"""distutils.archive_util

Utility functions for creating archive files (tarballs, zip files,
that sort of thing)."""

__revision__ = "$Id$"

import os
from distutils.errors import DistutilsExecError
from distutils.spawn import spawn
from distutils.dir_util import mkpath
from distutils import log

def make_tarball (base_name, base_dir, compress="gzip",
                  verbose=0, dry_run=0):
    """Create a (possibly compressed) tar file from all the files under
    'base_dir'.  'compress' must be "gzip" (the default), "compress",
    "bzip2", or None.  Both "tar" and the compression utility named by
    'compress' must be on the default program search path, so this is
    probably Unix-specific.  The output tar file will be named 'base_dir' +
    ".tar", possibly plus the appropriate compression extension (".gz",
    ".bz2" or ".Z").  Return the output filename.
    """
    # XXX GNU tar 1.13 has a nifty option to add a prefix directory.
    # It's pretty new, though, so we certainly can't require it --
    # but it would be nice to take advantage of it to skip the
    # "create a tree of hardlinks" step!  (Would also be nice to
    # detect GNU tar to use its 'z' option and save a step.)

    compress_ext = { 'gzip': ".gz",
                     'bzip2': '.bz2',
                     'compress': ".Z" }

    # flags for compression program, each element of list will be an argument
    compress_flags = {'gzip': ["-f9"],
                      'compress': ["-f"],
                      'bzip2': ['-f9']}

    if compress is not None and compress not in compress_ext.keys():
        raise ValueError(
              "bad value for 'compress': must be None, 'gzip', or 'compress'")

    archive_name = base_name + ".tar"
    mkpath(os.path.dirname(archive_name), dry_run=dry_run)
    cmd = ["tar", "-cf", archive_name, base_dir]
    spawn(cmd, dry_run=dry_run)

    if compress:
        spawn([compress] + compress_flags[compress] + [archive_name],
              dry_run=dry_run)
        return archive_name + compress_ext[compress]
    else:
        return archive_name

# make_tarball ()


def make_zipfile (base_name, base_dir, verbose=0, dry_run=0):
    """Create a zip file from all the files under 'base_dir'.  The output
    zip file will be named 'base_dir' + ".zip".  Uses either the "zipfile"
    Python module (if available) or the InfoZIP "zip" utility (if installed
    and found on the default search path).  If neither tool is available,
    raises DistutilsExecError.  Returns the name of the output zip file.
    """
    try:
        import zipfile
    except ImportError:
        zipfile = None

    zip_filename = base_name + ".zip"
    mkpath(os.path.dirname(zip_filename), dry_run=dry_run)

    # If zipfile module is not available, try spawning an external
    # 'zip' command.
    if zipfile is None:
        if verbose:
            zipoptions = "-r"
        else:
            zipoptions = "-rq"

        try:
            spawn(["zip", zipoptions, zip_filename, base_dir],
                  dry_run=dry_run)
        except DistutilsExecError:
            # XXX really should distinguish between "couldn't find
            # external 'zip' command" and "zip failed".
            raise DistutilsExecError(("unable to create zip file '%s': "
                   "could neither import the 'zipfile' module nor "
                   "find a standalone zip utility") % zip_filename)

    else:
        log.info("creating '%s' and adding '%s' to it",
                 zip_filename, base_dir)

        def visit (z, dirname, names):
            for name in names:
                path = os.path.normpath(os.path.join(dirname, name))
                if os.path.isfile(path):
                    z.write(path, path)
                    log.info("adding '%s'" % path)

        if not dry_run:
            z = zipfile.ZipFile(zip_filename, "w",
                                compression=zipfile.ZIP_DEFLATED)

            os.path.walk(base_dir, visit, z)
            z.close()

    return zip_filename

# make_zipfile ()


ARCHIVE_FORMATS = {
    'gztar': (make_tarball, [('compress', 'gzip')], "gzip'ed tar-file"),
    'bztar': (make_tarball, [('compress', 'bzip2')], "bzip2'ed tar-file"),
    'ztar':  (make_tarball, [('compress', 'compress')], "compressed tar file"),
    'tar':   (make_tarball, [('compress', None)], "uncompressed tar file"),
    'zip':   (make_zipfile, [],"ZIP file")
    }

def check_archive_formats (formats):
    for format in formats:
        if format not in ARCHIVE_FORMATS:
            return format
    else:
        return None

def make_archive (base_name, format,
                  root_dir=None, base_dir=None,
                  verbose=0, dry_run=0):
    """Create an archive file (eg. zip or tar).  'base_name' is the name
    of the file to create, minus any format-specific extension; 'format'
    is the archive format: one of "zip", "tar", "ztar", or "gztar".
    'root_dir' is a directory that will be the root directory of the
    archive; ie. we typically chdir into 'root_dir' before creating the
    archive.  'base_dir' is the directory where we start archiving from;
    ie. 'base_dir' will be the common prefix of all files and
    directories in the archive.  'root_dir' and 'base_dir' both default
    to the current directory.  Returns the name of the archive file.
    """
    save_cwd = os.getcwd()
    if root_dir is not None:
        log.debug("changing into '%s'", root_dir)
        base_name = os.path.abspath(base_name)
        if not dry_run:
            os.chdir(root_dir)

    if base_dir is None:
        base_dir = os.curdir

    kwargs = { 'dry_run': dry_run }

    try:
        format_info = ARCHIVE_FORMATS[format]
    except KeyError:
        raise ValueError("unknown archive format '%s'" % format)

    func = format_info[0]
    for (arg,val) in format_info[1]:
        kwargs[arg] = val
    filename = func(base_name, base_dir, **kwargs)

    if root_dir is not None:
        log.debug("changing back to '%s'", save_cwd)
        os.chdir(save_cwd)

    return filename

# make_archive ()