# Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
# Copyright (c) 2009 The Hewlett-Packard Development Company
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from slicc.symbols.Symbol import Symbol
from slicc.symbols.State import WildcardState

class Transition(Symbol):
    def __init__(self, table, machine, state, event, nextState, actions,
                 request_types, location):
        ident = "%s|%s" % (state, event)
        super(Transition, self).__init__(table, ident, location)

        self.state = machine.states[state]
        self.event = machine.events[event]
        if nextState == '*':
            # check to make sure there is a getNextState function declared
            found = False
            for func in machine.functions:
                if func.c_ident == 'getNextState':
                    found = True
                    break
            if found == False:
                fatal("Machine uses a wildcard transition without getNextState defined")
            self.nextState = WildcardState(machine.symtab,
                                           '*', location)
        else:
            self.nextState = machine.states[nextState]
        self.actions = [ machine.actions[a] for a in actions ]
        self.request_types = [ machine.request_types[s] for s in request_types ]
        self.resources = {}

        for action in self.actions:
            for var,value in action.resources.iteritems():
                num = int(value)
                if var in self.resources:
                    num += int(value)
                self.resources[var] = str(num)

    def __repr__(self):
      return "[Transition: (%r, %r) -> %r, %r]" % \
             (self.state, self.event, self.nextState, self.actions)

    def getActionShorthands(self):
        assert self.actions

        return ''.join(a.short for a in self.actions)

__all__ = [ "Transition" ]