import TKUnit = require("./TKUnit");

import observable = require("data/observable");

import weakEvents = require("ui/core/weak-event-listener");

import helper = require("./ui/helper");

class Target {

public counter: number = 0;

public onEvent(data: observable.EventData) {

this.counter++;

}

}

export function test_addWeakEventListener_throwsWhenCalledwitnInvalid_source() {

TKUnit.assertThrows(() => {

weakEvents.addWeakEventListener(undefined, "eventName", emptyHandler, {});

});

}

export function test_addWeakEventListener_throwsWhenCalledwitnInvalid_target() {

TKUnit.assertThrows(() => {

weakEvents.addWeakEventListener(new observable.Observable(), "eventName", emptyHandler, undefined);

});

}

export function test_addWeakEventListener_throwsWhenCalledwitnInvalid_handler() {

TKUnit.assertThrows(() => {

weakEvents.addWeakEventListener(new observable.Observable(), "eventName", undefined, {});

});

}

export function test_addWeakEventListener_throwsWhenCalledwitnInvalid_name() {

TKUnit.assertThrows(() => {

weakEvents.addWeakEventListener(new observable.Observable(), undefined, emptyHandler, {});

});

}

export function test_addWeakEventListener_listensForEvent() {

var source = new observable.Observable();

var target = new Target();

weakEvents.addWeakEventListener(

source,

observable.Observable.propertyChangeEvent,

target.onEvent,

target);

source.set("testProp", "some value");

TKUnit.assertEqual(target.counter, 1, "Handler not called.");

}

export function test_addWeakEventListener_listensForEven_multipleTargetst() {

var source = new observable.Observable();

var target1 = new Target();

var target2 = new Target();

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target1.onEvent, target1);

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target2.onEvent, target2);

source.set("testProp", "some value");

TKUnit.assertEqual(target1.counter, 1, "Handler not called.");

TKUnit.assertEqual(target2.counter, 1, "Handler not called.");

}

export function test_removeWeakEventListener_StopsListeningForEvet() {

var source = new observable.Observable();

var target = new Target();

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target.onEvent, target);

weakEvents.removeWeakEventListener(source, observable.Observable.propertyChangeEvent, target.onEvent, target)

source.set("testProp", "some value");

TKUnit.assertEqual(target.counter, 0, "Handler should not be called.");

}

export function test_handlerIsCalled_WithTargetAsThis() {

var source = new observable.Observable();

var target = new Object();

var callbackCalled = false;

var handler = function (args: observable.EventData) {

TKUnit.assertEqual(this, target, "this should be the target");

callbackCalled = true;

}

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, handler, target);

source.set("testProp", "some value");

TKUnit.assert(callbackCalled, "Handler not called.");

}

export function test_listnerDoesNotRetainTarget(done) {

var source = new observable.Observable();

var target = new Target();

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target.onEvent, target);

var targetRef = new WeakRef(target);

target = undefined;

TKUnit.waitUntilReady(() => {

helper.forceGC();

return !targetRef.get();

});

try {

TKUnit.assert(!targetRef.get(), "Target should be released after GC");

done(null);

}

catch (e) {

done(e);

}

}

export function test_listnerDoesNotRetainSource(done) {

var source = new observable.Observable();

var target = new Target();

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target.onEvent, target);

var sourceRef = new WeakRef(source);

source = undefined;

TKUnit.waitUntilReady(() => {

helper.forceGC();

return !sourceRef.get();

});

try {

TKUnit.assert(!sourceRef.get(), "Source should be released after GC");

done(null);

}

catch (e) {

done(e);

}

}

export function test_handlerIsDetached_WhenAllListenersAreRemoved() {

var source = new observable.Observable();

var target1 = new Target();

var target2 = new Target();

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target1.onEvent, target1);

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target2.onEvent, target2);

weakEvents.removeWeakEventListener(source, observable.Observable.propertyChangeEvent, target1.onEvent, target1)

weakEvents.removeWeakEventListener(source, observable.Observable.propertyChangeEvent, target2.onEvent, target2)

TKUnit.assert(!source.hasListeners(observable.Observable.propertyChangeEvent), "All events should be detached");

}

export function test_autoDetachingOfDeadReferences(done) {

var source = new observable.Observable();

for (var i = 0; i < 100; i++) {

addListenerWithSource(source);

}

try {

helper.forceGC();

var target = new Target();

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target.onEvent, target);

weakEvents.removeWeakEventListener(source, observable.Observable.propertyChangeEvent, target.onEvent, target)

TKUnit.waitUntilReady(() => { return !source.hasListeners(observable.Observable.propertyChangeEvent); });

var testPass = (<any>source)._observers[observable.Observable.propertyChangeEvent] ? (<any>source)._observers[observable.Observable.propertyChangeEvent].length <= 1 : true;

TKUnit.assert(testPass, "All events should be detached");

done(null);

}

catch (e) {

done(e);

}

}

function addListenerWithSource(source: observable.Observable) {

var target = new Target();

weakEvents.addWeakEventListener(source, observable.Observable.propertyChangeEvent, target.onEvent, target)

}

function emptyHandler(data: observable.EventData) {

// Do nothing.

}