#!/usr/bin/env python

import ihooks # for the import machinery

import os, glob # for getting suitably-named files

from imp import PY_SOURCE, PKG_DIRECTORY, C_BUILTIN # import machinery magic

import classfile, bytecode # Java class support

import zipfile # for Java archive inspection

# NOTE: Arbitrary constants pulled from thin air.

JAVA_PACKAGE = 20041113

JAVA_CLASS = 20041114

JAVA_ARCHIVE = 20041115

class ClassHooks(ihooks.Hooks):

    "A filesystem hooks class providing information about supported files."

    def get_suffixes(self):

        "Return the recognised suffixes."

        return [("", "", JAVA_PACKAGE), (os.extsep + "jar", "r", JAVA_ARCHIVE)] + ihooks.Hooks.get_suffixes(self)

    def path_isdir(self, x, archive=None):

        "Return whether 'x' is a directory in the given 'archive'."

        if archive is None:

            return ihooks.Hooks.path_isdir(self, x)

        return self._get_dirname(x) in archive.namelist()

    def _get_dirname(self, x):

        """

        Return the directory name for 'x'.

        In zip files, the presence of "/" seems to indicate a directory.

        """

        if x.endswith("/"):

            return x

        else:

            return x + "/"

    def listdir(self, x, archive=None):

        "Return the contents of the directory 'x' in the given 'archive'."

        if archive is None:

            return ihooks.Hooks.listdir(self, x)

        x = self._get_dirname(x)

        l = []

        for path in archive.namelist():

            # Find out if the path is within the given directory.

            if path != x and path.startswith(x):

                # Get the path below the given directory.

                subpath = path[len(x):]

                # Find out whether the path is an object in the current directory.

                if subpath.count("/") == 0 or subpath.count("/") == 1 and subpath.endswith("/"):

                    l.append(subpath)

        return l

    def matching(self, dir, extension, archive=None):

        """

        Return the matching files in the given directory 'dir' having the given

        'extension' within the given 'archive'. Produce a list containing full

        paths as opposed to simple filenames.

        """

        if archive is None:

            return glob.glob(self.path_join(dir, "*" + extension))

        dir = self._get_dirname(dir)

        l = []

        for path in self.listdir(dir, archive):

            if path.endswith(extension):

                l.append(self.path_join(dir, path))

        return l

    def read(self, filename, archive=None):

        """

        Return the contents of the file with the given 'filename' in the given

        'archive'.

        """

        if archive is None:

            f = open(filename, "rb")

            s = f.read()

            f.close()

            return s

        return archive.read(filename)

class ClassLoader(ihooks.ModuleLoader):

    "A class providing support for searching directories for supported files."

    def find_module(self, name, path=None):

        """

        Find the module with the given 'name', using the given 'path' to locate

        it. Note that ModuleLoader.find_module is almost sufficient, but does

        not provide enough support for "package unions" where the root of a

        package hierarchy may appear in several places.

        Return a list of locations (each being the "stuff" data structure used

        by load_module); this replaces the single "stuff" value or None returned

        by ModuleLoader.find_module.

        """

        if path is None:

            path = [None] + self.default_path()

        found_locations = []

        for dir in path:

            stuff = self.find_module_in_dir(name, dir)

            if stuff:

                found_locations.append(stuff)

        return found_locations

    def find_module_in_dir(self, name, dir, allow_packages=1):

        """

        Find the module with the given 'name' in the given directory 'dir'.

        Since Java packages/modules are directories containing class files,

        return the required information tuple only when the path constructed

        from 'dir' and 'name' refers to a directory containing class files.

        """

        result = ihooks.ModuleLoader.find_module_in_dir(self, name, dir, allow_packages)

        if result is not None:

            return result

        # An archive may be opened.

        archive = None

        # Provide a special name for the current directory.

        if name == "__this__":

            if dir == None:

                return (None, ".", ("", "", JAVA_PACKAGE))

            else:

                return None

        # Where no directory is given, return failure immediately.

        elif dir is None:

            return None

        # Detect archives.

        else:

            archive, archive_path, path = self._get_archive_and_path(dir, name)

        #print "Processing name", name, "in", dir, "producing", path, "within archive", archive

        if self._find_module_at_path(path, archive):

            if archive is not None:

                return (archive, archive_path + ":" + path, (os.extsep + "jar", "r", JAVA_ARCHIVE))

            else:

                return (None, path, ("", "", JAVA_PACKAGE))

        else:

            return None

    def _get_archive_and_path(self, dir, name):

        parts = dir.split(":")

        archive_path = parts[0]

        # Archives may include an internal path, but will in any case have

        # a primary part ending in .jar.

        if archive_path.endswith(os.extsep + "jar"):

            archive = zipfile.ZipFile(archive_path, "r")

            path = self.hooks.path_join(":".join(parts[1:]), name)

        # Otherwise, produce a filesystem-based path.

        else:

            archive = None

            path = self.hooks.path_join(dir, name)

        return archive, archive_path, path

    def _get_path_in_archive(self, path):

        parts = path.split(":")

        if len(parts) == 1:

            return parts[0]

        else:

            return ":".join(parts[1:])

    def _find_module_at_path(self, path, archive):

        if self.hooks.path_isdir(path, archive):

            #print "Looking in", path, "using archive", archive

            # Look for classes in the directory.

            if len(self.hooks.matching(path, os.extsep + "class", archive)) != 0:

                return 1

            # Otherwise permit importing where directories containing classes exist.

            #print "Filenames are", self.hooks.listdir(path, archive)

            for filename in self.hooks.listdir(path, archive):

                pathname = self.hooks.path_join(path, filename)

                result = self._find_module_at_path(pathname, archive)

                if result is not None:

                    return result

        return 0

    def load_module(self, name, stuff):

        """

        Load the module with the given 'name', with a list of 'stuff' items,

        each of which describes the location of the module and is a tuple of the

        form (file, filename, (suffix, mode, data type)).

        Return a module object or raise an ImportError if a problem occurred in

        the import operation.

        Note that the 'stuff' parameter is a list and not a single item as in

        ModuleLoader.load_module. This should still work, however, since the

        find_module method produces such a list.

        """

        # Set up the module.

        # A union of all locations is placed in the module's path.

        module = self.hooks.add_module(name)

        module.__path__ = [item_filename for (item_archive, item_filename, item_info) in stuff]

        # Just go into each package and find the class files.

        for stuff_item in stuff:

            # Extract the details, delegating loading responsibility to the

            # default loader where appropriate.

            # NOTE: Should we not be using some saved loader remembered upon

            # NOTE: installation?

            archive, filename, info = stuff_item

            suffix, mode, datatype = info

            if datatype not in (JAVA_PACKAGE, JAVA_ARCHIVE):

                return ihooks.ModuleLoader.load_module(self, name, stuff_item)

            #print "Loading", archive, filename, info

            # Prepare a dictionary of globals.

            global_names = module.__dict__

            global_names["__builtins__"] = __builtins__

            # Get the real filename.

            filename = self._get_path_in_archive(filename)

            #print "Real filename", filename

            # Load the class files.

            class_files = {}

            for class_filename in self.hooks.matching(filename, os.extsep + "class", archive):

                #print "Loading class", class_filename

                s = self.hooks.read(class_filename, archive)

                class_file = classfile.ClassFile(s)

                class_files[str(class_file.this_class.get_name())] = class_file

            # Get an index of the class files.

            class_file_index = class_files.keys()

            # NOTE: Unnecessary sorting for test purposes.

            class_file_index.sort()

            # Now go through the classes arranging them in a safe loading order.

            position = 0

            while position < len(class_file_index):

                class_name = class_file_index[position]

                super_class_name = str(class_files[class_name].super_class.get_name())

                # Discover whether the superclass appears later.

                try:

                    super_class_position = class_file_index.index(super_class_name)

                    if super_class_position > position:

                        # If the superclass appears later, swap this class and the

                        # superclass, then process the superclass.

                        class_file_index[position] = super_class_name

                        class_file_index[super_class_position] = class_name

                        continue

                except ValueError:

                    pass

                position += 1

            # Process each class file, producing a genuine Python class.

            # Create the classes, but establish a proper initialisation order.

            class_file_init_index = []

            class_file_init = {}

            for class_name in class_file_index:

                #print "* Class", class_name

                class_file = class_files[class_name]

                translator = bytecode.ClassTranslator(class_file)

                cls, external_names = translator.process(global_names)

                module.__dict__[cls.__name__] = cls

                # Process external names.

                this_class_name_parts = class_file.this_class.get_python_name().split(".")

                this_class_module, this_class_name = this_class_name_parts[:-1], this_class_name_parts[-1]

                for external_name in external_names:

                    #print "* Name", external_name

                    external_name_parts = external_name.split(".")

                    external_class_module, external_class_name = external_name_parts[:-1], external_name_parts[-1]

                    # Names not local to this package need importing.

                    if len(external_name_parts) > 1 and this_class_module != external_class_module:

                        external_module_name = ".".join(external_class_module)

                        #print "* Importing", external_module_name

                        obj = __import__(external_module_name, global_names, {}, [])

                        global_names[external_name_parts[0]] = obj

                    # Names local to this package may affect initialisation order.

                    elif external_class_name not in class_file_init_index:

                        try:

                            this_class_name_index = class_file_init_index.index(this_class_name)

                            # Either insert this name before the current class's

                            # name.

                            #print "* Inserting", external_class_name

                            class_file_init_index.insert(this_class_name_index, external_class_name)

                        except ValueError:

                            # Or add this name in anticipation of the current

                            # class's name appearing.

                            #print "* Including", external_class_name

                            class_file_init_index.append(external_class_name)

                # Add this class name to the initialisation index.

                if class_name not in class_file_init_index:

                    class_file_init_index.append(this_class_name)

                class_file_init[this_class_name] = (cls, class_file)

            # Finally, call __clinit__ methods for all relevant classes.

            #print "** Initialisation order", class_file_init_index

            for class_name in class_file_init_index:

                cls, class_file = class_file_init[class_name]

                #print "**", cls, class_file

                if hasattr(cls, "__clinit__"):

                    eval(cls.__clinit__.func_code, global_names)

        return module

ihooks.ModuleImporter(loader=ClassLoader(hooks=ClassHooks())).install()

# vim: tabstop=4 expandtab shiftwidth=4