I met a girl 1000 miles away on tinder and we just kicked off. We texted 2hrs every day for a week and finally a long video-chat followed by hours of flirting for 2 more days. We planned trips together along with all the exciting and naughty things we'll do in the trip. I usually don't fall for a girl so soon without even meeting her, but with this girl, I felt like I was going to fall for her. Nevertheless, I tried to keep things playful rather than serious.

Lately, she has started giving me a cold shoulder (she replies and even sends first texts but has stopped responding flirtatiously for similar texts). I see the following reasons why she is doing so and want to get some advice from girls or guys with tons of dating experience as to why she might be doing so. Figuring out is important so that I know what I should do.

1. She has found someone else online but still wants to be friends with me: If that is the case, I will continue to reply to her messages in a platonic way and would never be keen to text her first.
2. She is interested and is playing games unconsciously or consciously: In this case, I should either tell her my feelings for her straightaway or stop responding for a few day and test waters by checking out how how she goes about it.
3. She doesn't know if she is into me or she has found someone online and is still thinking who she wants to be with: In this scenario, I believe I should give her a call and tell he straight up how I feel about her without more fooling around.
4. Her whole idea being on tinder using her passport feature is just to pass time and kill her boredom: If that's the case, I should not take her seriously and continue to send her naughty or platonic texts depending on how she responds.

In all these cases, I have another option that I can keep on sending playful messages hoping that she responds enthusiastically as before.

Do let me know what the most probable scenario might be and whether it can ever be a good idea to tell a girl that you like her even before physically meeting her ever. I am especially hoping something from gals or experienced guys.