And Duterte is the best thing that happened to China.
Well, he's trying to make amends, isn't it? Though a little too late when you have lost a few islands already to the Chinese trawlers. Duterte was of the thought that China would accept you guys if you just simped around them; make no mistake - the current opposition in India also has a class of people (other than outright traitors) who think the same.
Being an island country, you guys need to concentrate on getting 3 main things:
1) A deadly anti-ship missile force mixing short and medium range anti-ship missiles
2) Drones that not only monitor but can also drop the stuff that goes BOOM (hate to admit it but Bayraktar TB2 or Akinci from Turkey makes a nice option, since we don't have our domestic platform ready yet)
3) An air defence system that can turn PLAAF/NAF pilots into fish food. Israeli Arrow 3, Indo-Israeli Barak 8, Indian Akash-NG, French Aster, etc, are good options.
Buying F-16s or Gripens at this point, unless you are buying at least 5-6 squadrons, is not sensible. 36 Gripens/F-16s won't do much damage - not to mention the time it will take your pilots to gain expertise in mastering the jets compared to PLAAF/NAF that have a lot more experience flying J-15s & JH-7s.
You have limited resources and have to concentrate on a brutal defensive position in order to screw the Paper Dragon.
China will always attack disproportionately to gain a psychological advantage. The key is to show them that you are willing to kill their troops at any cost. Once their pilots and sailors drop like flies in a few clashes, you will have enough time till the US Navy can send support and the world can limit China through economic/political means.
You need that time to steal a favorably negotiated deal.