import errno
import os
import subprocess
import shutil
import StringIO
import stat
import tempfile
import unittest
import urllib

from mercurial import context
from mercurial import commands
from mercurial import hg
from mercurial import node
from mercurial import ui

from hgsubversion import util

# Fixtures that need to be pulled at a subdirectory of the repo path
subdir = {'truncatedhistory.svndump': '/project2',
          'fetch_missing_files_subdir.svndump': '/foo',
          'empty_dir_in_trunk_not_repo_root.svndump': '/project',
          }

FIXTURES = os.path.join(os.path.abspath(os.path.dirname(__file__)),
                        'fixtures')

def fileurl(path):
    path = os.path.abspath(path)
    drive, path = os.path.splitdrive(path)
    path = urllib.pathname2url(path)
    if drive:
        drive = '/' + drive
    url = 'file://%s%s' % (drive, path)
    return url

def load_svndump_fixture(path, fixture_name):
    '''Loads an svnadmin dump into a fresh repo at path, which should not
    already exist.
    '''
    if os.path.exists(path): rmtree(path)
    subprocess.call(['svnadmin', 'create', path,],
                    stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    inp = open(os.path.join(FIXTURES, fixture_name))
    proc = subprocess.Popen(['svnadmin', 'load', path,], stdin=inp,
                            stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    proc.communicate()

def load_fixture_and_fetch(fixture_name, repo_path, wc_path, stupid=False, subdir='', noupdate=True):
    load_svndump_fixture(repo_path, fixture_name)
    if subdir:
        repo_path += '/' + subdir

    _ui = ui.ui()
    _ui.setconfig('hgsubversion', 'stupid', str(stupid))
    commands.clone(_ui, fileurl(repo_path), wc_path, noupdate=noupdate)
    _ui = ui.ui()
    _ui.setconfig('hgsubversion', 'stupid', str(stupid))
    return hg.repository(_ui, wc_path)

def rmtree(path):
    # Read-only files cannot be removed under Windows
    for root, dirs, files in os.walk(path):
        for f in files:
            f = os.path.join(root, f)
            try:
                s = os.stat(f)
            except OSError, e:
                if e.errno == errno.ENOENT:
                    continue
                raise
            if (s.st_mode & stat.S_IWRITE) == 0:
                os.chmod(f, s.st_mode | stat.S_IWRITE)
    shutil.rmtree(path)

class TestBase(unittest.TestCase):
    def setUp(self):
        self.oldwd = os.getcwd()
        self.tmpdir = tempfile.mkdtemp(
            'svnwrap_test', dir=os.environ.get('HGSUBVERSION_TEST_TEMP', None))
        self.hgrc = os.path.join(self.tmpdir, '.hgrc')
        os.environ['HGRCPATH'] = self.hgrc
        rc = open(self.hgrc, 'w')
        for l in '[extensions]', 'hgsubversion=':
            print >> rc, l

        self.repo_path = '%s/testrepo' % self.tmpdir
        self.wc_path = '%s/testrepo_wc' % self.tmpdir

        # Previously, we had a MockUI class that wrapped ui, and giving access
        # to the stream. The ui.pushbuffer() and ui.popbuffer() can be used
        # instead. Using the regular UI class, with all stderr redirected to
        # stdout ensures that the test setup is much more similar to usage
        # setups.
        self.patch = (ui.ui.write_err, ui.ui.write)
        setattr(ui.ui, self.patch[0].func_name, self.patch[1])

    def tearDown(self):
        rmtree(self.tmpdir)
        os.chdir(self.oldwd)
        setattr(ui.ui, self.patch[0].func_name, self.patch[0])

    def _load_fixture_and_fetch(self, fixture_name, subdir='', stupid=False):
        return load_fixture_and_fetch(fixture_name, self.repo_path,
                                      self.wc_path, subdir=subdir,
                                      stupid=stupid)

    # define this as a property so that it reloads anytime we need it
    @property
    def repo(self):
        return hg.repository(ui.ui(), self.wc_path)

    def pushrevisions(self, stupid=False):
        before = len(self.repo)
        self.repo.ui.setconfig('hgsubversion', 'stupid', str(stupid))
        commands.push(self.repo.ui, self.repo)
        after = len(self.repo)
        self.assertEqual(0, after - before)

    def svnls(self, path, rev='HEAD'):
        path = self.repo_path + '/' + path
        path = util.normalize_url(fileurl(path))
        args = ['svn', 'ls', '-r', rev, '-R', path]
        p = subprocess.Popen(args,
                             stdout=subprocess.PIPE,
                             stderr=subprocess.STDOUT)
        stdout, stderr = p.communicate()
        if p.returncode:
            raise Exception('svn ls failed on %s: %r' % (path, stderr))
        entries = [e.strip('/') for e in stdout.splitlines()]
        entries.sort()
        return entries

    def commitchanges(self, changes, parent='tip'):
        """Commit changes to mercurial directory

        'changes' is a sequence of tuples (source, dest, data). It can look
        like:
        - (source, source, data) to set source content to data
        - (source, dest, None) to set dest content to source one, and mark it as
        copied from source.
        - (source, dest, data) to set dest content to data, and mark it as copied
        from source.
        - (source, None, None) to remove source.
        """
        repo = self.repo
        parentctx = repo[parent]

        changed, removed = [], []
        for source, dest, newdata in changes:
            if dest is None:
                removed.append(source)
            else:
                changed.append(dest)

        def filectxfn(repo, memctx, path):
            if path in removed:
                raise IOError()
            entry = [e for e in changes if path == e[1]][0]
            source, dest, newdata = entry
            if newdata is None:
                newdata = parentctx[source].data()
            copied = None
            if source != dest:
                copied = source
            return context.memfilectx(path=dest,
                                      data=newdata,
                                      islink=False,
                                      isexec=False,
                                      copied=copied)

        ctx = context.memctx(repo,
                             (parentctx.node(), node.nullid),
                             'automated test',
                             changed + removed,
                             filectxfn,
                             'an_author',
                             '2008-10-07 20:59:48 -0500')
        nodeid = repo.commitctx(ctx)
        repo = self.repo
        hg.clean(repo, nodeid)
        return nodeid

    def assertchanges(self, changes, ctx):
        """Assert that all 'changes' (as in defined in commitchanged())
        went into ctx.
        """
        for source, dest, data in changes:
            if dest is None:
                self.assertTrue(source not in ctx)
                continue
            self.assertTrue(dest in ctx)
            if data is None:
                data = ctx.parents()[0][source].data()
            self.assertEqual(ctx[dest].data(), data)
            if dest != source:
                copy = ctx[dest].renamed()
                self.assertEqual(copy[0], source)