# vim: set fileencoding=utf-8 :
#
# (C) 2006-2011 Guido Guenther <agx@sigxcpu.org>
# (C) 2012 Intel Corporation <markus.lehtonen@linux.intel.com>
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
"""Common functionality for Debian and RPM buildpackage scripts"""

import os, os.path
import pipes
import tempfile
import shutil
import subprocess

from gbp.command_wrappers import (CatenateTarArchive)
from gbp.git.repository import GitRepository, GitRepositoryError
from gbp.errors import GbpError
import gbp.log

# when we want to reference the index in a treeish context we call it:
index_name = "INDEX"
# when we want to reference the working copy in treeish context we call it:
wc_names = {'WC':           {'force': True, 'untracked': True},
            'WC.TRACKED':   {'force': False, 'untracked': False},
            'WC.UNTRACKED': {'force': False, 'untracked': True},
            'WC.IGNORED':   {'force': True, 'untracked': True}}


def sanitize_prefix(prefix):
    """
    Sanitize the prefix used for generating source archives

    >>> sanitize_prefix('')
    '/'
    >>> sanitize_prefix('foo/')
    'foo/'
    >>> sanitize_prefix('/foo/bar')
    'foo/bar/'
    """
    if prefix:
        return prefix.strip('/') + '/'
    return '/'


def git_archive_submodules(repo, treeish, output, prefix, comp_type, comp_level, comp_opts):
    """
    Create tar.gz of an archive with submodules

    since git-archive always writes an end of tarfile trailer we concatenate
    the generated archives using tar and compress the result.

    Exception handling is left to the caller.
    """
    prefix = sanitize_prefix(prefix)
    tarfile = output.rsplit('.', 1)[0]
    tempdir = tempfile.mkdtemp()
    submodule_tarfile = os.path.join(tempdir, "submodule.tar")
    try:
        # generate main tarfile
        repo.archive(format='tar', prefix=prefix,
                     output=tarfile, treeish=treeish)

        # generate each submodule's tarfile and append it to the main archive
        for (subdir, commit) in repo.get_submodules(treeish):
            tarpath = [subdir, subdir[2:]][subdir.startswith("./")]

            gbp.log.debug("Processing submodule %s (%s)" % (subdir, commit[0:8]))
            repo.archive(format='tar', prefix='%s%s/' % (prefix, tarpath),
                         output=submodule_tarfile, treeish=commit, cwd=subdir)
            CatenateTarArchive(tarfile)(submodule_tarfile)

        # compress the output
        ret = os.system("%s -%s %s %s" % (comp_type, comp_level, comp_opts, tarfile))
        if ret:
            raise GbpError("Error creating %s: %d" % (output, ret))
    finally:
        shutil.rmtree(tempdir)


def git_archive_single(treeish, output, prefix, comp_type, comp_level, comp_opts):
    """
    Create tar.gz of an archive without submodules

    Exception handling is left to the caller.
    """
    prefix = sanitize_prefix(prefix)
    pipe = pipes.Template()
    pipe.prepend("git archive --format=tar --prefix=%s %s" % (prefix, treeish), '.-')
    pipe.append('%s -c -%s %s' % (comp_type, comp_level, comp_opts),  '--')
    ret = pipe.copy('', output)
    if ret:
        raise GbpError("Error creating %s: %d" % (output, ret))


def untar_data(outdir, data):
    """Extract tar provided as an iterable"""
    popen = subprocess.Popen(['tar', '-C', outdir, '-x'],
                             stdin=subprocess.PIPE)
    for chunk in data:
        popen.stdin.write(chunk)
    popen.stdin.close()
    if popen.wait():
        raise GbpError("Error extracting tar to %s" % outdir)


#{ Functions to handle export-dir
def dump_tree(repo, export_dir, treeish, with_submodules, recursive=True):
    """Dump a git tree-ish to output_dir"""
    if not os.path.exists(export_dir):
        os.makedirs(export_dir)
    if recursive:
        paths = ''
    else:
        paths = [nam for _mod, typ, _sha, nam in repo.list_tree(treeish) if
                    typ == 'blob']
    try:
        data = repo.archive('tar', '', None, treeish, paths)
        untar_data(export_dir, data)
        if recursive and with_submodules and repo.has_submodules():
            repo.update_submodules()
            for (subdir, commit) in repo.get_submodules(treeish):
                gbp.log.info("Processing submodule %s (%s)" % (subdir,
                                                               commit[0:8]))
                subrepo = GitRepository(os.path.join(repo.path, subdir))
                prefix = [subdir, subdir[2:]][subdir.startswith("./")] + '/'
                data = subrepo.archive('tar', prefix, None, treeish)
                untar_data(export_dir, data)
    except GitRepositoryError as err:
        gbp.log.err("Git error when dumping tree: %s" % err)
        return False
    return True


def wc_index(repo):
    """Get path of the temporary index file used for exporting working copy"""
    return os.path.join(repo.git_dir, "gbp_index")

def write_wc(repo, force=True, untracked=True):
    """write out the current working copy as a treeish object"""
    clone_index(repo)
    repo.add_files(repo.path, force=force, untracked=untracked, index_file=wc_index(repo))
    tree = repo.write_tree(index_file=wc_index(repo))
    return tree


def drop_index(repo):
    """drop our custom index"""
    if os.path.exists(wc_index(repo)):
        os.unlink(wc_index(repo))

def clone_index(repo):
    """Copy the current index file to our custom index file"""
    indexfn = os.path.join(repo.git_dir, "index")
    if os.path.exists(indexfn):
        shutil.copy2(indexfn, wc_index(repo))