// 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::HTMLLegendElementBinding;
use dom::bindings::codegen::Bindings::HTMLLegendElementBinding::HTMLLegendElementMethods;
use dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
use dom::bindings::inheritance::Castable;
use dom::bindings::js::{MutNullableJS, Root};
use dom::document::Document;
use dom::element::Element;
use dom::htmlelement::HTMLElement;
use dom::htmlfieldsetelement::HTMLFieldSetElement;
use dom::htmlformelement::{HTMLFormElement, FormControl};
use dom::node::{Node, UnbindContext};
use dom::virtualmethods::VirtualMethods;
use dom_struct::dom_struct;
use html5ever::{LocalName, Prefix};

#[dom_struct]
pub struct HTMLLegendElement {
    htmlelement: HTMLElement,
    form_owner: MutNullableJS<HTMLFormElement>,
}

impl HTMLLegendElement {
    fn new_inherited(local_name: LocalName,
                     prefix: Option<Prefix>,
                     document: &Document)
                     -> HTMLLegendElement {
        HTMLLegendElement {
            htmlelement: HTMLElement::new_inherited(local_name, prefix, document),
            form_owner: Default::default(),
        }
    }

    #[allow(unrooted_must_root)]
    pub fn new(local_name: LocalName,
               prefix: Option<Prefix>,
               document: &Document)
               -> Root<HTMLLegendElement> {
        Node::reflect_node(box HTMLLegendElement::new_inherited(local_name, prefix, document),
                           document,
                           HTMLLegendElementBinding::Wrap)
    }
}

impl VirtualMethods for HTMLLegendElement {
    fn super_type(&self) -> Option<&VirtualMethods> {
        Some(self.upcast::<HTMLElement>() as &VirtualMethods)
    }

    fn bind_to_tree(&self, tree_in_doc: bool) {
        if let Some(ref s) = self.super_type() {
            s.bind_to_tree(tree_in_doc);
        }

        self.upcast::<Element>().check_ancestors_disabled_state_for_form_control();
    }

    fn unbind_from_tree(&self, context: &UnbindContext) {
        self.super_type().unwrap().unbind_from_tree(context);

        let node = self.upcast::<Node>();
        let el = self.upcast::<Element>();
        if node.ancestors().any(|ancestor| ancestor.is::<HTMLFieldSetElement>()) {
            el.check_ancestors_disabled_state_for_form_control();
        } else {
            el.check_disabled_attribute();
        }
    }
}


impl HTMLLegendElementMethods for HTMLLegendElement {
    // https://html.spec.whatwg.org/multipage/#dom-legend-form
    fn GetForm(&self) -> Option<Root<HTMLFormElement>> {
        let parent = match self.upcast::<Node>().GetParentElement() {
            Some(parent) => parent,
            None => return None,
        };
        if parent.is::<HTMLFieldSetElement>() {
            return self.form_owner();
        }
        None
    }
}

impl FormControl for HTMLLegendElement {
    fn form_owner(&self) -> Option<Root<HTMLFormElement>> {
        self.form_owner.get()
    }

    fn set_form_owner(&self, form: Option<&HTMLFormElement>) {
        self.form_owner.set(form);
    }

    fn to_element<'a>(&'a self) -> &'a Element {
        self.upcast::<Element>()
    }
}