#!/usr/bin/python

__doc__ = """Filter a fast-import stream to include/exclude files & directories.

This command is useful for splitting a subdirectory or bunch of
files out from a project to create a new project complete with history
for just those files. It can also be used to create a new project
repository that removes all references to files that should not have
been committed, e.g. security-related information (like passwords),
commercially sensitive material, files with an incompatible license or
large binary files like CD images.

To specify standard input as the input stream, use a source name
of '-'. If the source name ends in '.gz', it is assumed to be
compressed in gzip format.

:File/directory filtering:

 This is supported by the -i and -x options. Excludes take precedence
 over includes.

 When filtering out a subdirectory (or file), the new stream uses the
 subdirectory (or subdirectory containing the file) as the root. As
 fast-import doesn't know in advance whether a path is a file or
 directory in the stream, you need to specify a trailing '/' on
 directories passed to the `--includes option`. If multiple files or
 directories are given, the new root is the deepest common directory.

 Note: If a path has been renamed, take care to specify the *original*
 path name, not the final name that it ends up with.

:History rewriting:

 By default fast-import-filter does quite aggressive history rewriting.
 Empty commits (or commits which had all their content filtered out) will
 be removed, and so are the references to commits not included in the stream.

 Flag --dont-squash-empty-commits reverses this behavior and makes it possible to
 use fast-import-filter on incremental streams.

:Examples:

 Create a new project from a library (note the trailing / on the
 directory name of the library)::

   front-end | fast-import-filter -i lib/xxx/ > xxx.fi
   fast-import xxx.fi mylibrary.bzr
   (lib/xxx/foo is now foo)

 Create a new repository without a sensitive file::

   front-end | fast-import-filter -x missile-codes.txt > clean.fi
   fast-import clean.fi clean.bzr
"""

import optparse
import sys

parser = optparse.OptionParser('fast-import-filter [options] SOURCE?')

parser.add_option('-v', '--verbose', dest="verbose", action="store_true",
                  help="Be verbose.", default=False)
parser.add_option('-i', '--include-paths', dest="include_paths",
                  action="append", type=str,
                  help="Only include commits affecting these paths."
                       " Directories should have a trailing /.")
parser.add_option('-x', '--exclude-paths', dest="exclude_paths",
                  type=str, help="Exclude these paths from commits.")
parser.add_option('--dont-squash-empty-commits',
                  dest="dont_squash_empty_commits", action="store_true",
                  help="Preserve all commits and links between them",
                  default=False)

(opts, args) = parser.parse_args()

if len(args) == 0:
    source_path = "-"
elif len(args) == 1:
    source_path = args[0]
else:
    parser.print_usage()

from fastimport.processors import filter_processor
params = {
    'include_paths': opts.include_paths,
    'exclude_paths': opts.exclude_paths,
    }
params['squash_empty_commits'] = (not opts.dont_squash_empty_commits)

from fastimport.errors import ParsingError
from fastimport import parser
from fastimport.helpers import get_source_stream
stream = get_source_stream(source_path)
proc = filter_processor.FilterProcessor(params=params, verbose=opts.verbose)
p = parser.ImportParser(stream, verbose=opts.verbose)
try:
    sys.exit(proc.process(p.iter_commands))
except ParsingError as e:
    sys.stderr.write("%d: Parse error: %s\n" % (e.lineno, e))
    sys.exit(1)