/* ObjectWindows modal-dialog methods from Code2. */

#include "tdkpin_dialog.h"

enum {
    OBJECT_WINDOW_HANDLE_OFFSET = 4,
    DIALOG_MODAL_FLAG_OFFSET = 0x25,
    DIALOG_CLOSE_SLOT = 0x50,
    DIALOG_CAN_CLOSE_SLOT = 0x3c,
    DIALOG_TRANSFER_SLOT = 0x44,
    DIALOG_MARK_CHILD_CALLBACK_OFFSET = 0x2bb1,
};

static void write_far(
    Win16FarPtr base, uint16_t offset, Win16FarPtr value)
{
    win16_write_u16(base, offset, win16_far_offset(value));
    win16_write_u16(
        base, (uint16_t)(offset + 2), win16_far_selector(value));
}

/*
 * 1008:2996 -- base ObjectWindows dialog constructor.  The hidden VMT value
 * is explicit in C.  A selector-zero template is an integer resource and is
 * retained verbatim; a real far C string is duplicated and owned by dialog.
 */
Win16FarPtr object_windows_dialog_construct(
    Win16FarPtr dialog,
    uint16_t vmt,
    Win16FarPtr template_name,
    Win16FarPtr parent)
{
    BorlandObjectCallFrame frame = {dialog, vmt};
    if (!borland_enter_object_constructor(&frame, 0)) {
        return frame.object;
    }
    frame.object = object_windows_object_construct(frame.object, 0, parent);
    object_windows_clear_flag_4(frame.object);
    Win16FarPtr stored_template = win16_far_selector(template_name) == 0
        ? template_name
        : borland_far_strdup(template_name);
    write_far(frame.object, 0x1d, stored_template);
    write_far(frame.object, 0x21, 0);
    win16_write_u8(win16_far_add_offset(frame.object, 0x25), 0);
    return frame.object;
}

/*
 * 1008:1607 -- derived text-entry dialog.  Template 7f02 is normal and 7f05
 * is selected by the process flag at 066a.  Four caller fields are then stored
 * unaligned at +26, +2a, +2e, and +32.
 */
Win16FarPtr object_windows_text_dialog_construct(
    Win16FarPtr dialog,
    uint16_t vmt,
    INT16 control_id,
    Win16FarPtr text_buffer,
    Win16FarPtr label,
    Win16FarPtr caption,
    Win16FarPtr parent)
{
    BorlandObjectCallFrame frame = {dialog, vmt};
    if (!borland_enter_object_constructor(&frame, 0)) {
        return frame.object;
    }
    uint16_t resource = g_dialog_alternate_template != 0 ? 0x7f05 : 0x7f02;
    frame.object = object_windows_dialog_construct(
        frame.object,
        0,
        win16_make_far_pointer(0, resource),
        parent);
    write_far(frame.object, 0x26, caption);
    write_far(frame.object, 0x2a, label);
    write_far(frame.object, 0x2e, text_buffer);
    win16_write_u16(frame.object, 0x32, (uint16_t)control_id);
    return frame.object;
}

static HWND16 dialog_parent_window(Win16FarPtr dialog)
{
    Win16FarPtr parent = win16_read_far_pointer(dialog, 6);
    return parent == 0
        ? 0
        : win16_read_u16(win16_far_add_offset(parent, 4));
}

/*
 * 1008:2a45 -- create a modeless dialog once.  AL is the Boolean result, but
 * AH is intentionally retained from CreateDialogParam (or incoming AX when a
 * preexisting status skips creation), matching MOV AL,0 / INC AX exactly.
 */
uint16_t object_windows_create_modeless_dialog(Win16FarPtr dialog)
{
    uint16_t status = win16_read_u16(win16_far_add_offset(dialog, 2));
    uint16_t high_byte;
    if (status == 0) {
        object_windows_clear_flag_4(dialog);
        object_windows_set_flag_1(dialog);
        win16_write_u8(win16_far_add_offset(dialog, 0x25), 0);
        HWND16 created = win16_call_create_dialog_param(
            g_win16_create_dialog_param,
            g_win16_instance,
            win16_read_far_pointer(dialog, 0x1d),
            dialog_parent_window(dialog),
            win16_read_far_pointer(dialog, 0x12),
            (LPARAM16)win16_read_far_pointer(dialog, 0x21));
        high_byte = created & 0xff00u;
        win16_write_u16(dialog, 4, created);
        if (created == 0) {
            win16_write_u16(dialog, 2, 0xffff);
        }
    } else {
        high_byte = win16_indeterminate_u16() & 0xff00u;
    }
    return high_byte |
        (win16_read_u16(win16_far_add_offset(dialog, 2)) == 0 ? 1u : 0u);
}

/*
 * 1008:2ae3 -- execute a modal dialog while temporarily publishing it as the
 * application's active dialog.  DialogBox failure -1 becomes status ffff;
 * the object HWND is always cleared after an attempted modal call.
 */
INT16 object_windows_execute_modal_dialog(Win16FarPtr dialog)
{
    uint16_t status = win16_read_u16(win16_far_add_offset(dialog, 2));
    if (status != 0) {
        return (INT16)status;
    }

    object_windows_clear_flag_4(dialog);
    object_windows_set_flag_1(dialog);
    win16_write_u8(win16_far_add_offset(dialog, 0x25), 1);

    Win16FarPtr previous_active =
        win16_read_far_pointer(g_object_windows_application, 0x0e);
    INT16 result = win16_call_dialog_box_param(
        g_win16_dialog_box_param,
        g_win16_instance,
        win16_read_far_pointer(dialog, 0x1d),
        dialog_parent_window(dialog),
        win16_read_far_pointer(dialog, 0x12),
        (LPARAM16)win16_read_far_pointer(dialog, 0x21));
    write_far(g_object_windows_application, 0x0e, previous_active);
    if (result == -1) {
        win16_write_u16(dialog, 2, 0xffff);
    }
    win16_write_u16(dialog, 4, 0);
    return result;
}

/*
 * 1008:2cf2 -- nonmodal windows use the ordinary close helper.  An active
 * modal dialog first asks VMT +3c; approval invokes +44(object,1) followed by
 * +50(object,1).  The incoming message record is intentionally ignored.
 */
void object_windows_dialog_validate_and_close(
    Win16FarPtr dialog, ObjectWindowsMessage *message)
{
    (void)message;
    if (win16_read_u8(win16_far_add_offset(
            dialog, DIALOG_MODAL_FLAG_OFFSET)) == 0) {
        object_windows_close_if_allowed(dialog);
        return;
    }

    uint16_t vmt = win16_read_u16(dialog);
    Win16FarPtr vmt_pointer = win16_dgroup_pointer(vmt);
    Win16FarPtr can_close =
        win16_read_far_pointer(vmt_pointer, DIALOG_CAN_CLOSE_SLOT);
    if (!win16_call_object_bool_method(can_close, dialog)) {
        return;
    }
    win16_call_object_u16_method(
        win16_read_far_pointer(vmt_pointer, DIALOG_TRANSFER_SLOT),
        dialog,
        1);
    win16_call_object_u16_method(
        win16_read_far_pointer(vmt_pointer, DIALOG_CLOSE_SLOT),
        dialog,
        1);
}

/* 1008:2bb1 — ForEach callback: mark a child only after HWND publication. */
void object_windows_dialog_mark_child(
    uint16_t ignored, Win16FarPtr child)
{
    object_windows_set_flag_4_if_windowed(ignored, child);
}

/* 1008:2bd1 — end an active modal dialog after marking all child windows. */
void object_windows_end_modal_dialog(
    Win16FarPtr dialog, INT16 result)
{
    if (win16_read_u8(win16_far_add_offset(
            dialog, DIALOG_MODAL_FLAG_OFFSET)) == 0) {
        return;
    }
    object_windows_for_each_child(
        dialog,
        win16_relocated_code_pointer(
            2, DIALOG_MARK_CHILD_CALLBACK_OFFSET));
    HWND16 window = win16_read_u16(win16_far_add_offset(
        dialog, OBJECT_WINDOW_HANDLE_OFFSET));
    (void)EndDialog16(window, result);
}

/*
 * 1008:2d3a — modal dialogs use VMT +0x50(object,2); nonmodal windows use the
 * ordinary close-if-allowed helper. The incoming event is ignored.
 */
void object_windows_dialog_close(
    Win16FarPtr dialog, ObjectWindowsMessage *message)
{
    (void)message;
    if (win16_read_u8(win16_far_add_offset(
            dialog, DIALOG_MODAL_FLAG_OFFSET)) == 0) {
        object_windows_close_if_allowed(dialog);
        return;
    }
    uint16_t vmt = win16_read_u16(dialog);
    Win16FarPtr procedure =
        win16_read_far_pointer(win16_dgroup_pointer(vmt), DIALOG_CLOSE_SLOT);
    win16_call_object_u16_method(procedure, dialog, 2);
}

/*
 * 1008:2a0e — derived dialog destructor. The binary tests only the selector
 * word of the unaligned string pointer at +0x1d/+0x1f before disposing it.
 */
void object_windows_dialog_destruct(Win16FarPtr dialog, uint16_t vmt)
{
    Win16FarPtr string = win16_read_far_pointer(dialog, 0x1d);
    if (win16_far_selector(string) != 0) {
        borland_far_strdispose(string);
    }
    object_windows_object_destruct(dialog, 0);
    BorlandObjectCallFrame frame = {dialog, vmt};
    borland_finish_object_destructor(&frame, 0);
}

/* 1008:168e — fill the dialog's far text buffer and always return AL=1. */
bool object_windows_dialog_read_text(Win16FarPtr dialog)
{
    HWND16 window = win16_read_u16(win16_far_add_offset(dialog, 4));
    Win16FarPtr buffer = win16_read_far_pointer(dialog, 0x2e);
    INT16 control_id = (INT16)win16_read_u16(
        win16_far_add_offset(dialog, 0x32));
    (void)GetDlgItemTextFar16(window, control_id, buffer, 0x65);
    return true;
}

/*
 * 1008:16be -- finish ObjectWindows preparation, publish the caption and two
 * control texts, then limit control +0x32 to length-1 with EM_LIMITTEXT 0415h.
 * Every USER return value is deliberately ignored.
 */
void object_windows_dialog_setup_text_fields(Win16FarPtr dialog)
{
    object_windows_prepare_window(dialog);
    HWND16 window = win16_read_u16(win16_far_add_offset(dialog, 4));
    (void)SetWindowTextFar16(
        window, win16_read_far_pointer(dialog, 0x26));
    (void)SetDlgItemText16(
        window, 100, win16_read_far_pointer(dialog, 0x2a));
    (void)SetDlgItemText16(
        window, 101, win16_read_far_pointer(dialog, 0x2e));
    uint16_t capacity = win16_read_u16(win16_far_add_offset(dialog, 0x32));
    (void)SendDlgItemMessage16(
        window, 101, 0x0415, (uint16_t)(capacity - 1), 0);
}