// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package atspi

/*
#include "adapter_native.h"
*/
import "C"

// Only the native owner calls this, after foreground validation. Counts use a
// fixed number of RPCs; no selected-row/column arrays or sheet walks are used.
// LibreOffice itself scans its row marks when answering selected-row counts.
func captureLibreOfficeSelection(source *C.AtspiAccessible) *LibreOfficeSelection {
	selection := C.atspi_accessible_get_selection_iface(source)
	table := C.atspi_accessible_get_table_iface(source)
	if selection == nil || table == nil {
		if selection != nil {
			C.g_object_unref(C.gpointer(selection))
		}
		if table != nil {
			C.g_object_unref(C.gpointer(table))
		}
		return nil
	}
	defer C.g_object_unref(C.gpointer(selection))
	defer C.g_object_unref(C.gpointer(table))
	var queryError *C.GError
	count := int(C.atspi_selection_get_n_selected_children(selection, &queryError))
	if queryError != nil {
		C.g_error_free(queryError)
		return nil
	}
	if count < 0 {
		return nil
	}
	result := &LibreOfficeSelection{Kind: "cells", Count: count, CountLimited: count == 1<<31-1}
	if count == 0 {
		result.Complete = true
		return result
	}
	rows := int(C.atspi_table_get_n_rows(table, &queryError))
	if queryError != nil {
		C.g_error_free(queryError)
		return nil
	}
	columns := int(C.atspi_table_get_n_columns(table, &queryError))
	if queryError != nil {
		C.g_error_free(queryError)
		return nil
	}
	selectedRows, selectedColumns := 0, 0
	// A small selection cannot contain a whole row or column. Avoid making
	// LibreOffice scan all its row marks for ordinary Shift+Arrow movement.
	if count >= columns {
		selectedRows = int(C.atspi_table_get_n_selected_rows(table, &queryError))
		if queryError != nil {
			C.g_error_free(queryError)
			return nil
		}
	}
	if count >= rows {
		selectedColumns = int(C.atspi_table_get_n_selected_columns(table, &queryError))
		if queryError != nil {
			C.g_error_free(queryError)
			return nil
		}
	}
	if rows <= 0 || columns <= 0 || selectedRows < 0 || selectedColumns < 0 {
		return nil
	}
	if selectedRows == rows || selectedColumns == columns {
		return &LibreOfficeSelection{Kind: "all", Complete: true}
	}
	stride := 1
	// Only classify pure row/column selections. Mixed selections retain an
	// honest cell count. GTK caps counts above INT_MAX, rather than wrapping.
	if !result.CountLimited && selectedRows > 0 && int64(selectedRows)*int64(columns) == int64(count) {
		result.Kind, result.Count, result.CountLimited = "rows", selectedRows, false
		stride = columns
	} else if !result.CountLimited && selectedColumns > 0 && int64(selectedColumns)*int64(rows) == int64(count) {
		result.Kind, result.Count, result.CountLimited = "columns", selectedColumns, false
	}
	indices := make([]int, 0, libreOfficeSelectionLimit)
	if result.Count > libreOfficeSelectionLimit {
		indices = append(indices, 0, count-1)
	} else {
		for index := 0; index < result.Count; index++ {
			indices = append(indices, index*stride)
		}
	}
	for _, index := range indices {
		child := C.atspi_selection_get_selected_child(selection, C.gint(index), &queryError)
		if queryError != nil {
			C.g_error_free(queryError)
			if child != nil {
				C.g_object_unref(C.gpointer(child))
			}
			return nil
		}
		if child == nil {
			return nil
		}
		cell := C.atspi_accessible_get_table_cell(child)
		var row, column C.gint
		valid := false
		if cell != nil {
			valid = C.atspi_table_cell_get_position(cell, &row, &column, &queryError) != 0
			C.g_object_unref(C.gpointer(cell))
		}
		C.g_object_unref(C.gpointer(child))
		if queryError != nil {
			C.g_error_free(queryError)
			return nil
		}
		if !valid || row < 0 || column < 0 || int(row) >= rows || int(column) >= columns {
			return nil
		}
		position := LibreOfficeCell{Row: int(row), Column: int(column)}
		if result.Kind == "rows" {
			position.Column = 0
		}
		if result.Kind == "columns" {
			position.Row = 0
		}
		result.Cells = append(result.Cells, position)
	}
	result.First, result.Last = result.Cells[0], result.Cells[len(result.Cells)-1]
	result.Complete = result.Count <= libreOfficeSelectionLimit
	if !result.Complete {
		result.Cells = nil
	}
	return result
}