"""

Main program for 2to3.

"""

from __future__ import with_statement, print_function

import sys

import os

import difflib

import logging

import shutil

import optparse

from . import refactor

def diff_texts(a, b, filename):

"""Return a unified diff of two strings."""

a = a.splitlines()

b = b.splitlines()

return difflib.unified_diff(a, b, filename, filename,

"(original)", "(refactored)",

lineterm="")

class StdoutRefactoringTool(refactor.MultiprocessRefactoringTool):

"""

A refactoring tool that can avoid overwriting its input files.

Prints output to stdout.

Output files can optionally be written to a different directory and or

have an extra file suffix appended to their name for use in situations

where you do not want to replace the input files.

"""

def __init__(self, fixers, options, explicit, nobackups, show_diffs,

input_base_dir='', output_dir='', append_suffix=''):

"""

Args:

fixers: A list of fixers to import.

options: A dict with RefactoringTool configuration.

explicit: A list of fixers to run even if they are explicit.

nobackups: If true no backup '.bak' files will be created for those

files that are being refactored.

show_diffs: Should diffs of the refactoring be printed to stdout?

input_base_dir: The base directory for all input files. This class

will strip this path prefix off of filenames before substituting

it with output_dir. Only meaningful if output_dir is supplied.

All files processed by refactor() must start with this path.

output_dir: If supplied, all converted files will be written into

this directory tree instead of input_base_dir.

append_suffix: If supplied, all files output by this tool will have

this appended to their filename. Useful for changing .py to

.py3 for example by passing append_suffix='3'.

"""

self.nobackups = nobackups

self.show_diffs = show_diffs

if input_base_dir and not input_base_dir.endswith(os.sep):

input_base_dir += os.sep

self._input_base_dir = input_base_dir

self._output_dir = output_dir

self._append_suffix = append_suffix

super(StdoutRefactoringTool, self).__init__(fixers, options, explicit)

def log_error(self, msg, *args, **kwargs):

self.errors.append((msg, args, kwargs))

self.logger.error(msg, *args, **kwargs)

def write_file(self, new_text, filename, old_text, encoding):

orig_filename = filename

if self._output_dir:

if filename.startswith(self._input_base_dir):

filename = os.path.join(self._output_dir,

filename[len(self._input_base_dir):])

else:

raise ValueError('filename %s does not start with the '

'input_base_dir %s' % (

filename, self._input_base_dir))

if self._append_suffix:

filename += self._append_suffix

if orig_filename != filename:

output_dir = os.path.dirname(filename)

if not os.path.isdir(output_dir) and output_dir:

os.makedirs(output_dir)

self.log_message('Writing converted %s to %s.', orig_filename,

filename)

if not self.nobackups:

# Make backup

backup = filename + ".bak"

if os.path.lexists(backup):

try:

os.remove(backup)

except OSError as err:

self.log_message("Can't remove backup %s", backup)

try:

os.rename(filename, backup)

except OSError as err:

self.log_message("Can't rename %s to %s", filename, backup)

# Actually write the new file

write = super(StdoutRefactoringTool, self).write_file

write(new_text, filename, old_text, encoding)

if not self.nobackups:

shutil.copymode(backup, filename)

if orig_filename != filename:

# Preserve the file mode in the new output directory.

shutil.copymode(orig_filename, filename)

def print_output(self, old, new, filename, equal):

if equal:

self.log_message("No changes to %s", filename)

else:

self.log_message("Refactored %s", filename)

if self.show_diffs:

diff_lines = diff_texts(old, new, filename)

try:

if self.output_lock is not None:

with self.output_lock:

for line in diff_lines:

print(line)

sys.stdout.flush()

else:

for line in diff_lines:

print(line)

except UnicodeEncodeError:

warn("couldn't encode %s's diff for your terminal" %

(filename,))

return

def warn(msg):

print("WARNING: %s" % (msg,), file=sys.stderr)

def main(fixer_pkg, args=None):

"""Main program.

Args:

fixer_pkg: the name of a package where the fixers are located.

args: optional; a list of command line arguments. If omitted,

sys.argv[1:] is used.

Returns a suggested exit status (0, 1, 2).

"""

# Set up option parser

parser = optparse.OptionParser(usage="2to3 [options] file|dir ...")

parser.add_option("-d", "--doctests_only", action="store_true",

help="Fix up doctests only")

parser.add_option("-f", "--fix", action="append", default=[],

help="Each FIX specifies a transformation; default: all")

parser.add_option("-j", "--processes", action="store", default=1,

type="int", help="Run 2to3 concurrently")

parser.add_option("-x", "--nofix", action="append", default=[],

help="Prevent a transformation from being run")

parser.add_option("-l", "--list-fixes", action="store_true",

help="List available transformations")

parser.add_option("-p", "--print-function", action="store_true",

help="Modify the grammar so that print() is a function")

parser.add_option("-v", "--verbose", action="store_true",

help="More verbose logging")

parser.add_option("--no-diffs", action="store_true",

help="Don't show diffs of the refactoring")

parser.add_option("-w", "--write", action="store_true",

help="Write back modified files")

parser.add_option("-n", "--nobackups", action="store_true", default=False,

help="Don't write backups for modified files")

parser.add_option("-o", "--output-dir", action="store", type="str",

default="", help="Put output files in this directory "

"instead of overwriting the input files. Requires -n.")

parser.add_option("-W", "--write-unchanged-files", action="store_true",

help="Also write files even if no changes were required"

" (useful with --output-dir); implies -w.")

parser.add_option("--add-suffix", action="store", type="str", default="",

help="Append this string to all output filenames."

" Requires -n if non-empty. "

"ex: --add-suffix='3' will generate .py3 files.")

# Parse command line arguments

refactor_stdin = False

flags = {}

options, args = parser.parse_args(args)

if options.write_unchanged_files:

flags["write_unchanged_files"] = True

if not options.write:

warn("--write-unchanged-files/-W implies -w.")

options.write = True

# If we allowed these, the original files would be renamed to backup names

# but not replaced.

if options.output_dir and not options.nobackups:

parser.error("Can't use --output-dir/-o without -n.")

if options.add_suffix and not options.nobackups:

parser.error("Can't use --add-suffix without -n.")

if not options.write and options.no_diffs:

warn("not writing files and not printing diffs; that's not very useful")

if not options.write and options.nobackups:

parser.error("Can't use -n without -w")

if options.list_fixes:

print("Available transformations for the -f/--fix option:")

for fixname in refactor.get_all_fix_names(fixer_pkg):

print(fixname)

if not args:

return 0

if not args:

print("At least one file or directory argument required.", file=sys.stderr)

print("Use --help to show usage.", file=sys.stderr)

return 2

if "-" in args:

refactor_stdin = True

if options.write:

print("Can't write to stdin.", file=sys.stderr)

return 2

if options.print_function:

flags["print_function"] = True

# Set up logging handler

level = logging.DEBUG if options.verbose else logging.INFO

logging.basicConfig(format='%(name)s: %(message)s', level=level)

logger = logging.getLogger('lib2to3.main')

# Initialize the refactoring tool

avail_fixes = set(refactor.get_fixers_from_package(fixer_pkg))

unwanted_fixes = set(fixer_pkg + ".fix_" + fix for fix in options.nofix)

explicit = set()

if options.fix:

all_present = False

for fix in options.fix:

if fix == "all":

all_present = True

else:

explicit.add(fixer_pkg + ".fix_" + fix)

requested = avail_fixes.union(explicit) if all_present else explicit

else:

requested = avail_fixes.union(explicit)

fixer_names = requested.difference(unwanted_fixes)

input_base_dir = os.path.commonprefix(args)

if (input_base_dir and not input_base_dir.endswith(os.sep)

and not os.path.isdir(input_base_dir)):

# One or more similar names were passed, their directory is the base.

# os.path.commonprefix() is ignorant of path elements, this corrects

# for that weird API.

input_base_dir = os.path.dirname(input_base_dir)

if options.output_dir:

input_base_dir = input_base_dir.rstrip(os.sep)

logger.info('Output in %r will mirror the input directory %r layout.',

options.output_dir, input_base_dir)

rt = StdoutRefactoringTool(

sorted(fixer_names), flags, sorted(explicit),

options.nobackups, not options.no_diffs,

input_base_dir=input_base_dir,

output_dir=options.output_dir,

append_suffix=options.add_suffix)

# Refactor all files and directories passed as arguments

if not rt.errors:

if refactor_stdin:

rt.refactor_stdin()

else:

try:

rt.refactor(args, options.write, options.doctests_only,

options.processes)

except refactor.MultiprocessingUnsupported:

assert options.processes > 1

print("Sorry, -j isn't supported on this platform.",

file=sys.stderr)

return 1

rt.summarize()

# Return error status (0 if rt.errors is zero)

return int(bool(rt.errors))