Rock-scissors-paper game server

This is written for educational purposes as a demo of an interactive web application.

How to build, start and stop

$ make deps
$ make
$ make start

After starting the server, you can check.

$ make state

You can stop the server any time.

$ make stop

Concept of the game

You (an event manager) should launch an event first.

$ make debug

Eshell V5.10.2  (abort with ^G)
(rsp@yourhost)1> 

Now in the erlang shell, you should start a new event.

(rsp@yourhost)1> rsp_event:start([{id,<<"e1">>}]).
{ok,<0.262.0>}
(rsp@yourhost)2> 

After creating the event, press CTRL+C twice to escape from the erlang shell.

Now a player, knowing the launch of the event somehow, tries to join by posting.

$ curl "http://localhost:8000/event/e1" -d "player=p1"

He might end up getting timeout if there is no other player. p1 can just retry joining the event by repeating the post again. Then another player (from another terminal session) comes while p1 is waiting.

$ curl "http://localhost:8000/event/e1" -d "player=p2"
df4cq43xyzh7hp3ehix45vp4ry

Now both the players got the same match df4cq43xyzh7hp3ehix45vp4ry.

They play a game in the match by posting like.

$ curl "http://localhost:8000/match/df4cq43xyzh7hp3ehix45vp4ry" -d "player=p1&move=rock"

(from another terminal session)

$ curl "http://localhost:8000/match/df4cq43xyzh7hp3ehix45vp4ry" -d "player=p2&move=paper"
win

In this case, p1 must have got loss as p2 got win. The rest is just standard rock-scissors-paper fashion.

A little bit internal

• You can watch what is happening inside the server by tail -f log/console.log.
• You will see the web logics in src/rsp_xxx_handler.erl files.
• Event and match are implemented in gen_server callbacks. Consult src/rsp_event.erl and src/rsp_match.erl respectively.
• You will see how the server initializes from src/rsp.erl, src/rsp_app.erl and src/rsp_sup.erl.
• You will see how the shell command works from Makefile and src/rsp_control.erl.
• You will see some of the configurations from rsp.config.

You may consider this code structure as quite standard in erlang system.