@page "/transfer"
@attribute [Authorize]
@inject IUserSessionService Session
@inject IUserContextAccessor UserContext
@inject ISessionManager SessionMgr
@inject IElevationCoordinator Elevation
@inject IFileTransferService TransferSvc
@rendermode InteractiveServer

<h1 class="page-title">File Transfer</h1>

@if (!Session.HasProfile) { <NoProfilePrompt /> return; }
@if (UserContext.Role < UserRole.TechN1) { <WriteGuard /> return; }

<div class="card">
    <div class="card-title">Source</div>
    <SitePicker Profile="Session.CurrentProfile!" @bind-SelectedSites="_srcSites" Single="true" />
    <div class="form-row mt-8">
        <div class="form-group">
            <label class="form-label">Source Library</label>
            <input class="form-input" @bind="_srcLibrary" placeholder="Shared Documents" />
        </div>
        <div class="form-group">
            <label class="form-label">Source Folder (optional)</label>
            <input class="form-input" @bind="_srcFolder" placeholder="SubFolder/Path" />
        </div>
    </div>
</div>

<div class="card">
    <div class="card-title">Destination</div>
    <SitePicker Profile="Session.CurrentProfile!" @bind-SelectedSites="_dstSites" Single="true" />
    <div class="form-row mt-8">
        <div class="form-group">
            <label class="form-label">Destination Library</label>
            <input class="form-input" @bind="_dstLibrary" placeholder="Shared Documents" />
        </div>
        <div class="form-group">
            <label class="form-label">Destination Folder (optional)</label>
            <input class="form-input" @bind="_dstFolder" />
        </div>
    </div>
    <div class="form-row">
        <div class="form-group">
            <label class="form-label">Transfer Mode</label>
            <select class="form-select" @bind="_mode" style="width:100px">
                <option value="Copy">Copy</option>
                <option value="Move">Move</option>
            </select>
        </div>
        <div class="form-group">
            <label class="form-label">Conflict Policy</label>
            <select class="form-select" @bind="_conflict" style="width:120px">
                <option value="Skip">Skip</option>
                <option value="Overwrite">Overwrite</option>
                <option value="Rename">Rename</option>
            </select>
        </div>
        <div class="form-group" style="display:flex;align-items:center;padding-top:20px">
            <label><input type="checkbox" @bind="_includeSourceFolder" /> Include source folder</label>
        </div>
    </div>
    <div class="flex-row mt-8">
        <button class="btn btn-primary" @onclick="RunTransfer" disabled="@_running">
            @(_running ? "Transferring…" : "Start Transfer")
        </button>
        @if (_running) { <button class="btn btn-secondary" @onclick="Cancel">Cancel</button> }
    </div>
    <ProgressPanel IsRunning="_running" StatusMessage="@_status" Current="_current" Total="_total" />
</div>

@if (!string.IsNullOrEmpty(_error)) { <div class="alert alert-error">@_error</div> }

@if (_summary != null)
{
    <div class="card">
        <div class="alert @(_summary.HasFailures ? "alert-warn" : "alert-success")">
            Transferred: @_summary.SuccessCount / @_summary.TotalCount files.
            @if (_summary.HasFailures) { <span>Failures: @_summary.FailedCount</span> }
        </div>
        @if (_summary.HasFailures)
        {
            <div class="data-table-wrap mt-8">
                <table class="data-table">
                    <thead><tr><th>File</th><th>Error</th></tr></thead>
                    <tbody>
                        @foreach (var f in _summary.FailedItems)
                        {
                            <tr><td>@f.Item</td><td style="color:var(--danger)">@f.ErrorMessage</td></tr>
                        }
                    </tbody>
                </table>
            </div>
        }
    </div>
}

@code {
    private List<SiteInfo> _srcSites = new(), _dstSites = new();
    private string _srcLibrary = string.Empty, _srcFolder = string.Empty;
    private string _dstLibrary = string.Empty, _dstFolder = string.Empty;
    private string _mode = "Copy", _conflict = "Skip";
    private bool _includeSourceFolder;
    private bool _running; private string _status = string.Empty, _error = string.Empty;
    private int _current, _total;
    private BulkOperationSummary<string>? _summary;
    private CancellationTokenSource? _cts;

    private async Task RunTransfer()
    {
        _error = string.Empty; _summary = null; _running = true;
        _cts = new CancellationTokenSource();
        var progress = new Progress<OperationProgress>(p => { _status = p.Message; _current = p.Current; _total = p.Total; InvokeAsync(StateHasChanged); });
        try
        {
            var srcUrl = _srcSites.FirstOrDefault()?.Url;
            var dstUrl = _dstSites.FirstOrDefault()?.Url;
            if (string.IsNullOrWhiteSpace(srcUrl)) { _error = "Please select a source site."; return; }
            if (string.IsNullOrWhiteSpace(dstUrl)) { _error = "Please select a destination site."; return; }
            var job = new TransferJob
            {
                SourceSiteUrl = srcUrl, SourceLibrary = _srcLibrary, SourceFolderPath = _srcFolder,
                DestinationSiteUrl = dstUrl, DestinationLibrary = _dstLibrary, DestinationFolderPath = _dstFolder,
                Mode = _mode == "Move" ? TransferMode.Move : TransferMode.Copy,
                ConflictPolicy = _conflict == "Overwrite" ? ConflictPolicy.Overwrite : _conflict == "Rename" ? ConflictPolicy.Rename : ConflictPolicy.Skip,
                IncludeSourceFolder = _includeSourceFolder
            };
            _summary = await Elevation.RunAsync(async c =>
            {
                // Closure rebuilds both contexts each attempt so an elevated retry re-issues cleanly.
                var srcCtx = await SessionMgr.GetOrCreateContextAsync(srcUrl, Session.CurrentProfile!, c);
                var dstCtx = await SessionMgr.GetOrCreateContextAsync(dstUrl, Session.CurrentProfile!, c);
                return await TransferSvc.TransferAsync(srcCtx, dstCtx, job, progress, c);
            }, _cts.Token);
            _status = $"Complete: {_summary.SuccessCount} transferred.";
        }
        catch (OperationCanceledException) { _status = "Cancelled."; }
        catch (Exception ex) { _error = ex.Message; }
        finally { _running = false; await InvokeAsync(StateHasChanged); }
    }

    private void Cancel() => _cts?.Cancel();
}