/* 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::attr::Attr;
use dom::attr::AttrHelpers;
use dom::bindings::codegen::Bindings::HTMLIFrameElementBinding;
use dom::bindings::codegen::Bindings::HTMLIFrameElementBinding::HTMLIFrameElementMethods;
use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
use dom::bindings::codegen::InheritTypes::{NodeCast, ElementCast};
use dom::bindings::codegen::InheritTypes::{HTMLElementCast, HTMLIFrameElementDerived};
use dom::bindings::js::{JSRef, Temporary, OptionalRootable};
use dom::document::Document;
use dom::element::{ElementTypeId, Element};
use dom::element::AttributeHandlers;
use dom::eventtarget::{EventTarget, EventTargetTypeId};
use dom::htmlelement::HTMLElement;
use dom::node::{Node, NodeHelpers, NodeTypeId, window_from_node};
use dom::urlhelper::UrlHelper;
use dom::virtualmethods::VirtualMethods;
use dom::window::Window;
use page::IterablePage;

use servo_msg::constellation_msg::{PipelineId, SubpageId};
use servo_msg::constellation_msg::{IFrameSandboxed, IFrameUnsandboxed};
use servo_msg::constellation_msg::{ConstellationChan, ScriptLoadedURLInIFrameMsg};
use servo_util::str::DOMString;

use std::ascii::AsciiExt;
use std::cell::Cell;
use url::{Url, UrlParser};

enum SandboxAllowance {
    AllowNothing = 0x00,
    AllowSameOrigin = 0x01,
    AllowTopNavigation = 0x02,
    AllowForms = 0x04,
    AllowScripts = 0x08,
    AllowPointerLock = 0x10,
    AllowPopups = 0x20
}

#[dom_struct]
pub struct HTMLIFrameElement {
    htmlelement: HTMLElement,
    size: Cell<Option<IFrameSize>>,
    sandbox: Cell<Option<u8>>,
}

impl HTMLIFrameElementDerived for EventTarget {
    fn is_htmliframeelement(&self) -> bool {
        *self.type_id() == EventTargetTypeId::Node(NodeTypeId::Element(ElementTypeId::HTMLIFrameElement))
    }
}

#[jstraceable]
#[privatize]
pub struct IFrameSize {
    pipeline_id: PipelineId,
    subpage_id: SubpageId,
}

impl IFrameSize {
    #[inline]
    pub fn pipeline_id<'a>(&'a self) -> &'a PipelineId {
        &self.pipeline_id
    }

    #[inline]
    pub fn subpage_id<'a>(&'a self) -> &'a SubpageId {
        &self.subpage_id
    }
}

pub trait HTMLIFrameElementHelpers {
    fn is_sandboxed(self) -> bool;
    fn get_url(self) -> Option<Url>;
    /// http://www.whatwg.org/html/#process-the-iframe-attributes
    fn process_the_iframe_attributes(self);
}

impl<'a> HTMLIFrameElementHelpers for JSRef<'a, HTMLIFrameElement> {
    fn is_sandboxed(self) -> bool {
        self.sandbox.get().is_some()
    }

    fn get_url(self) -> Option<Url> {
        let element: JSRef<Element> = ElementCast::from_ref(self);
        element.get_attribute(ns!(""), &atom!("src")).root().and_then(|src| {
            let url = src.value();
            if url.as_slice().is_empty() {
                None
            } else {
                let window = window_from_node(self).root();
                UrlParser::new().base_url(&window.page().get_url())
                    .parse(url.as_slice()).ok()
            }
        })
    }

    fn process_the_iframe_attributes(self) {
        let url = match self.get_url() {
            Some(url) => url.clone(),
            None => Url::parse("about:blank").unwrap(),
        };

        let sandboxed = if self.is_sandboxed() {
            IFrameSandboxed
        } else {
            IFrameUnsandboxed
        };

        // Subpage Id
        let window = window_from_node(self).root();
        let page = window.page();
        let subpage_id = page.get_next_subpage_id();

        self.size.set(Some(IFrameSize {
            pipeline_id: page.id,
            subpage_id: subpage_id,
        }));

        let ConstellationChan(ref chan) = page.constellation_chan;
        chan.send(ScriptLoadedURLInIFrameMsg(url, page.id, subpage_id, sandboxed));
    }
}

impl HTMLIFrameElement {
    fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> HTMLIFrameElement {
        HTMLIFrameElement {
            htmlelement: HTMLElement::new_inherited(ElementTypeId::HTMLIFrameElement, localName, prefix, document),
            size: Cell::new(None),
            sandbox: Cell::new(None),
        }
    }

    #[allow(unrooted_must_root)]
    pub fn new(localName: DOMString, prefix: Option<DOMString>, document: JSRef<Document>) -> Temporary<HTMLIFrameElement> {
        let element = HTMLIFrameElement::new_inherited(localName, prefix, document);
        Node::reflect_node(box element, document, HTMLIFrameElementBinding::Wrap)
    }

    #[inline]
    pub fn size(&self) -> Option<IFrameSize> {
        self.size.get()
    }
}

impl<'a> HTMLIFrameElementMethods for JSRef<'a, HTMLIFrameElement> {
    fn Src(self) -> DOMString {
        let element: JSRef<Element> = ElementCast::from_ref(self);
        element.get_string_attribute(&atom!("src"))
    }

    fn SetSrc(self, src: DOMString) {
        let element: JSRef<Element> = ElementCast::from_ref(self);
        element.set_url_attribute(&atom!("src"), src)
    }

    fn Sandbox(self) -> DOMString {
        let element: JSRef<Element> = ElementCast::from_ref(self);
        element.get_string_attribute(&atom!("sandbox"))
    }

    fn SetSandbox(self, sandbox: DOMString) {
        let element: JSRef<Element> = ElementCast::from_ref(self);
        element.set_string_attribute(&atom!("sandbox"), sandbox);
    }

    fn GetContentWindow(self) -> Option<Temporary<Window>> {
        self.size.get().and_then(|size| {
            let window = window_from_node(self).root();
            let children = window.page().children.borrow();
            let child = children.iter().find(|child| {
                child.subpage_id.unwrap() == size.subpage_id
            });
            child.and_then(|page| {
                page.frame.borrow().as_ref().map(|frame| {
                    Temporary::new(frame.window.clone())
                })
            })
        })
    }

    fn GetContentDocument(self) -> Option<Temporary<Document>> {
        self.GetContentWindow().root().and_then(|window| {
            let self_url = match self.get_url() {
                Some(self_url) => self_url,
                None => return None,
            };
            let win_url = window_from_node(self).root().page().get_url();

            if UrlHelper::SameOrigin(&self_url, &win_url) {
                Some(window.Document())
            } else {
                None
            }
        })
    }
}

impl<'a> VirtualMethods for JSRef<'a, HTMLIFrameElement> {
    fn super_type<'a>(&'a self) -> Option<&'a VirtualMethods> {
        let htmlelement: &JSRef<HTMLElement> = HTMLElementCast::from_borrowed_ref(self);
        Some(htmlelement as &VirtualMethods)
    }

    fn after_set_attr(&self, attr: JSRef<Attr>) {
        match self.super_type() {
            Some(ref s) => s.after_set_attr(attr),
            _ => ()
        }

        match attr.local_name() {
            &atom!("sandbox") => {
                let mut modes = SandboxAllowance::AllowNothing as u8;
                for word in attr.value().as_slice().split(' ') {
                    modes |= match word.to_ascii_lower().as_slice() {
                        "allow-same-origin" => SandboxAllowance::AllowSameOrigin,
                        "allow-forms" => SandboxAllowance::AllowForms,
                        "allow-pointer-lock" => SandboxAllowance::AllowPointerLock,
                        "allow-popups" => SandboxAllowance::AllowPopups,
                        "allow-scripts" => SandboxAllowance::AllowScripts,
                        "allow-top-navigation" => SandboxAllowance::AllowTopNavigation,
                        _ => SandboxAllowance::AllowNothing
                    } as u8;
                }
                self.sandbox.set(Some(modes));
            },
            &atom!("src") => {
                let node: JSRef<Node> = NodeCast::from_ref(*self);
                if node.is_in_doc() {
                    self.process_the_iframe_attributes()
                }
            },
            _ => ()
        }
    }

    fn before_remove_attr(&self, attr: JSRef<Attr>) {
        match self.super_type() {
            Some(ref s) => s.before_remove_attr(attr),
            _ => ()
        }

        match attr.local_name() {
            &atom!("sandbox") => self.sandbox.set(None),
            _ => ()
        }
    }

    fn bind_to_tree(&self, tree_in_doc: bool) {
        match self.super_type() {
            Some(ref s) => s.bind_to_tree(tree_in_doc),
            _ => (),
        }

        if tree_in_doc {
            self.process_the_iframe_attributes();
        }
    }
}