"""

Main program for 2to3.

"""

import sys

import os

import logging

import optparse

from . import refactor

class StdoutRefactoringTool(refactor.RefactoringTool):

    """

    Prints output to stdout.

    """

    def __init__(self, fixers, options, explicit, nobackups):

        self.nobackups = nobackups

        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):

        if not self.nobackups:

            # Make backup

            backup = filename + ".bak"

            if os.path.lexists(backup):

                try:

                    os.remove(backup)

                except os.error, err:

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

            try:

                os.rename(filename, backup)

            except os.error, err:

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

        # Actually write the new file

        super(StdoutRefactoringTool, self).write_file(new_text,

                                                      filename, old_text)

    def print_output(self, lines):

        for line in lines:

            print line

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="refactor.py [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("-x", "--nofix", action="append", default=[],

                      help="Prevent a fixer from being run.")

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

                      help="List available transformations (fixes/fix_*.py)")

    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("-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.")

    # Parse command line arguments

    refactor_stdin = False

    options, args = parser.parse_args(args)

    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 >>sys.stderr, "At least one file or directory argument required."

        print >>sys.stderr, "Use --help to show usage."

        return 2

    if "-" in args:

        refactor_stdin = True

        if options.write:

            print >>sys.stderr, "Can't write to stdin."

            return 2

    # Set up logging handler

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

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

    # Initialize the refactoring tool

    rt_opts = {"print_function" : options.print_function}

    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)

    rt = StdoutRefactoringTool(sorted(fixer_names), rt_opts, sorted(explicit),

                               options.nobackups)

    # Refactor all files and directories passed as arguments

    if not rt.errors:

        if refactor_stdin:

            rt.refactor_stdin()

        else:

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

        rt.summarize()

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

    return int(bool(rt.errors))