describe("Linked Channels", function(){
  describe( "When binding channel - one source to one destination", function () {
    describe( "with only channel values provided", function () {
      var destData = [],
        destEnv = [],
        linkages;
      before( function () {
        linkages = postal.linkChannels( { channel : "sourceChannel" }, { channel : "destinationChannel" } );
        subscription = postal.subscribe( { channel : "destinationChannel", topic : "Oh.Hai.There", callback : function ( data, env ) {
          destData.push( data );
          destEnv.push( env );
        }} );
        postal.publish( { channel: "sourceChannel", topic: "Oh.Hai.There", data: "I'm in yer bus, linkin' to yer subscriptionz..." } );
        linkages[0].unsubscribe();
        postal.publish( { channel: "sourceChannel", topic: "Oh.Hai.There", data : "I'm in yer bus, linkin' to yer subscriptionz..."} );
      } );
      after( function () {
        postal.utils.reset();
      } );
      it( "linked subscription should only have been invoked once", function () {
        expect( destData.length ).to.be( 1 );
        expect( destEnv.length ).to.be( 1 );
      } );
      it( "linked subscription data should match expected results", function () {
        expect( destData[0] ).to.be( "I'm in yer bus, linkin' to yer subscriptionz..." );
      } );
      it( "linked subscription envelope should match expected results", function () {
        expect( destEnv[0].channel ).to.be( "destinationChannel" );
        expect( destEnv[0].topic ).to.be( "Oh.Hai.There" );
      } );
    } );
    describe( "with channel and static topic values provided", function () {
      var destData = [],
        destEnv = [],
        linkages;
      before( function () {
        linkages = postal.linkChannels( { channel : "sourceChannel", topic : "Oh.Hai.There"  }, { channel : "destinationChannel", topic : "kthxbye" } );
        subscription = postal.subscribe( { channel : "destinationChannel", topic : "kthxbye", callback : function ( data, env ) {
          destData.push( data );
          destEnv.push( env );
        }} );
        postal.publish( { channel: "sourceChannel", topic: "Oh.Hai.There", data : "I'm in yer bus, linkin' to yer subscriptionz..."} );
        linkages[0].unsubscribe();
        postal.publish( { channel: "sourceChannel", topic: "Oh.Hai.There", data : "I'm in yer bus, linkin' to yer subscriptionz..."} );
      } );
      after( function () {
        postal.utils.reset();
      } );
      it( "linked subscription should only have been invoked once", function () {
        expect( destData.length ).to.be( 1 );
        expect( destEnv.length ).to.be( 1 );
      } );
      it( "linked subscription data should match expected results", function () {
        expect( destData[0] ).to.be( "I'm in yer bus, linkin' to yer subscriptionz..." );
      } );
      it( "linked subscription envelope should match expected results", function () {
        expect( destEnv[0].channel ).to.be( "destinationChannel" );
        expect( destEnv[0].topic ).to.be( "kthxbye" );
      } );
    } );
    describe( "with channel and topic transform values provided", function () {
      var destData = [],
        destEnv = [],
        linkages;
      before( function () {
        linkages = postal.linkChannels( { channel : "sourceChannel"  }, { channel : "destinationChannel", topic : function ( tpc ) {
          return "NewTopic." + tpc;
        } } );
        subscription = postal.subscribe( { channel : "destinationChannel", topic : "NewTopic.Oh.Hai.There", callback : function ( data, env ) {
          destData.push( data );
          destEnv.push( env );
        }} );
        postal.publish( { channel: "sourceChannel", topic: "Oh.Hai.There", data : "I'm in yer bus, linkin' to yer subscriptionz..."} );
        linkages[0].unsubscribe();
        postal.publish( { channel: "sourceChannel", topic: "Oh.Hai.There", data : "I'm in yer bus, linkin' to yer subscriptionz..."} );
      } );
      after( function () {
        postal.utils.reset();
      } );
      it( "linked subscription should only have been invoked once", function () {
        expect( destData.length ).to.be( 1 );
        expect( destEnv.length ).to.be( 1 );
      } );
      it( "linked subscription data should match expected results", function () {
        expect( destData[0] ).to.be( "I'm in yer bus, linkin' to yer subscriptionz..." );
      } );
      it( "linked subscription envelope should match expected results", function () {
        expect( destEnv[0].channel ).to.be( "destinationChannel" );
        expect( destEnv[0].topic ).to.be( "NewTopic.Oh.Hai.There" );
      } );
    } );
  } );
  describe( "When binding channel - one source to multiple destinations", function () {
    var destData = [],
      destEnv = [],
      callback = function ( data, env ) {
        destData.push( data );
        destEnv.push( env );
      };

    before( function () {
      linkages = postal.linkChannels(
        { channel : "sourceChannel", topic: "Oh.Hai.There" },
        [
          { channel : "destinationChannel", topic: "NewTopic.Oh.Hai" },
          { channel : "destinationChannel", topic: "NewTopic.Oh.Hai.There" }
        ]);
      postal.subscribe( { channel : "destinationChannel", topic : "NewTopic.Oh.Hai", callback : callback} );
      postal.subscribe( { channel : "destinationChannel", topic : "NewTopic.Oh.Hai.There", callback : callback } );
      postal.publish( { channel: "sourceChannel", topic: "Oh.Hai.There", data : "I'm in yer bus, linkin' to yer subscriptionz..."} );
    } );
    after( function () {
      postal.utils.reset();
    } );
    it( "linked subscriptions should each have been called once", function () {
      expect( destData.length ).to.be( 2 );
      expect( destEnv.length ).to.be( 2 );
    } );
  });
});