"""
AST (abstract syntax tree) nodes for the c3 language.
The tree is build by the parser.
Then it is checked
Finally code is generated from it.
"""

class Node:
   pass 

# Modules
class Package(Node):
    def __init__(self, name, loc):
        self.name = name
        self.loc = loc
        self.declarations = []
    def __repr__(self):
        return 'PACKAGE {}'.format(self.name)

class Designator(Node):
    def __init__(self, tname, loc):
        self.tname = tname
        self.loc = loc
    def __repr__(self):
        return 'DESIGNATOR {}'.format(self.tname)

"""
Type classes

types must be comparable.

There are the following types:
- base type
- struct type
- pointer type
- typedef type
- function type
"""

class Type(Node):
   def isType(self, b):
      return isType(self, b)

class BaseType(Type):
  def __init__(self, name):
    self.name = name
  def __repr__(self):
    return '{}'.format(self.name)

class FunctionType(Type):
   def __init__(self, parametertypes, returntype):
      self.parametertypes = parametertypes
      self.returntype = returntype
   def __repr__(self):
      params = ', '.join([str(v) for v in self.parametertypes])
      return '{1} f({0})'.format(params, self.returntype)

class PointerType(Type):
    def __init__(self, ptype):
        self.ptype = ptype

class StructureType(Type):
    def __init__(self, mems):
        self.mems = mems

class DefinedType(Type):
   def __init__(self, name, typ):
      self.name = name
      self.typ = typ
   def __repr__(self):
      return 'Named type {0} of type {1}'.format(self.name, self.typ)

# Variables, parameters, local variables, constants:
class Symbol(Node):
    def __init__(self, name):
      self.name = name
      self.refs = []
    def addRef(self, r):
      self.refs.append(r)
    @property
    def References(self):
      return self.refs

class Constant(Symbol):
    def __init__(self, name, typ, value):
      super().__init__(name)
      self.typ = typ
      self.value = value
    def __repr__(self):
      return 'CONSTANT {0} = {1}'.format(self.name, self.value)

class Variable(Symbol):
   def __init__(self, name, typ):
      super().__init__(name)
      self.typ = typ
      self.ival = None
      self.isLocal = False
      self.isReadOnly = False
      self.isParameter = False
   def __repr__(self):
      return 'Var {}'.format(self.name)

# Procedure types
class Function(Symbol):
    """ Actual implementation of a function """
    def __init__(self, name, loc):
        super().__init__(name)
        self.loc = loc
        self.declarations = []

    def __repr__(self):
        return 'Func {}'.format(self.name)

# Operations / Expressions:
class Unop(Node):
   def __init__(self, a, op):
      self.a = a
      self.op = op 
   def __repr__(self):
      return 'UNOP {}'.format(self.op)

class Binop(Node):
   def __init__(self, a, op, b, loc):
      self.a = a
      self.b = b
      self.op = op # Operation: '+', '-', '*', '/', 'mod'
      self.loc = loc
   def __repr__(self):
      return 'BINOP {}'.format(self.op)

class VariableUse(Node):
   def __init__(self, target, loc):
      self.target = target
      self.loc = loc
   def __repr__(self):
      nm = self.target.name if hasattr(self.target, 'name') else ''
      return 'VAR USE {}'.format(nm)

class Literal(Node):
   def __init__(self, val, loc):
      self.val = val
      self.loc = loc
   def __repr__(self):
      return 'LITERAL {}'.format(self.val)


# Statements
class CompoundStatement(Node):
   def __init__(self, statements):
      self.statements = statements
   def __repr__(self):
      return 'COMPOUND STATEMENT'

class EmptyStatement(Node):
   def __repr__(self):
      return 'NOP'

class ReturnStatement(Node):
   def __init__(self, expr):
      self.expr = expr
   def __repr__(self):
      return 'RETURN STATEMENT'

class Assignment(Node):
   def __init__(self, lval, rval, loc):
      self.lval = lval
      self.rval = rval
      self.loc = loc
   def __repr__(self):
      return 'ASSIGNMENT'

class FunctionCall(Node):
  def __init__(self, proc, args, loc):
    self.proc = proc
    self.args = args
    self.loc = loc
  def __repr__(self):
    return 'CALL {0} '.format(self.proc)

class IfStatement(Node):
   def __init__(self, condition, truestatement, falsestatement, loc):
      self.condition = condition
      self.truestatement = truestatement
      self.falsestatement = falsestatement
      self.loc = loc
   def __repr__(self):
      return 'IF-statement'

class WhileStatement(Node):
   def __init__(self, condition, statement, loc):
      self.condition = condition
      self.statement = statement
      self.loc = loc
   def __repr__(self):
      return 'WHILE-statement'