# statichttprepo.py - simple http repository class for mercurial
#
# This provides read-only repo access to repositories exported via static http
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

from i18n import _
import changelog, httprangereader
import repo, localrepo, manifest, util, store
import urllib, urllib2, errno

class rangereader(httprangereader.httprangereader):
    def read(self, size=None):
        try:
            return httprangereader.httprangereader.read(self, size)
        except urllib2.HTTPError, inst:
            num = inst.code == 404 and errno.ENOENT or None
            raise IOError(num, inst)
        except urllib2.URLError, inst:
            raise IOError(None, inst.reason[1])

def opener(base):
    """return a function that opens files over http"""
    p = base
    def o(path, mode="r"):
        f = "/".join((p, urllib.quote(path)))
        return rangereader(f)
    return o

class statichttprepository(localrepo.localrepository):
    def __init__(self, ui, path):
        self._url = path
        self.ui = ui

        self.path = path.rstrip('/') + "/.hg"
        self.opener = opener(self.path)

        # find requirements
        try:
            requirements = self.opener("requires").read().splitlines()
        except IOError, inst:
            if inst.errno != errno.ENOENT:
                raise
            # check if it is a non-empty old-style repository
            try:
                self.opener("00changelog.i").read(1)
            except IOError, inst:
                if inst.errno != errno.ENOENT:
                    raise
                # we do not care about empty old-style repositories here
                msg = _("'%s' does not appear to be an hg repository") % path
                raise repo.RepoError(msg)
            requirements = []

        # check them
        for r in requirements:
            if r not in self.supported:
                raise repo.RepoError(_("requirement '%s' not supported") % r)

        # setup store
        def pjoin(a, b):
            return a + '/' + b
        self.store = store.store(requirements, self.path, opener, pjoin)
        self.spath = self.store.path
        self.sopener = self.store.opener
        self.sjoin = self.store.join

        self.manifest = manifest.manifest(self.sopener)
        self.changelog = changelog.changelog(self.sopener)
        self.tagscache = None
        self.nodetagscache = None
        self.encodepats = None
        self.decodepats = None

    def url(self):
        return 'static-' + self._url

    def local(self):
        return False

    def lock(self, wait=True):
        raise util.Abort(_('cannot lock static-http repository'))

def instance(ui, path, create):
    if create:
        raise util.Abort(_('cannot create new static-http repository'))
    return statichttprepository(ui, path[7:])