@page "/design/schema-library"
@using ZB.MOM.WW.ScadaBridge.Security
@using ZB.MOM.WW.ScadaBridge.CentralUI.Services
@using ZB.MOM.WW.ScadaBridge.Commons.Entities.Schemas
@attribute [Authorize(Policy = AuthorizationPolicies.RequireDesign)]
@inject ISchemaLibraryService SchemaLibraryService
@inject IDialogService Dialog

@* Schema Library: list + create/edit (via SchemaBuilder) + delete the
   reusable named JSON-Schema library entries that the {"$ref":"lib:Name"} resolver
   resolves against. Every mutation is dispatched through ISchemaLibraryService
   — the guard-running ManagementActor path — never a direct repo write. *@

<div class="container-fluid mt-3">
    <div class="d-flex justify-content-between align-items-center mb-3">
        <h4 class="mb-0">Schema Library</h4>
        @if (!_editing)
        {
            <button class="btn btn-primary btn-sm" @onclick="BeginCreate">New Schema</button>
        }
    </div>

    <ToastNotification @ref="_toast" />

    @if (_editing)
    {
        <div class="card mb-3">
            <div class="card-body">
                <h5 class="card-title mb-3">@(_editId.HasValue ? $"Edit Schema: {_editOriginalName}" : "New Schema")</h5>

                <div class="row g-3 mb-3">
                    <div class="col-md-6">
                        <label class="form-label small">Name</label>
                        <input type="text" class="form-control form-control-sm"
                               placeholder="e.g. Address" @bind="_formName" />
                        <div class="form-text">Referenced as <code>lib:@(string.IsNullOrWhiteSpace(_formName) ? "Name" : _formName.Trim())</code>.</div>
                    </div>
                    <div class="col-md-6">
                        <label class="form-label small">Scope <span class="text-muted">(optional)</span></label>
                        <input type="text" class="form-control form-control-sm"
                               placeholder="(global)" @bind="_formScope" />
                    </div>
                </div>

                <label class="form-label small">Schema</label>
                <SchemaBuilder Mode="value"
                               Value="@_formSchemaJson"
                               ValueChanged="@(v => _formSchemaJson = v)" />

                @if (_formError != null)
                {
                    <div class="text-danger small mt-2">@_formError</div>
                }

                <div class="mt-3">
                    <button class="btn btn-success btn-sm me-1" @onclick="SaveSchema" disabled="@_busy">Save</button>
                    <button class="btn btn-outline-secondary btn-sm" @onclick="CancelEdit" disabled="@_busy">Cancel</button>
                </div>
            </div>
        </div>
    }

    @if (_loading)
    {
        <LoadingSpinner IsLoading="true" />
    }
    else if (_schemas.Count == 0)
    {
        <div class="text-center py-5 text-muted">
            <p class="mb-3">No library schemas defined.</p>
            @if (!_editing)
            {
                <button class="btn btn-primary btn-sm" @onclick="BeginCreate">Create your first schema</button>
            }
        </div>
    }
    else
    {
        <table class="table table-sm align-middle">
            <thead>
                <tr>
                    <th>Name</th>
                    <th>Scope</th>
                    <th>Reference</th>
                    <th class="text-end">Actions</th>
                </tr>
            </thead>
            <tbody>
                @foreach (var s in _schemas)
                {
                    <tr @key="s.Id">
                        <td class="fw-semibold">@s.Name</td>
                        <td>@(string.IsNullOrWhiteSpace(s.Scope) ? "—" : s.Scope)</td>
                        <td><code>lib:@s.Name</code></td>
                        <td class="text-end">
                            @* Row actions are disabled while the editor is open so the
                               row under edit (and its siblings) can't be deleted out from
                               under the form, and while a delete is in flight (_busy). *@
                            <button class="btn btn-outline-primary btn-sm me-1"
                                    @onclick="() => BeginEdit(s)" disabled="@(_editing || _busy)">Edit</button>
                            <button class="btn btn-outline-danger btn-sm"
                                    @onclick="() => DeleteSchema(s)" disabled="@(_editing || _busy)">Delete</button>
                        </td>
                    </tr>
                }
            </tbody>
        </table>
    }
</div>

@code {
    private List<SharedSchema> _schemas = new();
    private bool _loading = true;
    private bool _busy;

    private bool _editing;
    private int? _editId;
    private string _editOriginalName = string.Empty;
    private string _formName = string.Empty;
    private string? _formScope;
    private string? _formSchemaJson;
    private string? _formError;

    private ToastNotification _toast = default!;

    protected override async Task OnInitializedAsync()
    {
        await LoadAsync();
    }

    private async Task LoadAsync()
    {
        _loading = true;
        try
        {
            _schemas = (await SchemaLibraryService.ListAsync()).ToList();
        }
        finally
        {
            _loading = false;
        }
    }

    private void BeginCreate()
    {
        _editing = true;
        _editId = null;
        _editOriginalName = string.Empty;
        _formName = string.Empty;
        _formScope = null;
        // Seed an object-shaped schema so the builder opens with a useful default.
        _formSchemaJson = """{"type":"object","properties":{}}""";
        _formError = null;
    }

    private void BeginEdit(SharedSchema schema)
    {
        _editing = true;
        _editId = schema.Id;
        _editOriginalName = schema.Name;
        _formName = schema.Name;
        _formScope = schema.Scope;
        _formSchemaJson = schema.SchemaJson;
        _formError = null;
    }

    private void CancelEdit()
    {
        _editing = false;
        _formError = null;
    }

    private async Task SaveSchema()
    {
        _formError = null;
        var name = _formName?.Trim() ?? string.Empty;
        if (string.IsNullOrEmpty(name))
        {
            _formError = "Schema name is required.";
            return;
        }

        var scope = string.IsNullOrWhiteSpace(_formScope) ? null : _formScope.Trim();
        var schemaJson = _formSchemaJson ?? string.Empty;

        _busy = true;
        try
        {
            var result = _editId.HasValue
                ? await SchemaLibraryService.UpdateAsync(_editId.Value, name, scope, schemaJson)
                : await SchemaLibraryService.CreateAsync(name, scope, schemaJson);

            if (result.Success)
            {
                _toast.ShowSuccess(_editId.HasValue
                    ? $"Schema '{name}' updated."
                    : $"Schema '{name}' created.");
                _editing = false;
                await LoadAsync();
            }
            else
            {
                _formError = result.Error;
            }
        }
        finally
        {
            _busy = false;
        }
    }

    private async Task DeleteSchema(SharedSchema schema)
    {
        // In-flight guard: an editor-open row action is already disabled in the markup,
        // but the _busy gate is the authoritative guard against a double-invoked delete
        // (and mirrors the Save path's guard).
        if (_busy) return;

        var confirmed = await Dialog.ConfirmAsync(
            "Delete Schema",
            $"Delete library schema '{schema.Name}'? References to lib:{schema.Name} will no longer resolve.",
            danger: true);
        if (!confirmed) return;

        _busy = true;
        try
        {
            var result = await SchemaLibraryService.DeleteAsync(schema.Id);
            if (result.Success)
            {
                _toast.ShowSuccess($"Schema '{schema.Name}' deleted.");
                await LoadAsync();
            }
            else
            {
                _toast.ShowError(result.Error ?? "Delete failed.");
            }
        }
        finally
        {
            _busy = false;
        }
    }
}