#!/usr/bin/ruby

require 'rubygems'
require 'erlectricity'

## Avoid weird-!@#$! problem with:
## /usr/local/lib/ruby/gems/1.8/gems/erlectricity-0.2.0/lib/erlectricity/decoder.rb:7:in `read_any_from': uninitialized constant Erlectricity::Decoder::StringIO (NameError)
##  from /usr/local/lib/ruby/gems/1.8/gems/erlectricity-0.2.0/lib/erlectricity/port.rb:42:in `read_from_input'
## [...]
require 'active_support'

STDERR.write "Before top of loop\r\n"

# This 'while' wrapper loop is not necessary if each f.when() clause
# includes a final call to f.receive_loop.  However, it seems useful
# to include the wrapper in case you forget to call f.receive_loop.
#
# Do not use "while 1 do" for the wrapper!  If you do, this Ruby side
# will go into an infinite, CPU-eating loop when STDIN and STDOUT
# are closed by the Erlang side (e.g. by "erlang:port_close(RubyPort)").

while not STDIN.eof? do 
  STDERR.write "At top of loop\r\n"
  receive do |f|
    STDERR.write "Before when 1\r\n"
    f.when(:hello, Any) do |term|
      STDERR.write ["got :hello ", term.inspect, "\r\n"]
      f.receive_loop
    end 
    STDERR.write "After when 1\r\n"
    
    ## This clause will never match: it's exactly the same pattern
    ## as the previous clause.
    f.when(:hello, Any) do |term|
      STDERR.write ["got :hello (#2) ", term.inspect, "\r\n"]
      f.receive_loop
    end 
    STDERR.write "After when 1b\r\n"
    
    f.when(:sleep, Any) do |amount|
      STDERR.write "Going to sleep for #{amount} seconds ... "
      sleep amount
      STDERR.write "done\r\n"
      f.send! [:done_sleeping, amount]
      f.receive_loop
    end

    f.when(:sample) do 
      f.send! [:sample1, [:this, :is, :a, :tuple]]
      l = Erlectricity::List.new()
      ## l[1..4] = [:this, :is, :a, :list]
      f.send! [:sample2, l]
      f.receive_loop
    end

    f.when(Any) do |term|
      STDERR.write ["catchall: ", term.inspect, "\r\n"]
      ## Note: we omit calling f.receive_loop here to see what happens
      ## whith the after calls.
      ##### f.receive_loop
    end
    STDERR.write "After when 2\r\n"
  end
end

# Erlang equivalent, fwiw. 
#
# receive_loop() ->
#     receive
# 	{hello, Term} ->
# 	    io:format("got hello ~p\n", [Term]),
# 	    receive_loop();
# 	%% Erlang compiler will warn you about this.
# 	{hello, Term} ->
# 	    io:format("got hello ~p\n", [Term]),
# 	    receive_loop();
# 	{sleep, Amount} ->
# 	    io:format("Going to sleep for ~p seconds ... "),
# 	    timer:sleep(trunc(Amount * 1000)),
# 	    receive_loop();
# 	Term ->
# 	    io:format("catchall: ~p\n", [Term]),
# 	    receive_loop()
#     end.