import os
import time
import datetime
import urllib
import urllib2

from rhodecode.lib.vcs.backends.base import BaseRepository
from .workdir import MercurialWorkdir
from .changeset import MercurialChangeset
from .inmemory import MercurialInMemoryChangeset

from rhodecode.lib.vcs.exceptions import BranchDoesNotExistError, \
    ChangesetDoesNotExistError, EmptyRepositoryError, RepositoryError, \
    VCSError, TagAlreadyExistError, TagDoesNotExistError
from rhodecode.lib.vcs.utils import author_email, author_name, date_fromtimestamp, \
    makedate, safe_unicode
from rhodecode.lib.vcs.utils.lazy import LazyProperty
from rhodecode.lib.vcs.utils.ordered_dict import OrderedDict
from rhodecode.lib.vcs.utils.paths import abspath

from ...utils.hgcompat import ui, nullid, match, patch, diffopts, clone, \
    get_contact, pull, localrepository, RepoLookupError, Abort, RepoError, hex


class MercurialRepository(BaseRepository):
    """
    Mercurial repository backend
    """
    DEFAULT_BRANCH_NAME = 'default'
    scm = 'hg'

    def __init__(self, repo_path, create=False, baseui=None, src_url=None,
                 update_after_clone=False):
        """
        Raises RepositoryError if repository could not be find at the given
        ``repo_path``.

        :param repo_path: local path of the repository
        :param create=False: if set to True, would try to create repository if
           it does not exist rather than raising exception
        :param baseui=None: user data
        :param src_url=None: would try to clone repository from given location
        :param update_after_clone=False: sets update of working copy after
          making a clone
        """

        if not isinstance(repo_path, str):
            raise VCSError('Mercurial backend requires repository path to '
                           'be instance of <str> got %s instead' %
                           type(repo_path))

        self.path = abspath(repo_path)
        self.baseui = baseui or ui.ui()
        # We've set path and ui, now we can set _repo itself
        self._repo = self._get_repo(create, src_url, update_after_clone)

    @property
    def _empty(self):
        """
        Checks if repository is empty without any changesets
        """
        # TODO: Following raises errors when using InMemoryChangeset...
        # return len(self._repo.changelog) == 0
        return len(self.revisions) == 0

    @LazyProperty
    def revisions(self):
        """
        Returns list of revisions' ids, in ascending order.  Being lazy
        attribute allows external tools to inject shas from cache.
        """
        return self._get_all_revisions()

    @LazyProperty
    def name(self):
        return os.path.basename(self.path)

    @LazyProperty
    def branches(self):
        return self._get_branches()

    def _get_branches(self, closed=False):
        """
        Get's branches for this repository
        Returns only not closed branches by default

        :param closed: return also closed branches for mercurial
        """

        if self._empty:
            return {}

        def _branchtags(localrepo):
            """
            Patched version of mercurial branchtags to not return the closed
            branches

            :param localrepo: locarepository instance
            """

            bt = {}
            bt_closed = {}
            for bn, heads in localrepo.branchmap().iteritems():
                tip = heads[-1]
                if 'close' in localrepo.changelog.read(tip)[5]:
                    bt_closed[bn] = tip
                else:
                    bt[bn] = tip

            if closed:
                bt.update(bt_closed)
            return bt

        sortkey = lambda ctx: ctx[0]  # sort by name
        _branches = [(safe_unicode(n), hex(h),) for n, h in
                     _branchtags(self._repo).items()]

        return OrderedDict(sorted(_branches, key=sortkey, reverse=False))

    @LazyProperty
    def tags(self):
        """
        Get's tags for this repository
        """
        return self._get_tags()

    def _get_tags(self):
        if self._empty:
            return {}

        sortkey = lambda ctx: ctx[0]  # sort by name
        _tags = [(safe_unicode(n), hex(h),) for n, h in
                 self._repo.tags().items()]

        return OrderedDict(sorted(_tags, key=sortkey, reverse=True))

    def tag(self, name, user, revision=None, message=None, date=None,
            **kwargs):
        """
        Creates and returns a tag for the given ``revision``.

        :param name: name for new tag
        :param user: full username, i.e.: "Joe Doe <joe.doe@example.com>"
        :param revision: changeset id for which new tag would be created
        :param message: message of the tag's commit
        :param date: date of tag's commit

        :raises TagAlreadyExistError: if tag with same name already exists
        """
        if name in self.tags:
            raise TagAlreadyExistError("Tag %s already exists" % name)
        changeset = self.get_changeset(revision)
        local = kwargs.setdefault('local', False)

        if message is None:
            message = "Added tag %s for changeset %s" % (name,
                changeset.short_id)

        if date is None:
            date = datetime.datetime.now().ctime()

        try:
            self._repo.tag(name, changeset._ctx.node(), message, local, user,
                date)
        except Abort, e:
            raise RepositoryError(e.message)

        # Reinitialize tags
        self.tags = self._get_tags()
        tag_id = self.tags[name]

        return self.get_changeset(revision=tag_id)

    def remove_tag(self, name, user, message=None, date=None):
        """
        Removes tag with the given ``name``.

        :param name: name of the tag to be removed
        :param user: full username, i.e.: "Joe Doe <joe.doe@example.com>"
        :param message: message of the tag's removal commit
        :param date: date of tag's removal commit

        :raises TagDoesNotExistError: if tag with given name does not exists
        """
        if name not in self.tags:
            raise TagDoesNotExistError("Tag %s does not exist" % name)
        if message is None:
            message = "Removed tag %s" % name
        if date is None:
            date = datetime.datetime.now().ctime()
        local = False

        try:
            self._repo.tag(name, nullid, message, local, user, date)
            self.tags = self._get_tags()
        except Abort, e:
            raise RepositoryError(e.message)

    @LazyProperty
    def bookmarks(self):
        """
        Get's bookmarks for this repository
        """
        return self._get_bookmarks()

    def _get_bookmarks(self):
        if self._empty:
            return {}

        sortkey = lambda ctx: ctx[0]  # sort by name
        _bookmarks = [(safe_unicode(n), hex(h),) for n, h in
                 self._repo._bookmarks.items()]
        return OrderedDict(sorted(_bookmarks, key=sortkey, reverse=True))

    def _get_all_revisions(self):

        return map(lambda x: hex(x[7]), self._repo.changelog.index)[:-1]

    def get_diff(self, rev1, rev2, path='', ignore_whitespace=False,
                  context=3):
        """
        Returns (git like) *diff*, as plain text. Shows changes introduced by
        ``rev2`` since ``rev1``.

        :param rev1: Entry point from which diff is shown. Can be
          ``self.EMPTY_CHANGESET`` - in this case, patch showing all
          the changes since empty state of the repository until ``rev2``
        :param rev2: Until which revision changes should be shown.
        :param ignore_whitespace: If set to ``True``, would not show whitespace
          changes. Defaults to ``False``.
        :param context: How many lines before/after changed lines should be
          shown. Defaults to ``3``.
        """
        # Check if given revisions are present at repository (may raise
        # ChangesetDoesNotExistError)
        if rev1 != self.EMPTY_CHANGESET:
            self.get_changeset(rev1)
        self.get_changeset(rev2)

        file_filter = match(self.path, '', [path])
        return ''.join(patch.diff(self._repo, rev1, rev2, match=file_filter,
                          opts=diffopts(git=True,
                                        ignorews=ignore_whitespace,
                                        context=context)))

    def _check_url(self, url):
        """
        Function will check given url and try to verify if it's a valid
        link. Sometimes it may happened that mercurial will issue basic
        auth request that can cause whole API to hang when used from python
        or other external calls.

        On failures it'll raise urllib2.HTTPError, return code 200 if url
        is valid or True if it's a local path
        """

        from mercurial.util import url as Url

        # those authnadlers are patched for python 2.6.5 bug an
        # infinit looping when given invalid resources
        from mercurial.url import httpbasicauthhandler, httpdigestauthhandler

        # check first if it's not an local url
        if os.path.isdir(url) or url.startswith('file:'):
            return True

        handlers = []
        test_uri, authinfo = Url(url).authinfo()

        if authinfo:
            #create a password manager
            passmgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
            passmgr.add_password(*authinfo)

            handlers.extend((httpbasicauthhandler(passmgr),
                             httpdigestauthhandler(passmgr)))

        o = urllib2.build_opener(*handlers)
        o.addheaders = [('Content-Type', 'application/mercurial-0.1'),
                        ('Accept', 'application/mercurial-0.1')]

        q = {"cmd": 'between'}
        q.update({'pairs': "%s-%s" % ('0' * 40, '0' * 40)})
        qs = '?%s' % urllib.urlencode(q)
        cu = "%s%s" % (test_uri, qs)
        req = urllib2.Request(cu, None, {})

        try:
            resp = o.open(req)
            return resp.code == 200
        except Exception, e:
            # means it cannot be cloned
            raise urllib2.URLError(e)

    def _get_repo(self, create, src_url=None, update_after_clone=False):
        """
        Function will check for mercurial repository in given path and return
        a localrepo object. If there is no repository in that path it will
        raise an exception unless ``create`` parameter is set to True - in
        that case repository would be created and returned.
        If ``src_url`` is given, would try to clone repository from the
        location at given clone_point. Additionally it'll make update to
        working copy accordingly to ``update_after_clone`` flag
        """
        try:
            if src_url:
                url = str(self._get_url(src_url))
                opts = {}
                if not update_after_clone:
                    opts.update({'noupdate': True})
                try:
                    self._check_url(url)
                    clone(self.baseui, url, self.path, **opts)
#                except urllib2.URLError:
#                    raise Abort("Got HTTP 404 error")
                except Exception:
                    raise
                # Don't try to create if we've already cloned repo
                create = False
            return localrepository(self.baseui, self.path, create=create)
        except (Abort, RepoError), err:
            if create:
                msg = "Cannot create repository at %s. Original error was %s"\
                    % (self.path, err)
            else:
                msg = "Not valid repository at %s. Original error was %s"\
                    % (self.path, err)
            raise RepositoryError(msg)

    @LazyProperty
    def in_memory_changeset(self):
        return MercurialInMemoryChangeset(self)

    @LazyProperty
    def description(self):
        undefined_description = u'unknown'
        return safe_unicode(self._repo.ui.config('web', 'description',
                                   undefined_description, untrusted=True))

    @LazyProperty
    def contact(self):
        undefined_contact = u'Unknown'
        return safe_unicode(get_contact(self._repo.ui.config)
                            or undefined_contact)

    @LazyProperty
    def last_change(self):
        """
        Returns last change made on this repository as datetime object
        """
        return date_fromtimestamp(self._get_mtime(), makedate()[1])

    def _get_mtime(self):
        try:
            return time.mktime(self.get_changeset().date.timetuple())
        except RepositoryError:
            #fallback to filesystem
            cl_path = os.path.join(self.path, '.hg', "00changelog.i")
            st_path = os.path.join(self.path, '.hg', "store")
            if os.path.exists(cl_path):
                return os.stat(cl_path).st_mtime
            else:
                return os.stat(st_path).st_mtime

    def _get_hidden(self):
        return self._repo.ui.configbool("web", "hidden", untrusted=True)

    def _get_revision(self, revision):
        """
        Get's an ID revision given as str. This will always return a fill
        40 char revision number

        :param revision: str or int or None
        """

        if self._empty:
            raise EmptyRepositoryError("There are no changesets yet")

        if revision in [-1, 'tip', None]:
            revision = 'tip'

        try:
            revision = hex(self._repo.lookup(revision))
        except (IndexError, ValueError, RepoLookupError, TypeError):
            raise ChangesetDoesNotExistError("Revision %r does not "
                                    "exist for this repository %s" \
                                    % (revision, self))
        return revision

    def _get_archives(self, archive_name='tip'):
        allowed = self.baseui.configlist("web", "allow_archive",
                                         untrusted=True)
        for i in [('zip', '.zip'), ('gz', '.tar.gz'), ('bz2', '.tar.bz2')]:
            if i[0] in allowed or self._repo.ui.configbool("web",
                                                           "allow" + i[0],
                                                           untrusted=True):
                yield {"type": i[0], "extension": i[1], "node": archive_name}

    def _get_url(self, url):
        """
        Returns normalized url. If schema is not given, would fall
        to filesystem
        (``file:///``) schema.
        """
        url = str(url)
        if url != 'default' and not '://' in url:
            url = "file:" + urllib.pathname2url(url)
        return url

    def get_changeset(self, revision=None):
        """
        Returns ``MercurialChangeset`` object representing repository's
        changeset at the given ``revision``.
        """
        revision = self._get_revision(revision)
        changeset = MercurialChangeset(repository=self, revision=revision)
        return changeset

    def get_changesets(self, start=None, end=None, start_date=None,
                       end_date=None, branch_name=None, reverse=False):
        """
        Returns iterator of ``MercurialChangeset`` objects from start to end
        (both are inclusive)

        :param start: None, str, int or mercurial lookup format
        :param end:  None, str, int or mercurial lookup format
        :param start_date:
        :param end_date:
        :param branch_name:
        :param reversed: return changesets in reversed order
        """

        start_raw_id = self._get_revision(start)
        start_pos = self.revisions.index(start_raw_id) if start else None
        end_raw_id = self._get_revision(end)
        end_pos = self.revisions.index(end_raw_id) if end else None

        if None not in [start, end] and start_pos > end_pos:
            raise RepositoryError("start revision '%s' cannot be "
                                  "after end revision '%s'" % (start, end))

        if branch_name and branch_name not in self.branches.keys():
            raise BranchDoesNotExistError('Such branch %s does not exists for'
                                  ' this repository' % branch_name)
        if end_pos is not None:
            end_pos += 1

        slice_ = reversed(self.revisions[start_pos:end_pos]) if reverse else \
            self.revisions[start_pos:end_pos]

        for id_ in slice_:
            cs = self.get_changeset(id_)
            if branch_name and cs.branch != branch_name:
                continue
            if start_date and cs.date < start_date:
                continue
            if end_date and cs.date > end_date:
                continue

            yield cs

    def pull(self, url):
        """
        Tries to pull changes from external location.
        """
        url = self._get_url(url)
        try:
            pull(self.baseui, self._repo, url)
        except Abort, err:
            # Propagate error but with vcs's type
            raise RepositoryError(str(err))

    @LazyProperty
    def workdir(self):
        """
        Returns ``Workdir`` instance for this repository.
        """
        return MercurialWorkdir(self)

    def get_config_value(self, section, name, config_file=None):
        """
        Returns configuration value for a given [``section``] and ``name``.

        :param section: Section we want to retrieve value from
        :param name: Name of configuration we want to retrieve
        :param config_file: A path to file which should be used to retrieve
          configuration from (might also be a list of file paths)
        """
        if config_file is None:
            config_file = []
        elif isinstance(config_file, basestring):
            config_file = [config_file]

        config = self._repo.ui
        for path in config_file:
            config.readconfig(path)
        return config.config(section, name)

    def get_user_name(self, config_file=None):
        """
        Returns user's name from global configuration file.

        :param config_file: A path to file which should be used to retrieve
          configuration from (might also be a list of file paths)
        """
        username = self.get_config_value('ui', 'username')
        if username:
            return author_name(username)
        return None

    def get_user_email(self, config_file=None):
        """
        Returns user's email from global configuration file.

        :param config_file: A path to file which should be used to retrieve
          configuration from (might also be a list of file paths)
        """
        username = self.get_config_value('ui', 'username')
        if username:
            return author_email(username)
        return None