// ── Admin Page (User Management) ──

registerPage('admin', {
  async init() {
    if (!currentUser || !currentUser.isAdmin) {
      navigateTo('dashboard');
      return;
    }

    var users = [];
    var editingUserId = null;

    var list = document.getElementById('adminUserList');
    var newUserBtn = document.getElementById('adminNewUserBtn');
    var userForm = document.getElementById('adminUserForm');
    var formTitle = document.getElementById('adminFormTitle');
    var usernameInput = document.getElementById('adminUsername');
    var displayNameInput = document.getElementById('adminDisplayName');
    var passwordInput = document.getElementById('adminPassword');
    var passwordLabel = document.getElementById('adminPasswordLabel');
    var defaultPathInput = document.getElementById('adminDefaultPath');
    var defaultPathBrowse = document.getElementById('adminDefaultPathBrowse');
    var isAdminCheckbox = document.getElementById('adminIsAdmin');
    var canCreateAgentsCheckbox = document.getElementById('adminCanCreateAgents');
    var canUseCliCheckbox = document.getElementById('adminCanUseCli');
    var saveBtn = document.getElementById('adminFormSaveBtn');

    function renderUsers() {
      list.innerHTML = '';

      users.forEach(function(user) {
        var row = document.createElement('div');
        row.className = 'admin-user-row';

        var info = document.createElement('div');
        info.className = 'admin-user-info';

        var nameSpan = document.createElement('span');
        nameSpan.className = 'admin-user-name';
        nameSpan.textContent = user.displayName || user.username;

        var metaSpan = document.createElement('span');
        metaSpan.className = 'admin-user-meta';
        var metaParts = ['@' + user.username];
        if (user.isAdmin) metaParts.push('Administrator');
        if (user.defaultPath) metaParts.push(user.defaultPath);
        var perms = [];
        if (user.canCreateAgents === false) perms.push('keine Agents');
        if (user.canUseCli === false) perms.push('keine CLI');
        if (perms.length) metaParts.push(perms.join(', '));
        metaSpan.textContent = metaParts.join(' · ');

        info.appendChild(nameSpan);
        info.appendChild(metaSpan);

        var actions = document.createElement('div');
        actions.className = 'admin-user-actions';

        var editBtn = document.createElement('button');
        editBtn.className = 'icon-btn';
        editBtn.title = 'Bearbeiten';
        editBtn.innerHTML = '<i class="fa fa-pencil"></i>';
        editBtn.addEventListener('click', function() {
          startEdit(user);
        });
        actions.appendChild(editBtn);

        // Login-Link + Löschen (nicht für sich selbst)
        if (user.userId !== currentUser.userId) {
          var linkBtn = document.createElement('button');
          linkBtn.className = 'icon-btn';
          linkBtn.title = 'Login-Link generieren';
          linkBtn.innerHTML = '<i class="fa fa-link"></i>';
          linkBtn.addEventListener('click', function() {
            generateLoginLink(user);
          });
          actions.appendChild(linkBtn);

          var deleteBtn = document.createElement('button');
          deleteBtn.className = 'icon-btn';
          deleteBtn.title = 'Löschen';
          deleteBtn.innerHTML = '<i class="fa fa-trash"></i>';
          deleteBtn.addEventListener('click', function() {
            deleteUser(user);
          });
          actions.appendChild(deleteBtn);
        }

        row.appendChild(info);
        row.appendChild(actions);
        list.appendChild(row);
      });
    }

    async function loadUsers() {
      try {
        users = await apiAdminGetUsers();
        renderUsers();
      } catch (err) {
        showToast(err.message, 'error');
      }
    }

    function startEdit(user) {
      editingUserId = user.userId;
      formTitle.textContent = 'Benutzer bearbeiten';
      usernameInput.value = user.username;
      usernameInput.disabled = false;
      displayNameInput.value = user.displayName || '';
      passwordInput.value = '';
      passwordLabel.textContent = 'Neues Passwort (leer = unverändert)';
      passwordInput.placeholder = 'Neues Passwort (optional)';
      passwordInput.required = false;
      defaultPathInput.value = user.defaultPath || '';
      isAdminCheckbox.checked = user.isAdmin;
      canCreateAgentsCheckbox.checked = user.canCreateAgents !== false;
      canUseCliCheckbox.checked = user.canUseCli !== false;
      saveBtn.textContent = 'Speichern';
      userForm.hidden = false;
      usernameInput.focus();
    }

    async function deleteUser(user) {
      if (!confirm('Benutzer "' + (user.displayName || user.username) + '" wirklich löschen?\n\nAlle Tokens werden ebenfalls gelöscht.')) {
        return;
      }

      try {
        await apiAdminDeleteUser(user.userId);
        await loadUsers();
      } catch (err) {
        showToast(err.message, 'error');
      }
    }

    async function generateLoginLink(user) {
      try {
        var result = await apiAdminGetLoginLink(user.userId);
        var link = window.location.origin + '/api/auth/autologin?token=' + result.token;
        showLoginLinkModal(user, link);
      } catch (err) {
        showToast(err.message, 'error');
      }
    }

    function showLoginLinkModal(user, link) {
      const { body } = _createModal('Login-Link für ' + (user.displayName || user.username));

      var desc = document.createElement('p');
      desc.className = 'login-link-desc';
      desc.textContent = 'Dieser Link loggt automatisch als dieser Benutzer ein. Teile ihn nur mit vertrauenswürdigen Personen.';
      body.appendChild(desc);

      var inputRow = document.createElement('div');
      inputRow.className = 'login-link-input-row';

      var input = document.createElement('input');
      input.type = 'text';
      input.readOnly = true;
      input.value = link;
      input.className = 'login-link-input';

      var copyBtn = document.createElement('button');
      copyBtn.className = 'btn btn-primary';
      copyBtn.innerHTML = '<i class="fa fa-copy"></i> Kopieren';
      copyBtn.addEventListener('click', function() {
        navigator.clipboard.writeText(link).then(function() {
          copyBtn.innerHTML = '<i class="fa fa-check"></i> Kopiert!';
          setTimeout(function() {
            copyBtn.innerHTML = '<i class="fa fa-copy"></i> Kopieren';
          }, 2000);
        });
      });

      inputRow.appendChild(input);
      inputRow.appendChild(copyBtn);
      body.appendChild(inputRow);

      // Input selektieren für einfaches Kopieren
      input.select();
    }

    // ── Event-Listener ──

    // Default Path Browse
    if (defaultPathBrowse) {
      defaultPathBrowse.addEventListener('click', function() {
        openFolderBrowser({
          startPath: defaultPathInput.value.trim() || '/',
          onSelect: function(path) {
            defaultPathInput.value = path;
          }
        });
      });
    }

    // Neuer Benutzer
    newUserBtn.addEventListener('click', function() {
      editingUserId = null;
      formTitle.textContent = 'Neuer Benutzer';
      usernameInput.value = '';
      usernameInput.disabled = false;
      displayNameInput.value = '';
      passwordInput.value = '';
      passwordLabel.textContent = 'Passwort';
      passwordInput.placeholder = 'Passwort';
      passwordInput.required = true;
      defaultPathInput.value = '';
      isAdminCheckbox.checked = false;
      canCreateAgentsCheckbox.checked = true;
      canUseCliCheckbox.checked = true;
      saveBtn.textContent = 'Erstellen';
      userForm.hidden = false;
      usernameInput.focus();
    });

    // Speichern
    saveBtn.addEventListener('click', () => withButtonLoading(saveBtn, saveBtn.textContent, async () => {
      try {
        if (editingUserId) {
          var data = {
            username: usernameInput.value.trim(),
            displayName: displayNameInput.value.trim(),
            defaultPath: defaultPathInput.value.trim() || null,
            isAdmin: isAdminCheckbox.checked,
            canCreateAgents: canCreateAgentsCheckbox.checked,
            canUseCli: canUseCliCheckbox.checked
          };
          await apiAdminUpdateUser(editingUserId, data);

          var pw = passwordInput.value;
          if (pw) await apiAdminResetPassword(editingUserId, pw);

          showToast('Benutzer aktualisiert');
        } else {
          var username = usernameInput.value.trim();
          var password = passwordInput.value;

          if (!username || !password) {
            showToast('Benutzername und Passwort erforderlich', 'error');
            return;
          }

          await apiAdminCreateUser({
            username: username,
            password: password,
            displayName: displayNameInput.value.trim(),
            defaultPath: defaultPathInput.value.trim() || null,
            isAdmin: isAdminCheckbox.checked,
            canCreateAgents: canCreateAgentsCheckbox.checked,
            canUseCli: canUseCliCheckbox.checked
          });

          showToast('Benutzer erstellt');
        }

        userForm.hidden = true;
        await loadUsers();
      } catch (err) {
        showToast(err.message, 'error');
      }
    }));

    // ── Init: User laden ──
    await loadUsers();
  },

  destroy() {}
});