public class Roster {
  private Gtk.VBox rosterView;
  private RosterModel model;
  private Gee.TreeMap<string, GroupInfo> groups = new Gee.TreeMap<string, GroupInfo>();
  
  public signal void start_conversation(string jid);
  
  
  public Roster(Gtk.VBox rosterView0) {
    rosterView = rosterView0;
    model = new RosterModel(this);
  }
  
  public Gtk.TreeModel get_model() {
    return model;
  }
  
  public void update_contact(Contact c) {
    model.update_contact(c);
  }
  
  public Contact get_contact(string jid) {
    return model.get_contact(jid);
  }
  
  private Gtk.TreeView new_tree_view() {
    Gtk.TreeView view = new Gtk.TreeView();
    
    view.headers_visible = false;
    
    view.query_tooltip.connect((x, y, keyboard_tip, tooltip) => {
        Gtk.TreeModel model;
        Gtk.TreeIter iter;
        
        if(!view.get_tooltip_context(out x, out y, keyboard_tip, out model, null, out iter))
          return false;
        
        Value value;
        model.get_value(iter, 0, out value);
        
        Contact? c = value.get_object() as Contact;
        if(c == null)
          return false;
        
        Gee.Map.Entry<string, Contact.Resource>? r = c.get_resource_with_highest_priority();
        
        if(r == null)
          return false;
        
        tooltip.set_text("Resource: " + r.key + " (" + r.value.priority.to_string() + ")");
        
        return true;
      });
    view.has_tooltip = true;
    
    view.row_activated.connect((view, path, column) => {
        Gtk.TreeIter iter;
        view.model.get_iter(out iter, path);
        
        Value value;
        view.model.get_value(iter, 0, out value);
        
        Contact contact = value.get_object() as Contact;
        if(contact == null)
          return;
        
        Gee.Map.Entry<string, Contact.Resource> res = contact.get_resource_with_highest_priority();
        if(res == null)
          return; //FIXME
        
        start_conversation(contact.jid + "/" + res.key);
      });
    
    Gtk.TreeViewColumn presenceColumn = new Gtk.TreeViewColumn.with_attributes(null, new CellRendererPresence(), "contact", 0, null);
    presenceColumn.min_width = 32;
    view.append_column(presenceColumn);
    
    Gtk.TreeViewColumn contactColumn = new Gtk.TreeViewColumn();
    
    Gtk.CellRenderer cellRendererContact = new CellRendererContact();
    contactColumn.pack_start(cellRendererContact, true);
    contactColumn.set_attributes(cellRendererContact, "contact", 0, null);
    
    Gtk.CellRenderer cellRendererAvatar = new CellRendererAvatar();
    contactColumn.pack_end(cellRendererAvatar, false);
    contactColumn.set_attributes(cellRendererAvatar, "contact", 0, null);
    
    view.append_column(contactColumn);
    
    return view;
  }
  
  private void update_groups() {
    int i = 0;
    
    foreach(Gee.Map.Entry<string, GroupInfo> group in groups) {
      if(group.value.count <= 0) {
        rosterView.remove(group.value.expander);
        group.value.expander.remove(group.value.view);
        groups.remove(group.key);
        continue;
      }
      
      if(group.value.count > 0 && group.value.view == null) {
        group.value.view = new_tree_view();
        group.value.view.model = new GroupFilter(this, group.key);
        
        group.value.expander = new Gtk.Expander("<i>" + Markup.escape_text(group.key) + "</i>");
        group.value.expander.set_use_markup(true);
        group.value.expander.expanded = true;
        group.value.expander.add(group.value.view);
        group.value.expander.show_all();
        
        rosterView.pack_start(group.value.expander, false, false, 0);
      }
      
      rosterView.reorder_child(group.value.expander, i++);
    }
  }
  
  private class RosterModel : Object, Gtk.TreeModel {
    private Roster roster;
    private int stamp = 0;
    private Gee.TreeMap<string, Contact> entries = new Gee.TreeMap<string, Contact>();
  
    
    public RosterModel(Roster roster0) {
      roster = roster0;
    }
    
    public void update_contact(Contact c) {
      ++stamp;
      bool added = true;
      if(c.jid in entries) {
        added = false;
        
        foreach(string group in entries[c.jid].get_groups()) {
          if(group in roster.groups) {
            roster.groups[group].count--;
          }
          else {
            warn_if_reached();
          }
        }
      }
      
      
      entries[c.jid] = c;
      
      Gtk.TreeIter iter = Gtk.TreeIter();
      iter.stamp = stamp;
      iter.user_data = this;
      iter.user_data2 = c;
      
      Gtk.TreePath path = get_path(iter);
      
      if(added)
        row_inserted(path, iter);
      else
        row_changed(path, iter);

      foreach(string group in c.get_groups()) {
        if(!(group in roster.groups))
          roster.groups[group] = new GroupInfo();
        
        roster.groups[group].count++;
      }
      
      roster.update_groups();
    }
  
    public Contact get_contact(string jid) {
      string bareJID = jid.split("/", 2)[0];
    
      return entries[bareJID];
    }

    public Type get_column_type(int index) {
      switch(index) {
      case 0:
        return typeof(Contact);
      }
    
      return Type.INVALID;
    }
    
    public Gtk.TreeModelFlags get_flags() {
      return Gtk.TreeModelFlags.LIST_ONLY;
    }
    
    public bool get_iter(out Gtk.TreeIter iter, Gtk.TreePath path) {
      if(path.get_depth() != 1)
        return false;
      
      int index = path.get_indices()[0];
      if(index < 0 || index >= entries.size)
        return false;
      
      Gee.MapIterator<string, Contact> it = entries.map_iterator();
      it.first();
      for(int i = 0; i < index; ++i)
        it.next();
      
      iter.stamp = stamp;
      iter.user_data = this;
      iter.user_data2 = it.get_value();
      
      return true;
    }
  
    public int get_n_columns() {
      return 1;
    }
  
    public Gtk.TreePath get_path(Gtk.TreeIter iter) {
      if(iter.stamp != stamp || iter.user_data != this)
        return (Gtk.TreePath)null;
      
      int index = 0;
      
      foreach(Contact c in entries.values) {
        if(c == iter.user_data2)
          break;
        
        ++index;
      }
      
      return new Gtk.TreePath.from_indices(index, -1);
    }
    
    public void get_value(Gtk.TreeIter iter, int column, out Value value) {
      if (column != 0 || iter.stamp != stamp || iter.user_data != this) {
        value = Value(Type.INVALID);
        return;
      }
      
      Contact c = iter.user_data2 as Contact;
      value = Value(typeof(Contact));
      value.take_object(c);
    }
    
    public bool iter_children(out Gtk.TreeIter iter, Gtk.TreeIter? parent) {
      if (parent != null) {
        iter.stamp = -1;
        return false;
      }
      
      return get_iter(out iter, new Gtk.TreePath.from_indices(0, -1));
    }
    
    public bool iter_has_child(Gtk.TreeIter iter) {
      return false;
    }
    
    public int iter_n_children(Gtk.TreeIter? iter) {
      if (iter == null)
        return entries.size;
      else
        return 0;
    }
    
    public bool iter_next(ref Gtk.TreeIter iter) {
      if(iter.stamp != stamp || iter.user_data != this)
        return false;
      
      bool next = false;
      foreach(Contact c in entries.values) {
        if(next) {
          iter.user_data2 = c;
          return true;
        }
        
        if(c == iter.user_data2)
          next = true;
      }
      
      iter.stamp = -1;
      return false;
    }
    
    public bool iter_nth_child(out Gtk.TreeIter iter, Gtk.TreeIter? parent, int n) {
      if (parent != null) {
        iter.stamp = -1;
        return false;
      }
      
      return get_iter(out iter, new Gtk.TreePath.from_indices(n, -1));
    }
    
    public bool iter_parent(out Gtk.TreeIter iter, Gtk.TreeIter child) {
      iter.stamp = -1;
      return false;
    }
    
    public void ref_node(Gtk.TreeIter iter) {}
    public void unref_node(Gtk.TreeIter iter) {}
  }  
    
  private class GroupFilter : Gtk.TreeModelFilter {
    private Roster roster;
    private string group;
    
    public GroupFilter(Roster roster0, string group0) {
      Object(child_model: roster0.model);
      
      roster = roster0;
      group = group0;
      
      set_visible_func((model, iter) => {
          Value value;
          model.get_value(iter, 0, out value);
          
          Contact c = value.get_object() as Contact;
          
          if(c == null)
            return true;
          
          return (group in c.get_groups());
        });
    }
  }
  
  private class GroupInfo {
    public int count = 0;
    public Gtk.Expander expander = null;
    public Gtk.TreeView view = null;
  }
}