/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

use dom::bindings::codegen::Bindings::NodeIteratorBinding;
use dom::bindings::codegen::Bindings::NodeIteratorBinding::NodeIteratorMethods;
use dom::bindings::codegen::Bindings::NodeFilterBinding::NodeFilter;
use dom::bindings::error::Fallible;
use dom::bindings::global::GlobalRef;
use dom::bindings::js::{JS, JSRef, MutNullableHeap, Temporary, Rootable};
use dom::bindings::utils::{Reflector, reflect_dom_object};
use dom::document::{Document, DocumentHelpers};
use dom::node::{Node};

#[dom_struct]
pub struct NodeIterator {
    reflector_: Reflector,
    root_node: JS<Node>,
    reference_node: MutNullableHeap<JS<Node>>,
    what_to_show: u32,
    filter: Filter
}

impl NodeIterator {
    fn new_inherited(root_node: JSRef<Node>,
                         what_to_show: u32,
                         filter: Filter) -> NodeIterator {
        NodeIterator {
            reflector_: Reflector::new(),
            root_node: JS::from_rooted(root_node),
            reference_node: MutNullableHeap::new(Some(JS::from_rooted(root_node))),
            what_to_show: what_to_show,
            filter: filter
        }
    }

    pub fn new_with_filter(document: JSRef<Document>,
                           root_node: JSRef<Node>,
                           what_to_show: u32,
                           filter: Filter) -> Temporary<NodeIterator> {
        let window = document.window().root();
        reflect_dom_object(box NodeIterator::new_inherited(root_node, what_to_show, filter),
                           GlobalRef::Window(window.r()),
                           NodeIteratorBinding::Wrap)
    }

    pub fn new(document: JSRef<Document>,
               root_node: JSRef<Node>,
               what_to_show: u32,
               node_filter: Option<NodeFilter>) -> Temporary<NodeIterator> {
        let filter = match node_filter {
            None => Filter::None,
            Some(jsfilter) => Filter::JS(jsfilter)
        };
        NodeIterator::new_with_filter(document, root_node, what_to_show, filter)
    }
}

impl<'a> NodeIteratorMethods for JSRef<'a, NodeIterator> {
    // https://dom.spec.whatwg.org/#dom-nodeiterator-root
    fn Root(self) -> Temporary<Node> {
        Temporary::from_rooted(self.root_node)
    }

    // https://dom.spec.whatwg.org/#dom-nodeiterator-whattoshow
    fn WhatToShow(self) -> u32 {
        self.what_to_show
    }

    // https://dom.spec.whatwg.org/#dom-nodeiterator-filter
    fn GetFilter(self) -> Option<NodeFilter> {
        match self.filter {
            Filter::None => None,
            Filter::JS(nf) => Some(nf),
            Filter::Native(_) => panic!("Cannot convert native node filter to DOM NodeFilter")
        }
    }

    // https://dom.spec.whatwg.org/#dom-nodeiterator-referencenode
    fn GetReferenceNode(self) -> Option<Temporary<Node>> {
        self.reference_node.get().map(Temporary::from_rooted)
    }

    // https://dom.spec.whatwg.org/#dom-nodeiterator-previousnode
    fn PreviousNode(self) -> Fallible<Option<Temporary<Node>>> {
        self.prev_node()
    }

    // https://dom.spec.whatwg.org/#dom-nodeiterator-nextnode
    fn NextNode(self) -> Fallible<Option<Temporary<Node>>> {
        self.next_node()
    }
}

/*
trait PrivateNodeIteratorHelpers {
    //fn accept_node(self, node: JSRef<Node>) -> Fallible<u16>;
}
*/
pub trait NodeIteratorHelpers {
    fn next_node(self) -> Fallible<Option<Temporary<Node>>>;
    fn prev_node(self) -> Fallible<Option<Temporary<Node>>>;
}

impl<'a> NodeIteratorHelpers for JSRef<'a, NodeIterator> {
    // https://dom.spec.whatwg.org/#dom-nodeiterator-nextnode
    fn next_node(self) -> Fallible<Option<Temporary<Node>>> {
        Ok(None)
    }

    // https://dom.spec.whatwg.org/#dom-nodeiterator-previousnode
    fn prev_node(self) -> Fallible<Option<Temporary<Node>>> {
        Ok(None)
    }

}


#[jstraceable]
pub enum Filter {
    None,
    Native(fn (node: JSRef<Node>) -> u16),
    JS(NodeFilter)
}