@typeparam TItem

@*
 *                                dbMango
 *
 * Copyright 2025 Deutsche Bank AG
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *@

<div class="tree-container">

<style>

.tree-node {
    margin-left: 5px;
}

.node-header {
    display: flex;
    align-items: center;
}

.node-selected {
    background-color: @Night.BackgroundLight;
}

.node-text {
    cursor: pointer;
    margin-right: 10px;
}

.no-padding {
    margin: 0 !important;
    padding: 0 !important;
}

.btn-placeholder {
    width: 30px;
    height: 24px;
}

</style>


    <CascadingValue Value="_currentlyEditingNode" Name="CurrentlyEditingNodeRef">
        <CascadingValue Value="SetCurrentlyEditingNode" Name="SetCurrentlyEditingNodeRef">
            <CascadingValue Value="SelectedNode" Name="SelectedNodeRef">
                <CascadingValue Value="SetCurrentlySelectedNode" Name="SetSelectedNodeRef">
                    <CascadingValue Value="ReadOnly" Name="ReadOnly">
                        @if (AllowAddRootNode)
                        {
                            <button class="btn btn-secondary" @onclick="AddRootNode">Add Root Node</button>
                        }
                        <ul>
                            @foreach (var node in RootNodes)
                            {
                                <TreeNodeComponent Node="node" OnNodeChanged="OnNodeChanged" LabelTemplate="@LabelTemplate" BodyTemplate="@BodyTemplate"/>
                            }
                        </ul>
                    </CascadingValue>
                </CascadingValue>
            </CascadingValue>
        </CascadingValue>
    </CascadingValue>
</div>

@code {
    [Parameter] public List<TreeNode<TItem>>            RootNodes        { get; set; } = [];
    [Parameter] public EventCallback<TreeNode<TItem>>   OnNodeChanged    { get; set; }
    [Parameter] public bool                             AllowAddRootNode { get; set; }
    [Parameter] public bool                             ReadOnly         { get; set; }

    [Parameter] public RenderFragment<TreeNode<TItem>>? LabelTemplate    { get; set; }
    [Parameter] public RenderFragment<TreeNode<TItem>>? BodyTemplate     { get; set; }

    [Parameter]
    public TreeNode<TItem>? SelectedNode
    {
        get;
        set
        {
            if (!EqualityComparer<TreeNode<TItem>?>.Default.Equals(field, value))
            {
                field = value;
                SelectedNodeChanged.InvokeAsync(value);
                StateHasChanged();
            }
        }
    } = null;

    [Parameter]
    public EventCallback<TreeNode<TItem>?> SelectedNodeChanged { get; set; }

    private void AddRootNode()
    {
        var newNode = new TreeNode<TItem> { Data = default }; // Or initialize with a default TItem
        RootNodes.Add(newNode);
        OnNodeChanged.InvokeAsync(newNode);
    }

    private TreeNode<TItem>? _currentlyEditingNode = null;

    private void SetCurrentlyEditingNode(TreeNode<TItem>? node)
    {
        _currentlyEditingNode = node;
        StateHasChanged(); // Crucial to propagate the change
    }

    private void SetCurrentlySelectedNode(TreeNode<TItem>? node)
    {
        SelectedNode = node;
    }
}