# MIT License
#
# Copyright The SCons Foundation
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

import os 

import SCons.Node
import SCons.Node.FS
import SCons.Scanner
import SCons.Util


def _subst_libs(env, libs):
    """
    Substitute environment variables and split into list.
    """
    if SCons.Util.is_String(libs):
        libs = env.subst(libs)
        if SCons.Util.is_String(libs):
            libs = libs.split()
    elif SCons.Util.is_Sequence(libs):
        _libs = []
        for lib in libs:
            _libs += _subst_libs(env, lib)
        libs = _libs
    else:
        # libs is an object (Node, for example)
        libs = [libs]
    return libs


def _collect_classes(list, dirname, files):
    for fname in files:
        if os.path.splitext(fname)[1] == ".class":
            list.append(os.path.join(str(dirname), fname))


def scan(node, env, libpath=()):
    """Scan for files on the JAVACLASSPATH.

    The classpath can contain:
     - Explicit paths to JAR/Zip files
     - Wildcards (*)
     - Directories which contain classes in an unnamed package
     - Parent directories of the root package for classes in a named package

     Class path entries that are neither directories nor archives (.zip or JAR files) nor the asterisk (*) wildcard character are ignored.
     """
    classpath = env.get('JAVACLASSPATH', [])
    classpath = _subst_libs(env, classpath)

    result = []
    for path in classpath:
        if SCons.Util.is_String(path) and "*" in path:
            libs = env.Glob(path)
        else:
            libs = [path]

        for lib in libs:
            if os.path.isdir(str(lib)):
                # grab the in-memory nodes
                env.Dir(lib).walk(_collect_classes, result)
                # now the on-disk ones
                for root, dirs, files in os.walk(str(lib)):
                    _collect_classes(result, root, files)
            else:
                result.append(lib)

    return list(filter(lambda x: os.path.splitext(str(x))[1] in [".class", ".zip", ".jar"], result))


def JavaScanner():
    return SCons.Scanner.Base(scan, 'JavaScanner',
                              skeys=['.java'])

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