#!/usr/bin/env python
#
# This is a generalized framework for converting between SCM
# repository formats.
#
# To use, run:
#
# convert-repo <source> [<dest> [<mapfile>]]
#
# Currently accepted source formats: git, cvs
# Currently accepted destination formats: hg
#
# If destination isn't given, a new Mercurial repo named <src>-hg will
# be created. If <mapfile> isn't given, it will be put in a default
# location (<dest>/.hg/shamap by default)
#
# The <mapfile> is a simple text file that maps each source commit ID to
# the destination ID for that revision, like so:
#
# <source ID> <destination ID>
#
# If the file doesn't exist, it's automatically created.  It's updated
# on each commit copied, so convert-repo can be interrupted and can
# be run repeatedly to copy new commits.

import sys, os, zlib, sha, time, re, locale, socket
os.environ["HGENCODING"] = "utf-8"
from mercurial import hg, ui, util, fancyopts

class Abort(Exception): pass
class NoRepo(Exception): pass

class commit:
    def __init__(self, **parts):
        for x in "author date desc parents".split():
            if not x in parts:
                abort("commit missing field %s\n" % x)
        self.__dict__.update(parts)

quiet = 0
def status(msg):
    if not quiet: sys.stdout.write(str(msg))

def warn(msg):
    sys.stderr.write(str(msg))

def abort(msg):
    raise Abort(msg)

def recode(s):
    try:
        return s.decode("utf-8").encode("utf-8")
    except:
        try:
            return s.decode("latin-1").encode("utf-8")
        except:
            return s.decode("utf-8", "replace").encode("utf-8")

# CVS conversion code inspired by hg-cvs-import and git-cvsimport
class convert_cvs:
    def __init__(self, path):
        self.path = path
        cvs = os.path.join(path, "CVS")
        if not os.path.exists(cvs):
            raise NoRepo("couldn't open CVS repo %s" % path)

        self.changeset = {}
        self.files = {}
        self.tags = {}
        self.lastbranch = {}
        self.parent = {}
        self.socket = None
        self.cvsroot = file(os.path.join(cvs, "Root")).read()[:-1]
        self.cvsrepo = file(os.path.join(cvs, "Repository")).read()[:-1]
        self.encoding = locale.getpreferredencoding()
        self._parse()
        self._connect()

    def _parse(self):
        if self.changeset:
            return

        d = os.getcwd()
        try:
            os.chdir(self.path)
            id = None
            state = 0
            for l in os.popen("cvsps -A -u --cvs-direct -q"):
                if state == 0: # header
                    if l.startswith("PatchSet"):
                        id = l[9:-2]
                    elif l.startswith("Date"):
                        date = util.parsedate(l[6:-1], ["%Y/%m/%d %H:%M:%S"])
                        date = util.datestr(date)
                    elif l.startswith("Branch"):
                        branch = l[8:-1]
                        self.parent[id] = self.lastbranch.get(branch,'bad')
                        self.lastbranch[branch] = id
                    elif l.startswith("Ancestor branch"):
                        ancestor = l[17:-1]
                        self.parent[id] = self.lastbranch[ancestor]
                    elif l.startswith("Author"):
                        author = self.recode(l[8:-1])
                    elif l.startswith("Tag: "):
                        t = l[5:-1].rstrip()
                        if t != "(none)":
                            self.tags[t] = id
                    elif l.startswith("Log:"):
                        state = 1
                        log = ""
                elif state == 1: # log
                    if l == "Members: \n":
                        files = {}
                        log = self.recode(log[:-1])
                        if log.isspace():
                            log = "*** empty log message ***\n"
                        state = 2
                    else:
                        log += l
                elif state == 2:
                    if l == "\n": #
                        state = 0
                        p = [self.parent[id]]
                        if id == "1":
                            p = []
                        c = commit(author=author, date=date, parents=p,
                                   desc=log, branch=branch)
                        self.changeset[id] = c
                        self.files[id] = files
                    else:
                        file,rev = l[1:-2].rsplit(':',1)
                        rev = rev.split("->")[1]
                        files[file] = rev

            self.heads = self.lastbranch.values()
        finally:
            os.chdir(d)

    def _connect(self):
        root = self.cvsroot
        conntype = None
        user, host = None, None
        cmd = ['cvs', 'server']

        status("connecting to %s\n" % root)

        if root.startswith(":pserver:"):
            root = root[9:]
            m = re.match(r'(?:(.*?)(?::(.*?))?@)?([^:\/]*)(?::(\d*))?(.*)', root)
            if m:
                conntype = "pserver"
                user, passw, serv, port, root = m.groups()
                if not user:
                    user = "anonymous"
                rr = ":pserver:" + user + "@" + serv + ":" +  root
                if port:
                    rr2, port = "-", int(port)
                else:
                    rr2, port = rr, 2401
                rr += str(port)

                if not passw:
                    passw = "A"
                    pf = open(os.path.join(os.environ["HOME"], ".cvspass"))
                    for l in pf:
                        # :pserver:cvs@mea.tmt.tele.fi:/cvsroot/zmailer Ah<Z
                        m = re.match(r'(/\d+\s+/)?(.*)', l)
                        l = m.group(2)
                        w, p = l.split(' ', 1)
                        if w in [rr, rr2]:
                            passw = p
                            break
                    pf.close()

                sck = socket.socket()
                sck.connect((serv, port))
                sck.send("\n".join(["BEGIN AUTH REQUEST", root, user, passw, "END AUTH REQUEST", ""]))
                if sck.recv(128) != "I LOVE YOU\n":
                    raise NoRepo("CVS pserver authentication failed")

                self.writep = self.readp = sck.makefile('r+')

        if not conntype and root.startswith(":local:"):
            conntype = "local"
            root = root[7:]

        if not conntype:
            # :ext:user@host/home/user/path/to/cvsroot
            if root.startswith(":ext:"):
                root = root[5:]
            m = re.match(r'(?:([^@:/]+)@)?([^:/]+):?(.*)', root)
            if not m:
                conntype = "local"
            else:
                conntype = "rsh"
                user, host, root = m.group(1), m.group(2), m.group(3)

        if conntype != "pserver":
            if conntype == "rsh": 
                rsh = os.environ.get("CVS_RSH" or "rsh")
                if user:
                    cmd = [rsh, '-l', user, host] + cmd
                else:
                    cmd = [rsh, host] + cmd

            self.writep, self.readp = os.popen2(cmd)

        self.realroot = root

        self.writep.write("Root %s\n" % root)
        self.writep.write("Valid-responses ok error Valid-requests Mode"
                          " M Mbinary E Checked-in Created Updated"
                          " Merged Removed\n")
        self.writep.write("valid-requests\n")
        self.writep.flush()
        r = self.readp.readline()
        if not r.startswith("Valid-requests"):
            abort("server sucks\n")
        if "UseUnchanged" in r:
            self.writep.write("UseUnchanged\n")
            self.writep.flush()
            r = self.readp.readline()

    def getheads(self):
        return self.heads

    def _getfile(self, name, rev):
        if rev.endswith("(DEAD)"):
            raise IOError

        args = ("-N -P -kk -r %s --" % rev).split()
        args.append(os.path.join(self.cvsrepo, name))
        for x in args:
            self.writep.write("Argument %s\n" % x)
        self.writep.write("Directory .\n%s\nco\n" % self.realroot)
        self.writep.flush()

        data = ""
        while 1:
            line = self.readp.readline()
            if line.startswith("Created ") or line.startswith("Updated "):
                self.readp.readline() # path
                self.readp.readline() # entries
                mode = self.readp.readline()[:-1]
                count = int(self.readp.readline()[:-1])
                data = self.readp.read(count)
            elif line.startswith(" "):
                data += line[1:]
            elif line.startswith("M "):
                pass
            elif line.startswith("Mbinary "):
                count = int(self.readp.readline()[:-1])
                data = self.readp.read(count)
            else:
                if line == "ok\n":
                    return (data, "x" in mode and "x" or "")
                elif line.startswith("E "):
                    warn("cvs server: %s\n" % line[2:])
                elif line.startswith("Remove"):
                    l = self.readp.readline()
                    l = self.readp.readline()
                    if l != "ok\n":
                        abort("unknown CVS response: %s\n" % l)
                else:
                    abort("unknown CVS response: %s\n" % line)

    def getfile(self, file, rev):
        data, mode = self._getfile(file, rev)
        self.modecache[(file, rev)] = mode
        return data

    def getmode(self, file, rev):
        return self.modecache[(file, rev)]

    def getchanges(self, rev):
        self.modecache = {}
        files = self.files[rev]
        cl = files.items()
        cl.sort()
        return cl

    def recode(self, text):
        return text.decode(self.encoding, "replace").encode("utf-8")

    def getcommit(self, rev):
        return self.changeset[rev]

    def gettags(self):
        return self.tags

class convert_git:
    def __init__(self, path):
        if os.path.isdir(path + "/.git"):
            path += "/.git"
        self.path = path
        if not os.path.exists(path + "/objects"):
            raise NoRepo("couldn't open GIT repo %s" % path)

    def getheads(self):
        fh = os.popen("GIT_DIR=%s git-rev-parse --verify HEAD" % self.path)
        return [fh.read()[:-1]]

    def catfile(self, rev, type):
        if rev == "0" * 40: raise IOError()
        fh = os.popen("GIT_DIR=%s git-cat-file %s %s 2>/dev/null" % (self.path, type, rev))
        return fh.read()

    def getfile(self, name, rev):
        return self.catfile(rev, "blob")

    def getmode(self, name, rev):
        return self.modecache[(name, rev)]

    def getchanges(self, version):
        self.modecache = {}
        fh = os.popen("GIT_DIR=%s git-diff-tree --root -m -r %s" % (self.path, version))
        changes = []
        for l in fh:
            if "\t" not in l: continue
            m, f = l[:-1].split("\t")
            m = m.split()
            h = m[3]
            p = (m[1] == "100755")
            s = (m[1] == "120000")
            self.modecache[(f, h)] = (p and "x") or (s and "l") or ""
            changes.append((f, h))
        return changes

    def getcommit(self, version):
        c = self.catfile(version, "commit") # read the commit hash
        end = c.find("\n\n")
        message = c[end+2:]
        message = recode(message)
        l = c[:end].splitlines()
        manifest = l[0].split()[1]
        parents = []
        for e in l[1:]:
            n,v = e.split(" ", 1)
            if n == "author":
                p = v.split()
                tm, tz = p[-2:]
                author = " ".join(p[:-2])
                if author[0] == "<": author = author[1:-1]
                author = recode(author)
            if n == "committer":
                p = v.split()
                tm, tz = p[-2:]
                committer = " ".join(p[:-2])
                if committer[0] == "<": committer = committer[1:-1]
                committer = recode(committer)
                message += "\ncommitter: %s\n" % committer
            if n == "parent": parents.append(v)

        tzs, tzh, tzm = tz[-5:-4] + "1", tz[-4:-2], tz[-2:]
        tz = -int(tzs) * (int(tzh) * 3600 + int(tzm))
        date = tm + " " + str(tz)

        c = commit(parents=parents, date=date, author=author, desc=message)
        return c

    def gettags(self):
        tags = {}
        fh = os.popen('git-ls-remote --tags "%s" 2>/dev/null' % self.path)
        prefix = 'refs/tags/'
        for line in fh:
            line = line.strip()
            if not line.endswith("^{}"):
                continue
            node, tag = line.split(None, 1)
            if not tag.startswith(prefix):
                continue
            tag = tag[len(prefix):-3]
            tags[tag] = node

        return tags

class convert_mercurial:
    def __init__(self, path):
        self.path = path
        u = ui.ui()
        try:
            self.repo = hg.repository(u, path)
        except:
            raise NoRepo("could open hg repo %s" % path)

    def mapfile(self):
        return os.path.join(self.path, ".hg", "shamap")

    def getheads(self):
        h = self.repo.changelog.heads()
        return [ hg.hex(x) for x in h ]

    def putfile(self, f, e, data):
        self.repo.wwrite(f, data, e)
        if self.repo.dirstate.state(f) == '?':
            self.repo.dirstate.update([f], "a")

    def delfile(self, f):
        try:
            os.unlink(self.repo.wjoin(f))
            #self.repo.remove([f])
        except:
            pass

    def putcommit(self, files, parents, commit):
        seen = {}
        pl = []
        for p in parents:
            if p not in seen:
                pl.append(p)
                seen[p] = 1
        parents = pl

        if len(parents) < 2: parents.append("0" * 40)
        if len(parents) < 2: parents.append("0" * 40)
        p2 = parents.pop(0)

        text = commit.desc
        extra = {}
        try:
            extra["branch"] = commit.branch
        except AttributeError:
            pass

        while parents:
            p1 = p2
            p2 = parents.pop(0)
            a = self.repo.rawcommit(files, text, commit.author, commit.date,
                                    hg.bin(p1), hg.bin(p2), extra=extra)
            text = "(octopus merge fixup)\n"
            p2 = hg.hex(self.repo.changelog.tip())

        return p2

    def puttags(self, tags):
        try:
            old = self.repo.wfile(".hgtags").read()
            oldlines = old.splitlines(1)
            oldlines.sort()
        except:
            oldlines = []

        k = tags.keys()
        k.sort()
        newlines = []
        for tag in k:
            newlines.append("%s %s\n" % (tags[tag], tag))

        newlines.sort()

        if newlines != oldlines:
            status("updating tags\n")
            f = self.repo.wfile(".hgtags", "w")
            f.write("".join(newlines))
            f.close()
            if not oldlines: self.repo.add([".hgtags"])
            date = "%s 0" % int(time.mktime(time.gmtime()))
            self.repo.rawcommit([".hgtags"], "update tags", "convert-repo",
                                date, self.repo.changelog.tip(), hg.nullid)
            return hg.hex(self.repo.changelog.tip())

converters = [convert_cvs, convert_git, convert_mercurial]

def converter(path):
    if not os.path.isdir(path):
        abort("%s: not a directory\n" % path)
    for c in converters:
        try:
            return c(path)
        except NoRepo:
            pass
    abort("%s: unknown repository type\n" % path)

class convert:
    def __init__(self, source, dest, mapfile, opts):

        self.source = source
        self.dest = dest
        self.mapfile = mapfile
        self.opts = opts
        self.commitcache = {}

        self.map = {}
        try:
            for l in file(self.mapfile):
                sv, dv = l[:-1].split()
                self.map[sv] = dv
        except IOError:
            pass

    def walktree(self, heads):
        visit = heads
        known = {}
        parents = {}
        while visit:
            n = visit.pop(0)
            if n in known or n in self.map: continue
            known[n] = 1
            self.commitcache[n] = self.source.getcommit(n)
            cp = self.commitcache[n].parents
            for p in cp:
                parents.setdefault(n, []).append(p)
                visit.append(p)

        return parents

    def toposort(self, parents):
        visit = parents.keys()
        seen = {}
        children = {}

        while visit:
            n = visit.pop(0)
            if n in seen: continue
            seen[n] = 1
            pc = 0
            if n in parents:
                for p in parents[n]:
                    if p not in self.map: pc += 1
                    visit.append(p)
                    children.setdefault(p, []).append(n)
            if not pc: root = n

        s = []
        removed = {}
        visit = children.keys()
        while visit:
            n = visit.pop(0)
            if n in removed: continue
            dep = 0
            if n in parents:
                for p in parents[n]:
                    if p in self.map: continue
                    if p not in removed:
                        # we're still dependent
                        visit.append(n)
                        dep = 1
                        break

            if not dep:
                # all n's parents are in the list
                removed[n] = 1
                if n not in self.map:
                    s.append(n)
                if n in children:
                    for c in children[n]:
                        visit.insert(0, c)

        if opts.get('datesort'):
            depth = {}
            for n in s:
                depth[n] = 0
                pl = [p for p in self.commitcache[n].parents if p not in self.map]
                if pl:
                    depth[n] = max([depth[p] for p in pl]) + 1

            s = [(depth[n], self.commitcache[n].date, n) for n in s]
            s.sort()
            s = [e[2] for e in s]

        return s

    def copy(self, rev):
        c = self.commitcache[rev]
        files = self.source.getchanges(rev)

        for f,v in files:
            try:
                data = self.source.getfile(f, v)
            except IOError, inst:
                self.dest.delfile(f)
            else:
                e = self.source.getmode(f, v)
                self.dest.putfile(f, e, data)

        r = [self.map[v] for v in c.parents]
        f = [f for f,v in files]
        self.map[rev] = self.dest.putcommit(f, r, c)
        file(self.mapfile, "a").write("%s %s\n" % (rev, self.map[rev]))

    def convert(self):
        status("scanning source...\n")
        heads = self.source.getheads()
        parents = self.walktree(heads)
        status("sorting...\n")
        t = self.toposort(parents)
        num = len(t)
        c = None

        status("converting...\n")
        for c in t:
            num -= 1
            desc = self.commitcache[c].desc
            if "\n" in desc:
                desc = desc.splitlines()[0]
            status("%d %s\n" % (num, desc))
            self.copy(c)

        tags = self.source.gettags()
        ctags = {}
        for k in tags:
            v = tags[k]
            if v in self.map:
                ctags[k] = self.map[v]

        if c and ctags:
            nrev = self.dest.puttags(ctags)
            # write another hash correspondence to override the previous
            # one so we don't end up with extra tag heads
            if nrev:
                file(self.mapfile, "a").write("%s %s\n" % (c, nrev))

def command(src, dest=None, mapfile=None, **opts):
    srcc = converter(src)
    if not hasattr(srcc, "getcommit"):
        abort("%s: can't read from this repo type\n" % src)

    if not dest:
        dest = src + "-hg"
        status("assuming destination %s\n" % dest)
        if not os.path.isdir(dest):
            status("creating repository %s\n" % dest)
            os.system("hg init " + dest)
    destc = converter(dest)
    if not hasattr(destc, "putcommit"):
        abort("%s: can't write to this repo type\n" % src)

    if not mapfile:
        try:
            mapfile = destc.mapfile()
        except:
            mapfile = os.path.join(destc, "map")

    c = convert(srcc, destc, mapfile, opts)
    c.convert()

options = [('q', 'quiet', None, 'suppress output'),
           ('', 'datesort', None, 'try to sort changesets by date')]
opts = {}
args = fancyopts.fancyopts(sys.argv[1:], options, opts)

if opts['quiet']:
    quiet = 1

try:
    command(*args, **opts)
except Abort, inst:
    warn(inst)
except KeyboardInterrupt:
    status("interrupted\n")