// Cthulhu screen reader.
// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <https://www.gnu.org/licenses/gpl-3.0.html>.

package atspi

import (
	"context"
	"errors"
	"testing"
)

func reviewTree(t *testing.T) (*AccessibleTree, ObjectID) {
	t.Helper()
	id := func(path string) ObjectID { return NewObjectID(":1.42", path) }
	node := func(path, role string, children ...ObjectID) TreeNode {
		s := NewSnapshot(path, path, role, "", "")
		s.BusName = ":1.42"
		return TreeNode{Snapshot: s, Children: children}
	}
	tree, err := NewAccessibleTree(id("/desktop"), []TreeNode{
		node("/desktop", "desktop frame", id("/window"), id("/other")),
		node("/window", "frame", id("/button"), id("/dialog")),
		node("/button", "push button"),
		node("/dialog", "dialog", id("/entry")),
		node("/entry", "entry"),
		node("/other", "frame"),
	})
	if err != nil {
		t.Fatal(err)
	}
	return tree, id("/button")
}

func TestReviewWindowScopeAndOwnership(t *testing.T) {
	tree, focus := reviewTree(t)
	snapshot, err := tree.ReviewWindow(context.Background(), focus)
	nodes := snapshot.Nodes
	if err != nil {
		t.Fatal(err)
	}
	if len(nodes) != 4 || nodes[0].Snapshot.Path != "/window" || nodes[1].Snapshot.Path != "/button" || nodes[3].Snapshot.Path != "/entry" {
		t.Fatalf("unexpected window: %#v", nodes)
	}
	nodes[0].Children[0] = ObjectID{}
	focus.Path = "/entry"
	snapshot, err = tree.ReviewWindow(context.Background(), focus)
	nodes = snapshot.Nodes
	if err != nil || len(nodes) != 2 || nodes[0].Snapshot.Path != "/dialog" {
		t.Fatalf("dialog scope: %#v, %v", nodes, err)
	}
	focus.Path = "/button"
	if _, err := tree.ReviewWindow(context.Background(), focus); err != nil {
		t.Fatal("caller mutated tree:", err)
	}
}

func TestReviewWindowRejectsStaleDataAndCancellation(t *testing.T) {
	for _, tc := range []struct {
		name       string
		invalidate func(*AccessibleTree, ObjectID)
		want       error
	}{
		{"children", func(tree *AccessibleTree, id ObjectID) { tree.InvalidateChildren(id) }, ErrIncompleteTree},
		{"geometry", func(tree *AccessibleTree, id ObjectID) { tree.InvalidateGeometry(id) }, ErrStaleGeometry},
		{"text", func(tree *AccessibleTree, id ObjectID) { tree.InvalidateText(id) }, ErrStaleText},
	} {
		t.Run(tc.name, func(t *testing.T) {
			tree, focus := reviewTree(t)
			tc.invalidate(tree, focus)
			if snapshot, err := tree.ReviewWindow(context.Background(), focus); snapshot.Nodes != nil || !errors.Is(err, tc.want) {
				t.Fatalf("nodes=%v err=%v", snapshot.Nodes, err)
			}
		})
	}
	tree, focus := reviewTree(t)
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	if _, err := tree.ReviewWindow(ctx, focus); !errors.Is(err, context.Canceled) {
		t.Fatal(err)
	}
	focus.Path = "/desktop"
	if _, err := tree.ReviewWindow(context.Background(), focus); !errors.Is(err, ErrNoReviewWindow) {
		t.Fatal(err)
	}
}