generate_file() - Code Metrics - Inspection of "Add skip-if-file-exists when doing overwrite-if-ex..." - audreyr/cookiecutter - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#1076)

unknown

created 2018-05-28 16:47 UTC

generate_file() C

↳ Parent: Project

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Metric	Value
cc	7
dl	0
loc	69
rs	5.7452
c	0
b	0
f	0

How to fix Long Method

# -*- coding: utf-8 -*-

"""Functions for generating a project from a project template."""
from __future__ import unicode_literals

import fnmatch
import io
import json
import logging
import os
import shutil
from collections import OrderedDict

from binaryornot.check import is_binary
from jinja2 import FileSystemLoader
from jinja2.exceptions import TemplateSyntaxError, UndefinedError

from .environment import StrictEnvironment
from .exceptions import (
    NonTemplatedInputDirException,
    ContextDecodingException,
    FailedHookException,
    OutputDirExistsException,
    UndefinedVariableInTemplate
)
from .find import find_template
from .hooks import run_hook
from .utils import make_sure_path_exists, work_in, rmtree

logger = logging.getLogger(__name__)


def is_copy_only_path(path, context):
    """Check whether the given `path` should only be copied and not rendered.

    Returns True if `path` matches a pattern in the given `context` dict,
    otherwise False.

    :param path: A file-system path referring to a file or dir that
        should be rendered or just copied.
    :param context: cookiecutter context.
    """
    try:
        for dont_render in context['cookiecutter']['_copy_without_render']:
            if fnmatch.fnmatch(path, dont_render):
                return True
    except KeyError:
        return False

    return False


def apply_overwrites_to_context(context, overwrite_context):
    """Modify the given context in place based on the overwrite_context."""
    for variable, overwrite in overwrite_context.items():
        if variable not in context:
            # Do not include variables which are not used in the template
            continue

        context_value = context[variable]

        if isinstance(context_value, list):
            # We are dealing with a choice variable
            if overwrite in context_value:
                # This overwrite is actually valid for the given context
                # Let's set it as default (by definition first item in list)
                # see ``cookiecutter.prompt.prompt_choice_for_config``
                context_value.remove(overwrite)
                context_value.insert(0, overwrite)
        else:
            # Simply overwrite the value for this variable
            context[variable] = overwrite


def generate_context(context_file='cookiecutter.json', default_context=None,
                     extra_context=None):
    """Generate the context for a Cookiecutter project template.

    Loads the JSON file as a Python object, with key being the JSON filename.

    :param context_file: JSON file containing key/value pairs for populating
        the cookiecutter's variables.
    :param default_context: Dictionary containing config to take into account.
    :param extra_context: Dictionary containing configuration overrides
    """
    context = {}

    try:
        with open(context_file) as file_handle:
            obj = json.load(file_handle, object_pairs_hook=OrderedDict)
    except ValueError as e:
        # JSON decoding error.  Let's throw a new exception that is more
        # friendly for the developer or user.
        full_fpath = os.path.abspath(context_file)
        json_exc_message = str(e)
        our_exc_message = (
            'JSON decoding error while loading "{0}".  Decoding'
            ' error details: "{1}"'.format(full_fpath, json_exc_message))
        raise ContextDecodingException(our_exc_message)

    # Add the Python object to the context dictionary
    file_name = os.path.split(context_file)[1]
    file_stem = file_name.split('.')[0]
    context[file_stem] = obj

    # Overwrite context variable defaults with the default context from the
    # user's global config, if available
    if default_context:
        apply_overwrites_to_context(obj, default_context)
    if extra_context:
        apply_overwrites_to_context(obj, extra_context)

    logger.debug('Context generated is {}'.format(context))
    return context


def generate_file(project_dir, infile, context, env,
                  skip_if_file_exists=False):
    """Render filename of infile as name of outfile, handle infile correctly.

    Dealing with infile appropriately:

        a. If infile is a binary file, copy it over without rendering.
        b. If infile is a text file, render its contents and write the
           rendered infile to outfile.

    Precondition:

        When calling `generate_file()`, the root template dir must be the
        current working directory. Using `utils.work_in()` is the recommended
        way to perform this directory change.

    :param project_dir: Absolute path to the resulting generated project.
    :param infile: Input file to generate the file from. Relative to the root
        template dir.
    :param context: Dict for populating the cookiecutter's variables.
    :param env: Jinja2 template execution environment.
    """
    logger.debug('Processing file {}'.format(infile))

    # Render the path to the output file (not including the root project dir)
    outfile_tmpl = env.from_string(infile)

    outfile = os.path.join(project_dir, outfile_tmpl.render(**context))
    file_name_is_empty = os.path.isdir(outfile)
    if file_name_is_empty:
        logger.debug('The resulting file name is empty: {0}'.format(outfile))
        return

    if skip_if_file_exists and os.path.exists(outfile):
        logger.debug('The resulting file already exists: {0}'.format(outfile))
        return

    logger.debug('Created file at {0}'.format(outfile))

    # Just copy over binary files. Don't render.
    logger.debug("Check {} to see if it's a binary".format(infile))
    if is_binary(infile):
        logger.debug(
            'Copying binary {} to {} without rendering'
            ''.format(infile, outfile)
        )
        shutil.copyfile(infile, outfile)
    else:
        # Force fwd slashes on Windows for get_template
        # This is a by-design Jinja issue
        infile_fwd_slashes = infile.replace(os.path.sep, '/')

        # Render the file
        try:
            tmpl = env.get_template(infile_fwd_slashes)
        except TemplateSyntaxError as exception:
            # Disable translated so that printed exception contains verbose
            # information about syntax error location
            exception.translated = False
            raise
        rendered_file = tmpl.render(**context)

        logger.debug('Writing contents to file {}'.format(outfile))

        with io.open(outfile, 'w', encoding='utf-8') as fh:
            fh.write(rendered_file)

    # Apply file permissions to output file
    shutil.copymode(infile, outfile)


def render_and_create_dir(dirname, context, output_dir, environment,
                          overwrite_if_exists=False,
                          skip_if_file_exists=False):
    """Render name of a directory, create the directory, return its path."""
    name_tmpl = environment.from_string(dirname)
    rendered_dirname = name_tmpl.render(**context)

    dir_to_create = os.path.normpath(
        os.path.join(output_dir, rendered_dirname)
    )

    logger.debug('Rendered dir {} must exist in output_dir {}'.format(
        dir_to_create,
        output_dir
    ))

    output_dir_exists = os.path.exists(dir_to_create)

    if output_dir_exists:
        if overwrite_if_exists:
            logger.debug(
                'Output directory {} already exists,'
                'overwriting it'.format(dir_to_create)
            )
        else:
            msg = 'Error: "{}" directory already exists'.format(dir_to_create)
            raise OutputDirExistsException(msg)
    else:
        make_sure_path_exists(dir_to_create)

    return dir_to_create, not output_dir_exists


def ensure_dir_is_templated(dirname):
    """Ensure that dirname is a templated directory name."""
    if '{{' in dirname and '}}' in dirname:
        return True
    else:
        raise NonTemplatedInputDirException


def _run_hook_from_repo_dir(repo_dir, hook_name, project_dir, context,
                            delete_project_on_failure):
    """Run hook from repo directory, clean project directory if hook fails.

    :param repo_dir: Project template input directory.
    :param hook_name: The hook to execute.
    :param project_dir: The directory to execute the script from.
    :param context: Cookiecutter project context.
    :param delete_project_on_failure: Delete the project directory on hook
        failure?
    """
    with work_in(repo_dir):
        try:
            run_hook(hook_name, project_dir, context)
        except FailedHookException:
            if delete_project_on_failure:
                rmtree(project_dir)
            logger.error(
                "Stopping generation because {} hook "
                "script didn't exit successfully".format(hook_name)
            )
            raise


def generate_files(repo_dir, context=None, output_dir='.',
                   overwrite_if_exists=False, skip_if_file_exists=False):
    """Render the templates and saves them to files.

    :param repo_dir: Project template input directory.
    :param context: Dict for populating the template's variables.
    :param output_dir: Where to output the generated project dir into.
    :param overwrite_if_exists: Overwrite the contents of the output directory
        if it exists.
    """
    template_dir = find_template(repo_dir)
    logger.debug('Generating project from {}...'.format(template_dir))
    context = context or {}

    unrendered_dir = os.path.split(template_dir)[1]
    ensure_dir_is_templated(unrendered_dir)
    env = StrictEnvironment(
        context=context,
        keep_trailing_newline=True,
    )
    try:
        project_dir, output_directory_created = render_and_create_dir(
            unrendered_dir,
            context,
            output_dir,
            env,
            overwrite_if_exists,
            skip_if_file_exists
        )
    except UndefinedError as err:
        msg = "Unable to create project directory '{}'".format(unrendered_dir)
        raise UndefinedVariableInTemplate(msg, err, context)

    # We want the Jinja path and the OS paths to match. Consequently, we'll:
    #   + CD to the template folder
    #   + Set Jinja's path to '.'
    #
    #  In order to build our files to the correct folder(s), we'll use an
    # absolute path for the target folder (project_dir)

    project_dir = os.path.abspath(project_dir)
    logger.debug('Project directory is {}'.format(project_dir))

    # if we created the output directory, then it's ok to remove it
    # if rendering fails
    delete_project_on_failure = output_directory_created

    _run_hook_from_repo_dir(
        repo_dir,
        'pre_gen_project',
        project_dir,
        context,
        delete_project_on_failure
    )

    with work_in(template_dir):
        env.loader = FileSystemLoader('.')

        for root, dirs, files in os.walk('.'):
            # We must separate the two types of dirs into different lists.
            # The reason is that we don't want ``os.walk`` to go through the
            # unrendered directories, since they will just be copied.
            copy_dirs = []
            render_dirs = []

            for d in dirs:
                d_ = os.path.normpath(os.path.join(root, d))
                # We check the full path, because that's how it can be
                # specified in the ``_copy_without_render`` setting, but
                # we store just the dir name
                if is_copy_only_path(d_, context):
                    copy_dirs.append(d)
                else:
                    render_dirs.append(d)

            for copy_dir in copy_dirs:
                indir = os.path.normpath(os.path.join(root, copy_dir))
                outdir = os.path.normpath(os.path.join(project_dir, indir))
                logger.debug(
                    'Copying dir {} to {} without rendering'
                    ''.format(indir, outdir)
                )
                shutil.copytree(indir, outdir)

            # We mutate ``dirs``, because we only want to go through these dirs
            # recursively
            dirs[:] = render_dirs
            for d in dirs:
                unrendered_dir = os.path.join(project_dir, root, d)
                try:
                    render_and_create_dir(
                        unrendered_dir,
                        context,
                        output_dir,
                        env,
                        overwrite_if_exists,
                        skip_if_file_exists
                    )
                except UndefinedError as err:
                    if delete_project_on_failure:
                        rmtree(project_dir)
                    _dir = os.path.relpath(unrendered_dir, output_dir)
                    msg = "Unable to create directory '{}'".format(_dir)
                    raise UndefinedVariableInTemplate(msg, err, context)

            for f in files:
                infile = os.path.normpath(os.path.join(root, f))
                if is_copy_only_path(infile, context):
                    outfile_tmpl = env.from_string(infile)
                    outfile_rendered = outfile_tmpl.render(**context)
                    outfile = os.path.join(project_dir, outfile_rendered)
                    logger.debug(
                        'Copying file {} to {} without rendering'
                        ''.format(infile, outfile)
                    )
                    shutil.copyfile(infile, outfile)
                    shutil.copymode(infile, outfile)
                    continue
                try:
                    generate_file(project_dir, infile, context, env,
                                  skip_if_file_exists)
                except UndefinedError as err:
                    if delete_project_on_failure:
                        rmtree(project_dir)
                    msg = "Unable to create file '{}'".format(infile)
                    raise UndefinedVariableInTemplate(msg, err, context)

    _run_hook_from_repo_dir(
        repo_dir,
        'post_gen_project',
        project_dir,
        context,
        delete_project_on_failure
    )

    return project_dir


1			# -- coding: utf-8 --
2
3			"""Functions for generating a project from a project template."""
4			from __future__ import unicode_literals
5
6			import fnmatch
7			import io
8			import json
9			import logging
10			import os
11			import shutil
12			from collections import OrderedDict
13
14			from binaryornot.check import is_binary
15			from jinja2 import FileSystemLoader
16			from jinja2.exceptions import TemplateSyntaxError, UndefinedError
17
18			from .environment import StrictEnvironment
19			from .exceptions import (
20			NonTemplatedInputDirException,
21			ContextDecodingException,
22			FailedHookException,
23			OutputDirExistsException,
24			UndefinedVariableInTemplate
25			)
26			from .find import find_template
27			from .hooks import run_hook
28			from .utils import make_sure_path_exists, work_in, rmtree
29
30			logger = logging.getLogger(__name__)
31
32
33			def is_copy_only_path(path, context):
34			"""Check whether the given `path` should only be copied and not rendered.
35
36			Returns True if `path` matches a pattern in the given `context` dict,
37			otherwise False.
38
39			:param path: A file-system path referring to a file or dir that
40			should be rendered or just copied.
41			:param context: cookiecutter context.
42			"""
43			try:
44			for dont_render in context['cookiecutter']['_copy_without_render']:
45			if fnmatch.fnmatch(path, dont_render):
46			return True
47			except KeyError:
48			return False
49
50			return False
51
52
53			def apply_overwrites_to_context(context, overwrite_context):
54			"""Modify the given context in place based on the overwrite_context."""
55			for variable, overwrite in overwrite_context.items():
56			if variable not in context:
57			# Do not include variables which are not used in the template
58			continue
59
60			context_value = context[variable]
61
62			if isinstance(context_value, list):
63			# We are dealing with a choice variable
64			if overwrite in context_value:
65			# This overwrite is actually valid for the given context
66			# Let's set it as default (by definition first item in list)
67			# see ``cookiecutter.prompt.prompt_choice_for_config``
68			context_value.remove(overwrite)
69			context_value.insert(0, overwrite)
70			else:
71			# Simply overwrite the value for this variable
72			context[variable] = overwrite
73
74
75			def generate_context(context_file='cookiecutter.json', default_context=None,
76			extra_context=None):
77			"""Generate the context for a Cookiecutter project template.
78
79			Loads the JSON file as a Python object, with key being the JSON filename.
80
81			:param context_file: JSON file containing key/value pairs for populating
82			the cookiecutter's variables.
83			:param default_context: Dictionary containing config to take into account.
84			:param extra_context: Dictionary containing configuration overrides
85			"""
86			context = {}
87
88			try:
89			with open(context_file) as file_handle:
90			obj = json.load(file_handle, object_pairs_hook=OrderedDict)
91			except ValueError as e:
92			# JSON decoding error. Let's throw a new exception that is more
93			# friendly for the developer or user.
94			full_fpath = os.path.abspath(context_file)
95			json_exc_message = str(e)
96			our_exc_message = (
97			'JSON decoding error while loading "{0}". Decoding'
98			' error details: "{1}"'.format(full_fpath, json_exc_message))
99			raise ContextDecodingException(our_exc_message)
100
101			# Add the Python object to the context dictionary
102			file_name = os.path.split(context_file)[1]
103			file_stem = file_name.split('.')[0]
104			context[file_stem] = obj
105
106			# Overwrite context variable defaults with the default context from the
107			# user's global config, if available
108			if default_context:
109			apply_overwrites_to_context(obj, default_context)
110			if extra_context:
111			apply_overwrites_to_context(obj, extra_context)
112
113			logger.debug('Context generated is {}'.format(context))
114			return context
115
116
117			def generate_file(project_dir, infile, context, env,
118			skip_if_file_exists=False):
119			"""Render filename of infile as name of outfile, handle infile correctly.
120
121			Dealing with infile appropriately:
122
123			a. If infile is a binary file, copy it over without rendering.
124			b. If infile is a text file, render its contents and write the
125			rendered infile to outfile.
126
127			Precondition:
128
129			When calling `generate_file()`, the root template dir must be the
130			current working directory. Using `utils.work_in()` is the recommended
131			way to perform this directory change.
132
133			:param project_dir: Absolute path to the resulting generated project.
134			:param infile: Input file to generate the file from. Relative to the root
135			template dir.
136			:param context: Dict for populating the cookiecutter's variables.
137			:param env: Jinja2 template execution environment.
138			"""
139			logger.debug('Processing file {}'.format(infile))
140
141			# Render the path to the output file (not including the root project dir)
142			outfile_tmpl = env.from_string(infile)
143
144			outfile = os.path.join(project_dir, outfile_tmpl.render(**context))
145			file_name_is_empty = os.path.isdir(outfile)
146			if file_name_is_empty:
147			logger.debug('The resulting file name is empty: {0}'.format(outfile))
148			return
149
150			if skip_if_file_exists and os.path.exists(outfile):
151			logger.debug('The resulting file already exists: {0}'.format(outfile))
152			return
153
154			logger.debug('Created file at {0}'.format(outfile))
155
156			# Just copy over binary files. Don't render.
157			logger.debug("Check {} to see if it's a binary".format(infile))
158			if is_binary(infile):
159			logger.debug(
160			'Copying binary {} to {} without rendering'
161			''.format(infile, outfile)
162			)
163			shutil.copyfile(infile, outfile)
164			else:
165			# Force fwd slashes on Windows for get_template
166			# This is a by-design Jinja issue
167			infile_fwd_slashes = infile.replace(os.path.sep, '/')
168
169			# Render the file
170			try:
171			tmpl = env.get_template(infile_fwd_slashes)
172			except TemplateSyntaxError as exception:
173			# Disable translated so that printed exception contains verbose
174			# information about syntax error location
175			exception.translated = False
176			raise
177			rendered_file = tmpl.render(**context)
178
179			logger.debug('Writing contents to file {}'.format(outfile))
180
181			with io.open(outfile, 'w', encoding='utf-8') as fh:
182			fh.write(rendered_file)
183
184			# Apply file permissions to output file
185			shutil.copymode(infile, outfile)
186
187
188			def render_and_create_dir(dirname, context, output_dir, environment,
189			overwrite_if_exists=False,
190			skip_if_file_exists=False):
191			"""Render name of a directory, create the directory, return its path."""
192			name_tmpl = environment.from_string(dirname)
193			rendered_dirname = name_tmpl.render(**context)
194
195			dir_to_create = os.path.normpath(
196			os.path.join(output_dir, rendered_dirname)
197			)
198
199			logger.debug('Rendered dir {} must exist in output_dir {}'.format(
200			dir_to_create,
201			output_dir
202			))
203
204			output_dir_exists = os.path.exists(dir_to_create)
205
206			if output_dir_exists:
207			if overwrite_if_exists:
208			logger.debug(
209			'Output directory {} already exists,'
210			'overwriting it'.format(dir_to_create)
211			)
212			else:
213			msg = 'Error: "{}" directory already exists'.format(dir_to_create)
214			raise OutputDirExistsException(msg)
215			else:
216			make_sure_path_exists(dir_to_create)
217
218			return dir_to_create, not output_dir_exists
219
220
221			def ensure_dir_is_templated(dirname):
222			"""Ensure that dirname is a templated directory name."""
223			if '{{' in dirname and '}}' in dirname:
224			return True
225			else:
226			raise NonTemplatedInputDirException
227
228
229			def _run_hook_from_repo_dir(repo_dir, hook_name, project_dir, context,
230			delete_project_on_failure):
231			"""Run hook from repo directory, clean project directory if hook fails.
232
233			:param repo_dir: Project template input directory.
234			:param hook_name: The hook to execute.
235			:param project_dir: The directory to execute the script from.
236			:param context: Cookiecutter project context.
237			:param delete_project_on_failure: Delete the project directory on hook
238			failure?
239			"""
240			with work_in(repo_dir):
241			try:
242			run_hook(hook_name, project_dir, context)
243			except FailedHookException:
244			if delete_project_on_failure:
245			rmtree(project_dir)
246			logger.error(
247			"Stopping generation because {} hook "
248			"script didn't exit successfully".format(hook_name)
249			)
250			raise
251
252
253			def generate_files(repo_dir, context=None, output_dir='.',
254			overwrite_if_exists=False, skip_if_file_exists=False):
255			"""Render the templates and saves them to files.
256
257			:param repo_dir: Project template input directory.
258			:param context: Dict for populating the template's variables.
259			:param output_dir: Where to output the generated project dir into.
260			:param overwrite_if_exists: Overwrite the contents of the output directory
261			if it exists.
262			"""
263			template_dir = find_template(repo_dir)
264			logger.debug('Generating project from {}...'.format(template_dir))
265			context = context or {}
266
267			unrendered_dir = os.path.split(template_dir)[1]
268			ensure_dir_is_templated(unrendered_dir)
269			env = StrictEnvironment(
270			context=context,
271			keep_trailing_newline=True,
272			)
273			try:
274			project_dir, output_directory_created = render_and_create_dir(
275			unrendered_dir,
276			context,
277			output_dir,
278			env,
279			overwrite_if_exists,
280			skip_if_file_exists
281			)
282			except UndefinedError as err:
283			msg = "Unable to create project directory '{}'".format(unrendered_dir)
284			raise UndefinedVariableInTemplate(msg, err, context)
285
286			# We want the Jinja path and the OS paths to match. Consequently, we'll:
287			# + CD to the template folder
288			# + Set Jinja's path to '.'
289			#
290			# In order to build our files to the correct folder(s), we'll use an
291			# absolute path for the target folder (project_dir)
292
293			project_dir = os.path.abspath(project_dir)
294			logger.debug('Project directory is {}'.format(project_dir))
295
296			# if we created the output directory, then it's ok to remove it
297			# if rendering fails
298			delete_project_on_failure = output_directory_created
299
300			_run_hook_from_repo_dir(
301			repo_dir,
302			'pre_gen_project',
303			project_dir,
304			context,
305			delete_project_on_failure
306			)
307
308			with work_in(template_dir):
309			env.loader = FileSystemLoader('.')
310
311			for root, dirs, files in os.walk('.'):
312			# We must separate the two types of dirs into different lists.
313			# The reason is that we don't want ``os.walk`` to go through the
314			# unrendered directories, since they will just be copied.
315			copy_dirs = []
316			render_dirs = []
317
318			for d in dirs:
319			d_ = os.path.normpath(os.path.join(root, d))
320			# We check the full path, because that's how it can be
321			# specified in the ``_copy_without_render`` setting, but
322			# we store just the dir name
323			if is_copy_only_path(d_, context):
324			copy_dirs.append(d)
325			else:
326			render_dirs.append(d)
327
328			for copy_dir in copy_dirs:
329			indir = os.path.normpath(os.path.join(root, copy_dir))
330			outdir = os.path.normpath(os.path.join(project_dir, indir))
331			logger.debug(
332			'Copying dir {} to {} without rendering'
333			''.format(indir, outdir)
334			)
335			shutil.copytree(indir, outdir)
336
337			# We mutate ``dirs``, because we only want to go through these dirs
338			# recursively
339			dirs[:] = render_dirs
340			for d in dirs:
341			unrendered_dir = os.path.join(project_dir, root, d)
342			try:
343			render_and_create_dir(
344			unrendered_dir,
345			context,
346			output_dir,
347			env,
348			overwrite_if_exists,
349			skip_if_file_exists
350			)
351			except UndefinedError as err:
352			if delete_project_on_failure:
353			rmtree(project_dir)
354			_dir = os.path.relpath(unrendered_dir, output_dir)
355			msg = "Unable to create directory '{}'".format(_dir)
356			raise UndefinedVariableInTemplate(msg, err, context)
357
358			for f in files:
359			infile = os.path.normpath(os.path.join(root, f))
360			if is_copy_only_path(infile, context):
361			outfile_tmpl = env.from_string(infile)
362			outfile_rendered = outfile_tmpl.render(**context)
363			outfile = os.path.join(project_dir, outfile_rendered)
364			logger.debug(
365			'Copying file {} to {} without rendering'
366			''.format(infile, outfile)
367			)
368			shutil.copyfile(infile, outfile)
369			shutil.copymode(infile, outfile)
370			continue
371			try:
372			generate_file(project_dir, infile, context, env,
373			skip_if_file_exists)
374			except UndefinedError as err:
375			if delete_project_on_failure:
376			rmtree(project_dir)
377			msg = "Unable to create file '{}'".format(infile)
378			raise UndefinedVariableInTemplate(msg, err, context)
379
380			_run_hook_from_repo_dir(
381			repo_dir,
382			'post_gen_project',
383			project_dir,
384			context,
385			delete_project_on_failure
386			)
387
388			return project_dir
389

audreyr / cookiecutter

Pull Request — master (#1076)

generate_file() C

Complexity

Size

Duplication

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How to fix Long Method

Long Method

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