# Python Workbench prototype
# Basic system for creating and running components
# (C)Sky Coyote, June 2007

# List of created components
clist = []

# Class functions ++++++++++++++++++++++++++++++++++++++++++++++++++++++++

# Basic component type
class Component:
   # Initialize
   def __init__(self, name):
      self.name = name
      self.inputs = []
      self.outputs = []
      # Add to list
      clist.append(self)
   
   # Update state
   def run(self):
      if self.done(): return
      print "Component.run(): " + self.name
      # For each input from another component...
      for index, i in enumerate(self.inputs):
         if len(i['queue']) > 0:
            # ...get data...
            e = i['queue'].pop(0)
            print self.name + " got " + repr(e) + " from " + i['component'].name
            # ...and send to another component
            self.send(index, e)
      
   # Print description of state
   def describe(self):
      print "name = " + self.name
      print "inputs:"
      for i in self.inputs:
         # Print all fields of inputs
         print i['component'].name + " " + repr(i['queue']) + " " + \
            repr(i['buffer'])
      print "outputs:"
      for o in self.outputs:
         print o.name
         
   # Send data to another component by index number
   def send(self, output, data):
      if output < len(self.outputs):
         self.outputs[output].receive(self, data)
      
   # Get data from another component (put in intermediate buffer)
   def receive(self, input, data):
      for i in self.inputs:
         if i['component'] == input:
            i['buffer'].append(data)
      
   # Transfer data from intermediate buffers to input queues
   def update(self):
      for i in self.inputs:
         while len(i['buffer']) > 0:
            i['queue'].append(i['buffer'].pop(0))
            
   # Decide if program shuld stop
   def done(self):
      return False
      
   # reset state
   def reset(self):
      for i in self.inputs:
         i['queue'] = []
         i['buffer'] = []
      
# Non-class functions ++++++++++++++++++++++++++++++++++++++++++++++++++++++++

# Connect components
def connect(c1, c2):
   # Connect to output if not already there
   if not c2 in c1.outputs:
      c1.outputs.append(c2)
   # See if already in input
   found = False
   for i in c2.inputs:
      if i['component'] == c1: found = True
   if not found:
      # Creat new input with component, queue, and intermediate buffer
      c2.inputs.append({'component': c1, 'queue': [], 'buffer': []})
   
# Run a list of components one or more times
def run(iters):
   if iters < 0:
      while not done(): run(1)
   else:
      for i in range(iters):
         print '---'
         for c in clist:
            # Update state
            c.run()
         for c in clist:
            # Transfer data to input queue
            c.update()

# Reset all components
def reset():
   for c in clist:
      c.reset()

# Decide if program should stop
def done():
   result = True
   for c in clist:
      if not c.done(): result = False
   return result

# Describe all components in list  
def describe():
   for c in clist:
      print '---'
      c.describe()