@using ZB.MOM.WW.ScadaBridge.Commons.Types
@using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums

@*
    M10 residual: body component for the template "Add / Edit Attribute" dialog
    hosted by IDialogService.ShowAsync. Renders ONLY the form fields + action
    buttons inside the host's .modal-body; the host owns the backdrop, header,
    focus trap, Escape, and focus restoration.

    Mirrors MoveDataConnectionDialog: the save round-trip runs from inside the
    body, a failure is shown INLINE and the dialog STAYS OPEN, and success closes
    with Close(true) so the page toasts and reloads. The actual persistence stays
    on the page (TemplateEdit owns TemplateService + the inherited-member rules)
    and is reached through the OnSaveAsync delegate, which returns null on success
    or the error message to display.
*@
<div class="row g-3">
    <div class="col-12">
        <label class="form-label" for="attr-name">Name</label>
        <input id="attr-name" type="text" class="form-control" @bind="_name" readonly="@Editing" />
    </div>
    <div class="col-12">
        <label class="form-label" for="attr-data-type">Data Type</label>
        <select id="attr-data-type" class="form-select" value="@_dataType" @onchange="OnDataTypeChanged" disabled="@Editing">
            @foreach (var dt in Enum.GetValues<DataType>())
            {
                <option value="@dt">@dt</option>
            }
        </select>
        @if (Editing)
        {
            <div class="form-text">Data type is fixed once the attribute is created.</div>
        }
    </div>
    @if (_dataType == DataType.List)
    {
        <div class="col-12">
            @* List VALUE stays editable when editing; only DataType/ElementDataType are server-fixed (ShowElementType hides the type select on edit). *@
            <AttributeListEditor @bind-ElementDataType="_elementDataType"
                                 @bind-Rows="_listRows"
                                 ShowElementType="@(!Editing)"
                                 Disabled="false" />
        </div>
    }
    else
    {
        <div class="col-12">
            <label class="form-label" for="attr-value">Value</label>
            <input id="attr-value" type="text" class="form-control" @bind="_value" />
        </div>
    }
    <div class="col-12">
        <label class="form-label" for="attr-data-source-ref">Data Source Ref</label>
        <input id="attr-data-source-ref" type="text" class="form-control" @bind="_dataSourceRef" placeholder="Tag path" />
    </div>
    <div class="col-12">
        <div class="form-check">
            <input class="form-check-input" type="checkbox" @bind="_isLocked" id="attrLocked" />
            <label class="form-check-label" for="attrLocked">Locked</label>
        </div>
    </div>
    @if (_error != null)
    {
        <div class="col-12"><div class="text-danger small" data-test="attr-form-error">@_error</div></div>
    }
</div>

<div class="modal-footer px-0 pb-0 mt-3">
    <button class="btn btn-outline-secondary btn-sm" @onclick="() => Context.Cancel()" disabled="@_busy">Cancel</button>
    <button class="btn btn-success btn-sm" @onclick="Submit" disabled="@_busy">@(Editing ? "Save" : "Add")</button>
</div>

@code {
    /// <summary>Host-supplied context: Close(true) on a successful save, Cancel on dismiss.</summary>
    [Parameter, EditorRequired] public DialogContext<bool> Context { get; set; } = default!;

    /// <summary>True when editing an existing attribute (name + data type become read-only).</summary>
    [Parameter] public bool Editing { get; set; }

    [Parameter] public string InitialName { get; set; } = string.Empty;
    [Parameter] public string? InitialValue { get; set; }
    [Parameter] public DataType InitialDataType { get; set; }
    [Parameter] public DataType InitialElementDataType { get; set; } = DataType.String;
    [Parameter] public IReadOnlyList<string> InitialListRows { get; set; } = Array.Empty<string>();
    [Parameter] public bool InitialIsLocked { get; set; }
    [Parameter] public string? InitialDataSourceRef { get; set; }

    /// <summary>
    /// Persists the draft. Returns <c>null</c> on success (the dialog closes with
    /// <c>true</c>) or the message to render inline, leaving the dialog open.
    /// </summary>
    [Parameter, EditorRequired] public Func<AttributeDraft, Task<string?>> OnSaveAsync { get; set; } = default!;

    private string _name = string.Empty;
    private string? _value;
    private DataType _dataType;
    private DataType _elementDataType = DataType.String;
    private List<string> _listRows = new();
    private bool _isLocked;
    private string? _dataSourceRef;
    private string? _error;
    private bool _busy;

    protected override void OnInitialized()
    {
        _name = InitialName;
        _value = InitialValue;
        _dataType = InitialDataType;
        _elementDataType = InitialElementDataType;
        _listRows = InitialListRows.ToList();
        _isLocked = InitialIsLocked;
        _dataSourceRef = InitialDataSourceRef;
    }

    // Switching the data type clears stale list state so a List ⇄ scalar
    // toggle never carries the other mode's value into the submit.
    private void OnDataTypeChanged(ChangeEventArgs e)
    {
        if (!Enum.TryParse<DataType>((string?)e.Value, out var dt) || dt == _dataType) return;
        _dataType = dt;
        if (dt == DataType.List)
        {
            _value = null;
            _listRows = new();
            if (!AttributeValueCodec.IsValidElementType(_elementDataType))
                _elementDataType = DataType.String;
        }
        else
        {
            _listRows = new();
        }
    }

    private async Task Submit()
    {
        if (_busy) return;
        _error = null;
        if (string.IsNullOrWhiteSpace(_name)) { _error = "Name is required."; return; }

        _busy = true;
        try
        {
            var draft = new AttributeDraft(
                _name,
                _dataType,
                _elementDataType,
                _listRows.ToList(),
                _value,
                _dataSourceRef,
                _isLocked);

            var error = await OnSaveAsync(draft);
            if (error == null)
            {
                Context.Close(true);
            }
            else
            {
                _error = error;
            }
        }
        finally
        {
            _busy = false;
        }
    }

    /// <summary>
    /// The authored attribute as submitted. The page resolves the stored value
    /// (list encoding + validation for <see cref="DataType.List"/>) and performs
    /// the add/update, so this record carries the raw form state only.
    /// </summary>
    /// <param name="Name">Attribute name (ignored on edit — the stored name is fixed).</param>
    /// <param name="DataType">Selected data type (fixed on edit).</param>
    /// <param name="ElementDataType">Element scalar type; meaningful only for a List attribute.</param>
    /// <param name="ListRows">Per-element string rows; meaningful only for a List attribute.</param>
    /// <param name="Value">Scalar value; meaningful only for a non-List attribute.</param>
    /// <param name="DataSourceRef">Tag path binding, or null.</param>
    /// <param name="IsLocked">Whether instances may override the attribute.</param>
    public sealed record AttributeDraft(
        string Name,
        DataType DataType,
        DataType ElementDataType,
        List<string> ListRows,
        string? Value,
        string? DataSourceRef,
        bool IsLocked);
}