"""The code in this module is mostly copy/pasted out of the distutils2 source
code, as recommended by Tarek Ziade.  As such, it may be subject to some change
as distutils2 development continues, and will have to be kept up to date.

I didn't want to use it directly from distutils2 itself, since I do not want it
to be an installation dependency for our packages yet--it is still too unstable
(the latest version on PyPI doesn't even install).
"""

# These first two imports are not used, but are needed to get around an
# irritating Python bug that can crop up when using ./setup.py test.
# See: http://www.eby-sarna.com/pipermail/peak/2010-May/003355.html
try:
    import multiprocessing
except ImportError:
    pass
import logging

import os
import re
import sys
import traceback

from collections import defaultdict

import distutils.ccompiler

from distutils import log
from distutils.errors import (DistutilsOptionError, DistutilsModuleError,
                              DistutilsFileError)
from setuptools.command.egg_info import manifest_maker
from setuptools.dist import Distribution
from setuptools.extension import Extension

from .extern.six import moves as m
RawConfigParser = m.configparser.RawConfigParser


# A simplified RE for this; just checks that the line ends with version
# predicates in ()
_VERSION_SPEC_RE = re.compile(r'\s*(.*?)\s*\((.*)\)\s*$')


# Mappings from setup() keyword arguments to setup.cfg options;
# The values are (section, option) tuples, or simply (section,) tuples if
# the option has the same name as the setup() argument
D1_D2_SETUP_ARGS = {
    "name": ("metadata",),
    "version": ("metadata",),
    "author": ("metadata",),
    "author_email": ("metadata",),
    "maintainer": ("metadata",),
    "maintainer_email": ("metadata",),
    "url": ("metadata", "home_page"),
    "description": ("metadata", "summary"),
    "keywords": ("metadata",),
    "long_description": ("metadata", "description"),
    "download-url": ("metadata",),
    "classifiers": ("metadata", "classifier"),
    "platforms": ("metadata", "platform"),  # **
    "license": ("metadata",),
    # Use setuptools install_requires, not
    # broken distutils requires
    "install_requires": ("metadata", "requires_dist"),
    "setup_requires": ("metadata", "setup_requires_dist"),
    "provides": ("metadata", "provides_dist"),  # **
    "obsoletes": ("metadata", "obsoletes_dist"),  # **
    "package_dir": ("files", 'packages_root'),
    "packages": ("files",),
    "package_data": ("files",),
    "data_files": ("files",),
    "scripts": ("files",),
    "py_modules": ("files", "modules"),   # **
    "cmdclass": ("global", "commands"),
    # Not supported in distutils2, but provided for
    # backwards compatibility with setuptools
    "use_2to3": ("backwards_compat", "use_2to3"),
    "zip_safe": ("backwards_compat", "zip_safe"),
    "tests_require": ("backwards_compat", "tests_require"),
    "dependency_links": ("backwards_compat",),
    "include_package_data": ("backwards_compat",),
}

# setup() arguments that can have multiple values in setup.cfg
MULTI_FIELDS = ("classifiers",
                "platforms",
                "install_requires",
                "provides",
                "obsoletes",
                "packages",
                "package_data",
                "data_files",
                "scripts",
                "py_modules",
                "dependency_links",
                "setup_requires",
                "tests_require",
                "cmdclass")

# setup() arguments that contain boolean values
BOOL_FIELDS = ("use_2to3", "zip_safe", "include_package_data")


CSV_FIELDS = ("keywords",)


log.set_verbosity(log.INFO)


def resolve_name(name):
    """Resolve a name like ``module.object`` to an object and return it.

    Raise ImportError if the module or name is not found.
    """

    parts = name.split('.')
    cursor = len(parts) - 1
    module_name = parts[:cursor]
    attr_name = parts[-1]

    while cursor > 0:
        try:
            ret = __import__('.'.join(module_name), fromlist=[attr_name])
            break
        except ImportError:
            if cursor == 0:
                raise
            cursor -= 1
            module_name = parts[:cursor]
            attr_name = parts[cursor]
            ret = ''

    for part in parts[cursor:]:
        try:
            ret = getattr(ret, part)
        except AttributeError:
            raise ImportError(name)

    return ret


def cfg_to_args(path='setup.cfg'):
    """ Distutils2 to distutils1 compatibility util.

        This method uses an existing setup.cfg to generate a dictionary of
        keywords that can be used by distutils.core.setup(kwargs**).

        :param file:
            The setup.cfg path.
        :raises DistutilsFileError:
            When the setup.cfg file is not found.

    """

    # The method source code really starts here.
    parser = RawConfigParser()
    if not os.path.exists(path):
        raise DistutilsFileError("file '%s' does not exist" %
                                 os.path.abspath(path))
    parser.read(path)
    config = {}
    for section in parser.sections():
        config[section] = dict(parser.items(section))

    # Run setup_hooks, if configured
    setup_hooks = has_get_option(config, 'global', 'setup_hooks')
    package_dir = has_get_option(config, 'files', 'packages_root')

    # Add the source package directory to sys.path in case it contains
    # additional hooks, and to make sure it's on the path before any existing
    # installations of the package
    if package_dir:
        package_dir = os.path.abspath(package_dir)
        sys.path.insert(0, package_dir)

    try:
        if setup_hooks:
            setup_hooks = split_multiline(setup_hooks)
            for hook in setup_hooks:
                hook_fn = resolve_name(hook)
                try :
                    hook_fn(config)
                except SystemExit:
                    log.error('setup hook %s terminated the installation')
                except:
                    e = sys.exc_info()[1]
                    log.error('setup hook %s raised exception: %s\n' %
                              (hook, e))
                    log.error(traceback.format_exc())
                    sys.exit(1)

        kwargs = setup_cfg_to_setup_kwargs(config)

        register_custom_compilers(config)

        ext_modules = get_extension_modules(config)
        if ext_modules:
            kwargs['ext_modules'] = ext_modules

        entry_points = get_entry_points(config)
        if entry_points:
            kwargs['entry_points'] = entry_points

        wrap_commands(kwargs)

        # Handle the [files]/extra_files option
        extra_files = has_get_option(config, 'files', 'extra_files')
        if extra_files:
            extra_files = split_multiline(extra_files)
            # Let's do a sanity check
            for filename in extra_files:
                if not os.path.exists(filename):
                    raise DistutilsFileError(
                        '%s from the extra_files option in setup.cfg does not '
                        'exist' % filename)
            # Unfortunately the only really sensible way to do this is to
            # monkey-patch the manifest_maker class
            @monkeypatch_method(manifest_maker)
            def add_defaults(self, extra_files=extra_files, log=log):
                log.info('[d2to1] running patched manifest_maker command '
                          'with extra_files support')
                add_defaults._orig(self)
                self.filelist.extend(extra_files)

    finally:
        # Perform cleanup if any paths were added to sys.path
        if package_dir:
            sys.path.pop(0)

    return kwargs


def setup_cfg_to_setup_kwargs(config):
    """Processes the setup.cfg options and converts them to arguments accepted
    by setuptools' setup() function.
    """

    kwargs = {}

    for arg in D1_D2_SETUP_ARGS:
        if len(D1_D2_SETUP_ARGS[arg]) == 2:
            # The distutils field name is different than distutils2's.
            section, option = D1_D2_SETUP_ARGS[arg]

        elif len(D1_D2_SETUP_ARGS[arg]) == 1:
            # The distutils field name is the same thant distutils2's.
            section = D1_D2_SETUP_ARGS[arg][0]
            option = arg

        in_cfg_value = has_get_option(config, section, option)
        if not in_cfg_value:
            # There is no such option in the setup.cfg
            if arg == "long_description":
                in_cfg_value = has_get_option(config, section,
                                              "description_file")
                if in_cfg_value:
                    in_cfg_value = split_multiline(in_cfg_value)
                    value = ''
                    for filename in in_cfg_value:
                        description_file = open(filename)
                        try:
                            value += description_file.read().strip() + '\n\n'
                        finally:
                            description_file.close()
                    in_cfg_value = value
            else:
                continue

        if arg in CSV_FIELDS:
            in_cfg_value = split_csv(in_cfg_value)
        if arg in MULTI_FIELDS:
            in_cfg_value = split_multiline(in_cfg_value)
        elif arg in BOOL_FIELDS:
            # Provide some flexibility here...
            if in_cfg_value.lower() in ('true', 't', '1', 'yes', 'y'):
                in_cfg_value = True
            else:
                in_cfg_value = False

        if in_cfg_value:
            if arg in ('install_requires', 'tests_require'):
                # Replaces PEP345-style version specs with the sort expected by
                # setuptools
                in_cfg_value = [_VERSION_SPEC_RE.sub(r'\1\2', pred)
                                for pred in in_cfg_value]
            elif arg == 'package_dir':
                in_cfg_value = {'': in_cfg_value}
            elif arg in ('package_data', 'data_files'):
                data_files = {}
                firstline = True
                prev = None
                for line in in_cfg_value:
                    if '=' in line:
                        key, value = line.split('=', 1)
                        key, value = (key.strip(), value.strip())
                        if key in data_files:
                            # Multiple duplicates of the same package name;
                            # this is for backwards compatibility of the old
                            # format prior to d2to1 0.2.6.
                            prev = data_files[key]
                            prev.extend(value.split())
                        else:
                            prev = data_files[key.strip()] = value.split()
                    elif firstline:
                        raise DistutilsOptionError(
                            'malformed package_data first line %r (misses '
                            '"=")' % line)
                    else:
                        prev.extend(line.strip().split())
                    firstline = False
                if arg == 'data_files':
                    # the data_files value is a pointlessly different structure
                    # from the package_data value
                    data_files = list(data_files.items())
                in_cfg_value = data_files
            elif arg == 'cmdclass':
                cmdclass = {}
                dist = Distribution()
                for cls in in_cfg_value:
                    cls = resolve_name(cls)
                    cmd = cls(dist)
                    cmdclass[cmd.get_command_name()] = cls
                in_cfg_value = cmdclass

        kwargs[arg] = in_cfg_value

    return kwargs


def register_custom_compilers(config):
    """Handle custom compilers; this has no real equivalent in distutils, where
    additional compilers could only be added programmatically, so we have to
    hack it in somehow.
    """

    compilers = has_get_option(config, 'global', 'compilers')
    if compilers:
        compilers = split_multiline(compilers)
        for compiler in compilers:
            compiler = resolve_name(compiler)

            # In distutils2 compilers these class attributes exist; for
            # distutils1 we just have to make something up
            if hasattr(compiler, 'name'):
                name = compiler.name
            else:
                name = compiler.__name__
            if hasattr(compiler, 'description'):
                desc = compiler.description
            else:
                desc = 'custom compiler %s' % name

            module_name = compiler.__module__
            # Note; this *will* override built in compilers with the same name
            # TODO: Maybe display a warning about this?
            cc = distutils.ccompiler.compiler_class
            cc[name] = (module_name, compiler.__name__, desc)

            # HACK!!!!  Distutils assumes all compiler modules are in the
            # distutils package
            sys.modules['distutils.' + module_name] = sys.modules[module_name]


def get_extension_modules(config):
    """Handle extension modules"""

    EXTENSION_FIELDS = ("sources",
                        "include_dirs",
                        "define_macros",
                        "undef_macros",
                        "library_dirs",
                        "libraries",
                        "runtime_library_dirs",
                        "extra_objects",
                        "extra_compile_args",
                        "extra_link_args",
                        "export_symbols",
                        "swig_opts",
                        "depends")

    ext_modules = []
    for section in config:
        if ':' in section:
            labels = section.split(':', 1)
        else:
            # Backwards compatibility for old syntax; don't use this though
            labels = section.split('=', 1)
        labels = [l.strip() for l in labels]
        if (len(labels) == 2) and (labels[0] == 'extension'):
            ext_args = {}
            for field in EXTENSION_FIELDS:
                value = has_get_option(config, section, field)
                # All extension module options besides name can have multiple
                # values
                if not value:
                    continue
                value = split_multiline(value)
                if field == 'define_macros':
                    macros = []
                    for macro in value:
                        macro = macro.split('=', 1)
                        if len(macro) == 1:
                            macro = (macro[0].strip(), None)
                        else:
                            macro = (macro[0].strip(), macro[1].strip())
                        macros.append(macro)
                    value = macros
                ext_args[field] = value
            if ext_args:
                if 'name' not in ext_args:
                    ext_args['name'] = labels[1]
                ext_modules.append(Extension(ext_args.pop('name'),
                                             **ext_args))
    return ext_modules


def get_entry_points(config):
    """Process the [entry_points] section of setup.cfg to handle setuptools
    entry points.  This is, of course, not a standard feature of
    distutils2/packaging, but as there is not currently a standard alternative
    in packaging, we provide support for them.
    """

    if not 'entry_points' in config:
        return {}

    return dict((option, split_multiline(value))
                for option, value in config['entry_points'].items())


def wrap_commands(kwargs):
    dist = Distribution()

    # This should suffice to get the same config values and command classes
    # that the actual Distribution will see (not counting cmdclass, which is
    # handled below)
    dist.parse_config_files()

    for cmd, _ in dist.get_command_list():
        hooks = {}
        for opt, val in dist.get_option_dict(cmd).items():
            val = val[1]
            if opt.startswith('pre_hook.') or opt.startswith('post_hook.'):
                hook_type, alias = opt.split('.', 1)
                hook_dict = hooks.setdefault(hook_type, {})
                hook_dict[alias] = val
        if not hooks:
            continue

        if 'cmdclass' in kwargs and cmd in kwargs['cmdclass']:
            cmdclass = kwargs['cmdclass'][cmd]
        else:
            cmdclass = dist.get_command_class(cmd)

        new_cmdclass = wrap_command(cmd, cmdclass, hooks)
        kwargs.setdefault('cmdclass', {})[cmd] = new_cmdclass


def wrap_command(cmd, cmdclass, hooks):
    def run(self, cmdclass=cmdclass):
        self.run_command_hooks('pre_hook')
        cmdclass.run(self)
        self.run_command_hooks('post_hook')

    return type(cmd, (cmdclass, object),
                {'run': run, 'run_command_hooks': run_command_hooks,
                 'pre_hook': hooks.get('pre_hook'),
                 'post_hook': hooks.get('post_hook')})


def run_command_hooks(cmd_obj, hook_kind):
    """Run hooks registered for that command and phase.

    *cmd_obj* is a finalized command object; *hook_kind* is either
    'pre_hook' or 'post_hook'.
    """

    if hook_kind not in ('pre_hook', 'post_hook'):
        raise ValueError('invalid hook kind: %r' % hook_kind)

    hooks = getattr(cmd_obj, hook_kind, None)

    if hooks is None:
        return

    for hook in hooks.values():
        if isinstance(hook, str):
            try:
                hook_obj = resolve_name(hook)
            except ImportError:
                err = sys.exc_info()[1] # For py3k
                raise DistutilsModuleError('cannot find hook %s: %s' %
                                           (hook,err))
        else:
            hook_obj = hook

        if not hasattr(hook_obj, '__call__'):
            raise DistutilsOptionError('hook %r is not callable' % hook)

        log.info('running %s %s for command %s',
                 hook_kind, hook, cmd_obj.get_command_name())

        try :
            hook_obj(cmd_obj)
        except:
            e = sys.exc_info()[1]
            log.error('hook %s raised exception: %s\n' % (hook, e))
            log.error(traceback.format_exc())
            sys.exit(1)


def has_get_option(config, section, option):
    if section in config and option in config[section]:
        return config[section][option]
    elif section in config and option.replace('_', '-') in config[section]:
        return config[section][option.replace('_', '-')]
    else:
        return False


def split_multiline(value):
    """Special behaviour when we have a multi line options"""

    value = [element for element in
             (line.strip() for line in value.split('\n'))
             if element]
    return value


def split_csv(value):
    """Special behaviour when we have a comma separated options"""

    value = [element for element in
             (chunk.strip() for chunk in value.split(','))
             if element]
    return value


def monkeypatch_method(cls):
    """A function decorator to monkey-patch a method of the same name on the
    given class.
    """

    def wrapper(func):
        orig = getattr(cls, func.__name__, None)
        if orig and not hasattr(orig, '_orig'):  # Already patched
            setattr(func, '_orig', orig)
            setattr(cls, func.__name__, func)
        return func

    return wrapper


# The following classes are used to hack Distribution.command_options a bit
class DefaultGetDict(defaultdict):
    """Like defaultdict, but the get() method also sets and returns the default
    value.
    """

    def get(self, key, default=None):
        if default is None:
            default = self.default_factory()
        return super(DefaultGetDict, self).setdefault(key, default)


class IgnoreDict(dict):
    """A dictionary that ignores any insertions in which the key is a string
    matching any string in `ignore`.  The ignore list can also contain wildcard
    patterns using '*'.
    """

    def __init__(self, ignore):
        self.__ignore = re.compile(r'(%s)' % ('|'.join(
                                   [pat.replace('*', '.*')
                                    for pat in ignore])))

    def __setitem__(self, key, val):
        if self.__ignore.match(key):
            return
        super(IgnoreDict, self).__setitem__(key, val)
