/* TDKPIN's bounded Win16 queue drain and two close-method pairs. */

#include "tdkpin_message_pump.h"

enum {
    WIN16_PM_REMOVE = 1,
    TDKPIN_MAX_DRAIN_MESSAGE = 0x0032,
    TDKPIN_TIMER_MESSAGE = 0x0580,
    WIN16_WM_KEYDOWN_LOCAL = 0x0100,
    WIN16_WM_KEYUP_LOCAL = 0x0101,
};

/* 1008:00e2 — drain messages 0..0x32 until PeekMessage reports empty. */
void tdkpin_drain_messages_except_input(void)
{
    MSG16 message;
    while (PeekMessage16(
               &message,
               0,
               0,
               TDKPIN_MAX_DRAIN_MESSAGE,
               WIN16_PM_REMOVE) != 0) {
        if (message.message != TDKPIN_TIMER_MESSAGE &&
            message.message != WIN16_WM_KEYDOWN_LOCAL &&
            message.message != WIN16_WM_KEYUP_LOCAL) {
            (void)TranslateMessage16(&message);
            (void)DispatchMessage16(&message);
        }
    }
}

static void drain_and_close(Win16FarPtr window)
{
    tdkpin_drain_messages_except_input();
    object_windows_close_if_allowed(window);
}

/* 1000:5ee6 and 6202 — identical methods in two derived window VMTs. */
void tdkpin_close_variant_a(Win16FarPtr window)
{
    drain_and_close(window);
}

void tdkpin_close_variant_b(Win16FarPtr window)
{
    drain_and_close(window);
}

static uint16_t conditional_drain_and_close(
    Win16FarPtr window,
    ObjectWindowsMessage *message,
    uint8_t suppressed_notification)
{
    uint8_t notification =
        (uint8_t)((uint32_t)message->lparam >> 16);
    if (notification != suppressed_notification) {
        drain_and_close(window);
    }
    return win16_indeterminate_u16();
}

/*
 * 1000:5efc and 6218 — suppress close for notification 0x1c/0x3b.
 * Both routines return an uninitialized local word on every path.
 */
uint16_t tdkpin_conditional_close_variant_a(
    Win16FarPtr window, ObjectWindowsMessage *message)
{
    return conditional_drain_and_close(window, message, 0x1c);
}

uint16_t tdkpin_conditional_close_variant_b(
    Win16FarPtr window, ObjectWindowsMessage *message)
{
    return conditional_drain_and_close(window, message, 0x3b);
}