import os
import re
from pip import call_subprocess
from pip.index import Link
from pip.util import rmtree, display_path
from pip.log import logger
from pip.vcs import vcs, VersionControl

_svn_xml_url_re = re.compile('url="([^"]+)"')
_svn_rev_re = re.compile('committed-rev="(\d+)"')
_svn_url_re = re.compile(r'URL: (.+)')
_svn_revision_re = re.compile(r'Revision: (.+)')

class Subversion(VersionControl):
    name = 'svn'
    dirname = '.svn'
    repo_name = 'checkout'
    schemes = ('svn', 'svn+ssh', 'svn+http', 'svn+https')
    bundle_file = 'svn-checkout.txt'
    guide = ('# This was an svn checkout; to make it a checkout again run:\n'
            'svn checkout --force -r %(rev)s %(url)s .\n')

    def get_info(self, location):
        """Returns (url, revision), where both are strings"""
        assert not location.rstrip('/').endswith(self.dirname), 'Bad directory: %s' % location
        output = call_subprocess(
            ['svn', 'info', location], show_stdout=False, extra_environ={'LANG': 'C'})
        match = _svn_url_re.search(output)
        if not match:
            logger.warn('Cannot determine URL of svn checkout %s' % display_path(location))
            logger.info('Output that cannot be parsed: \n%s' % output)
            return None, None
        url = match.group(1).strip()
        match = _svn_revision_re.search(output)
        if not match:
            logger.warn('Cannot determine revision of svn checkout %s' % display_path(location))
            logger.info('Output that cannot be parsed: \n%s' % output)
            return url, None
        return url, match.group(1)

    def parse_vcs_bundle_file(self, content):
        for line in content.splitlines():
            if not line.strip() or line.strip().startswith('#'):
                continue
            match = re.search(r'^-r\s*([^ ])?', line)
            if not match:
                return None, None
            rev = match.group(1)
            rest = line[match.end():].strip().split(None, 1)[0]
            return rest, rev
        return None, None

    def unpack(self, location):
        """Check out the svn repository at the url to the destination location"""
        url, rev = self.get_url_rev()
        logger.notify('Checking out svn repository %s to %s' % (url, location))
        logger.indent += 2
        try:
            if os.path.exists(location):
                # Subversion doesn't like to check out over an existing directory
                # --force fixes this, but was only added in svn 1.5
                rmtree(location)
            call_subprocess(
                ['svn', 'checkout', url, location],
                filter_stdout=self._filter, show_stdout=False)
        finally:
            logger.indent -= 2

    def export(self, location):
        """Export the svn repository at the url to the destination location"""
        url, rev = self.get_url_rev()
        logger.notify('Checking out svn repository %s to %s' % (url, location))
        logger.indent += 2
        try:
            if os.path.exists(location):
                # Subversion doesn't like to check out over an existing directory
                # --force fixes this, but was only added in svn 1.5
                rmtree(location)
            call_subprocess(
                ['svn', 'export', url, location],
                filter_stdout=self._filter, show_stdout=False)
        finally:
            logger.indent -= 2

    def switch(self, dest, url, rev_options):
        call_subprocess(
            ['svn', 'switch'] + rev_options + [url, dest])

    def update(self, dest, rev_options):
        call_subprocess(
            ['svn', 'update'] + rev_options + [dest])

    def obtain(self, dest):
        url, rev = self.get_url_rev()
        if rev:
            rev_options = ['-r', rev]
            rev_display = ' (to revision %s)' % rev
        else:
            rev_options = []
            rev_display = ''
        if self.check_destination(dest, url, rev_options, rev_display):
            logger.notify('Checking out %s%s to %s'
                          % (url, rev_display, display_path(dest)))
            call_subprocess(
                ['svn', 'checkout', '-q'] + rev_options + [url, dest])

    def get_location(self, dist, dependency_links):
        egg_fragment_re = re.compile(r'#egg=(.*)$')
        for url in dependency_links:
            egg_fragment = Link(url).egg_fragment
            if not egg_fragment:
                continue
            if '-' in egg_fragment:
                ## FIXME: will this work when a package has - in the name?
                key = '-'.join(egg_fragment.split('-')[:-1]).lower()
            else:
                key = egg_fragment
            if key == dist.key:
                return url.split('#', 1)[0]
        return None

    def get_revision(self, location):
        """
        Return the maximum revision for all files under a given location
        """
        # Note: taken from setuptools.command.egg_info
        revision = 0

        for base, dirs, files in os.walk(location):
            if self.dirname not in dirs:
                dirs[:] = []
                continue    # no sense walking uncontrolled subdirs
            dirs.remove(self.dirname)
            entries_fn = os.path.join(base, self.dirname, 'entries')
            if not os.path.exists(entries_fn):
                ## FIXME: should we warn?
                continue
            f = open(entries_fn)
            data = f.read()
            f.close()

            if data.startswith('8') or data.startswith('9') or data.startswith('10'):
                data = map(str.splitlines,data.split('\n\x0c\n'))
                del data[0][0]  # get rid of the '8'
                dirurl = data[0][3]
                revs = [int(d[9]) for d in data if len(d)>9 and d[9]]+[0]
                if revs:
                    localrev = max(revs)
                else:
                    localrev = 0
            elif data.startswith('<?xml'):
                dirurl = _svn_xml_url_re.search(data).group(1)    # get repository URL
                revs = [int(m.group(1)) for m in _svn_rev_re.finditer(data)]+[0]
                if revs:
                    localrev = max(revs)
                else:
                    localrev = 0
            else:
                logger.warn("Unrecognized .svn/entries format; skipping %s", base)
                dirs[:] = []
                continue
            if base == location:
                base_url = dirurl+'/'   # save the root url
            elif not dirurl.startswith(base_url):
                dirs[:] = []
                continue    # not part of the same svn tree, skip it
            revision = max(revision, localrev)
        return revision

    def get_url(self, location):
        # In cases where the source is in a subdirectory, not alongside setup.py
        # we have to look up in the location until we find a real setup.py
        orig_location = location
        while not os.path.exists(os.path.join(location, 'setup.py')):
            last_location = location
            location = os.path.dirname(location)
            if location == last_location:
                # We've traversed up to the root of the filesystem without finding setup.py
                logger.warn("Could not find setup.py for directory %s (tried all parent directories)"
                            % orig_location)
                return None
        f = open(os.path.join(location, self.dirname, 'entries'))
        data = f.read()
        f.close()
        if data.startswith('8') or data.startswith('9') or data.startswith('10'):
            data = map(str.splitlines,data.split('\n\x0c\n'))
            del data[0][0]  # get rid of the '8'
            return data[0][3]
        elif data.startswith('<?xml'):
            match = _svn_xml_url_re.search(data)
            if not match:
                raise ValueError('Badly formatted data: %r' % data)
            return match.group(1)    # get repository URL
        else:
            logger.warn("Unrecognized .svn/entries format in %s" % location)
            # Or raise exception?
            return None

    def get_tag_revs(self, svn_tag_url):
        stdout = call_subprocess(
            ['svn', 'ls', '-v', svn_tag_url], show_stdout=False)
        results = []
        for line in stdout.splitlines():
            parts = line.split()
            rev = int(parts[0])
            tag = parts[-1].strip('/')
            results.append((tag, rev))
        return results

    def find_tag_match(self, rev, tag_revs):
        best_match_rev = None
        best_tag = None
        for tag, tag_rev in tag_revs:
            if (tag_rev > rev and
                (best_match_rev is None or best_match_rev > tag_rev)):
                # FIXME: Is best_match > tag_rev really possible?
                # or is it a sign something is wacky?
                best_match_rev = tag_rev
                best_tag = tag
        return best_tag

    def get_src_requirement(self, dist, location, find_tags=False):
        repo = self.get_url(location)
        if repo is None:
            return None
        parts = repo.split('/')
        ## FIXME: why not project name?
        egg_project_name = dist.egg_name().split('-', 1)[0]
        rev = self.get_revision(location)
        if parts[-2] in ('tags', 'tag'):
            # It's a tag, perfect!
            full_egg_name = '%s-%s' % (egg_project_name, parts[-1])
        elif parts[-2] in ('branches', 'branch'):
            # It's a branch :(
            full_egg_name = '%s-%s-r%s' % (dist.egg_name(), parts[-1], rev)
        elif parts[-1] == 'trunk':
            # Trunk :-/
            full_egg_name = '%s-dev_r%s' % (dist.egg_name(), rev)
            if find_tags:
                tag_url = '/'.join(parts[:-1]) + '/tags'
                tag_revs = self.get_tag_revs(tag_url)
                match = self.find_tag_match(rev, tag_revs)
                if match:
                    logger.notify('trunk checkout %s seems to be equivalent to tag %s' % match)
                    repo = '%s/%s' % (tag_url, match)
                    full_egg_name = '%s-%s' % (egg_project_name, match)
        else:
            # Don't know what it is
            logger.warn('svn URL does not fit normal structure (tags/branches/trunk): %s' % repo)
            full_egg_name = '%s-dev_r%s' % (egg_project_name, rev)
        return 'svn+%s@%s#egg=%s' % (repo, rev, full_egg_name)

vcs.register(Subversion)
