// Permission section definitions and normalization helpers for RBAC.

const PERMISSION_SECTIONS = [
  {
    sectionName: 'Main navigation',
    order: 10,
    permissions: [
      {
        key: 'dashboard',
        order: 10,
        name: 'Dashboard',
        permissions: [
          { key: 'read', name: 'Read', description: 'Access the dashboard overview.' },
          { key: 'allow', name: 'Allow', description: 'Send global player commands.' }
        ]
      },
      {
        key: 'clients',
        order: 20,
        name: 'Connected clients',
        permissions: [
          { key: 'read', name: 'Read', description: 'View connected player clients and live status.' },
          { key: 'allow', name: 'Allow', description: 'Use the connected client command buttons.' }
        ]
      }
    ]
  },
  {
    sectionName: 'Content',
    order: 20,
    permissions: [
      {
        key: 'screens',
        order: 10,
        name: 'Screens',
        permissions: [
          { key: 'read', name: 'Read', description: 'View the screen list and open screen details.' },
          { key: 'create', name: 'Create', description: 'Create new screens.' },
          { key: 'update', name: 'Update', description: 'Update screens.' },
          { key: 'delete', name: 'Delete', description: 'Delete screens.' }
        ]
      },
      {
        key: 'playlists',
        order: 20,
        name: 'Playlists',
        permissions: [
          { key: 'read', name: 'Read', description: 'View playlists and playlist contents.' },
          { key: 'create', name: 'Create', description: 'Create new playlists.' },
          { key: 'update', name: 'Update', description: 'Update playlists and playlist slides.' },
          { key: 'delete', name: 'Delete', description: 'Delete playlists.' }
        ]
      },
      {
        key: 'slides',
        order: 30,
        name: 'Slides',
        permissions: [
          { key: 'read', name: 'Read', description: 'View slides.' },
          { key: 'create', name: 'Create', description: 'Create new slides.' },
          { key: 'update', name: 'Update', description: 'Update slide content.' },
          { key: 'delete', name: 'Delete', description: 'Delete slides.' }
        ]
      },
      {
        key: 'templates',
        order: 40,
        name: 'Slide templates',
        permissions: [
          { key: 'read', name: 'Read', description: 'View slide templates.' },
          { key: 'create', name: 'Create', description: 'Create new slide templates.' },
          { key: 'update', name: 'Update', description: 'Update slide templates.' },
          { key: 'delete', name: 'Delete', description: 'Delete slide templates.' }
        ]
      },
      {
        key: 'canvas-sizes',
        order: 50,
        name: 'Canvas sizes',
        permissions: [
          { key: 'read', name: 'Read', description: 'View canvas sizes.' },
          { key: 'create', name: 'Create', description: 'Create new canvas sizes.' },
          { key: 'update', name: 'Update', description: 'Update canvas sizes.' },
          { key: 'delete', name: 'Delete', description: 'Delete canvas sizes.' }
        ]
      },
      {
        key: 'announcements',
        order: 60,
        name: 'Announcements',
        permissions: [
          { key: 'read', name: 'Read', description: 'View announcements.' },
          { key: 'create', name: 'Create', description: 'Create new announcements.' },
          { key: 'update', name: 'Update', description: 'Update announcements.' },
          { key: 'delete', name: 'Delete', description: 'Delete announcements.' }
        ]
      }
    ]
  },
  {
    sectionName: 'Data Sources',
    order: 30,
    permissions: [
      {
        key: 'rss-feeds',
        order: 10,
        name: 'RSS feeds',
        permissions: [
          { key: 'read', name: 'Read', description: 'View configured RSS feeds.' },
          { key: 'create', name: 'Create', description: 'Create new RSS feeds.' },
          { key: 'update', name: 'Update', description: 'Update RSS feeds.' },
          { key: 'delete', name: 'Delete', description: 'Delete RSS feeds.' }
        ]
      },
      {
        key: 'api-sources',
        order: 20,
        name: 'API sources',
        permissions: [
          { key: 'read', name: 'Read', description: 'View configured API sources.' },
          { key: 'create', name: 'Create', description: 'Create new API sources.' },
          { key: 'update', name: 'Update', description: 'Update API sources.' },
          { key: 'delete', name: 'Delete', description: 'Delete API sources.' }
        ]
      },
      {
        key: 'timetables',
        order: 30,
        name: 'Timetables',
        permissions: [
          { key: 'read', name: 'Read', description: 'View configured timetable groups.' },
          { key: 'create', name: 'Create', description: 'Create new timetable groups.' },
          { key: 'update', name: 'Update', description: 'Update timetable groups and entries.' },
          { key: 'delete', name: 'Delete', description: 'Delete timetable groups.' }
        ]
      }
    ]
  },
  {
    sectionName: 'Settings',
    order: 40,
    permissions: [
      {
        key: 'users',
        order: 10,
        name: 'Users',
        permissions: [
          { key: 'read', name: 'Read', description: 'View users and role assignments.' },
          { key: 'create', name: 'Create', description: 'Create new users.' },
          { key: 'update', name: 'Update', description: 'Update users, passwords, and role assignments.' },
          { key: 'delete', name: 'Delete', description: 'Delete users.' }
        ]
      },
      {
        key: 'rbac',
        order: 20,
        name: 'Roles and permissions',
        permissions: [
          { key: 'read', name: 'Read', description: 'View roles and permissions.' },
          { key: 'create', name: 'Create', description: 'Create new roles.' },
          { key: 'update', name: 'Update', description: 'Update role details and permissions.' },
          { key: 'delete', name: 'Delete', description: 'Delete roles.' }
        ]
      },
      {
        key: 'fonts',
        order: 30,
        name: 'Fonts',
        permissions: [
          { key: 'read', name: 'Read', description: 'View managed fonts.' },
          { key: 'create', name: 'Create', description: 'Upload managed fonts.' },
          { key: 'delete', name: 'Delete', description: 'Remove managed fonts.' }
        ]
      },
      {
        key: 'background-tasks',
        order: 40,
        name: 'Task Queue',
        permissions: [
          { key: 'read', name: 'Read', description: 'View queued background tasks.' },
          { key: 'allow', name: 'Allow', description: 'Manage queued background tasks and clear finished items.' }
        ]
      },
      {
        key: 'scheduled-tasks',
        order: 50,
        name: 'Scheduled tasks',
        permissions: [
          { key: 'read', name: 'Read', description: 'View scheduled refresh tasks.' },
          { key: 'allow', name: 'Allow', description: 'Run scheduled refreshes manually.' }
        ]
      }
    ]
  }
];

const PERMISSIONS = PERMISSION_SECTIONS.flatMap(function (section, sectionIndex) {
  return (Array.isArray(section.permissions) ? section.permissions : []).flatMap(function (resource, resourceIndex) {
    return (Array.isArray(resource.permissions) ? resource.permissions : []).map(function (action, actionIndex) {
      return {
        key: `${resource.key}.${action.key}`,
        name: resource.name,
        sectionOrder: section.order,
        sectionIndex: sectionIndex,
        actionName: action.name,
        permissionOrder: actionIndex + 1,
        permissionIndex: actionIndex,
        sectionName: section.sectionName,
        resourceKey: resource.key,
        resourceOrder: resource.order,
        resourceIndex: resourceIndex,
        resourceName: resource.name,
        actionKey: action.key,
        description: action.description
      };
    });
  });
});

const DEFAULT_ROLE = {
  key: 'administrators',
  name: 'Administrators',
  description: 'Full access to the admin interface.'
};

function normalizePermissionKey(permissionKey) {
  return String(permissionKey || '').trim();
}

const PERMISSION_DENIED_MESSAGE = 'You do not have permissions to do this.';

function normalizePermissionKeys(permissionKeys) {
  const normalized = [];

  (Array.isArray(permissionKeys) ? permissionKeys : []).forEach(function (permissionKey) {
    const normalizedPermissionKey = normalizePermissionKey(permissionKey);
    if (!normalizedPermissionKey) {
      return;
    }

    const parts = normalizedPermissionKey.split('.');
    if (parts.length !== 2) {
      normalized.push(normalizedPermissionKey);
      return;
    }

    const sectionKey = parts[0];
    const actionKey = parts[1];
    normalized.push(`${sectionKey}.${actionKey}`);

    if (actionKey === 'create' || actionKey === 'update' || actionKey === 'delete') {
      normalized.push(`${sectionKey}.read`);
    }
    if (actionKey === 'manage') {
      normalized.push(`${sectionKey}.read`);
      normalized.push(`${sectionKey}.create`);
      normalized.push(`${sectionKey}.update`);
      normalized.push(`${sectionKey}.delete`);
    }
    if (actionKey === 'view') {
      normalized.push(`${sectionKey}.read`);
    }
  });

  return Array.from(new Set(normalized));
}

function hasPermission(currentUser, permissionKey) {
  const normalizedPermissionKey = normalizePermissionKey(permissionKey);
  if (!normalizedPermissionKey || !currentUser) {
    return false;
  }

  const permissionKeys = Array.isArray(currentUser.permissionKeys)
    ? currentUser.permissionKeys
    : Array.isArray(currentUser.permissions)
      ? currentUser.permissions
      : [];

  return normalizePermissionKeys(permissionKeys).includes(normalizedPermissionKey);
}

function hasAnyPermission(currentUser, permissionKeys) {
  const normalizedPermissionKeys = normalizePermissionKeys(permissionKeys);
  if (!normalizedPermissionKeys.length || !currentUser) {
    return false;
  }

  return normalizedPermissionKeys.some(function (permissionKey) {
    return hasPermission(currentUser, permissionKey);
  });
}

function requirePermission(permissionKey, options) {
  const normalizedPermissionKey = normalizePermissionKey(permissionKey);
  if (!normalizedPermissionKey) {
    throw new Error('requirePermission requires a permission key.');
  }

  const setAuthMessageCookie = options && options.setAuthMessageCookie;

  return function (req, res, next) {
    if (!req.currentUser) {
      if (typeof setAuthMessageCookie === 'function') {
        setAuthMessageCookie(res, 'Please sign in to continue.');
        return res.redirect('/login');
      }

      return res.redirect('/login');
    }

    if (hasPermission(req.currentUser, normalizedPermissionKey)) {
      return next();
    }

    const error = new Error(PERMISSION_DENIED_MESSAGE);
    error.statusCode = 403;
    error.expose = true;
    next(error);
  };
}

module.exports = {
  PERMISSIONS,
  PERMISSION_SECTIONS,
  DEFAULT_ROLE,
  hasPermission,
  hasAnyPermission,
  requirePermission,
  normalizePermissionKeys,
  PERMISSION_DENIED_MESSAGE
};