#include "global.h"
#include "battle.h"
#include "battle_anim.h"
#include "battle_bg.h"
#include "battle_main.h"
#include "battle_message.h"
#include "battle_setup.h"
#include "battle_environment.h"
#include "bg.h"
#include "data.h"
#include "decompress.h"
#include "gpu_regs.h"
#include "graphics.h"
#include "link.h"
#include "main.h"
#include "menu.h"
#include "overworld.h"
#include "palette.h"
#include "sound.h"
#include "sprite.h"
#include "task.h"
#include "test_runner.h"
#include "text_window.h"
#include "trig.h"
#include "window.h"
#include "constants/rgb.h"
#include "constants/songs.h"
#include "constants/trainers.h"
#include "constants/battle_anim.h"
#include "constants/battle_partner.h"
#include "data/battle_environment.h"

// .rodata

static const struct OamData sVsLetter_V_OamData =
{
    .y = 0,
    .affineMode = ST_OAM_AFFINE_DOUBLE,
    .objMode = ST_OAM_OBJ_NORMAL,
    .mosaic = FALSE,
    .bpp = ST_OAM_4BPP,
    .shape = SPRITE_SHAPE(64x64),
    .x = 0,
    .matrixNum = 0,
    .size = SPRITE_SIZE(64x64),
    .tileNum = 0,
    .priority = 0,
    .paletteNum = 0,
    .affineParam = 0,
};

static const struct OamData sVsLetter_S_OamData =
{
    .y = 0,
    .affineMode = ST_OAM_AFFINE_DOUBLE,
    .objMode = ST_OAM_OBJ_NORMAL,
    .mosaic = FALSE,
    .bpp = ST_OAM_4BPP,
    .shape = SPRITE_SHAPE(64x64),
    .x = 0,
    .matrixNum = 0,
    .size = SPRITE_SIZE(64x64),
    .tileNum = 64,
    .priority = 0,
    .paletteNum = 0,
    .affineParam = 0,
};

static const union AffineAnimCmd sVsLetterAffineAnimCmds0[] =
{
    AFFINEANIMCMD_FRAME(0x0080, 0x0080, 0x00, 0x00),
    AFFINEANIMCMD_END,
};

static const union AffineAnimCmd sVsLetterAffineAnimCmds1[] =
{
    AFFINEANIMCMD_FRAME(0x0080, 0x0080, 0x00, 0x00),
    AFFINEANIMCMD_FRAME(0x0018, 0x0018, 0x00, 0x80),
    AFFINEANIMCMD_FRAME(0x0018, 0x0018, 0x00, 0x80),
    AFFINEANIMCMD_END,
};

static const union AffineAnimCmd *const sVsLetterAffineAnimTable[] =
{
    sVsLetterAffineAnimCmds0,
    sVsLetterAffineAnimCmds1,
};

#define TAG_VS_LETTERS 10000

static const struct SpriteTemplate sVsLetter_V_SpriteTemplate =
{
    .tileTag = TAG_VS_LETTERS,
    .paletteTag = TAG_VS_LETTERS,
    .oam = &sVsLetter_V_OamData,
    .anims = gDummySpriteAnimTable,
    .images = NULL,
    .affineAnims = sVsLetterAffineAnimTable,
    .callback = SpriteCB_VsLetterDummy
};

static const struct SpriteTemplate sVsLetter_S_SpriteTemplate =
{
    .tileTag = TAG_VS_LETTERS,
    .paletteTag = TAG_VS_LETTERS,
    .oam = &sVsLetter_S_OamData,
    .anims = gDummySpriteAnimTable,
    .images = NULL,
    .affineAnims = sVsLetterAffineAnimTable,
    .callback = SpriteCB_VsLetterDummy
};

static const struct CompressedSpriteSheet sVsLettersSpriteSheet =
{
    gVsLettersGfx, 0x1000, TAG_VS_LETTERS
};

const struct BgTemplate gBattleBgTemplates[] =
{
    {
        .bg = 0,
        .charBaseIndex = 0,
        .mapBaseIndex = 24,
        .screenSize = 2,
        .paletteMode = 0,
        .priority = 0,
        .baseTile = 0
    },
    {
        .bg = 1,
        .charBaseIndex = 1,
        .mapBaseIndex = 28,
        .screenSize = 2,
        .paletteMode = 0,
        .priority = 0,
        .baseTile = 0
    },
    {
        .bg = 2,
        .charBaseIndex = 1,
        .mapBaseIndex = 30,
        .screenSize = 1,
        .paletteMode = 0,
        .priority = 1,
        .baseTile = 0
    },
   {
        .bg = 3,
        .charBaseIndex = 2,
        .mapBaseIndex = 26,
        .screenSize = 1,
        .paletteMode = 0,
        .priority = 3,
        .baseTile = 0
    },
};

static const struct WindowTemplate sStandardBattleWindowTemplates[] =
{
    [B_WIN_MSG] = {
        .bg = 0,
        .tilemapLeft = 2,
        .tilemapTop = 15,
        .width = 26,
        .height = 4,
        .paletteNum = 0,
        .baseBlock = 0x0090,
    },
    [B_WIN_ACTION_PROMPT] = {
        .bg = 0,
        .tilemapLeft = 1,
        .tilemapTop = 35,
        .width = 14,
        .height = 4,
        .paletteNum = 0,
        .baseBlock = 0x01c0,
    },
    [B_WIN_ACTION_MENU] = {
        .bg = 0,
        .tilemapLeft = 17,
        .tilemapTop = 35,
        .width = 12,
        .height = 4,
        .paletteNum = 5,
        .baseBlock = 0x0190,
    },
    [B_WIN_MOVE_NAME_1] = {
        .bg = 0,
        .tilemapLeft = 2,
        .tilemapTop = 55,
        .width = 16,    //for z move names
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0300,
    },
    [B_WIN_MOVE_NAME_2] = {
        .bg = 0,
        .tilemapLeft = 11,
        .tilemapTop = 55,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0318,
    },
    [B_WIN_MOVE_NAME_3] = {
        .bg = 0,
        .tilemapLeft = 2,
        .tilemapTop = 57,
        .width = 16,    //for z effect descriptions
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0328,
    },
    [B_WIN_MOVE_NAME_4] = {
        .bg = 0,
        .tilemapLeft = 11,
        .tilemapTop = 57,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0340,
    },
    [B_WIN_PP] = {
        .bg = 0,
        .tilemapLeft = 21,
        .tilemapTop = 55,
        .width = 4,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0290,
    },
    [B_WIN_DUMMY] = {
        .bg = 0,
        .tilemapLeft = 21,
        .tilemapTop = 57,
        .width = 0,
        .height = 0,
        .paletteNum = 5,
        .baseBlock = 0x0298,
    },
    [B_WIN_PP_REMAINING] = {
        .bg = 0,
        .tilemapLeft = 25,
        .tilemapTop = 55,
        .width = 4,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0298,
    },
    [B_WIN_MOVE_TYPE] = {
        .bg = 0,
        .tilemapLeft = 21,
        .tilemapTop = 57,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x02a0,
    },
    [B_WIN_SWITCH_PROMPT] = {
        .bg = 0,
        .tilemapLeft = 21,
        .tilemapTop = 55,
        .width = 8,
        .height = 4,
        .paletteNum = 5,
        .baseBlock = 0x02b0,
    },
    [B_WIN_YESNO] = {
        .bg = 0,
        .tilemapLeft = 26,
        .tilemapTop = 9,
        .width = 3,
        .height = 4,
        .paletteNum = 5,
        .baseBlock = 0x0100,
    },
    [B_WIN_LEVEL_UP_BOX] = {
        .bg = 1,
        .tilemapLeft = 19,
        .tilemapTop = 8,
        .width = 10,
        .height = 11,
        .paletteNum = 5,
        .baseBlock = 0x0100,
    },
    [B_WIN_LEVEL_UP_BANNER] = {
        .bg = 2,
        .tilemapLeft = 18,
        .tilemapTop = 0,
        .width = 12,
        .height = 3,
        .paletteNum = 6,
        .baseBlock = 0x016e,
    },
    [B_WIN_VS_PLAYER] = {
        .bg = 1,
        .tilemapLeft = 2,
        .tilemapTop = 3,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0020,
    },
    [B_WIN_VS_OPPONENT] = {
        .bg = 2,
        .tilemapLeft = 2,
        .tilemapTop = 3,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0040,
    },
    [B_WIN_VS_MULTI_PLAYER_1] = {
        .bg = 1,
        .tilemapLeft = 2,
        .tilemapTop = 2,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0020,
    },
    [B_WIN_VS_MULTI_PLAYER_2] = {
        .bg = 2,
        .tilemapLeft = 2,
        .tilemapTop = 2,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0040,
    },
    [B_WIN_VS_MULTI_PLAYER_3] = {
        .bg = 1,
        .tilemapLeft = 2,
        .tilemapTop = 6,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0060,
    },
    [B_WIN_VS_MULTI_PLAYER_4] = {
        .bg = 2,
        .tilemapLeft = 2,
        .tilemapTop = 6,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0080,
    },
    [B_WIN_VS_OUTCOME_DRAW] = {
        .bg = 0,
        .tilemapLeft = 12,
        .tilemapTop = 2,
        .width = 6,
        .height = 2,
        .paletteNum = 0,
        .baseBlock = 0x00a0,
    },
    [B_WIN_VS_OUTCOME_LEFT] = {
        .bg = 0,
        .tilemapLeft = 4,
        .tilemapTop = 2,
        .width = 7,
        .height = 2,
        .paletteNum = 0,
        .baseBlock = 0x00a0,
    },
    [B_WIN_VS_OUTCOME_RIGHT] = {
        .bg = 0,
        .tilemapLeft = 19,
        .tilemapTop = 2,
        .width = 7,
        .height = 2,
        .paletteNum = 0,
        .baseBlock = 0x00b0,
    },
    [B_WIN_MOVE_DESCRIPTION] = {
        .bg = 0,
        .tilemapLeft = 1,
        .tilemapTop = 47,
        .width = 18,
        .height = 6,
        .paletteNum = 5,
        .baseBlock = 0x0350,
    },
    DUMMY_WIN_TEMPLATE
};

static const struct WindowTemplate sBattleArenaWindowTemplates[] =
{
    [B_WIN_MSG] = {
        .bg = 0,
        .tilemapLeft = 2,
        .tilemapTop = 15,
        .width = 26,
        .height = 4,
        .paletteNum = 0,
        .baseBlock = 0x0090,
    },
    [B_WIN_ACTION_PROMPT] = {
        .bg = 0,
        .tilemapLeft = 1,
        .tilemapTop = 35,
        .width = 14,
        .height = 4,
        .paletteNum = 0,
        .baseBlock = 0x01c0,
    },
    [B_WIN_ACTION_MENU] = {
        .bg = 0,
        .tilemapLeft = 17,
        .tilemapTop = 35,
        .width = 12,
        .height = 4,
        .paletteNum = 5,
        .baseBlock = 0x0190,
    },
    [B_WIN_MOVE_NAME_1] = {
        .bg = 0,
        .tilemapLeft = 2,
        .tilemapTop = 55,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0300,
    },
    [B_WIN_MOVE_NAME_2] = {
        .bg = 0,
        .tilemapLeft = 11,
        .tilemapTop = 55,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0310,
    },
    [B_WIN_MOVE_NAME_3] = {
        .bg = 0,
        .tilemapLeft = 2,
        .tilemapTop = 57,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0320,
    },
    [B_WIN_MOVE_NAME_4] = {
        .bg = 0,
        .tilemapLeft = 11,
        .tilemapTop = 57,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0330,
    },
    [B_WIN_PP] = {
        .bg = 0,
        .tilemapLeft = 21,
        .tilemapTop = 55,
        .width = 4,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0290,
    },
    [B_WIN_DUMMY] = {
        .bg = 0,
        .tilemapLeft = 21,
        .tilemapTop = 57,
        .width = 0,
        .height = 0,
        .paletteNum = 5,
        .baseBlock = 0x0298,
    },
    [B_WIN_PP_REMAINING] = {
        .bg = 0,
        .tilemapLeft = 25,
        .tilemapTop = 55,
        .width = 4,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0298,
    },
    [B_WIN_MOVE_TYPE] = {
        .bg = 0,
        .tilemapLeft = 21,
        .tilemapTop = 57,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x02a0,
    },
    [B_WIN_SWITCH_PROMPT] = {
        .bg = 0,
        .tilemapLeft = 21,
        .tilemapTop = 55,
        .width = 8,
        .height = 4,
        .paletteNum = 5,
        .baseBlock = 0x02b0,
    },
    [B_WIN_YESNO] = {
        .bg = 0,
        .tilemapLeft = 26,
        .tilemapTop = 9,
        .width = 3,
        .height = 4,
        .paletteNum = 5,
        .baseBlock = 0x0100,
    },
    [B_WIN_LEVEL_UP_BOX] = {
        .bg = 1,
        .tilemapLeft = 19,
        .tilemapTop = 8,
        .width = 10,
        .height = 11,
        .paletteNum = 5,
        .baseBlock = 0x0100,
    },
    [B_WIN_LEVEL_UP_BANNER] = {
        .bg = 2,
        .tilemapLeft = 18,
        .tilemapTop = 0,
        .width = 12,
        .height = 3,
        .paletteNum = 6,
        .baseBlock = 0x016e,
    },
    [ARENA_WIN_PLAYER_NAME] = {
        .bg = 0,
        .tilemapLeft = 6,
        .tilemapTop = 1,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0100,
    },
    [ARENA_WIN_VS] = {
        .bg = 0,
        .tilemapLeft = 14,
        .tilemapTop = 1,
        .width = 2,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0110,
    },
    [ARENA_WIN_OPPONENT_NAME] = {
        .bg = 0,
        .tilemapLeft = 16,
        .tilemapTop = 1,
        .width = 8,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0114,
    },
    [ARENA_WIN_MIND] = {
        .bg = 0,
        .tilemapLeft = 12,
        .tilemapTop = 4,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0124,
    },
    [ARENA_WIN_SKILL] = {
        .bg = 0,
        .tilemapLeft = 12,
        .tilemapTop = 6,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0130,
    },
    [ARENA_WIN_BODY] = {
        .bg = 0,
        .tilemapLeft = 12,
        .tilemapTop = 8,
        .width = 6,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x013c,
    },
    [ARENA_WIN_JUDGMENT_TITLE] = {
        .bg = 0,
        .tilemapLeft = 8,
        .tilemapTop = 11,
        .width = 14,
        .height = 2,
        .paletteNum = 5,
        .baseBlock = 0x0148,
    },
    [ARENA_WIN_JUDGMENT_TEXT] = {
        .bg = 0,
        .tilemapLeft = 2,
        .tilemapTop = 15,
        .width = 26,
        .height = 4,
        .paletteNum = 7,
        .baseBlock = 0x0090,
    },
    [B_WIN_MOVE_DESCRIPTION] = {
        .bg = 0,
        .tilemapLeft = 1,
        .tilemapTop = 47,
        .width = 18,
        .height = 6,
        .paletteNum = 5,
        .baseBlock = 0x0350,
    },
    DUMMY_WIN_TEMPLATE
};

const struct WindowTemplate *const gBattleWindowTemplates[] =
{
    [B_WIN_TYPE_NORMAL] = sStandardBattleWindowTemplates,
    [B_WIN_TYPE_ARENA]  = sBattleArenaWindowTemplates,
};

// If current map scene equals any of the values in sMapBattleSceneMapping,
// use its battle terrain value. Otherwise, use the default.
static u8 GetBattleEnvironmentByMapScene(u8 mapBattleScene)
{
    int i;
    for (i = 0; i < NELEMS(sMapBattleSceneMapping); i++)
    {
        if (mapBattleScene == sMapBattleSceneMapping[i].mapScene)
            return sMapBattleSceneMapping[i].battleEnvironment;
    }
    return BATTLE_ENVIRONMENT_PLAIN;
}

// Loads the initial battle terrain.
static void LoadBattleEnvironmentGfx(u16 terrain)
{
    if (terrain >= NELEMS(gBattleEnvironmentInfo))
        terrain = BATTLE_ENVIRONMENT_PLAIN;  // If higher than the number of entries in gBattleEnvironmentInfo, use the default.
    // Copy to bg3
    DecompressDataWithHeaderVram(gBattleEnvironmentInfo[terrain].background.tileset, (void *)(BG_CHAR_ADDR(2)));
    DecompressDataWithHeaderVram(gBattleEnvironmentInfo[terrain].background.tilemap, (void *)(BG_SCREEN_ADDR(26)));
    LoadPalette(gBattleEnvironmentInfo[terrain].background.palette, BG_PLTT_ID(2), 3 * PLTT_SIZE_4BPP);
}

// Loads the entry associated with the battle terrain.
// This can be the grass moving on the screen at the start of a wild encounter in tall grass.
static void LoadBattleEnvironmentEntryGfx(u16 terrain)
{
    if (terrain >= NELEMS(gBattleEnvironmentInfo))
        terrain = BATTLE_ENVIRONMENT_PLAIN;
    // Copy to bg1
    DecompressDataWithHeaderVram(gBattleEnvironmentInfo[terrain].background.entryTileset, (void *)BG_CHAR_ADDR(1));
    DecompressDataWithHeaderVram(gBattleEnvironmentInfo[terrain].background.entryTilemap, (void *)BG_SCREEN_ADDR(28));
}

static u8 GetBattleEnvironmentOverride(void)
{
    u8 battleScene = GetCurrentMapBattleScene();

    if (TestRunner_Battle_GetForcedEnvironment()
     && gBattleEnvironmentInfo[gBattleEnvironment].background.tilemap
     && gBattleEnvironmentInfo[gBattleEnvironment].background.tileset)
    {
        return gBattleEnvironment;
    }
    else if (gBattleTypeFlags & (BATTLE_TYPE_FRONTIER | BATTLE_TYPE_LINK | BATTLE_TYPE_RECORDED_LINK | BATTLE_TYPE_EREADER_TRAINER))
        return BATTLE_ENVIRONMENT_FRONTIER;
    else if (gBattleTypeFlags & BATTLE_TYPE_LEGENDARY)
    {
        switch (GetMonData(&gEnemyParty[0], MON_DATA_SPECIES, NULL))
        {
        case SPECIES_GROUDON:
            return BATTLE_ENVIRONMENT_GROUDON;
        case SPECIES_KYOGRE:
            return BATTLE_ENVIRONMENT_KYOGRE;
        case SPECIES_RAYQUAZA:
            return BATTLE_ENVIRONMENT_RAYQUAZA;
        default:
            return gBattleEnvironment;
        }
    }
    else if (gBattleTypeFlags & BATTLE_TYPE_TRAINER)
    {
        u32 trainerClass = GetTrainerClassFromId(TRAINER_BATTLE_PARAM.opponentA);
        if (trainerClass == TRAINER_CLASS_LEADER)
            return BATTLE_ENVIRONMENT_LEADER;
        else if (trainerClass == TRAINER_CLASS_CHAMPION)
            return BATTLE_ENVIRONMENT_CHAMPION;
    }

    if (battleScene == MAP_BATTLE_SCENE_NORMAL)
        return gBattleEnvironment;

    return GetBattleEnvironmentByMapScene(battleScene);
}

void BattleInitBgsAndWindows(void)
{
    ResetBgsAndClearDma3BusyFlags(0);
    InitBgsFromTemplates(0, gBattleBgTemplates, ARRAY_COUNT(gBattleBgTemplates));

    if (gBattleTypeFlags & BATTLE_TYPE_ARENA)
    {
        gBattleScripting.windowsType = B_WIN_TYPE_ARENA;
        SetBgTilemapBuffer(1, gBattleAnimBgTilemapBuffer);
        SetBgTilemapBuffer(2, gBattleAnimBgTilemapBuffer);
    }
    else
    {
        gBattleScripting.windowsType = B_WIN_TYPE_NORMAL;
    }

    InitWindows(gBattleWindowTemplates[gBattleScripting.windowsType]);
    DeactivateAllTextPrinters();
}

void InitBattleBgsVideo(void)
{
    DisableInterrupts(INTR_FLAG_HBLANK);
    EnableInterrupts(INTR_FLAG_VBLANK | INTR_FLAG_VCOUNT | INTR_FLAG_TIMER3 | INTR_FLAG_SERIAL);
    BattleInitBgsAndWindows();
    SetGpuReg(REG_OFFSET_BLDCNT, 0);
    SetGpuReg(REG_OFFSET_BLDALPHA, 0);
    SetGpuReg(REG_OFFSET_BLDY, 0);
    SetGpuReg(REG_OFFSET_DISPCNT, DISPCNT_OBJWIN_ON | DISPCNT_WIN0_ON | DISPCNT_OBJ_ON | DISPCNT_OBJ_1D_MAP);
}

void LoadBattleMenuWindowGfx(void)
{
    LoadUserWindowBorderGfx(2, 0x12, BG_PLTT_ID(1));
    LoadUserWindowBorderGfx(2, 0x22, BG_PLTT_ID(1));
    LoadPalette(gBattleWindowTextPalette, BG_PLTT_ID(5), PLTT_SIZE_4BPP);

    if (gBattleTypeFlags & BATTLE_TYPE_ARENA)
    {
        // Load graphics for the Battle Arena referee's mid-battle messages.
        Menu_LoadStdPalAt(BG_PLTT_ID(7));
        LoadMessageBoxGfx(0, 0x30, BG_PLTT_ID(7));
        gPlttBufferUnfaded[BG_PLTT_ID(7) + 6] = 0;
        CpuCopy16(&gPlttBufferUnfaded[BG_PLTT_ID(7) + 6], &gPlttBufferFaded[BG_PLTT_ID(7) + 6], PLTT_SIZEOF(1));
    }
}

void DrawMainBattleBackground(void)
{
    LoadBattleEnvironmentGfx(GetBattleEnvironmentOverride());
}

void LoadBattleTextboxAndBackground(void)
{
    DecompressDataWithHeaderVram(gBattleTextboxTiles, (void *)(BG_CHAR_ADDR(0)));
    CopyToBgTilemapBuffer(0, gBattleTextboxTilemap, 0, 0);
    CopyBgTilemapBufferToVram(0);
    LoadPalette(gBattleTextboxPalette, BG_PLTT_ID(0), 2 * PLTT_SIZE_4BPP);
    LoadBattleMenuWindowGfx();
    if (B_TERRAIN_BG_CHANGE == TRUE)
        DrawTerrainTypeBattleBackground();
    else
        DrawMainBattleBackground();
}

static void DrawLinkBattleParticipantPokeballs(u8 taskId, u8 multiplayerId, u8 bgId, u8 destX, u8 destY)
{
    s32 i;
    u16 pokeballStatuses = 0;
    u16 tiles[6];

    if (gBattleTypeFlags & BATTLE_TYPE_MULTI)
    {
        if (gTasks[taskId].data[5] != 0)
        {
            switch (multiplayerId)
            {
            case 0:
                pokeballStatuses = 0x3F & gTasks[taskId].data[3];
                break;
            case 1:
                pokeballStatuses = (0xFC0 & gTasks[taskId].data[4]) >> 6;
                break;
            case 2:
                pokeballStatuses = (0xFC0 & gTasks[taskId].data[3]) >> 6;
                break;
            case 3:
                pokeballStatuses = 0x3F & gTasks[taskId].data[4];
                break;
            }
        }
        else
        {
            switch (multiplayerId)
            {
            case 0:
                pokeballStatuses = 0x3F & gTasks[taskId].data[3];
                break;
            case 1:
                pokeballStatuses = 0x3F & gTasks[taskId].data[4];
                break;
            case 2:
                pokeballStatuses = (0xFC0 & gTasks[taskId].data[3]) >> 6;
                break;
            case 3:
                pokeballStatuses = (0xFC0 & gTasks[taskId].data[4]) >> 6;
                break;
            }
        }

        for (i = 0; i < 3; i++)
            tiles[i] = ((pokeballStatuses & (3 << (i * 2))) >> (i * 2)) + 0x6001;

        CopyToBgTilemapBufferRect_ChangePalette(bgId, tiles, destX, destY, 3, 1, 0x11);
        CopyBgTilemapBufferToVram(bgId);
    }
    else
    {
        if (multiplayerId == gBattleScripting.multiplayerId)
            pokeballStatuses = gTasks[taskId].data[3];
        else
            pokeballStatuses = gTasks[taskId].data[4];

        for (i = 0; i < 6; i++)
            tiles[i] = ((pokeballStatuses & (3 << (i * 2))) >> (i * 2)) + 0x6001;

        CopyToBgTilemapBufferRect_ChangePalette(bgId, tiles, destX, destY, 6, 1, 0x11);
        CopyBgTilemapBufferToVram(bgId);
    }
}

static void DrawLinkBattleVsScreenOutcomeText(void)
{
    if (gBattleOutcome == B_OUTCOME_DREW)
    {
        BattlePutTextOnWindow(gText_Draw, B_WIN_VS_OUTCOME_DRAW);
    }
    else if (gBattleTypeFlags & BATTLE_TYPE_MULTI)
    {
        if (gBattleOutcome == B_OUTCOME_WON)
        {
            switch (gLinkPlayers[gBattleScripting.multiplayerId].id)
            {
            case 0:
                BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_LEFT);
                BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_RIGHT);
                break;
            case 1:
                BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_RIGHT);
                BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_LEFT);
                break;
            case 2:
                BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_LEFT);
                BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_RIGHT);
                break;
            case 3:
                BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_RIGHT);
                BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_LEFT);
                break;
            }
        }
        else
        {
            switch (gLinkPlayers[gBattleScripting.multiplayerId].id)
            {
            case 0:
                BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_RIGHT);
                BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_LEFT);
                break;
            case 1:
                BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_LEFT);
                BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_RIGHT);
                break;
            case 2:
                BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_RIGHT);
                BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_LEFT);
                break;
            case 3:
                BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_LEFT);
                BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_RIGHT);
                break;
            }
        }
    }
    else if (gBattleOutcome == B_OUTCOME_WON)
    {
        if (gLinkPlayers[gBattleScripting.multiplayerId].id != 0)
        {
            BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_RIGHT);
            BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_LEFT);
        }
        else
        {
            BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_LEFT);
            BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_RIGHT);
        }
    }
    else
    {
        if (gLinkPlayers[gBattleScripting.multiplayerId].id != 0)
        {
            BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_LEFT);
            BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_RIGHT);
        }
        else
        {
            BattlePutTextOnWindow(gText_Win, B_WIN_VS_OUTCOME_RIGHT);
            BattlePutTextOnWindow(gText_Loss, B_WIN_VS_OUTCOME_LEFT);
        }
    }
}

void InitLinkBattleVsScreen(u8 taskId)
{
    struct LinkPlayer *linkPlayer;
    u8 *name;
    s32 i, palId;

    switch (gTasks[taskId].data[0])
    {
    case 0:
        if (gBattleTypeFlags & BATTLE_TYPE_MULTI)
        {
            for (i = 0; i < MAX_LINK_PLAYERS; i++)
            {
                name = gLinkPlayers[i].name;
                linkPlayer = &gLinkPlayers[i];

                switch (linkPlayer->id)
                {
                case 0:
                    BattlePutTextOnWindow(name, B_WIN_VS_MULTI_PLAYER_1);
                    DrawLinkBattleParticipantPokeballs(taskId, linkPlayer->id, 1, 2, 4);
                    break;
                case 1:
                    BattlePutTextOnWindow(name, B_WIN_VS_MULTI_PLAYER_2);
                    DrawLinkBattleParticipantPokeballs(taskId, linkPlayer->id, 2, 2, 4);
                    break;
                case 2:
                    BattlePutTextOnWindow(name, B_WIN_VS_MULTI_PLAYER_3);
                    DrawLinkBattleParticipantPokeballs(taskId, linkPlayer->id, 1, 2, 8);
                    break;
                case 3:
                    BattlePutTextOnWindow(name, B_WIN_VS_MULTI_PLAYER_4);
                    DrawLinkBattleParticipantPokeballs(taskId, linkPlayer->id, 2, 2, 8);
                    break;
                }
            }
        }
        else
        {
            u8 playerId = gBattleScripting.multiplayerId;
            u8 opponentId = playerId ^ BIT_SIDE;
            u8 opponentId_copy = opponentId;

            if (gLinkPlayers[playerId].id != 0)
                opponentId = playerId, playerId = opponentId_copy;

            name = gLinkPlayers[playerId].name;
            BattlePutTextOnWindow(name, B_WIN_VS_PLAYER);

            name = gLinkPlayers[opponentId].name;
            BattlePutTextOnWindow(name, B_WIN_VS_OPPONENT);

            DrawLinkBattleParticipantPokeballs(taskId, playerId, 1, 2, 7);
            DrawLinkBattleParticipantPokeballs(taskId, opponentId, 2, 2, 7);
        }
        gTasks[taskId].data[0]++;
        break;
    case 1:
        palId = AllocSpritePalette(TAG_VS_LETTERS);
        gPlttBufferUnfaded[OBJ_PLTT_ID(palId) + 15] = gPlttBufferFaded[OBJ_PLTT_ID(palId) + 15] = RGB_WHITE;
        gBattleStruct->linkBattleVsSpriteId_V = CreateSprite(&sVsLetter_V_SpriteTemplate, 111, 80, 0);
        gBattleStruct->linkBattleVsSpriteId_S = CreateSprite(&sVsLetter_S_SpriteTemplate, 129, 80, 0);
        gSprites[gBattleStruct->linkBattleVsSpriteId_V].invisible = TRUE;
        gSprites[gBattleStruct->linkBattleVsSpriteId_S].invisible = TRUE;
        gTasks[taskId].data[0]++;
        break;
    case 2:
        if (gTasks[taskId].data[5] != 0)
        {
            gBattle_BG1_X = -(20) - (Sin2(gTasks[taskId].data[1]) / 32);
            gBattle_BG2_X = -(140) - (Sin2(gTasks[taskId].data[2]) / 32);
            gBattle_BG1_Y = -36;
            gBattle_BG2_Y = -36;
        }
        else
        {
            gBattle_BG1_X = -(20) - (Sin2(gTasks[taskId].data[1]) / 32);
            gBattle_BG1_Y = (Cos2(gTasks[taskId].data[1]) / 32) - 164;
            gBattle_BG2_X = -(140) - (Sin2(gTasks[taskId].data[2]) / 32);
            gBattle_BG2_Y = (Cos2(gTasks[taskId].data[2]) / 32) - 164;
        }

        if (gTasks[taskId].data[2] != 0)
        {
            gTasks[taskId].data[2] -= 2;
            gTasks[taskId].data[1] += 2;
        }
        else
        {
            if (gTasks[taskId].data[5] != 0)
                DrawLinkBattleVsScreenOutcomeText();

            PlaySE(SE_M_HARDEN);
            DestroyTask(taskId);
            gSprites[gBattleStruct->linkBattleVsSpriteId_V].invisible = FALSE;
            gSprites[gBattleStruct->linkBattleVsSpriteId_S].invisible = FALSE;
            gSprites[gBattleStruct->linkBattleVsSpriteId_S].oam.tileNum += 0x40;
            gSprites[gBattleStruct->linkBattleVsSpriteId_V].data[0] = 0;
            gSprites[gBattleStruct->linkBattleVsSpriteId_S].data[0] = 1;
            gSprites[gBattleStruct->linkBattleVsSpriteId_V].data[1] = gSprites[gBattleStruct->linkBattleVsSpriteId_V].x;
            gSprites[gBattleStruct->linkBattleVsSpriteId_S].data[1] = gSprites[gBattleStruct->linkBattleVsSpriteId_S].x;
            gSprites[gBattleStruct->linkBattleVsSpriteId_V].data[2] = 0;
            gSprites[gBattleStruct->linkBattleVsSpriteId_S].data[2] = 0;
        }
        break;
    }
}

void DrawBattleEntryBackground(void)
{
    if (gBattleTypeFlags & BATTLE_TYPE_LINK)
    {
        DecompressDataWithHeaderVram(gBattleVSFrame_Gfx, (void *)(BG_CHAR_ADDR(1)));
        DecompressDataWithHeaderVram(gVsLettersGfx, (void *)OBJ_VRAM0);
        LoadPalette(gBattleVSFrame_Pal, BG_PLTT_ID(6), PLTT_SIZE_4BPP);
        SetBgAttribute(1, BG_ATTR_SCREENSIZE, 1);
        SetGpuReg(REG_OFFSET_BG1CNT, 0x5C04);
        CopyToBgTilemapBuffer(1, gBattleVSFrame_Tilemap, 0, 0);
        CopyToBgTilemapBuffer(2, gBattleVSFrame_Tilemap, 0, 0);
        CopyBgTilemapBufferToVram(1);
        CopyBgTilemapBufferToVram(2);
        SetGpuReg(REG_OFFSET_WININ, WININ_WIN0_BG1 | WININ_WIN0_BG2 | WININ_WIN0_OBJ | WININ_WIN0_CLR);
        SetGpuReg(REG_OFFSET_WINOUT, WINOUT_WIN01_BG1 | WINOUT_WIN01_BG2 | WINOUT_WIN01_OBJ | WINOUT_WIN01_CLR);
        gBattle_BG1_Y = 0xFF5C;
        gBattle_BG2_Y = 0xFF5C;
        LoadCompressedSpriteSheetUsingHeap(&sVsLettersSpriteSheet);
    }
    else if (gBattleTypeFlags & (BATTLE_TYPE_FRONTIER | BATTLE_TYPE_LINK | BATTLE_TYPE_RECORDED_LINK | BATTLE_TYPE_EREADER_TRAINER))
    {
        if (TestRunner_Battle_GetForcedEnvironment()
         && gBattleEnvironmentInfo[gBattleEnvironment].background.tilemap
         && gBattleEnvironmentInfo[gBattleEnvironment].background.tileset)
        {
            LoadBattleEnvironmentEntryGfx(gBattleEnvironment);
        }
        else if (!(gBattleTypeFlags & BATTLE_TYPE_INGAME_PARTNER) || gPartnerTrainerId > TRAINER_PARTNER(PARTNER_NONE))
        {
            LoadBattleEnvironmentEntryGfx(BATTLE_ENVIRONMENT_BUILDING);
        }
        else
        {
            // Set up bg for the multi battle intro where both teams slide in facing the screen.
            // Note Steven's multi battle (which has a dedicated back pic) is excluded above.
            SetBgAttribute(1, BG_ATTR_CHARBASEINDEX, 2);
            SetBgAttribute(2, BG_ATTR_CHARBASEINDEX, 2);
            CopyToBgTilemapBuffer(1, gMultiBattleIntroBg_Opponent_Tilemap, 0, 0);
            CopyToBgTilemapBuffer(2, gMultiBattleIntroBg_Player_Tilemap, 0, 0);
            CopyBgTilemapBufferToVram(1);
            CopyBgTilemapBufferToVram(2);
        }
    }
    else if (gBattleTypeFlags & BATTLE_TYPE_LEGENDARY)
    {
        switch (GetMonData(&gEnemyParty[0], MON_DATA_SPECIES, NULL))
        {
        case SPECIES_GROUDON:
            LoadBattleEnvironmentEntryGfx(BATTLE_ENVIRONMENT_CAVE);
            break;
        case SPECIES_KYOGRE:
            LoadBattleEnvironmentEntryGfx(BATTLE_ENVIRONMENT_UNDERWATER);
            break;
        case SPECIES_RAYQUAZA:
            LoadBattleEnvironmentEntryGfx(BATTLE_ENVIRONMENT_RAYQUAZA);
            break;
        default:
            DecompressDataWithHeaderVram(gBattleEnvironmentInfo[gBattleEnvironment].background.entryTileset, (void *)(BG_CHAR_ADDR(1)));
            DecompressDataWithHeaderVram(gBattleEnvironmentInfo[gBattleEnvironment].background.entryTilemap, (void *)(BG_SCREEN_ADDR(28)));
            break;
        }
    }
    else
    {
        if (gBattleTypeFlags & BATTLE_TYPE_TRAINER)
        {
            enum TrainerClassID trainerClass = GetTrainerClassFromId(TRAINER_BATTLE_PARAM.opponentA);
            if (trainerClass == TRAINER_CLASS_LEADER)
            {
                LoadBattleEnvironmentEntryGfx(BATTLE_ENVIRONMENT_BUILDING);
                return;
            }
            else if (trainerClass == TRAINER_CLASS_CHAMPION)
            {
                LoadBattleEnvironmentEntryGfx(BATTLE_ENVIRONMENT_BUILDING);
                return;
            }
        }

        if (GetCurrentMapBattleScene() == MAP_BATTLE_SCENE_NORMAL)
        {
            LoadBattleEnvironmentEntryGfx(gBattleEnvironment);
        }
        else
        {
            LoadBattleEnvironmentEntryGfx(gBattleEnvironment);
        }
    }
}

bool8 LoadChosenBattleElement(u8 caseId)
{
    bool8 ret = FALSE;

    switch (caseId)
    {
    case 0:
        DecompressDataWithHeaderVram(gBattleTextboxTiles, (void *)(BG_CHAR_ADDR(0)));
        break;
    case 1:
        CopyToBgTilemapBuffer(0, gBattleTextboxTilemap, 0, 0);
        CopyBgTilemapBufferToVram(0);
        break;
    case 2:
        LoadPalette(gBattleTextboxPalette, BG_PLTT_ID(0), 2 * PLTT_SIZE_4BPP);
        break;
    case 3:
        DecompressDataWithHeaderVram(gBattleEnvironmentInfo[GetBattleEnvironmentOverride()].background.tileset, (void *)(BG_CHAR_ADDR(2)));
        break;
    case 4:
        DecompressDataWithHeaderVram(gBattleEnvironmentInfo[GetBattleEnvironmentOverride()].background.tilemap, (void *)(BG_SCREEN_ADDR(26)));
        break;
    case 5:
        LoadPalette(gBattleEnvironmentInfo[GetBattleEnvironmentOverride()].background.palette, BG_PLTT_ID(2), 3 * PLTT_SIZE_4BPP);
        break;
    case 6:
        LoadBattleMenuWindowGfx();
        break;
    default:
        ret = TRUE;
        break;
    }

    return ret;
}

void DrawTerrainTypeBattleBackground(void)
{
    switch (gFieldStatuses & STATUS_FIELD_TERRAIN_ANY)
    {
    case STATUS_FIELD_GRASSY_TERRAIN:
        LoadMoveBg(BG_GRASSY_TERRAIN);
        break;
    case STATUS_FIELD_MISTY_TERRAIN:
        LoadMoveBg(BG_MISTY_TERRAIN);
        break;
    case STATUS_FIELD_ELECTRIC_TERRAIN:
        LoadMoveBg(BG_ELECTRIC_TERRAIN);
        break;
    case STATUS_FIELD_PSYCHIC_TERRAIN:
        LoadMoveBg(BG_PSYCHIC_TERRAIN);
        break;
    default:
        DrawMainBattleBackground();
        break;
    }
}