# hg.py - repository classes for mercurial

#

# Copyright 2005 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.

import sys, struct, sha, socket, os, time, base64, re, urllib2

import urllib

from mercurial import byterange

from mercurial.transaction import *

from mercurial.revlog import *

class filelog(revlog):

    def __init__(self, opener, path):

        s = self.encodepath(path)

        revlog.__init__(self, opener, os.path.join("data", s + "i"),

                        os.path.join("data", s))

    def encodepath(self, path):

        s = sha.sha(path).digest()

        s = base64.encodestring(s)[:-3]

        s = re.sub("\+", "%", s)

        s = re.sub("/", "_", s)

        return s

    def read(self, node):

        return self.revision(node)

    def add(self, text, transaction, link, p1=None, p2=None):

        return self.addrevision(text, transaction, link, p1, p2)

    def resolvedag(self, old, new, transaction, link):

        """resolve unmerged heads in our DAG"""

        if old == new: return None

        a = self.ancestor(old, new)

        return self.merge3(old, new, a, transaction, link)

    def merge3(self, my, other, base, transaction, link):

        """perform a 3-way merge and append the result"""

        def temp(prefix, node):

            (fd, name) = tempfile.mkstemp(prefix)

            f = os.fdopen(fd, "w")

            f.write(self.revision(node))

            f.close()

            return name

        a = temp("local", my)

        b = temp("remote", other)

        c = temp("parent", base)

        cmd = os.environ["HGMERGE"]

        r = os.system("%s %s %s %s" % (cmd, a, b, c))

        if r:

            raise "Merge failed, implement rollback!"

        t = open(a).read()

        os.unlink(a)

        os.unlink(b)

        os.unlink(c)

        return self.addrevision(t, transaction, link, my, other)

    def merge(self, other, transaction, linkseq, link):

        """perform a merge and resolve resulting heads"""

        (o, n) = self.mergedag(other, transaction, linkseq)

        return self.resolvedag(o, n, transaction, link)

class manifest(revlog):

    def __init__(self, opener):

        self.mapcache = None

        self.listcache = None

        self.addlist = None

        revlog.__init__(self, opener, "00manifest.i", "00manifest.d")

    def read(self, node):

        if self.mapcache and self.mapcache[0] == node:

            return self.mapcache[1]

        text = self.revision(node)

        map = {}

        self.listcache = (text, text.splitlines(1))

        for l in self.listcache[1]:

            (f, n) = l.split('\0')

            map[f] = bin(n[:40])

        self.mapcache = (node, map)

        return map

    def diff(self, a, b):

        # this is sneaky, as we're not actually using a and b

        if self.listcache and len(self.listcache[0]) == len(a):

            return mdiff.diff(self.listcache[1], self.addlist, 1)

        else:

            return mdiff.textdiff(a, b)

    def add(self, map, transaction, link, p1=None, p2=None):

        files = map.keys()

        files.sort()

        self.addlist = ["%s\000%s\n" % (f, hex(map[f])) for f in files]

        text = "".join(self.addlist)

        n = self.addrevision(text, transaction, link, p1, p2)

        self.mapcache = (n, map)

        self.listcache = (text, self.addlist)

        return n

class changelog(revlog):

    def __init__(self, opener):

        revlog.__init__(self, opener, "00changelog.i", "00changelog.d")

    def extract(self, text):

        if not text:

            return (nullid, "", "0", [], "")

        last = text.index("\n\n")

        desc = text[last + 2:]

        l = text[:last].splitlines()

        manifest = bin(l[0])

        user = l[1]

        date = l[2]

        files = l[3:]

        return (manifest, user, date, files, desc)

    def read(self, node):

        return self.extract(self.revision(node))

    def add(self, manifest, list, desc, transaction, p1=None, p2=None):

        try: user = os.environ["HGUSER"]

        except: user = os.environ["LOGNAME"] + '@' + socket.getfqdn()

        date = "%d %d" % (time.time(), time.timezone)

        list.sort()

        l = [hex(manifest), user, date] + list + ["", desc]

        text = "\n".join(l)

        return self.addrevision(text, transaction, self.count(), p1, p2)

    def merge3(self, my, other, base):

        pass

class dircache:

    def __init__(self, opener, ui):

        self.opener = opener

        self.dirty = 0

        self.ui = ui

        self.map = None

    def __del__(self):

        if self.dirty: self.write()

    def __getitem__(self, key):

        try:

            return self.map[key]

        except TypeError:

            self.read()

            return self[key]

    def read(self):

        if self.map is not None: return self.map

        self.map = {}

        try:

            st = self.opener("dircache").read()

        except: return

        pos = 0

        while pos < len(st):

            e = struct.unpack(">llll", st[pos:pos+16])

            l = e[3]

            pos += 16

            f = st[pos:pos + l]

            self.map[f] = e[:3]

            pos += l

    def update(self, files):

        if not files: return

        self.read()

        self.dirty = 1

        for f in files:

            try:

                s = os.stat(f)

                self.map[f] = (s.st_mode, s.st_size, s.st_mtime)

            except IOError:

                self.remove(f)

    def taint(self, files):

        if not files: return

        self.read()

        self.dirty = 1

        for f in files:

            self.map[f] = (0, -1, 0)

    def remove(self, files):

        if not files: return

        self.read()

        self.dirty = 1

        for f in files:

            try:

                del self.map[f]

            except KeyError:

                self.ui.warn("Not in dircache: %s\n" % f)

                pass

    def clear(self):

        self.map = {}

        self.dirty = 1

    def write(self):

        st = self.opener("dircache", "w")

        for f, e in self.map.items():

            e = struct.pack(">llll", e[0], e[1], e[2], len(f))

            st.write(e + f)

        self.dirty = 0

    def copy(self):

        self.read()

        return self.map.copy()

# used to avoid circular references so destructors work

def opener(base):

    p = base

    def o(path, mode="r"):

        if p[:7] == "http://":

            f = os.path.join(p, urllib.quote(path))

            return httprangereader(f)

        f = os.path.join(p, path)

        if mode != "r" and os.path.isfile(f):

            s = os.stat(f)

            if s.st_nlink > 1:

                file(f + ".tmp", "w").write(file(f).read())

                os.rename(f+".tmp", f)

        return file(f, mode)

    return o

class repository:

    def __init__(self, ui, path=None, create=0):

        self.remote = 0

        if path and path[:7] == "http://":

            self.remote = 1

            self.path = path

        else:

            if not path:

                p = os.getcwd()

                while not os.path.isdir(os.path.join(p, ".hg")):

                    p = os.path.dirname(p)

                    if p == "/": raise "No repo found"

                path = p

            self.path = os.path.join(path, ".hg")

        self.root = path

        self.ui = ui

        if create:

            os.mkdir(self.path)  

            os.mkdir(self.join("data"))

        self.opener = opener(self.path)

        self.manifest = manifest(self.opener)

        self.changelog = changelog(self.opener)

        self.ignorelist = None

        if not self.remote:

            self.dircache = dircache(self.opener, ui)

            try:

                self.current = bin(self.opener("current").read())

            except IOError:

                self.current = None

    def setcurrent(self, node):

        self.current = node

        self.opener("current", "w").write(hex(node))

    def ignore(self, f):

        if self.ignorelist is None:

            self.ignorelist = []

            try:

                l = open(os.path.join(self.root, ".hgignore")).readlines()

                for pat in l:

                    if pat != "\n":

                        self.ignorelist.append(re.compile(pat[:-1]))

            except IOError: pass

        for pat in self.ignorelist:

            if pat.search(f): return True

        return False

    def join(self, f):

        return os.path.join(self.path, f)

    def file(self, f):

        return filelog(self.opener, f)

    def transaction(self):

        return transaction(self.opener, self.join("journal"))

    def merge(self, other):

        tr = self.transaction()

        changed = {}

        new = {}

        seqrev = self.changelog.count()

        # some magic to allow fiddling in nested scope

        nextrev = [seqrev]

        # helpers for back-linking file revisions to local changeset

        # revisions so we can immediately get to changeset from annotate

        def accumulate(text):

            # track which files are added in which changeset and the

            # corresponding _local_ changeset revision

            files = self.changelog.extract(text)[3]

            for f in files:

                changed.setdefault(f, []).append(nextrev[0])

            nextrev[0] += 1

        def seq(start):

            while 1:

                yield start

                start += 1

        def lseq(l):

            for r in l:

                yield r

        # begin the import/merge of changesets

        self.ui.status("merging new changesets\n")

        (co, cn) = self.changelog.mergedag(other.changelog, tr,

                                           seq(seqrev), accumulate)

        resolverev = self.changelog.count()

        # is there anything to do?

        if co == cn:

            tr.close()

            return

        # do we need to resolve?

        simple = (co == self.changelog.ancestor(co, cn))

        # merge all files changed by the changesets,

        # keeping track of the new tips

        changelist = changed.keys()

        changelist.sort()

        for f in changelist:

            sys.stdout.write(".")

            sys.stdout.flush()

            r = self.file(f)

            node = r.merge(other.file(f), tr, lseq(changed[f]), resolverev)

            if node:

                new[f] = node

        sys.stdout.write("\n")

        # begin the merge of the manifest

        self.ui.status("merging manifests\n")

        (mm, mo) = self.manifest.mergedag(other.manifest, tr, seq(seqrev))

        # For simple merges, we don't need to resolve manifests or changesets

        if simple:

            tr.close()

            return

        ma = self.manifest.ancestor(mm, mo)

        # resolve the manifest to point to all the merged files

        self.ui.status("resolving manifests\n")

        mmap = self.manifest.read(mm) # mine

        omap = self.manifest.read(mo) # other

        amap = self.manifest.read(ma) # ancestor

        nmap = {}

        for f, mid in mmap.iteritems():

            if f in omap:

                if mid != omap[f]: 

                    nmap[f] = new.get(f, mid) # use merged version