/*  Task evaluator */

file = arg(1)

p=0

/* Load it into memory */

do forever
   a=linein(file)
   if a="#" then leave
   p=p+1
   program.p=a
end

/* 

enumerate number of subs 

This thing assumes that the coder knows how to put Sub and Endsub after the routine. 
If they dont match, it will dump a lot of weird stuff into the sub 

*/

numsub=0
name=1
startpos=2
endpos=3
len=4

do i=1 to p

   a=program.i                             /* Drop the program into a temp variable */

   if word(a,1)="Sub" then do              /* if the first word is 'Sub' its probably the start of a sub */
        numsub=numsub+1                    /* Yay! bump the sub count -- we found another sub */
        subs.numsub.name=word(a,2)         /* Throw the name of the sub into the subname field */
        subs.numsub.startpos=i             /* Derive the start position from the INCing program line number */
   end

   if word(a,1)="Endsub" then do           /* We reached the end of the sub */
        subs.numsub.endpos=i               /* Store the location of the end of the sub for later yanking */
   end

end

/* 

Store the subs

This will dump each sub into a different stem so we can multithread them all easier
in rexx ... 

*/

do i=1 to numsub                           /* Do this for all the subs we found */

   routine.i.len = endpos - startpos       /* determine the length of the code */
   floo=0                                  /* clear floo so we can keep track of the routine stem count */

   do q=subs.i.startpos to subs.i.endpos   /* Do a loop where it starts to where it stops */

      floo=floo+1                          /* INC floop for our routine stem count */
      routine.i.floo = program.q           /* Drop the program into our routine stem */

   end

end

/* 

First, we will execute sub main to see what we end up launching.  

*/

count = 0                                  /* clear the program counter */
threads = 1                                /* tell the interpreter we have 1 thread */
thread.1 = 1                               /* tell the interpreter the thread is "main" */
subpointer.1 = 1                           /* setup the sub pointer to start at the first line */
lock.1 = 0                                 /* avoid lockup of thread */
var = 0                                    /* clear the variable count ?? */
varnum = 0                                 /* clear variable count */
markdo.1 = 0                               /* clear the only do go-back */
sleep.1 = 0                                /* clear the sleep holder */
history.1 = 0                              /* clear the wait history value */


main:

do i=1 to threads                           /* We are going to do a loop so we can check on our threads one by one */

   the_thread=thread.i                     /* store the current thread's sub number into a variable */ 
   the_pointer=subpointer.i                /* store the current thread's program counter into a variable */      

   code=routine.the_thread.the_pointer     /* Get the current line of code */

   if lock.the_thread = 0 then do          /* the lock is just to pause threads we dont like from doing anything */

     inst=word(code,1)                /* Grab out the current instruction */

     /* say "thread: "i" SubLine: "the_pointer" Code: "code  */
 
     if inst="Comm" then call sub_comm
     if inst="ChildWait" then call sub_childwait
     if inst="Do" then call sub_do
     if inst="Sleep" then call sub_sleep
     if inst="Loop" then call sub_loop
     if inst="Print" then call sub_print
     if inst="Let" then call sub_let
     if inst="Sub" then call sub_submain
     if inst="EndSub" then call sub_endsub
     if inst="Wait" then call sub_wait
   
   end

end

signal main


sub_submain:

/* these subs should be parsed out out the sub stems, but im lazy */

subpointer.i=subpointer.i+1

return




sub_endsub:

/* 

these subs should be parsed out out the sub stems, but im lazy 

Im just going to halt execution of everything at this point -- later on it should just kill that
particular child.

*/

say "###TASK -- EndSub reached in routine "sub.the_thread.name
say "###TASK -- Exiting"
exit

return


sub_comm:

description=1
content=2

the_variable=substr(word(code,2),2)
the_value=word(code,3)

if the_value="" then the_value=0

do
      var=var+1                                         /* inc the var count */
      storge.var.description = the_variable             /* populate the name */
      storage.var.content = the_value                   /* populate the value */
      subpointer.i=subpointer.i+1                       /* everything is good, bump the program counter for that sub */
end

return


sub_childwait:

/* 

This will pause execution until all the children launched ends..

For simplicity sake, it will never end in this version

*/

lock.the_thread=1           /* Lock up the thread just so this call never returns      */

z=words(code)               /* Figure out how many childs we have to pull out of the function */

z=z-1                       /* subtract the "ChildWait" word */


do y=1 to z                                     /* Do it for all the childs to launch */

    new_threads = y + 1                         /* Start this off at word 2 so we dont count the function as a thread */
    do x=1 to numsub                            /* Check the full list of sub names so we can match it up with the sub number */
       
       if subs.x.name = word(code,new_threads) then do            /* Did we find it? */
         
             threads = threads + 1                               /* bump the thread count */
             thread.threads = x                                  /* set the thread up for the right sub number */
             subpointer.threads = 1                              /* set the new thread's counter to 1 */
             lock.threads = 0                                    /* Dont lock it up */
             markdo.threads = 0                                  /* Clear the single do go-back */
             sleep.threads = 0                                   /* clear the sleep counter */
             history.threads = 0                                 /* clear the single wait history check */

       end

      /* We wont do any error checking right now to see if the sub really was found or not */

    end

end


return


sub_do:

z=subpointer.i

markdo.i = z

subpointer.i=subpointer.i+1 

return




sub_sleep:

seconds = time('s')
sleept = sleeptil.i

if sleep.i=0 then do
   timewait = word(code,2)
   sleeptil.i= seconds + timewait
   sleep.i=1
end

if sleep.i=1 then do
   if seconds > sleept then subpointer.i=subpointer.i+1
   if seconds > sleept then sleep.i=0
end

return


sub_loop:

subpointer.i = markdo.i

return



sub_print:

subpointer.i=subpointer.i+1

stuffthere=0

temp=""

if substr(word(code,2),1,1)="$" then do
    stuffthere=1
    call get_var
    temp=results
end

if stuffthere=1 then do
    say temp
end

if stuffthere=0 then do
    start=index(code,'"')
    stop=index(code,'"',start+1)
    stopoff=stop-start
    say substr(code,start+1,stopoff-1)
end

return



get_var:
results="NULL"
svar=word(code,2)
svar=substr(svar,2)

if svar="rand" then do
    z = random(1,9999,time('s'))
    results=z
    return
end

if var=0 then do
   results="NULL"
   return
end

do y=1 to var
   if storage.var.description=svar then do
      results=storage.var.content
      return
   end
end

return


sub_let:

subpointer.i=subpointer.i+1

svar=word(code,2)
svar=substr(svar,2)

if var=0 then do
   var=1
   storage.var.description=svar
   storage.var.content=word(code,3)
   if word(code,3) = "$rand" then do
         storage.var.content=random(1,9999,time('s'))
   end
   return
end

/* check to see if this variable exists before we deligate a new one */

do z=1 to var
   if storage.z.description=svar then do
      storage.z.content=word(code,3)
      if word(code,3) = "$rand" then do
         storage.var.content=random(1,9999,time('s'))
      end
      return
   end
end

/* we will have to deligate a new one cuz we didnt find it */

do
   var=var+1
   storage.var.description=svar
   varlist.var.content=word(code,3)
   if word(code,3) = "$rand" then do
         storage.var.content=random(1,9999,time('s'))
   end
end


return



sub_wait:

svar=word(code,2)

do z=1 to var
   if storage.z.description=svar then do
      if storage.z.content~=history.i then do 
          subpointer.i=subpointer.i+1
          history.i=storage.z.content
          return
      end
   end
end

return