/* Low-level TDKPIN background/overlay bitmap blits. */

#include "tdkpin_render.h"

#include "tdkpin_arithmetic.h"

enum {
    DGROUP_BACKGROUND_BITMAP = 0x085b,
    DGROUP_OVERLAY_BITMAP_B = 0x085d,
    DGROUP_OVERLAY_BITMAP_A = 0x085f,
    WIN16_SRCCOPY = 0x00cc0020,
    WIN16_SRCAND = 0x008800c6,
    DGROUP_DIGIT_BITMAP = 0x0861,
    DGROUP_PLAYER_SCORE_INDEX_BASE = 0x097e,
};

static HBITMAP16 dgroup_bitmap(uint16_t offset)
{
    return win16_read_u16(win16_dgroup_pointer(offset));
}

/* 1008:07b6 — copy a supplied bitmap's origin into the background bitmap. */
void tdkpin_blit_bitmap_to_background(
    HBITMAP16 bitmap,
    INT16 height,
    INT16 width,
    INT16 y,
    INT16 x,
    HDC16 reference_dc)
{
    HDC16 background_dc = CreateCompatibleDC16(reference_dc);
    HDC16 bitmap_dc = CreateCompatibleDC16(reference_dc);
    HGDIOBJ16 old_background = SelectObject16(
        background_dc, dgroup_bitmap(DGROUP_BACKGROUND_BITMAP));
    HGDIOBJ16 old_bitmap = SelectObject16(bitmap_dc, bitmap);
    (void)BitBlt16(
        background_dc, x, y, width, height,
        bitmap_dc, 0, 0, WIN16_SRCCOPY);
    (void)SelectObject16(bitmap_dc, old_bitmap);
    (void)SelectObject16(background_dc, old_background);
    (void)DeleteDC16(bitmap_dc);
    (void)DeleteDC16(background_dc);
}

/* 1008:0837 — restore a rectangle from overlay bitmap 085f. */
void tdkpin_restore_background_region_a(
    INT16 height,
    INT16 width,
    INT16 y,
    INT16 x,
    HDC16 reference_dc)
{
    HDC16 background_dc = CreateCompatibleDC16(reference_dc);
    HDC16 overlay_dc = CreateCompatibleDC16(reference_dc);
    HGDIOBJ16 old_background = SelectObject16(
        background_dc, dgroup_bitmap(DGROUP_BACKGROUND_BITMAP));
    HGDIOBJ16 old_overlay = SelectObject16(
        overlay_dc, dgroup_bitmap(DGROUP_OVERLAY_BITMAP_A));
    (void)BitBlt16(
        background_dc, x, y, width, height,
        overlay_dc, x, y, WIN16_SRCCOPY);
    (void)SelectObject16(overlay_dc, old_overlay);
    (void)SelectObject16(background_dc, old_background);
    (void)DeleteDC16(overlay_dc);
    (void)DeleteDC16(background_dc);
}

/* 1008:08bb — byte-identical restore using overlay bitmap 085d. */
void tdkpin_restore_background_region_b(
    INT16 height,
    INT16 width,
    INT16 y,
    INT16 x,
    HDC16 reference_dc)
{
    HDC16 background_dc = CreateCompatibleDC16(reference_dc);
    HDC16 overlay_dc = CreateCompatibleDC16(reference_dc);
    HGDIOBJ16 old_background = SelectObject16(
        background_dc, dgroup_bitmap(DGROUP_BACKGROUND_BITMAP));
    HGDIOBJ16 old_overlay = SelectObject16(
        overlay_dc, dgroup_bitmap(DGROUP_OVERLAY_BITMAP_B));
    (void)BitBlt16(
        background_dc, x, y, width, height,
        overlay_dc, x, y, WIN16_SRCCOPY);
    (void)SelectObject16(overlay_dc, old_overlay);
    (void)SelectObject16(background_dc, old_background);
    (void)DeleteDC16(overlay_dc);
    (void)DeleteDC16(background_dc);
}

/* 1008:093f — copy one background rectangle to the destination DC. */
void tdkpin_present_background_region(
    INT16 height,
    INT16 width,
    INT16 y,
    INT16 x,
    HDC16 destination)
{
    HDC16 background_dc = CreateCompatibleDC16(destination);
    HGDIOBJ16 old_background = SelectObject16(
        background_dc, dgroup_bitmap(DGROUP_BACKGROUND_BITMAP));
    (void)BitBlt16(
        destination, x, y, width, height,
        background_dc, x, y, WIN16_SRCCOPY);
    (void)SelectObject16(background_dc, old_background);
    (void)DeleteDC16(background_dc);
}

static int16_t score_destination_x(uint16_t player_or_value)
{
    switch (player_or_value) {
    case 1:
        return 0x129 - 20;
    case 2:
        return 0x155 - 20;
    case 3:
        return 0x181 - 20;
    case 4:
        return 0x1ad - 20;
    default:
        return 0x0fd - 20;
    }
}

static int32_t resolve_score_value(int32_t value_or_player)
{
    if (value_or_player < 1 || value_or_player > 4) {
        return value_or_player;
    }
    uint16_t offset = (uint16_t)(
        DGROUP_PLAYER_SCORE_INDEX_BASE + (uint16_t)value_or_player * 4);
    return (int32_t)win16_read_u32(win16_dgroup_pointer(offset));
}

/*
 * 1008:0996 — compose an eight-place decimal score into a 40x150 temporary
 * bitmap. Values 1..4 select the corresponding one-based player score; all
 * other int32 values render directly. Leading zeroes are suppressed except the
 * least-significant position, and digit sprites are combined with SRCAND.
 */
void tdkpin_draw_score(HDC16 destination, int32_t value_or_player)
{
    HDC16 background_dc = CreateCompatibleDC16(destination);
    HDC16 score_dc = CreateCompatibleDC16(destination);
    HBITMAP16 score_bitmap =
        CreateCompatibleBitmap16(destination, 40, 150);
    int16_t destination_x =
        score_destination_x((uint16_t)value_or_player);
    int32_t value = resolve_score_value(value_or_player);

    HGDIOBJ16 old_background = SelectObject16(
        background_dc, dgroup_bitmap(DGROUP_BACKGROUND_BITMAP));
    HGDIOBJ16 old_score = SelectObject16(score_dc, score_bitmap);
    (void)BitBlt16(
        score_dc, 0, 0, 40, 130,
        background_dc, destination_x, 478, WIN16_SRCCOPY);

    for (uint8_t position = 0; position < 8; position++) {
        BorlandDivI32Result digit_division = borland_divide_i32(value, 10);
        uint8_t digit = (uint8_t)digit_division.remainder;
        BorlandDivI32Result quotient_division = borland_divide_i32(value, 10);
        value = quotient_division.quotient;
        if (digit != 0 || value > 0 || position == 0) {
            (void)SelectObject16(
                background_dc, dgroup_bitmap(DGROUP_DIGIT_BITMAP));
            (void)BitBlt16(
                score_dc,
                0,
                (INT16)((7 - position) * 16),
                28,
                16,
                background_dc,
                (INT16)((uint16_t)digit << 4),
                0,
                WIN16_SRCAND);
        }
    }
    (void)BitBlt16(
        destination, destination_x, 478, 40, 130,
        score_dc, 0, 0, WIN16_SRCCOPY);
    (void)SelectObject16(background_dc, old_background);
    (void)SelectObject16(score_dc, old_score);
    (void)DeleteObject16(score_bitmap);
    (void)DeleteDC16(background_dc);
    (void)DeleteDC16(score_dc);
}