/* TDKPIN asset-loading progress and bitmap ownership paths. */

#include "tdkpin_game_assets.h"

#include "tdkpin_palette.h"
#include "tdkpin_window_placement.h"

enum {
    FRAME_MEMORY_DC = -0x0c,
    FRAME_PREVIOUS_BITMAP = -0x04,
    FRAME_LOADING_BITMAP = -0x02,
    FRAME_DESTINATION_DC = 0x0e,
    LOADING_DESTINATION_X = 202,
    LOADING_DESTINATION_Y = 328,
    LOADING_HEIGHT = 13,
    WIN16_SRCCOPY = 0x00cc0020,
    DGROUP_OVERLAY_BITMAP = 0x0867,
    WINDOW_HANDLE_OFFSET = 4,
    OVERLAY_DAT_RESOURCE = 993,
    DGROUP_PALETTE_UPDATE_ACTIVE = 0x07c4,
    MESSAGE_WPARAM_OFFSET = 4,
    MESSAGE_RESULT_OFFSET = 10,
    DGROUP_PALETTE_HANDLE = 0x444e,
    DGROUP_BOARD_INDEX = 0x07cd,
    BOARD_DAT_RESOURCE_BASE = 1000,
    WIN16_IDC_WAIT = 0x7f02,
    WIN16_IDC_ARROW = 0x7f00,
    BOARD_WIDTH = 640,
    BOARD_HEIGHT = 460,
};

static Win16FarPtr frame_field(Win16FarPtr caller_bp, int16_t offset)
{
    return win16_far_add_offset(caller_bp, (uint16_t)offset);
}

/*
 * 1000:531e — draw one numbered asset-loading stage. The target receives the
 * caller's BP, mutates its scratch HDC/HGDIOBJ words, and deletes the compatible
 * DC through DeleteObject16 (not DeleteDC16). This unusual API choice is kept.
 */
void tdkpin_draw_loading_stage(Win16FarPtr caller_bp, uint8_t stage)
{
    HDC16 destination =
        win16_read_u16(frame_field(caller_bp, FRAME_DESTINATION_DC));
    HDC16 memory_dc = CreateCompatibleDC16(destination);
    win16_write_u16(
        frame_field(caller_bp, FRAME_MEMORY_DC), 0, memory_dc);
    HBITMAP16 loading_bitmap =
        win16_read_u16(frame_field(caller_bp, FRAME_LOADING_BITMAP));
    HGDIOBJ16 previous = SelectObject16(memory_dc, loading_bitmap);
    win16_write_u16(
        frame_field(caller_bp, FRAME_PREVIOUS_BITMAP), 0, previous);
    uint16_t wrapped_width = (uint16_t)(((uint16_t)stage - 1) * 7);
    (void)BitBlt16(
        destination,
        LOADING_DESTINATION_X,
        LOADING_DESTINATION_Y,
        (INT16)wrapped_width,
        LOADING_HEIGHT,
        memory_dc,
        0,
        0,
        WIN16_SRCCOPY);
    (void)SelectObject16(memory_dc, previous);
    (void)DeleteObject16(memory_dc);
}

/* 1000:5be5 — finish TWindow setup, load DAT 993, then focus the HWND. */
void tdkpin_setup_overlay_window(Win16FarPtr window)
{
    object_windows_setup_window(window);
    HBITMAP16 overlay = tdkpin_load_bitmap_resource(
        win16_make_far_pointer(0, OVERLAY_DAT_RESOURCE), g_win16_instance);
    win16_write_u16(
        win16_dgroup_pointer(DGROUP_OVERLAY_BITMAP), 0, overlay);
    (void)SetFocus16(
        win16_read_u16(win16_far_add_offset(window, WINDOW_HANDLE_OFFSET)));
}

static void invalidate_palette_window(
    Win16FarPtr window, Win16FarPtr message)
{
    HWND16 handle =
        win16_read_u16(win16_far_add_offset(window, WINDOW_HANDLE_OFFSET));
    win16_write_u8(
        win16_dgroup_pointer(DGROUP_PALETTE_UPDATE_ACTIVE), 1);
    (void)InvalidateRect16(handle, 0, 0);
    (void)UpdateWindow16(handle);
    win16_write_u32(message, MESSAGE_RESULT_OFFSET, 0);
}

/*
 * 1000:58e7 — reset on wParam zero; otherwise begin one non-iconic palette
 * refresh only while the reentrancy byte is clear. Suppressed paths return the
 * target's uninitialized local word.
 */
uint16_t tdkpin_palette_change_variant_a(
    Win16FarPtr window, Win16FarPtr message)
{
    uint16_t wparam =
        win16_read_u16(win16_far_add_offset(message, MESSAGE_WPARAM_OFFSET));
    if (wparam == 0) {
        win16_write_u8(
            win16_dgroup_pointer(DGROUP_PALETTE_UPDATE_ACTIVE), 0);
        return 0;
    }
    if (win16_read_u8(
            win16_dgroup_pointer(DGROUP_PALETTE_UPDATE_ACTIVE)) == 0) {
        HWND16 handle = win16_read_u16(
            win16_far_add_offset(window, WINDOW_HANDLE_OFFSET));
        if (IsIconic16(handle) == 0) {
            invalidate_palette_window(window, message);
            return 0;
        }
    }
    return win16_indeterminate_u16();
}

/* 1000:5956 — zero-wParam refresh variant without the IsIconic test. */
void tdkpin_palette_change_variant_b(
    Win16FarPtr window, Win16FarPtr message)
{
    uint16_t wparam =
        win16_read_u16(win16_far_add_offset(message, MESSAGE_WPARAM_OFFSET));
    if (wparam == 0 &&
        win16_read_u8(
            win16_dgroup_pointer(DGROUP_PALETTE_UPDATE_ACTIVE)) == 0) {
        invalidate_palette_window(window, message);
    }
}

/*
 * 1000:59a0 — WM_PALETTECHANGED. Ignore notifications originating from this
 * window or its child; otherwise realize the global palette as a background
 * palette, update mapped colors, restore the previous palette, and consume it.
 */
static uint16_t wm_palette_changed_impl(
    Win16FarPtr window, Win16FarPtr message)
{
    HWND16 window_handle =
        win16_read_u16(win16_far_add_offset(window, WINDOW_HANDLE_OFFSET));
    HWND16 changed_window =
        win16_read_u16(win16_far_add_offset(message, MESSAGE_WPARAM_OFFSET));
    if (changed_window == window_handle ||
        GetParent16(changed_window) == window_handle) {
        return 1;
    }

    HDC16 dc = GetDC16(window_handle);
    HPALETTE16 palette = win16_read_u16(
        win16_dgroup_pointer(DGROUP_PALETTE_HANDLE));
    HPALETTE16 previous = SelectPalette16(dc, palette, 1);
    (void)RealizePalette16(dc);
    (void)UpdateColors16(dc);
    (void)SelectPalette16(dc, previous, 0);
    (void)ReleaseDC16(window_handle, dc);
    win16_write_u32(message, MESSAGE_RESULT_OFFSET, 0);
    return 0;
}

uint16_t tdkpin_wm_palette_changed(
    Win16FarPtr window, Win16FarPtr message)
{
    return wm_palette_changed_impl(window, message);
}

uint16_t tdkpin_wm_palette_changed_variant_b(
    Win16FarPtr window, Win16FarPtr message)
{
    return wm_palette_changed_impl(window, message);
}

uint16_t tdkpin_wm_palette_changed_variant_c(
    Win16FarPtr window, Win16FarPtr message)
{
    return wm_palette_changed_impl(window, message);
}

/*
 * 1000:5a37 — WM_QUERYNEWPALETTE. Return/publish the signed number of palette
 * entries remapped and invalidate the whole window only when that count > 0.
 */
static int16_t wm_query_new_palette_impl(
    Win16FarPtr window, Win16FarPtr message)
{
    HWND16 window_handle =
        win16_read_u16(win16_far_add_offset(window, WINDOW_HANDLE_OFFSET));
    HDC16 dc = GetDC16(window_handle);
    HPALETTE16 palette = win16_read_u16(
        win16_dgroup_pointer(DGROUP_PALETTE_HANDLE));
    HPALETTE16 previous = SelectPalette16(dc, palette, 0);
    int16_t changed = (int16_t)RealizePalette16(dc);
    (void)SelectPalette16(dc, previous, 0);
    (void)ReleaseDC16(window_handle, dc);
    if (changed > 0) {
        (void)InvalidateRect16(window_handle, 0, 0);
    }
    win16_write_u32(message, MESSAGE_RESULT_OFFSET, (uint16_t)changed);
    return changed;
}

int16_t tdkpin_wm_query_new_palette(
    Win16FarPtr window, Win16FarPtr message)
{
    return wm_query_new_palette_impl(window, message);
}

int16_t tdkpin_wm_query_new_palette_variant_b(
    Win16FarPtr window, Win16FarPtr message)
{
    return wm_query_new_palette_impl(window, message);
}

int16_t tdkpin_wm_query_new_palette_variant_c(
    Win16FarPtr window, Win16FarPtr message)
{
    return wm_query_new_palette_impl(window, message);
}

/* 1000:6129 — setup one board window and load DAT 1000+board_index. */
void tdkpin_setup_board_window(Win16FarPtr window)
{
    object_windows_setup_window(window);
    HCURSOR16 wait_cursor = LoadCursor16(
        0, win16_make_far_pointer(0, WIN16_IDC_WAIT));
    (void)SetCursor16(wait_cursor);
    uint16_t board_index = win16_read_u16(
        win16_dgroup_pointer(DGROUP_BOARD_INDEX));
    uint16_t resource_id =
        (uint16_t)(board_index + BOARD_DAT_RESOURCE_BASE);
    HBITMAP16 bitmap = tdkpin_load_bitmap_resource(
        win16_make_far_pointer(0, resource_id), g_win16_instance);
    win16_write_u16(
        win16_dgroup_pointer(DGROUP_OVERLAY_BITMAP), 0, bitmap);
    (void)SetFocus16(
        win16_read_u16(win16_far_add_offset(window, WINDOW_HANDLE_OFFSET)));
}

/*
 * 1000:616e — draw the current 640x460 board DAT through a compatible DC,
 * preserving the caller's palette/object selections and restoring Arrow.
 */
void tdkpin_draw_board_overlay(
    Win16FarPtr ignored_object,
    uint16_t ignored_1,
    uint16_t ignored_2,
    HDC16 destination)
{
    (void)ignored_object;
    (void)ignored_1;
    (void)ignored_2;
    HPALETTE16 palette = win16_read_u16(
        win16_dgroup_pointer(DGROUP_PALETTE_HANDLE));
    HPALETTE16 previous_palette = SelectPalette16(destination, palette, 0);
    (void)UnrealizeObject16(palette);
    (void)RealizePalette16(destination);
    HDC16 source = CreateCompatibleDC16(destination);
    HBITMAP16 bitmap = win16_read_u16(
        win16_dgroup_pointer(DGROUP_OVERLAY_BITMAP));
    HGDIOBJ16 previous_bitmap = SelectObject16(source, bitmap);
    (void)BitBlt16(
        destination,
        0,
        0,
        BOARD_WIDTH,
        BOARD_HEIGHT,
        source,
        0,
        0,
        WIN16_SRCCOPY);
    (void)SelectObject16(source, previous_bitmap);
    (void)DeleteDC16(source);
    (void)SelectPalette16(destination, previous_palette, 0);
    HCURSOR16 arrow = LoadCursor16(
        0, win16_make_far_pointer(0, WIN16_IDC_ARROW));
    (void)SetCursor16(arrow);
}