#include "global.h"
#include "input.h"
#include "bg.h"

extern u16 gRawKeyInput;
extern u8 gBldAlpha_CoeffA;
extern u8 gBldAlpha_CoeffB;
extern u16 gBldAlpha;
extern u8 gUnknown_202D7FE;

extern struct BGControlStruct gBG0Control;
extern struct BGControlStruct gBG1Control;
extern struct BGControlStruct gBG2Control;
extern struct BGControlStruct gBG3Control;

void ReadKeyInput(struct Inputs *r0)
{
    u16 keyInput = REG_KEYINPUT ^ KEYS_MASK;
    r0->held = 0;

    if((keyInput & DPAD_UP) != 0)
        r0->held = DPAD_UP;

    if((keyInput & DPAD_DOWN) != 0)
        r0->held |= DPAD_DOWN;

    if((keyInput & DPAD_LEFT) != 0)
        r0->held |= DPAD_LEFT;

    if((keyInput & DPAD_RIGHT) != 0)
        r0->held |= DPAD_RIGHT;

    if((keyInput & A_BUTTON) != 0)
        r0->held |= A_BUTTON;

    if((keyInput & B_BUTTON) != 0)
        r0->held |= B_BUTTON;

    if((keyInput & START_BUTTON) != 0)
        r0->held |= START_BUTTON;

    if((keyInput & SELECT_BUTTON) != 0)
        r0->held |= SELECT_BUTTON;

    if((keyInput & R_BUTTON) != 0)
        r0->held |= R_BUTTON;

    if((keyInput & L_BUTTON) != 0)
        r0->held |= L_BUTTON;

    gRawKeyInput = keyInput;
}

void SetBldAlphaReg(s32 lowAlpha, s32 highAlpha)
{
    if(lowAlpha < 0)
    {
        lowAlpha = 0;
    }
    else if(lowAlpha > 16)
    {
        lowAlpha = 16;
    }

    if(highAlpha < 0)
    {
        highAlpha = 0;
    }
    else if(highAlpha > 16)
    {
        highAlpha = 16;
    }

    gBldAlpha_CoeffA = lowAlpha;
    gBldAlpha_CoeffB = highAlpha;

    gBldAlpha = BLDALPHA_BLEND1(gBldAlpha_CoeffA, gBldAlpha_CoeffB);
}

void SetBG0RegOffsets(s32 xoffset, s32 yoffset)
{
    gBG0Control.hofs = xoffset;
    gBG0Control.vofs = yoffset;
}

void SetBG1RegOffsets(s32 xoffset, s32 yoffset)
{
    gBG1Control.hofs = xoffset;
    gBG1Control.vofs = yoffset;
}

void SetBG2RegOffsets(s32 xoffset, s32 yoffset)
{
    gBG2Control.hofs = xoffset;
    gBG2Control.vofs = yoffset;
}

void SetBG3RegOffsets(s32 xoffset, s32 yoffset)
{
    gBG3Control.hofs = xoffset;
    gBG3Control.vofs = yoffset;
}

void SetBGRegOffsets(s32 reg, u32 xoffset, s32 yoffset)
{
    switch (reg) {
        default:
        case 0: return SetBG0RegOffsets(xoffset, yoffset);
        case 1: return SetBG1RegOffsets(xoffset, yoffset);
        case 2: return SetBG2RegOffsets(xoffset, yoffset);
        case 3: return SetBG3RegOffsets(xoffset, yoffset);
    }
}

void SetBGRegXOffset(s32 reg, s32 offset)
{
    switch (reg) {
        default:
        case 0:
            gBG0Control.hofs = offset;
            break;
        case 1:
            gBG1Control.hofs = offset;
            break;
        case 2:
            gBG2Control.hofs = offset;
            break;
        case 3:
            gBG3Control.hofs = offset;
            break;
    }
}

void SetBGRegYOffset(s32 reg, s32 offset)
{
    switch (reg) {
        default:
        case 0:
            gBG0Control.vofs = offset;
            break;
        case 1:
            gBG1Control.vofs = offset;
            break;
        case 2:
            gBG2Control.vofs = offset;
            break;
        case 3:
            gBG3Control.vofs = offset;
            break;
    }
}

void sub_800CD64(s32 r0, u8 r1)
{
    gUnknown_202D7FE = r1;
    gBG2Control.unk2 = r0 ? 0x8000 : 0; 
}

void SetBGOBJEnableFlags(u32 mask)
{
    REG_DISPCNT = (REG_DISPCNT & 0xe0ff) | (~(mask << 8) & (DISPCNT_BG_ALL_ON | DISPCNT_OBJ_ON));
}