEAXES
        int32_t MouseAnalogueScale[2];  // MAXMOUSEAXES
        int32_t JoystickFunctions[32+4][2];  // MAXJOYBUTTONS
        int32_t JoystickDigitalFunctions[8][2];  // MAXJOYAXES
        int32_t JoystickAnalogueAxes[8];  // MAXJOYAXES
        int32_t JoystickAnalogueScale[8];  // MAXJOYAXES
        int32_t JoystickAnalogueDead[8];  // MAXJOYAXES
        int32_t JoystickAnalogueSaturate[8];  // MAXJOYAXES
        uint8_t KeyboardKeys[56][2];  // NUMGAMEFUNCTIONS

        //
        // Sound variables
        //
        int32_t FXDevice;
        int32_t MusicDevice;
        int32_t FXVolume;
        int32_t MusicVolume;
        int32_t SoundToggle;
        int32_t MusicToggle;
        int32_t VoiceToggle;
        int32_t AmbienceToggle;

        int32_t NumVoices;
        int32_t NumChannels;
        int32_t NumBits;
        int32_t MixRate;

        int32_t ReverseStereo;

        //
        // Screen variables
        //

        int32_t ScreenMode;

        int32_t ScreenWidth;
        int32_t ScreenHeight;
        int32_t ScreenBPP;

        int32_t ForceSetup;
        int32_t NoAutoLoad;

        int32_t scripthandle;
        int32_t setupread;

        int32_t CheckForUpdates;
        int32_t LastUpdateCheck;
        int32_t useprecache;
    } config;

    char overhead_on,last_overhead,showweapons;
    char god,warp_on,cashman,eog,showallmap;
    char show_help,scrollmode,clipping;
    char ridecule[10][40];
    char savegame[10][22];
    char pwlockout[128],rtsname[128];
    char display_bonus_screen;
    char show_level_text;
} user_defs;

int32_t engine_main_arrays_are_static;
]]

-- NOTE TO SELF: This is not C, never EVER write
--    if (x)
-- when checking a C variable x for 'thuthiness'
if (ffi.C.engine_main_arrays_are_static ~= 0) then
--    print('main arrays are static');
    ffi.cdef[[
sectortype sector[];
walltype wall[];
spritetype sprite[];
spriteext_t spriteext[];
]]
else
--    print('main arrays are pointers');
    ffi.cdef[[
sectortype *sector;
walltype *wall;
spritetype *sprite;
spriteext_t *spriteext;
]]
end

ffi.cdef[[
const int16_t numsectors, numwalls;
const int32_t numyaxbunches;

const int16_t headspritesect[16384+1], headspritestat[1024+1];
const int16_t prevspritesect[16384], prevspritestat[16384];
const int16_t nextspritesect[16384], nextspritestat[16384];

const int16_t headsectbunch[2][256], nextsectbunch[2][4096];
]]

ffi.cdef[[
actor_t actor[16384];
user_defs ud;
]]

---- _G tweaks -- pull in only 'safe' stuff ----

local G_ = {}  -- our soon-to-be global environment
local oG = _G

G_.coroutine = coroutine
G_.assert = assert
G_.tostring = tostring
G_.tonumber = tonumber
--rawget
G_.xpcall = xpcall
G_.ipairs = ipairs
G_.print = print
G_.pcall = pcall
--gcinfo --DEPRECATED
--module
--setfenv
--require
--rawset
--jit
G_.bit = bit
--package
G_.error = error
--debug
--loadfile
--rawequal
--load
G_.unpack = unpack
G_.pairs = pairs
G_.table = table
G_._VERSION = _VERSION
--newproxy --NOT STD?
--collectgarbage
--dofile
G_.next = next
G_.math = math
--loadstring
--_G
G_.select = select
G_.string = string
G_.type = type
--getmetatable
--getfenv
--setmetatable

G_._G = G_

-- REMOVE this for release
DBG_ = {}
DBG_.loadstring = oG.loadstring

---- Set up restricted access to ffi.C from lunatic. ----
local ffiC = ffi.C

-- error(..., 2) is to blame the caller and get its line numbers

local det = {}  -- dummy empty table
local tmpmt = {
    __index = function() error('dummy variable: read access forbidden', 2) end,
    __newindex = function() error('dummy variable: write access forbidden', 2) end,
    __metatable = true  -- forbid setting the metatable
}
oG.setmetatable(det, tmpmt)

-- GLOBAL gv: provides access to C global *scalars*
gv = {
    -- all non-scalars need to be explicitly listed
    -- and access to them is redirected to the dummy
    -- empty table... this is somewhat ugly
    sector = det,
    wall = det,
    sprite = det,
    spriteext = det,

    headspritesect = det, headspritestat = det,
    prevspritesect = det, prevspritestat = det,
    nextspritesect = det, nextspritestat = det,

    actor = det,

    -- "constants", actually you'd be able to assign to them now...
    CEILING = 0,
    FLOOR = 1,
}
local tmpmt = {
    __index = ffiC,
    __newindex = function() error("cannot create new or write into existing fields of 'gv'", 2) end,
    __metatable = true,
}
oG.setmetatable(gv, tmpmt)

---- indirect C array access ----
sector = {}
local tmpmt = {
    __index = function(tab, key)
                  if (key >= 0 and key < ffiC.numsectors) then return ffiC.sector[key] end
                  error('out-of-bounds sector[] read access', 2)
              end,

    __newindex = function(tab, key, val) error('cannot write directly to sector[] struct', 2) end,
    __metatable = true,
}
oG.setmetatable(sector, tmpmt)

wall = {}
local tmpmt = {
    __index = function(tab, key)
                  if (key >= 0 and key < ffiC.numwalls) then return ffiC.wall[key] end
                  error('out-of-bounds wall[] read access', 2)
              end,

    __newindex = function(tab, key, val) error('cannot write directly to wall[] struct', 2) end,
    __metatable = true,
}
oG.setmetatable(wall, tmpmt)

-- create a safe indirection for a ffi.C array
local function creategtab(ctab, maxidx, name)
    local tab = {}
    local tmpmt = {
        __index = function(tab, key)
                      if (key>=0 and key < maxidx) then
                          return ctab[key]
                      end
                      error('out-of-bounds '..name..' read access', 2)
                  end,
        __newindex = function(tab, key, val)
                         error('cannot write directly to '..name, 2)
                     end,
        __metatable = true,
    }
    oG.setmetatable(tab, tmpmt)
    return tab
end

sprite = creategtab(ffiC.sprite, 16384, 'sprite[] struct')
spriteext = creategtab(ffiC.spriteext, 16384, 'spriteext[] struct')
headspritesect = creategtab(ffiC.headspritesect, 16384, 'headspritesect[]')
headspritestat = creategtab(ffiC.headspritestat, 1024, 'headspritestat[]')
nextspritesect = creategtab(ffiC.nextspritesect, 16384, 'nextspritesect[]')
nextspritestat = creategtab(ffiC.nextspritestat, 16384, 'nextspritestat[]')
prevspritesect = creategtab(ffiC.prevspritesect, 16384, 'prevspritesect[]')
prevspritestat = creategtab(ffiC.prevspritestat, 16384, 'prevspritestat[]')

actor = creategtab(ffiC.actor, 16384, 'actor[]')

function TEMP_getvollev()  -- REMOVE
    return ffiC.ud.volume_number+1, ffiC.ud.level_number+1
end

---- per-sector/per-statnum sprite iterators ----
local function iter_spritesofsect(sect, i)
    if (i < 0) then
        i = ffiC.headspritesect[sect]
    else
        i = ffiC.nextspritesect[i]
    end

    if (i >= 0) then return i end
end

function spritesofsect(sect)
    if (sect < 0 or sect >= ffiC.numsectors) then
        error("passed invalid sectnum to spritesofsect iterator", 2)
    end

    return iter_spritesofsect, sect, -1
end

local function iter_spritesofstat(stat, i)
    if (i < 0) then
        i = ffiC.headspritestat[stat]
    else
        i = ffiC.nextspritestat[i]
    end

    if (i >= 0) then return i end
end

function spritesofstat(stat)
    if (stat < 0 or stat >= 1024) then
        error("passed invalid statnum to spritesofstat iterator", 2)
    end

    return iter_spritesofstat, stat, -1
end

-- TROR iterators
local function iter_sectorsofbunch(cf, i)
    if (i < 0) then
        i = ffiC.headsectbunch[cf][-i-1];
    else
        i = ffiC.nextsectbunch[cf][i];
    end

    if (i >= 0) then return i end
end

function sectorsofbunch(bunchnum, cf)
    if (bunchnum < 0 or bunchnum >= ffiC.numyaxbunches) then
        error("passed invalid bunchnum to sectorsofbunch iterator", 2)
    end
    if (cf ~= 0 and cf ~= 1) then
        error("passed invalid 'cf' to sectorsofbunch iterator, must be 0 or 1", 2)
    end

    return iter_sectorsofbunch, cf, -bunchnum-1
end


-- 'simple' code for prohibiting initial assignments to create new variables,
-- from 14.2 of PiL
function gamevar(name, initval)  -- aka 'declare'
    rawset(G_, name, initval or false)
end


-- add new variables/functions living in the global environment
G_.DBG_ = DBG_  -- REMOVE this for release
G_.gv = gv
G_.sector = sector
G_.wall = wall
G_.sprite = sprite
G_.spriteext = spriteext
G_.headspritesect = headspritesect
G_.headspritestat = headspritestat
G_.nextspritesect = nextspritesect
G_.nextspritestat = nextspritestat
G_.prevspritesect = prevspritesect
G_.prevspritestat = prevspritestat

G_.actor = actor

-- functions
G_.spritesofsect = spritesofsect
G_.spritesofstat = spritesofstat
G_.sectorsofbunch = sectorsofbunch

G_.TEMP_getvollev = TEMP_getvollev  -- REMOVE
G_.gamevar = gamevar

-- PiL 14.2 continued
setmetatable(
    G_, {
        __newindex = function (_, n)
            error("attempt to write to undeclared variable "..n, 2)
        end,
        __index = function (_, n)
            error("attempt to read undeclared variable "..n, 2)
        end,
        })

-- change the environment of the running Lua thread to the table G_
setfenv(0, G_)