"""Parse a Python module and describe its classes and methods.

Parse enough of a Python file to recognize imports and class and

method definitions, and to find out the superclasses of a class.

The interface consists of a single function:

        readmodule_ex(module [, path])

where module is the name of a Python module, and path is an optional

list of directories where the module is to be searched.  If present,

path is prepended to the system search path sys.path.  The return

value is a dictionary.  The keys of the dictionary are the names of

the classes defined in the module (including classes that are defined

via the from XXX import YYY construct).  The values are class

instances of the class Class defined here.  One special key/value pair

is present for packages: the key '__path__' has a list as its value

which contains the package search path.

A class is described by the class Class in this module.  Instances

of this class have the following instance variables:

        module -- the module name

        name -- the name of the class

        super -- a list of super classes (Class instances)

        methods -- a dictionary of methods

        file -- the file in which the class was defined

        lineno -- the line in the file on which the class statement occurred

The dictionary of methods uses the method names as keys and the line

numbers on which the method was defined as values.

If the name of a super class is not recognized, the corresponding

entry in the list of super classes is not a class instance but a

string giving the name of the super class.  Since import statements

are recognized and imported modules are scanned as well, this

shouldn't happen often.

A function is described by the class Function in this module.

Instances of this class have the following instance variables:

        module -- the module name

        name -- the name of the class

        file -- the file in which the class was defined

        lineno -- the line in the file on which the class statement occurred

"""

import sys

import imp

import tokenize

from token import NAME, DEDENT, OP

from operator import itemgetter

__all__ = ["readmodule", "readmodule_ex", "Class", "Function"]

_modules = {}                           # cache of modules we've seen

# each Python class is represented by an instance of this class

class Class:

    '''Class to represent a Python class.'''

    def __init__(self, module, name, super, file, lineno):

        self.module = module

        self.name = name

        if super is None:

            super = []

        self.super = super

        self.methods = {}

        self.file = file

        self.lineno = lineno

    def _addmethod(self, name, lineno):

        self.methods[name] = lineno

class Function:

    '''Class to represent a top-level Python function'''

    def __init__(self, module, name, file, lineno):

        self.module = module

        self.name = name

        self.file = file

        self.lineno = lineno

def readmodule(module, path=None):

    '''Backwards compatible interface.

    Call readmodule_ex() and then only keep Class objects from the

    resulting dictionary.'''

    res = {}

    for key, value in _readmodule(module, path or []).items():

        if isinstance(value, Class):

            res[key] = value

    return res

def readmodule_ex(module, path=None):

    '''Read a module file and return a dictionary of classes.

    Search for MODULE in PATH and sys.path, read and parse the

    module and return a dictionary with one entry for each class

    found in the module.

    '''

    return _readmodule(module, path or [])

def _readmodule(module, path, inpackage=None):

    '''Do the hard work for readmodule[_ex].

    If INPACKAGE is given, it must be the dotted name of the package in

    which we are searching for a submodule, and then PATH must be the

    package search path; otherwise, we are searching for a top-level

    module, and PATH is combined with sys.path.

    '''

    # Compute the full module name (prepending inpackage if set)

    if inpackage is not None:

        fullmodule = "%s.%s" % (inpackage, module)

    else:

        fullmodule = module

    # Check in the cache

    if fullmodule in _modules:

        return _modules[fullmodule]

    # Initialize the dict for this module's contents

    dict = {}

    # Check if it is a built-in module; we don't do much for these

    if module in sys.builtin_module_names and inpackage is None:

        _modules[module] = dict

        return dict

    # Check for a dotted module name

    i = module.rfind('.')

    if i >= 0:

        package = module[:i]

        submodule = module[i+1:]

        parent = _readmodule(package, path, inpackage)

        if inpackage is not None:

            package = "%s.%s" % (inpackage, package)

        return _readmodule(submodule, parent['__path__'], package)

    # Search the path for the module

    f = None

    if inpackage is not None:

        f, fname, (_s, _m, ty) = imp.find_module(module, path)

    else:

        f, fname, (_s, _m, ty) = imp.find_module(module, path + sys.path)

    if ty == imp.PKG_DIRECTORY:

        dict['__path__'] = [fname]

        path = [fname] + path

        f, fname, (_s, _m, ty) = imp.find_module('__init__', [fname])

    _modules[fullmodule] = dict

    if ty != imp.PY_SOURCE:

        # not Python source, can't do anything with this module

        f.close()

        return dict

    stack = [] # stack of (class, indent) pairs

    g = tokenize.generate_tokens(f.readline)

    try:

        for tokentype, token, start, _end, _line in g:

            if tokentype == DEDENT:

                lineno, thisindent = start

                # close nested classes and defs

                while stack and stack[-1][1] >= thisindent:

                    del stack[-1]

            elif token == 'def':

                lineno, thisindent = start

                # close previous nested classes and defs

                while stack and stack[-1][1] >= thisindent:

                    del stack[-1]

                tokentype, meth_name, start = g.next()[0:3]

                if tokentype != NAME:

                    continue # Syntax error

                if stack:

                    cur_class = stack[-1][0]

                    if isinstance(cur_class, Class):

                        # it's a method

                        cur_class._addmethod(meth_name, lineno)

                    # else it's a nested def

                else:

                    # it's a function

                    dict[meth_name] = Function(fullmodule, meth_name,

                                               fname, lineno)

                stack.append((None, thisindent)) # Marker for nested fns

            elif token == 'class':

                lineno, thisindent = start

                # close previous nested classes and defs

                while stack and stack[-1][1] >= thisindent:

                    del stack[-1]

                tokentype, class_name, start = g.next()[0:3]

                if tokentype != NAME:

                    continue # Syntax error

                # parse what follows the class name

                tokentype, token, start = g.next()[0:3]

                inherit = None

                if token == '(':

                    names = [] # List of superclasses

                    # there's a list of superclasses

                    level = 1

                    super = [] # Tokens making up current superclass

                    while True:

                        tokentype, token, start = g.next()[0:3]

                        if token in (')', ',') and level == 1:

                            n = "".join(super)

                            if n in dict:

                                # we know this super class

                                n = dict[n]

                            else:

                                c = n.split('.')

                                if len(c) > 1:

                                    # super class is of the form

                                    # module.class: look in module for

                                    # class

                                    m = c[-2]

                                    c = c[-1]

                                    if m in _modules:

                                        d = _modules[m]

                                        if c in d:

                                            n = d[c]

                            names.append(n)

                            super = []

                        if token == '(':

                            level += 1

                        elif token == ')':

                            level -= 1

                            if level == 0:

                                break

                        elif token == ',' and level == 1:

                            pass

                        # only use NAME and OP (== dot) tokens for type name

                        elif tokentype in (NAME, OP) and level == 1:

                            super.append(token)

                        # expressions in the base list are not supported

                    inherit = names

                cur_class = Class(fullmodule, class_name, inherit,

                                  fname, lineno)

                if not stack:

                    dict[class_name] = cur_class

                stack.append((cur_class, thisindent))

            elif token == 'import' and start[1] == 0:

                modules = _getnamelist(g)

                for mod, _mod2 in modules:

                    try:

                        # Recursively read the imported module

                        if inpackage is None:

                            _readmodule(mod, path)

                        else:

                            try:

                                _readmodule(mod, path, inpackage)

                            except ImportError:

                                _readmodule(mod, [])

                    except:

                        # If we can't find or parse the imported module,

                        # too bad -- don't die here.

                        pass

            elif token == 'from' and start[1] == 0:

                mod, token = _getname(g)

                if not mod or token != "import":

                    continue

                names = _getnamelist(g)

                try:

                    # Recursively read the imported module

                    d = _readmodule(mod, path, inpackage)

                except:

                    # If we can't find or parse the imported module,

                    # too bad -- don't die here.

                    continue

                # add any classes that were defined in the imported module

                # to our name space if they were mentioned in the list

                for n, n2 in names:

                    if n in d:

                        dict[n2 or n] = d[n]

                    elif n == '*':

                        # don't add names that start with _

                        for n in d:

                            if n[0] != '_':

                                dict[n] = d[n]

    except StopIteration:

        pass

    f.close()

    return dict

def _getnamelist(g):

    # Helper to get a comma-separated list of dotted names plus 'as'

    # clauses.  Return a list of pairs (name, name2) where name2 is

    # the 'as' name, or None if there is no 'as' clause.

    names = []

    while True:

        name, token = _getname(g)

        if not name:

            break

        if token == 'as':

            name2, token = _getname(g)

        else:

            name2 = None

        names.append((name, name2))

        while token != "," and "\n" not in token:

            token = g.next()[1]

        if token != ",":

            break

    return names

def _getname(g):

    # Helper to get a dotted name, return a pair (name, token) where

    # name is the dotted name, or None if there was no dotted name,

    # and token is the next input token.

    parts = []

    tokentype, token = g.next()[0:2]

    if tokentype != NAME and token != '*':

        return (None, token)

    parts.append(token)

    while True:

        tokentype, token = g.next()[0:2]

        if token != '.':

            break

        tokentype, token = g.next()[0:2]

        if tokentype != NAME:

            break

        parts.append(token)

    return (".".join(parts), token)

def _main():

    # Main program for testing.

    import os

    mod = sys.argv[1]

    if os.path.exists(mod):

        path = [os.path.dirname(mod)]

        mod = os.path.basename(mod)

        if mod.lower().endswith(".py"):

            mod = mod[:-3]

    else:

        path = []

    dict = readmodule_ex(mod, path)

    objs = dict.values()

    objs.sort(lambda a, b: cmp(getattr(a, 'lineno', 0),

                               getattr(b, 'lineno', 0)))

    for obj in objs:

        if isinstance(obj, Class):

            print "class", obj.name, obj.super, obj.lineno

            methods = sorted(obj.methods.iteritems(), key=itemgetter(1))

            for name, lineno in methods:

                if name != "__path__":

                    print "  def", name, lineno

        elif isinstance(obj, Function):

            print "def", obj.name, obj.lineno

if __name__ == "__main__":

    _main()