/* 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::InheritTypes::{ElementCast};
use dom::bindings::codegen::HTMLCollectionBinding;
use dom::bindings::js::JS;
use dom::bindings::utils::{Reflectable, Reflector, reflect_dom_object};
use dom::element::{Element, AttributeHandlers};
use dom::node::{Node, NodeHelpers};
use dom::window::Window;
use servo_util::namespace::Namespace;
use servo_util::str::DOMString;

#[deriving(Encodable)]
pub struct HTMLCollection {
    elements: ~[JS<Element>],
    reflector_: Reflector,
    window: JS<Window>,
}

impl HTMLCollection {
    pub fn new_inherited(window: JS<Window>, elements: ~[JS<Element>]) -> HTMLCollection {
        HTMLCollection {
            elements: elements,
            reflector_: Reflector::new(),
            window: window,
        }
    }

    pub fn new(window: &JS<Window>, elements: ~[JS<Element>]) -> JS<HTMLCollection> {
        reflect_dom_object(~HTMLCollection::new_inherited(window.clone(), elements),
                           window, HTMLCollectionBinding::Wrap)
    }
}

impl HTMLCollection {
    pub fn create(window: &JS<Window>, root: &JS<Node>, predicate: |elem: &JS<Element>| -> bool) -> JS<HTMLCollection> {
        let mut elements = ~[];
        for child in root.traverse_preorder() {
            if child.is_element() {
                let elem: JS<Element> = ElementCast::to(&child).unwrap();
                if predicate(&elem) {
                    elements.push(elem);
                }
            }
        }
        HTMLCollection::new(window, elements)
    }

    pub fn by_tag_name(window: &JS<Window>, root: &JS<Node>, tag_name: DOMString) -> JS<HTMLCollection> {
        HTMLCollection::create(window, root, |elem| elem.get().tag_name == tag_name)
    }

    pub fn by_tag_name_ns(window: &JS<Window>, root: &JS<Node>, tag_name: DOMString, namespace: Namespace) -> JS<HTMLCollection> {
        HTMLCollection::create(window, root, |elem| elem.get().namespace == namespace && elem.get().tag_name == tag_name)
    }

    pub fn by_class_name(window: &JS<Window>, root: &JS<Node>, classes: DOMString) -> JS<HTMLCollection> {
        // FIXME: https://github.com/mozilla/servo/issues/1840
        let classes: ~[&str] = classes.split(' ').collect();
        HTMLCollection::create(window, root, |elem| classes.iter().all(|class| elem.has_class(*class)))
    }
}

impl HTMLCollection {
    // http://dom.spec.whatwg.org/#dom-htmlcollection-length
    pub fn Length(&self) -> u32 {
        self.elements.len() as u32
    }

    // http://dom.spec.whatwg.org/#dom-htmlcollection-item
    pub fn Item(&self, index: u32) -> Option<JS<Element>> {
        if index < self.Length() {
            Some(self.elements[index].clone())
        } else {
            None
        }
    }

    // http://dom.spec.whatwg.org/#dom-htmlcollection-nameditem
    pub fn NamedItem(&self, key: DOMString) -> Option<JS<Element>> {
        // Step 1.
        if key.is_empty() {
            return None;
        }

        // Step 2.
        self.elements.iter().find(|elem| {
            elem.get_string_attribute("name") == key || elem.get_string_attribute("id") == key
        }).map(|maybe_elem| maybe_elem.clone())
    }
}

impl HTMLCollection {
    pub fn IndexedGetter(&self, index: u32, found: &mut bool) -> Option<JS<Element>> {
        let maybe_elem = self.Item(index);
        *found = maybe_elem.is_some();
        maybe_elem
    }

    pub fn NamedGetter(&self, maybe_name: Option<DOMString>, found: &mut bool) -> Option<JS<Element>> {
        match maybe_name {
            Some(name) => {
                let maybe_elem = self.NamedItem(name);
                *found = maybe_elem.is_some();
                maybe_elem
            },
            None => {
                *found = false;
                None
            }
        }
    }
}

impl Reflectable for HTMLCollection {
    fn reflector<'a>(&'a self) -> &'a Reflector {
        &self.reflector_
    }

    fn mut_reflector<'a>(&'a mut self) -> &'a mut Reflector {
        &mut self.reflector_
    }
}