class EXPRESSION:
    pp_count = 0

    def __init__(self):
        self.pp = EXPRESSION.pp_count
        EXPRESSION.pp_count += 1

    @staticmethod
    def copy():
        return EXPRESSION()

    def allNodes(self):
        ret = [self]
        for node in (self.__getattribute__(a) for a in self.__dict__.keys()):
            if isinstance(node, EXPRESSION):
                ret += node.allNodes()
            if isinstance(node, list):
                for n in node:
                    if isinstance(n, EXPRESSION):
                        ret += n.allNodes()
        return ret

    def children(self):
        """Return a list of (name, childNode)."""
        out = []
        for key, value in self.__dict__.items():
            if key == "pp":
                continue
            if isinstance(value, EXPRESSION):
                out.append((key, value))
            elif isinstance(value, list):
                for i, elem in enumerate(value):
                    if isinstance(elem, EXPRESSION):
                        out.append((f"{key}[{i}]", elem))
        return out

    def to_dot(self, out):
        # node label is class name or class name + value
        label = type(self).__name__
        if hasattr(self, "operator"):  # AOP/EQOP/COMP/LOP
            label += f"({self.operator})"
        if hasattr(self, "name"):  # ID
            label += f"({self.name})"
        if hasattr(self, "value"):  # CONST
            label += f"({self.value})"

        out.write(f'  node{self.pp} [label="{label}"];\n')

        for (edge_name, child) in self.children():
            out.write(f'  node{self.pp} -> node{child.pp} [label="{edge_name}"];\n')
            child.to_dot(out)

class LET(EXPRESSION):
    def __init__(self, declarations, body):
        super().__init__()
        self.declarations = declarations
        self.body = body

    def __str__(self):
        return "let " + ", ".join(str(d) for d in self.declarations) + " in " + str(self.body)

class DECL(EXPRESSION):
    def __init__(self, f_name, params, body):
        super().__init__()
        self.f_name = f_name
        self.params = params
        self.body = body

    def __str__(self):
        return f"{self.f_name}({self.params}) {{ {self.body} }}"

class CALL(EXPRESSION):
    def __init__(self, f_name, arguments):
        super().__init__()
        self.f_name = f_name
        self.arguments = arguments

    def __str__(self):
        return self.f_name + "(" + ",".join(str(a) for a in self.arguments) + ")"

class ID(EXPRESSION):
    def __init__(self, name):
        super().__init__()
        self.name = name

    def __str__(self):
        return self.name

class CONST(EXPRESSION):
    def __init__(self, value):
        super().__init__()
        self.value = value

    def __str__(self):
        return str(self.value)

class AOP(EXPRESSION):
    def __init__(self, operator, arg1, arg2):
        super().__init__()
        self.operator = operator
        self.arg1 = arg1
        self.arg2 = arg2

    def __str__(self):
        return "(" + str(self.arg1) + " " + str(self.operator) + " " + str(self.arg2) + ")"

class EQOP(EXPRESSION):
    def __init__(self, operator, arg1, arg2):
        super().__init__()
        self.operator = operator
        self.arg1 = arg1
        self.arg2 = arg2

    def __str__(self):
        return "(" + str(self.arg1) + " " + str(self.operator) + " " + str(self.arg2) + ")"

class COMP(EXPRESSION):
    def __init__(self, operator, arg1, arg2):
        super().__init__()
        self.operator = operator
        self.arg1 = arg1
        self.arg2 = arg2

    def __str__(self):
        return "(" + str(self.arg1) + " " + str(self.operator) + " " + str(self.arg2) + ")"

class LOP(EXPRESSION):
    def __init__(self, operator, arg1, arg2):
        super().__init__()
        self.operator = operator
        self.arg1 = arg1
        self.arg2 = arg2

    def __str__(self):
        return "(" + str(self.arg1) + " " + str(self.operator) + " " + str(self.arg2) + ")"

class ASSIGN(EXPRESSION):
    def __init__(self, variable, expression):
        super().__init__()
        self.variable = variable
        self.expression = expression

    def __str__(self):
        return self.variable.name + " = " + str(self.expression)

class SEQ(EXPRESSION):
    def __init__(self, exp1, exp2):
        super().__init__()
        self.exp1 = exp1
        self.exp2 = exp2

    def __str__(self):
        return str(self.exp1) + "; " + str(self.exp2)

class IF(EXPRESSION):
    def __init__(self, condition, exp1, exp2):
        super().__init__()
        self.condition = condition
        self.exp1 = exp1
        self.exp2 = exp2

    def __str__(self):
        return "if (" + str(self.condition) + ") then { " + str(self.exp1) + " } else { " + str(self.exp2) + " }"

class WHILE(EXPRESSION):
    def __init__(self, condition, body):
        super().__init__()
        self.condition = condition
        self.body = body

    def __str__(self):
        return "while (" + str(self.condition) + ") do { " + str(self.body) + " }"