/// <summary>
/// Update a manager's password to a new value.
/// </summary>
/// <param name="managerId">Manager ID</param>
/// <param name="newPassword">New password (clear-text)</param>
/// <returns></returns>
public async Task UpdatePassword(string managerId, string newPassword)
{
// Lookup manager information so that we have access to the salt.
var manager = await _database.GetManagerById(managerId);
// Create a new password hash using the original manager salt.
var newPasswordInfo = _password.CreatePassword(newPassword);
// Save the new password.
await _database.ManagerUpdatePassword(manager.Id, newPasswordInfo.HashedPassword, newPasswordInfo.Salt);
// Deactivate all previous manager sessions (force logout).
await _database.ManagerDeactivateSessions(manager.Id);
}