/* 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::WindowBinding;
use dom::bindings::utils::{Reflectable, Reflector, Traceable};
use dom::bindings::utils::{trace_option, trace_reflector};
use dom::document::AbstractDocument;
use dom::eventtarget::{EventTarget, WindowTypeId};
use dom::node::AbstractNode;
use dom::console::Console;
use dom::location::Location;
use dom::navigator::Navigator;

use layout_interface::{ReflowForDisplay, DocumentDamageLevel};
use script_task::{ExitWindowMsg, FireTimerMsg, Page, ScriptChan};
use servo_msg::compositor_msg::ScriptListener;
use servo_net::image_cache_task::ImageCacheTask;
use servo_util::str::DOMString;
use servo_util::task::{spawn_named};

use js::glue::*;
use js::jsapi::{JSObject, JSContext, JS_DefineProperty, JSTracer, JSVal};
use js::{JSVAL_NULL, JSPROP_ENUMERATE};

use std::cast;
use std::comm::SharedChan;
use std::comm::Select;
use std::hashmap::HashSet;
use std::io::timer::Timer;
use std::num;
use std::ptr;
use std::to_bytes::Cb;

pub enum TimerControlMsg {
    TimerMessage_Fire(~TimerData),
    TimerMessage_Close,
    TimerMessage_TriggerExit //XXXjdm this is just a quick hack to talk to the script task
}

pub struct TimerHandle {
    handle: i32,
    cancel_chan: Option<Chan<()>>,
}

impl IterBytes for TimerHandle {
    fn iter_bytes(&self, lsb0: bool, f: Cb) -> bool {
        self.handle.iter_bytes(lsb0, f)
    }
}

impl Eq for TimerHandle {
    fn eq(&self, other: &TimerHandle) -> bool {
        self.handle == other.handle
    }
}

impl TimerHandle {
    fn cancel(&self) {
        self.cancel_chan.as_ref().map(|chan| chan.send(()));
    }
}

pub struct Window {
    eventtarget: EventTarget,
    page: @mut Page,
    script_chan: ScriptChan,
    compositor: @ScriptListener,
    console: Option<@mut Console>,
    timer_chan: SharedChan<TimerControlMsg>,
    location: Option<@mut Location>,
    navigator: Option<@mut Navigator>,
    image_cache_task: ImageCacheTask,
    active_timers: ~HashSet<TimerHandle>,
    next_timer_handle: i32,
}

impl Window {
    pub fn get_cx(&self) -> *JSObject {
        self.page.js_info.get_ref().js_compartment.cx.ptr
    }
}

#[unsafe_destructor]
impl Drop for Window {
    fn drop(&mut self) {
        self.timer_chan.send(TimerMessage_Close);
        for handle in self.active_timers.iter() {
            handle.cancel();
        }
    }
}

// Holder for the various JS values associated with setTimeout
// (ie. function value to invoke and all arguments to pass
//      to the function when calling it)
pub struct TimerData {
    handle: i32,
    funval: JSVal,
    args: ~[JSVal],
}

impl Window {
    pub fn Alert(&self, s: DOMString) {
        // Right now, just print to the console
        println(format!("ALERT: {:s}", s));
    }

    pub fn Close(&self) {
        self.timer_chan.send(TimerMessage_TriggerExit);
    }

    pub fn Document(&self) -> AbstractDocument {
        self.page.frame.unwrap().document
    }

    pub fn Name(&self) -> DOMString {
        ~""
    }

    pub fn SetName(&self, _name: DOMString) {
    }

    pub fn Status(&self) -> DOMString {
        ~""
    }

    pub fn SetStatus(&self, _status: DOMString) {
    }

    pub fn Closed(&self) -> bool {
        false
    }

    pub fn Stop(&self) {
    }

    pub fn Focus(&self) {
    }

    pub fn Blur(&self) {
    }

    pub fn GetFrameElement(&self) -> Option<AbstractNode> {
        None
    }

    pub fn Location(&mut self) -> @mut Location {
        if self.location.is_none() {
            self.location = Some(Location::new(self, self.page));
        }
        self.location.unwrap()
    }

    pub fn Console(&mut self) -> @mut Console {
        if self.console.is_none() {
            self.console = Some(Console::new(self));
        }
        self.console.unwrap()
    }

    pub fn Navigator(&mut self) -> @mut Navigator {
        if self.navigator.is_none() {
            self.navigator = Some(Navigator::new(self));
        }
        self.navigator.unwrap()
    }

    pub fn Confirm(&self, _message: DOMString) -> bool {
        false
    }

    pub fn Prompt(&self, _message: DOMString, _default: DOMString) -> Option<DOMString> {
        None
    }

    pub fn Print(&self) {
    }

    pub fn ShowModalDialog(&self, _cx: *JSContext, _url: DOMString, _argument: JSVal) -> JSVal {
        JSVAL_NULL
    }
}

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

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

impl Window {
    pub fn SetTimeout(&mut self, _cx: *JSContext, callback: JSVal, timeout: i32) -> i32 {
        let timeout = num::max(0, timeout) as u64;
        let handle = self.next_timer_handle;
        self.next_timer_handle += 1;

        // Post a delayed message to the per-window timer task; it will dispatch it
        // to the relevant script handler that will deal with it.
        let tm = Timer::new().unwrap();
        let (cancel_port, cancel_chan) = Chan::new();
        let chan = self.timer_chan.clone();
        spawn_named("Window:SetTimeout", proc() {
            let mut tm = tm;
            let mut timeout_port = tm.oneshot(timeout);
            let mut cancel_port = cancel_port;

            let select = Select::new();
            let timeout_handle = select.add(&mut timeout_port);
            let _cancel_handle = select.add(&mut cancel_port);
            let id = select.wait();
            if id == timeout_handle.id {
                chan.send(TimerMessage_Fire(~TimerData {
                    handle: handle,
                    funval: callback,
                    args: ~[],
                }));
            }
        });
        self.active_timers.insert(TimerHandle { handle: handle, cancel_chan: Some(cancel_chan) });
        handle
    }

    pub fn ClearTimeout(&mut self, handle: i32) {
        // FIXME(#1477): active_timers should be a HashMap and this should
        // cancel the removed timer.
        self.active_timers.remove(&TimerHandle { handle: handle, cancel_chan: None });
    }

    pub fn damage_and_reflow(&self, damage: DocumentDamageLevel) {
        // FIXME This should probably be ReflowForQuery, not Display. All queries currently
        // currently rely on the display list, which means we can't destroy it by
        // doing a query reflow.
        self.page.damage(damage);
        self.page.reflow(ReflowForDisplay, self.script_chan.clone(), self.compositor);
    }

    pub fn wait_until_safe_to_modify_dom(&self) {
        // FIXME: This disables concurrent layout while we are modifying the DOM, since
        //        our current architecture is entirely unsafe in the presence of races.
        self.page.join_layout();
    }

    pub fn new(cx: *JSContext,
               page: @mut Page,
               script_chan: ScriptChan,
               compositor: @ScriptListener,
               image_cache_task: ImageCacheTask)
               -> @mut Window {
        let win = @mut Window {
            eventtarget: EventTarget::new_inherited(WindowTypeId),
            page: page,
            script_chan: script_chan.clone(),
            compositor: compositor,
            console: None,
            timer_chan: {
                let (timer_port, timer_chan): (Port<TimerControlMsg>, SharedChan<TimerControlMsg>) = SharedChan::new();
                let id = page.id.clone();
                spawn_named("timer controller", proc() {
                    loop {
                        match timer_port.recv() {
                            TimerMessage_Close => break,
                            TimerMessage_Fire(td) => script_chan.send(FireTimerMsg(id, td)),
                            TimerMessage_TriggerExit => script_chan.send(ExitWindowMsg(id)),
                        }
                    }
                });
                timer_chan
            },
            location: None,
            navigator: None,
            image_cache_task: image_cache_task,
            active_timers: ~HashSet::new(),
            next_timer_handle: 0
        };

        let global = WindowBinding::Wrap(cx, ptr::null(), win);
        unsafe {
            let fn_names = ["window","self"];
            for str in fn_names.iter() {
                (*str).to_c_str().with_ref(|name| {
                    JS_DefineProperty(cx, global,  name,
                                      RUST_OBJECT_TO_JSVAL(global),
                                      Some(cast::transmute(GetJSClassHookStubPointer(PROPERTY_STUB))),
                                      Some(cast::transmute(GetJSClassHookStubPointer(STRICT_PROPERTY_STUB))),
                                      JSPROP_ENUMERATE);
                })

            }

        }
        win
    }
}

impl Traceable for Window {
    fn trace(&self, tracer: *mut JSTracer) {
        debug!("tracing window");

        self.page.frame.map(|frame| trace_reflector(tracer, "document", frame.document.reflector()));
        trace_option(tracer, "location", self.location);
        trace_option(tracer, "navigator", self.navigator);
    }
}