@page "/user-management"
@attribute [Authorize(Roles = "Administrator")]
@inject IAuthService AuthService
@inject IEmailService EmailService
@inject ILocalizationService Loc
@inject NavigationManager Navigation

@rendermode InteractiveServer

<PageTitle>@Loc["usermanagement.title"] - Author Buddy</PageTitle>

<div class="usermanagement-page">
    <div class="usermanagement-header">
        <h3>@Loc["usermanagement.title"]</h3>
        <button class="btn btn-primary" @onclick="ShowCreateDialog">+ Neuen Benutzer</button>
    </div>

    <table class="usermanagement-table">
        <thead>
            <tr>
                <th>Name</th>
                <th>E-Mail</th>
                <th>Rolle</th>
                <th>Status</th>
                <th>Aktionen</th>
            </tr>
        </thead>
        <tbody>
            @foreach (var u in users)
            {
                <tr class="@(u.Id == currentUserId ? "usermanagement-current" : "") @(!u.IsActive ? "usermanagement-inactive" : "")">
                    <td>@u.Name @(u.Id == currentUserId ? "(Du)" : "")</td>
                    <td>@(!string.IsNullOrEmpty(u.Email) ? u.Email : "—")</td>
                    <td>@string.Join(", ", u.Roles.Select(RoleName))</td>
                    <td>
                        @if (u.IsActive)
                        {
                            <span class="usermanagement-status-active">Aktiv</span>
                        }
                        else
                        {
                            <span class="usermanagement-status-inactive">Inaktiv</span>
                        }
                    </td>
                    <td class="usermanagement-actions">
                        <button class="btn btn-sm" @onclick="() => BeginEdit(u)" title="Bearbeiten">✎</button>
                        @if (!string.IsNullOrEmpty(u.Email) && EmailService.IsConfigured)
                        {
                            <button class="btn btn-sm" @onclick="() => SendRecovery(u)" title="Passwort zurücksetzen per E-Mail">📧</button>
                        }
                        @if (u.Id != currentUserId)
                        {
                            @if (u.IsActive)
                            {
                                <button class="btn btn-sm" @onclick="() => DeactivateUser(u.Id)" title="Deaktivieren">🔴</button>
                            }
                            else
                            {
                                <button class="btn btn-sm btn-primary" @onclick="() => ActivateUser(u.Id)" title="Aktivieren">🟢</button>
                            }
                            <button class="btn btn-sm btn-danger" @onclick="() => BeginDelete(u)" title="Löschen">🗑</button>
                        }
                    </td>
                </tr>
            }
        </tbody>
    </table>

    @if (!string.IsNullOrEmpty(statusMessage))
    {
        <div class="usermanagement-status">@statusMessage</div>
    }
</div>

@* Create User Dialog *@
@if (showCreateDialog)
{
    <div class="modal-overlay">
        <div class="modal-dialog">
            <div class="modal-title">Neuen Benutzer anlegen</div>
            <div class="modal-body">
                <div class="form-group">
                    <label>Benutzername</label>
                    <input @bind="_newUsername" />
                </div>
                <div class="form-group">
                    <label>E-Mail</label>
                    <input @bind="_newEmail" type="email" />
                </div>
                <div class="form-group">
                    <label>Rollen</label>
                    <div class="um-role-checkboxes">
                        @foreach (var (role, label) in UmRoleOptions)
                        {
                            <label><input type="checkbox" checked="@_newRoles.Contains(role)" @onchange="() => ToggleNewRole(role)" /> @label</label>
                        }
                    </div>
                </div>
                <div class="form-group">
                    <label>Passwort</label>
                    <div style="display:flex;gap:8px;">
                        <input @bind="_newPassword" type="password" style="flex:1;" />
                        <button class="btn btn-sm" @onclick="GeneratePassword" type="button">Generieren</button>
                    </div>
                    @if (!string.IsNullOrEmpty(_generatedPassword))
                    {
                        <small style="color:#c00;font-family:monospace;">@_generatedPassword</small>
                    }
                </div>
            </div>
            <div class="modal-actions">
                <button @onclick="CancelCreate">Abbrechen</button>
                <button @onclick="CreateUser" class="primary" disabled="@(string.IsNullOrWhiteSpace(_newUsername) || string.IsNullOrWhiteSpace(_newPassword))">Anlegen</button>
            </div>
        </div>
    </div>
}

@* Edit User Dialog *@
@if (showEditDialog && _editUser != null)
{
    <div class="modal-overlay">
        <div class="modal-dialog">
            <div class="modal-title">Benutzer bearbeiten – @_editUser.Name</div>
            <div class="modal-body">
                <div class="form-group">
                    <label>E-Mail</label>
                    <input @bind="_editEmail" type="email" />
                </div>
                <div class="form-group">
                    <label>Rollen</label>
                    <div class="um-role-checkboxes">
                        @foreach (var (role, label) in UmRoleOptions)
                        {
                            <label><input type="checkbox" checked="@_editRoles.Contains(role)" @onchange="() => ToggleEditRole(role)" /> @label</label>
                        }
                    </div>
                </div>
            </div>
            <div class="modal-actions">
                <button @onclick="CancelEdit">Abbrechen</button>
                <button @onclick="SaveEdit" class="primary">Speichern</button>
            </div>
        </div>
    </div>
}

@* Delete Confirmation Dialog *@
@if (showDeleteDialog && _deleteUser != null)
{
    <div class="modal-overlay">
        <div class="modal-dialog">
            <div class="modal-title">Benutzer löschen</div>
            <div class="modal-body">
                <p>Soll der Benutzer <strong>@_deleteUser.Name</strong> wirklich gelöscht werden?</p>
            </div>
            <div class="modal-actions">
                <button @onclick="CancelDelete">Abbrechen</button>
                <button @onclick="ConfirmDelete" class="btn-danger">Löschen</button>
            </div>
        </div>
    </div>
}

@code {
    private List<UserEntity> users = new();
    private int currentUserId;
    private string statusMessage = string.Empty;

    private bool showCreateDialog;
    private string _newUsername = string.Empty;
    private string _newEmail = string.Empty;
    private List<string> _newRoles = new() { "Author" };
    private string _newPassword = string.Empty;
    private string? _generatedPassword;

    private bool showEditDialog;
    private UserEntity? _editUser;
    private string _editEmail = string.Empty;
    private List<string> _editRoles = new();

    private bool showDeleteDialog;
    private UserEntity? _deleteUser;

    private static (string role, string label)[] UmRoleOptions => new[]
    {
        ("Author", "Autor"),
        ("Blogger", "Blogger"),
        ("Chat", "Chat"),
        ("Administrator", "Administrator")
    };

    private string RoleName(UserRole role) => role switch
    {
        UserRole.Administrator => "Administrator",
        UserRole.Blogger => "Blogger",
        UserRole.Chat => "Chat",
        _ => "Autor"
    };

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

    private async Task LoadUsers()
    {
        users = await AuthService.GetAllUsersAsync();
        currentUserId = AuthService.CurrentUser?.Id ?? 0;
    }

    private async Task ActivateUser(int userId)
    {
        var ok = await AuthService.SetUserActiveAsync(userId, true);
        statusMessage = ok ? "Benutzer aktiviert." : "Fehler";
        await LoadUsers();
    }

    private async Task DeactivateUser(int userId)
    {
        var ok = await AuthService.SetUserActiveAsync(userId, false);
        statusMessage = ok ? "Benutzer deaktiviert." : "Fehler";
        await LoadUsers();
    }

    private void ShowCreateDialog()
    {
        _newUsername = string.Empty;
        _newEmail = string.Empty;
        _newRoles = new List<string> { "Author" };
        _newPassword = string.Empty;
        _generatedPassword = null;
        showCreateDialog = true;
    }

    private void CancelCreate()
    {
        showCreateDialog = false;
    }

    private void ToggleNewRole(string role)
    {
        if (_newRoles.Contains(role))
            _newRoles.Remove(role);
        else
            _newRoles.Add(role);
    }

    private void ToggleEditRole(string role)
    {
        if (_editRoles.Contains(role))
            _editRoles.Remove(role);
        else
            _editRoles.Add(role);
    }

    private void GeneratePassword()
    {
        using var rng = System.Security.Cryptography.RandomNumberGenerator.Create();
        var bytes = new byte[10];
        rng.GetBytes(bytes);
        _generatedPassword = Convert.ToBase64String(bytes).TrimEnd('=').Replace('+', 'X').Replace('/', 'Y');
        _newPassword = _generatedPassword;
    }

    private async Task CreateUser()
    {
        if (string.IsNullOrWhiteSpace(_newUsername) || string.IsNullOrWhiteSpace(_newPassword))
            return;

        if (_newRoles.Count == 0)
        {
            statusMessage = "Mindestens eine Rolle erforderlich.";
            return;
        }

        var roles = _newRoles.Select(r => r switch
        {
            "Administrator" => UserRole.Administrator,
            "Blogger" => UserRole.Blogger,
            "Chat" => UserRole.Chat,
            _ => UserRole.Author
        }).Distinct().ToList();

        var ok = await AuthService.CreateUserAsync(_newUsername.Trim(), _newPassword, _newEmail.Trim(), roles);
        statusMessage = ok
            ? $"Benutzer '{_newUsername}' angelegt."
            : "Benutzername bereits vergeben oder maximal ein Admin erlaubt.";
        showCreateDialog = false;
        await LoadUsers();
    }

    private void BeginEdit(UserEntity user)
    {
        _editUser = user;
        _editEmail = user.Email;
        _editRoles = user.Roles.Select(r => r.ToString()).ToList();
        showEditDialog = true;
    }

    private void CancelEdit()
    {
        showEditDialog = false;
        _editUser = null;
    }

    private async Task SaveEdit()
    {
        if (_editUser == null) return;

        if (_editRoles.Count == 0)
        {
            statusMessage = "Mindestens eine Rolle erforderlich.";
            return;
        }

        var roles = _editRoles.Select(r => r switch
        {
            "Administrator" => UserRole.Administrator,
            "Blogger" => UserRole.Blogger,
            "Chat" => UserRole.Chat,
            _ => UserRole.Author
        }).Distinct().ToList();

        string? email = _editEmail?.Trim();
        if (string.IsNullOrEmpty(email)) email = null;

        var ok = await AuthService.UpdateUserAsync(_editUser.Id, email, roles);
        statusMessage = ok ? "Benutzer aktualisiert." : "Fehler (max. ein Admin erlaubt).";
        showEditDialog = false;
        _editUser = null;
        await LoadUsers();
    }

    private void BeginDelete(UserEntity user)
    {
        _deleteUser = user;
        showDeleteDialog = true;
    }

    private void CancelDelete()
    {
        showDeleteDialog = false;
        _deleteUser = null;
    }

    private async Task ConfirmDelete()
    {
        if (_deleteUser == null) return;
        var ok = await AuthService.DeleteUserAsync(_deleteUser.Id);
        statusMessage = ok ? "Benutzer gelöscht." : "Fehler";
        showDeleteDialog = false;
        _deleteUser = null;
        await LoadUsers();
    }

    private async Task SendRecovery(UserEntity user)
    {
        if (string.IsNullOrEmpty(user.Email)) return;

        var newPassword = await AuthService.ResetPasswordAsync(user.Id);
        if (string.IsNullOrEmpty(newPassword))
        {
            statusMessage = "Fehler beim Zurücksetzen des Passworts.";
            return;
        }

        var sent = await EmailService.SendPasswordAsync(user.Email, user.Name, newPassword);
        statusMessage = sent
            ? $"Neues Passwort an {user.Email} gesendet."
            : "E-Mail konnte nicht gesendet werden (SMTP-Konfiguration prüfen).";
    }
}