#!/usr/bin/env python

"""
ctypesgencore.descriptions contains classes to represent a description of a
struct, union, enum, function, constant, variable, or macro. All the
description classes are subclassed from an abstract base class, Description.
The descriptions module also contains a class, DescriptionCollection, to hold
lists of Description objects.
"""


class DescriptionCollection(object):
    """Represents a collection of Descriptions."""

    def __init__(self, constants, typedefs, structs, enums, functions, variables,
                 macros, all, output_order):
        self.constants = constants
        self.typedefs = typedefs
        self.structs = structs
        self.enums = enums
        self.functions = functions
        self.variables = variables
        self.macros = macros
        self.all = all
        self.output_order = output_order


class Description(object):
    """Represents a constant, typedef, struct, function, variable, enum,
    or macro description. Description is an abstract base class."""

    def __init__(self, src=None):
        self.src = src  # A tuple of (filename, lineno)

        # If object will be included in output file. Values are "yes", "never",
        # and "if_needed".
        self.include_rule = "yes"

        # A word about requirements, and dependents:
        # If X requires Y, Y is in X.requirements.
        # If X is in Y.requirements, then Y is in X.dependents.
        self.requirements = set()
        self.dependents = set()

        # If the processor module finds a fatal error that prevents a
        # a description from being output, then it appends a string describing
        # the problem to 'errors'. If it finds a nonfatal error, it appends a
        # string to 'warnings'. If the description would have been output, then
        # the errors and warnings are printed.

        # If there is anything in 'errors' after processing is complete, the
        # description is not output.

        self.errors = []
        self.warnings = []

    def add_requirements(self, reqs):
        self.requirements = self.requirements.union(reqs)
        for req in reqs:
            req.dependents.add(self)

    def error(self, msg, cls=None):
        self.errors.append((msg, cls))

    def warning(self, msg, cls=None):
        self.warnings.append((msg, cls))

    def __repr__(self):
        return "<Description: %s>" % self.casual_name()

    def casual_name(self):
        """Return a name to show the user."""

    def py_name(self):
        """Return the name associated with this description in Python code."""

    def c_name(self):
        """Return the name associated with this description in C code."""


class ConstantDescription(Description):
    """Simple class to contain information about a constant."""

    def __init__(self, name, value, src=None):
        Description.__init__(self, src)
        # Name of constant, a string
        self.name = name
        # Value of constant, as an ExpressionNode object
        self.value = value

    def casual_name(self):
        return "Constant \"%s\"" % self.name

    def py_name(self):
        return self.name

    def c_name(self):
        return self.name


class TypedefDescription(Description):
    """Simple container class for a type definition."""

    def __init__(self, name, ctype, src=None):
        Description.__init__(self, src)
        self.name = name  # Name, a string
        self.ctype = ctype  # The base type as a ctypedescs.CtypeType object

    def casual_name(self):
        return "Typedef \"%s\"" % self.name

    def py_name(self):
        return self.name

    def c_name(self):
        return self.name


class StructDescription(Description):
    """Simple container class for a structure or union definition."""

    def __init__(self, tag, packed, variety, members, opaque, ctype, src=None):
        Description.__init__(self, src)
        # The name of the structure minus the "struct" or "union"
        self.tag = tag
        self.packed = packed
        # A string "struct" or "union"
        self.variety = variety
        # A list of pairs of (name,ctype)
        self.members = members
        # True if struct body was not specified in header file
        self.opaque = opaque
        # The original CtypeStruct that created the struct
        self.ctype = ctype

    def casual_name(self):
        return "%s \"%s\"" % (self.variety.capitalize(), self.tag)

    def py_name(self):
        return "%s_%s" % (self.variety, self.tag)

    def c_name(self):
        return "%s %s" % (self.variety, self.tag)


class EnumDescription(Description):
    """Simple container class for an enum definition."""

    def __init__(self, tag, members, ctype, src=None):
        Description.__init__(self, src)
        # The name of the enum, minus the "enum"
        self.tag = tag
        # A list of (name,value) pairs where value is a number
        self.members = members
        # The original CtypeEnum that created the enum
        self.ctype = ctype

    def casual_name(self):
        return "Enum \"%s\"" % self.tag

    def py_name(self):
        return "enum_%s" % self.tag

    def c_name(self):
        return "enum %s" % self.tag


class FunctionDescription(Description):
    """Simple container class for a C function."""

    def __init__(self, name, restype, argtypes, errcheck, variadic=False, src=None):
        Description.__init__(self, src)
        # Name, a string
        self.name = name
        # Name according to C - stored in case description is renamed
        self.cname = name
        # A ctype representing return type
        self.restype = restype
        # A list of ctypes representing the argument types
        self.argtypes = argtypes
        # An optional error checker/caster
        self.errcheck = errcheck
        # Does this function accept a variable number of arguments?
        self.variadic = variadic

    def casual_name(self):
        return "Function \"%s\"" % self.name

    def py_name(self):
        return self.name

    def c_name(self):
        return self.cname


class VariableDescription(Description):
    """Simple container class for a C variable declaration."""

    def __init__(self, name, ctype, src=None):
        Description.__init__(self, src)
        # Name, a string
        self.name = name
        # Name according to C - stored in case description is renamed
        self.cname = name
        # The type of the variable
        self.ctype = ctype

    def casual_name(self):
        return "Variable \"%s\"" % self.name

    def py_name(self):
        return self.name

    def c_name(self):
        return self.cname


class MacroDescription(Description):
    """Simple container class for a C macro."""

    def __init__(self, name, params, expr, src=None):
        Description.__init__(self, src)
        self.name = name
        self.params = params
        self.expr = expr  # ExpressionNode for the macro's body

    def casual_name(self):
        return "Macro \"%s\"" % self.name

    def py_name(self):
        return self.name

    def c_name(self):
        return self.name
