/* 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::StorageBinding;
use dom::bindings::codegen::Bindings::StorageBinding::StorageMethods;
use dom::bindings::error::{Error, ErrorResult};
use dom::bindings::inheritance::Castable;
use dom::bindings::refcounted::Trusted;
use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
use dom::bindings::root::DomRoot;
use dom::bindings::str::DOMString;
use dom::event::{Event, EventBubbles, EventCancelable};
use dom::storageevent::StorageEvent;
use dom::window::Window;
use dom_struct::dom_struct;
use ipc_channel::ipc::{self, IpcSender};
use net_traits::IpcSend;
use net_traits::storage_thread::{StorageThreadMsg, StorageType};
use script_traits::ScriptMsg;
use servo_url::ServoUrl;
use task_source::TaskSource;

#[dom_struct]
pub struct Storage {
    reflector_: Reflector,
    storage_type: StorageType
}

impl Storage {
    fn new_inherited(storage_type: StorageType) -> Storage {
        Storage {
            reflector_: Reflector::new(),
            storage_type: storage_type
        }
    }

    pub fn new(global: &Window, storage_type: StorageType) -> DomRoot<Storage> {
        reflect_dom_object(Box::new(Storage::new_inherited(storage_type)), global, StorageBinding::Wrap)
    }

    fn get_url(&self) -> ServoUrl {
        self.global().get_url()
    }

    fn get_storage_thread(&self) -> IpcSender<StorageThreadMsg> {
        self.global().resource_threads().sender()
    }

}

impl StorageMethods for Storage {
    // https://html.spec.whatwg.org/multipage/#dom-storage-length
    fn Length(&self) -> u32 {
        let (sender, receiver) = ipc::channel().unwrap();

        self.get_storage_thread().send(StorageThreadMsg::Length(sender, self.get_url(), self.storage_type)).unwrap();
        receiver.recv().unwrap() as u32
    }

    // https://html.spec.whatwg.org/multipage/#dom-storage-key
    fn Key(&self, index: u32) -> Option<DOMString> {
        let (sender, receiver) = ipc::channel().unwrap();

        self.get_storage_thread()
            .send(StorageThreadMsg::Key(sender, self.get_url(), self.storage_type, index))
            .unwrap();
        receiver.recv().unwrap().map(DOMString::from)
    }

    // https://html.spec.whatwg.org/multipage/#dom-storage-getitem
    fn GetItem(&self, name: DOMString) -> Option<DOMString> {
        let (sender, receiver) = ipc::channel().unwrap();
        let name = String::from(name);

        let msg = StorageThreadMsg::GetItem(sender, self.get_url(), self.storage_type, name);
        self.get_storage_thread().send(msg).unwrap();
        receiver.recv().unwrap().map(DOMString::from)
    }

    // https://html.spec.whatwg.org/multipage/#dom-storage-setitem
    fn SetItem(&self, name: DOMString, value: DOMString) -> ErrorResult {
        let (sender, receiver) = ipc::channel().unwrap();
        let name = String::from(name);
        let value = String::from(value);

        let msg = StorageThreadMsg::SetItem(sender, self.get_url(), self.storage_type, name.clone(), value.clone());
        self.get_storage_thread().send(msg).unwrap();
        match receiver.recv().unwrap() {
            Err(_) => Err(Error::QuotaExceeded),
            Ok((changed, old_value)) => {
              if changed {
                  self.broadcast_change_notification(Some(name), old_value, Some(value));
              }
              Ok(())
            }
        }
    }

    // https://html.spec.whatwg.org/multipage/#dom-storage-removeitem
    fn RemoveItem(&self, name: DOMString) {
        let (sender, receiver) = ipc::channel().unwrap();
        let name = String::from(name);

        let msg = StorageThreadMsg::RemoveItem(sender, self.get_url(), self.storage_type, name.clone());
        self.get_storage_thread().send(msg).unwrap();
        if let Some(old_value) = receiver.recv().unwrap() {
            self.broadcast_change_notification(Some(name), Some(old_value), None);
        }
    }

    // https://html.spec.whatwg.org/multipage/#dom-storage-clear
    fn Clear(&self) {
        let (sender, receiver) = ipc::channel().unwrap();

        self.get_storage_thread().send(StorageThreadMsg::Clear(sender, self.get_url(), self.storage_type)).unwrap();
        if receiver.recv().unwrap() {
            self.broadcast_change_notification(None, None, None);
        }
    }

    // https://html.spec.whatwg.org/multipage/#the-storage-interface:supported-property-names
    fn SupportedPropertyNames(&self) -> Vec<DOMString> {
        let (sender, receiver) = ipc::channel().unwrap();

        self.get_storage_thread().send(StorageThreadMsg::Keys(sender, self.get_url(), self.storage_type)).unwrap();
        receiver.recv()
                .unwrap()
                .into_iter()
                .map(DOMString::from)
                .collect()
    }

    // check-tidy: no specs after this line
    fn NamedGetter(&self, name: DOMString) -> Option<DOMString> {
        self.GetItem(name)
    }

    fn NamedSetter(&self, name: DOMString, value: DOMString) -> ErrorResult {
        self.SetItem(name, value)
    }

    fn NamedDeleter(&self, name: DOMString) {
        self.RemoveItem(name);
    }
}


impl Storage {
    /// <https://html.spec.whatwg.org/multipage/#send-a-storage-notification>
    fn broadcast_change_notification(&self, key: Option<String>, old_value: Option<String>,
                                     new_value: Option<String>) {
        let storage = self.storage_type;
        let url = self.get_url();
        let msg = ScriptMsg::BroadcastStorageEvent(storage, url, key, old_value, new_value);
        self.global().script_to_constellation_chan().send(msg).unwrap();
    }

    /// <https://html.spec.whatwg.org/multipage/#send-a-storage-notification>
    pub fn queue_storage_event(
        &self,
        url: ServoUrl,
        key: Option<String>,
        old_value: Option<String>,
        new_value: Option<String>,
    ) {
        let global = self.global();
        let this = Trusted::new(self);
        global.as_window().dom_manipulation_task_source().queue(
            task!(send_storage_notification: move || {
                let this = this.root();
                let global = this.global();
                let event = StorageEvent::new(
                    global.as_window(),
                    atom!("storage"),
                    EventBubbles::DoesNotBubble,
                    EventCancelable::NotCancelable,
                    key.map(DOMString::from),
                    old_value.map(DOMString::from),
                    new_value.map(DOMString::from),
                    DOMString::from(url.into_string()),
                    Some(&this),
                );
                event.upcast::<Event>().fire(global.upcast());
            }),
            global.upcast(),
        ).unwrap();
    }
}
