@page "/admin/data-connections"
@using ScadaLink.Security
@using ScadaLink.Commons.Entities.Sites
@using ScadaLink.Commons.Interfaces.Repositories
@attribute [Authorize(Policy = AuthorizationPolicies.RequireAdmin)]
@inject ISiteRepository SiteRepository

<div class="container-fluid mt-3">
    <div class="d-flex justify-content-between align-items-center mb-3">
        <h4 class="mb-0">Data Connections</h4>
        <button class="btn btn-primary btn-sm" @onclick="ShowAddForm">Add Connection</button>
    </div>

    <ToastNotification @ref="_toast" />
    <ConfirmDialog @ref="_confirmDialog" />

    @if (_loading)
    {
        <LoadingSpinner IsLoading="true" />
    }
    else if (_errorMessage != null)
    {
        <div class="alert alert-danger">@_errorMessage</div>
    }
    else
    {
        @if (_showForm)
        {
            <div class="card mb-3">
                <div class="card-body">
                    <h6 class="card-title">@(_editingConnection == null ? "Add New Connection" : "Edit Connection")</h6>
                    <div class="row g-2 align-items-end">
                        <div class="col-md-3">
                            <label class="form-label small">Name</label>
                            <input type="text" class="form-control form-control-sm" @bind="_formName" />
                        </div>
                        <div class="col-md-2">
                            <label class="form-label small">Protocol</label>
                            <select class="form-select form-select-sm" @bind="_formProtocol">
                                <option value="">Select...</option>
                                <option value="OpcUa">OPC UA</option>
                                <option value="LmxProxy">LMX Proxy</option>
                                <option value="Custom">Custom</option>
                            </select>
                        </div>
                        <div class="col-md-4">
                            <label class="form-label small">Configuration (JSON)</label>
                            <input type="text" class="form-control form-control-sm" @bind="_formConfiguration"
                                   placeholder='e.g. {"endpoint":"opc.tcp://..."}' />
                        </div>
                        <div class="col-md-3">
                            <button class="btn btn-success btn-sm me-1" @onclick="SaveConnection">Save</button>
                            <button class="btn btn-outline-secondary btn-sm" @onclick="CancelForm">Cancel</button>
                        </div>
                    </div>
                    @if (_formError != null)
                    {
                        <div class="text-danger small mt-1">@_formError</div>
                    }
                </div>
            </div>
        }

        @* Assignment form *@
        @if (_showAssignForm)
        {
            <div class="card mb-3">
                <div class="card-body">
                    <h6 class="card-title">Assign Connection to Site</h6>
                    <div class="row g-2 align-items-end">
                        <div class="col-md-3">
                            <label class="form-label small">Connection</label>
                            <select class="form-select form-select-sm" @bind="_assignConnectionId">
                                <option value="0">Select connection...</option>
                                @foreach (var conn in _connections)
                                {
                                    <option value="@conn.Id">@conn.Name (@conn.Protocol)</option>
                                }
                            </select>
                        </div>
                        <div class="col-md-3">
                            <label class="form-label small">Site</label>
                            <select class="form-select form-select-sm" @bind="_assignSiteId">
                                <option value="0">Select site...</option>
                                @foreach (var site in _sites)
                                {
                                    <option value="@site.Id">@site.Name</option>
                                }
                            </select>
                        </div>
                        <div class="col-md-3">
                            <button class="btn btn-success btn-sm me-1" @onclick="SaveAssignment">Assign</button>
                            <button class="btn btn-outline-secondary btn-sm" @onclick="CancelAssignForm">Cancel</button>
                        </div>
                    </div>
                    @if (_assignError != null)
                    {
                        <div class="text-danger small mt-1">@_assignError</div>
                    }
                </div>
            </div>
        }

        <div class="mb-2">
            <button class="btn btn-outline-info btn-sm" @onclick="ShowAssignForm">Assign to Site</button>
        </div>

        <table class="table table-sm table-striped table-hover">
            <thead class="table-dark">
                <tr>
                    <th>ID</th>
                    <th>Name</th>
                    <th>Protocol</th>
                    <th>Configuration</th>
                    <th>Assigned Sites</th>
                    <th style="width: 160px;">Actions</th>
                </tr>
            </thead>
            <tbody>
                @if (_connections.Count == 0)
                {
                    <tr>
                        <td colspan="6" class="text-muted text-center">No data connections configured.</td>
                    </tr>
                }
                @foreach (var conn in _connections)
                {
                    <tr>
                        <td>@conn.Id</td>
                        <td>@conn.Name</td>
                        <td><span class="badge bg-secondary">@conn.Protocol</span></td>
                        <td class="text-muted small text-truncate" style="max-width: 300px;">@(conn.Configuration ?? "—")</td>
                        <td>
                            @{
                                var assignedSites = _connectionSites.GetValueOrDefault(conn.Id);
                            }
                            @if (assignedSites != null && assignedSites.Count > 0)
                            {
                                @foreach (var assignment in assignedSites)
                                {
                                    var siteName = _sites.FirstOrDefault(s => s.Id == assignment.SiteId)?.Name ?? $"Site {assignment.SiteId}";
                                    <span class="badge bg-info text-dark me-1">
                                        @siteName
                                        <button type="button" class="btn-close btn-close-white ms-1"
                                                style="font-size: 0.5rem;"
                                                @onclick="() => RemoveAssignment(assignment)"></button>
                                    </span>
                                }
                            }
                            else
                            {
                                <span class="text-muted small">None</span>
                            }
                        </td>
                        <td>
                            <button class="btn btn-outline-primary btn-sm py-0 px-1 me-1"
                                    @onclick="() => EditConnection(conn)">Edit</button>
                            <button class="btn btn-outline-danger btn-sm py-0 px-1"
                                    @onclick="() => DeleteConnection(conn)">Delete</button>
                        </td>
                    </tr>
                }
            </tbody>
        </table>
    }
</div>

@code {
    private List<DataConnection> _connections = new();
    private List<Site> _sites = new();
    private Dictionary<int, List<SiteDataConnectionAssignment>> _connectionSites = new();
    private bool _loading = true;
    private string? _errorMessage;

    private bool _showForm;
    private DataConnection? _editingConnection;
    private string _formName = string.Empty;
    private string _formProtocol = string.Empty;
    private string? _formConfiguration;
    private string? _formError;

    private bool _showAssignForm;
    private int _assignConnectionId;
    private int _assignSiteId;
    private string? _assignError;

    private ToastNotification _toast = default!;
    private ConfirmDialog _confirmDialog = default!;

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

    private async Task LoadDataAsync()
    {
        _loading = true;
        _errorMessage = null;
        try
        {
            _sites = (await SiteRepository.GetAllSitesAsync()).ToList();
            _connections = (await SiteRepository.GetAllDataConnectionsAsync()).ToList();

            // Load site assignments for each connection
            _connectionSites.Clear();
            foreach (var site in _sites)
            {
                var siteConns = await SiteRepository.GetDataConnectionsBySiteIdAsync(site.Id);
                foreach (var conn in siteConns)
                {
                    if (!_connectionSites.ContainsKey(conn.Id))
                        _connectionSites[conn.Id] = new List<SiteDataConnectionAssignment>();

                    var assignment = await SiteRepository.GetSiteDataConnectionAssignmentAsync(site.Id, conn.Id);
                    if (assignment != null)
                        _connectionSites[conn.Id].Add(assignment);
                }
            }
        }
        catch (Exception ex)
        {
            _errorMessage = $"Failed to load data: {ex.Message}";
        }
        _loading = false;
    }

    private void ShowAddForm()
    {
        _editingConnection = null;
        _formName = string.Empty;
        _formProtocol = string.Empty;
        _formConfiguration = null;
        _formError = null;
        _showForm = true;
    }

    private void EditConnection(DataConnection conn)
    {
        _editingConnection = conn;
        _formName = conn.Name;
        _formProtocol = conn.Protocol;
        _formConfiguration = conn.Configuration;
        _formError = null;
        _showForm = true;
    }

    private void CancelForm()
    {
        _showForm = false;
        _editingConnection = null;
        _formError = null;
    }

    private async Task SaveConnection()
    {
        _formError = null;
        if (string.IsNullOrWhiteSpace(_formName)) { _formError = "Name is required."; return; }
        if (string.IsNullOrWhiteSpace(_formProtocol)) { _formError = "Protocol is required."; return; }

        try
        {
            if (_editingConnection != null)
            {
                _editingConnection.Name = _formName.Trim();
                _editingConnection.Protocol = _formProtocol;
                _editingConnection.Configuration = _formConfiguration?.Trim();
                await SiteRepository.UpdateDataConnectionAsync(_editingConnection);
            }
            else
            {
                var conn = new DataConnection(_formName.Trim(), _formProtocol)
                {
                    Configuration = _formConfiguration?.Trim()
                };
                await SiteRepository.AddDataConnectionAsync(conn);
            }
            await SiteRepository.SaveChangesAsync();
            _showForm = false;
            _toast.ShowSuccess("Connection saved.");
            await LoadDataAsync();
        }
        catch (Exception ex)
        {
            _formError = $"Save failed: {ex.Message}";
        }
    }

    private async Task DeleteConnection(DataConnection conn)
    {
        var confirmed = await _confirmDialog.ShowAsync(
            $"Delete data connection '{conn.Name}'?", "Delete Connection");
        if (!confirmed) return;

        try
        {
            await SiteRepository.DeleteDataConnectionAsync(conn.Id);
            await SiteRepository.SaveChangesAsync();
            _toast.ShowSuccess($"Connection '{conn.Name}' deleted.");
            await LoadDataAsync();
        }
        catch (Exception ex)
        {
            _toast.ShowError($"Delete failed: {ex.Message}");
        }
    }

    private void ShowAssignForm()
    {
        _assignConnectionId = 0;
        _assignSiteId = 0;
        _assignError = null;
        _showAssignForm = true;
    }

    private void CancelAssignForm()
    {
        _showAssignForm = false;
        _assignError = null;
    }

    private async Task SaveAssignment()
    {
        _assignError = null;
        if (_assignConnectionId == 0) { _assignError = "Select a connection."; return; }
        if (_assignSiteId == 0) { _assignError = "Select a site."; return; }

        try
        {
            var assignment = new SiteDataConnectionAssignment
            {
                SiteId = _assignSiteId,
                DataConnectionId = _assignConnectionId
            };
            await SiteRepository.AddSiteDataConnectionAssignmentAsync(assignment);
            await SiteRepository.SaveChangesAsync();
            _showAssignForm = false;
            _toast.ShowSuccess("Connection assigned to site.");
            await LoadDataAsync();
        }
        catch (Exception ex)
        {
            _assignError = $"Assignment failed: {ex.Message}";
        }
    }

    private async Task RemoveAssignment(SiteDataConnectionAssignment assignment)
    {
        try
        {
            await SiteRepository.DeleteSiteDataConnectionAssignmentAsync(assignment.Id);
            await SiteRepository.SaveChangesAsync();
            _toast.ShowSuccess("Assignment removed.");
            await LoadDataAsync();
        }
        catch (Exception ex)
        {
            _toast.ShowError($"Remove failed: {ex.Message}");
        }
    }
}