#!/usr/bin/env python

#

# Minimal support for git commands on an hg repository

#

# Copyright 2005 Chris Mason <mason@suse.com>

#

# This software may be used and distributed according to the terms

# of the GNU General Public License, incorporated herein by reference.

import time, sys, signal

from mercurial import hg, mdiff, fancyopts, commands, ui

def difftree(args, repo):

    def __difftree(repo, files = None, node1 = None, node2 = None):

        def date(c):

            return time.asctime(time.gmtime(float(c[2].split(' ')[0])))

        if node2:

            change = repo.changelog.read(node2)

            mmap2 = repo.manifest.read(change[0])

            (c, a, d) = repo.diffrevs(node1, node2)

            def read(f): return repo.file(f).read(mmap2[f])

            date2 = date(change)

        else:

            date2 = time.asctime()

            (c, a, d, u) = repo.diffdir(repo.root, node1)

            if not node1:

                node1 = repo.dirstate.parents()[0]

            def read(f): return file(os.path.join(repo.root, f)).read()

        change = repo.changelog.read(node1)

        mmap = repo.manifest.read(change[0])

        date1 = date(change)

        empty = "0" * 40;

        if files:

            c, a, d = map(lambda x: filterfiles(files, x), (c, a, d))

        for f in c:

            # TODO get file permissions

            print ":100664 100664 %s %s %s %s" % (hg.hex(mmap[f]), 

                                                      hg.hex(mmap2[f]), f, f)

        for f in a:

            print ":000000 100664 %s %s %s %s" % (empty, hg.hex(mmap2[f]), f, f)

        for f in d:

            print ":100664 000000 %s %s %s %s" % (hg.hex(mmap[f]), empty, f, f)

    ##

    revs = []

    if args:

        doptions = {}

        opts = [('p', 'patch', None, 'patch'),

                ('r', 'recursive', None, 'recursive')]

        args = fancyopts.fancyopts(args, opts, doptions,

                                   'hg diff-tree [options] sha1 sha1')

    if len(args) < 2:

        help()

        sys.exit(1)

    revs.append(repo.lookup(args[0]))

    revs.append(repo.lookup(args[1]))

    args = args[2:]

    if doptions['patch']:

        commands.dodiff(repo, args, *revs)

    else:

        __difftree(repo, args, *revs)

def catcommit(repo, n, prefix):

    nlprefix = '\n' + prefix;

    changes = repo.changelog.read(n)

    (p1, p2) = repo.changelog.parents(n)

    (h, h1, h2) = map(hg.hex, (n, p1, p2))

    (i1, i2) = map(repo.changelog.rev, (p1, p2))

    print "tree %s" % (h)

    if i1 != -1: print "%sparent %s" % (prefix, h1)

    if i2 != -1: print "%sparent %s" % (prefix, h2)

    date_ar = changes[2].split(' ')

    date = int(float(date_ar[0]))

    print "%sauthor <%s> %s %s" % (prefix, changes[1], date, date_ar[1])

    print "%scommitter <%s> %s %s" % (prefix, changes[1], date, date_ar[1])

    print prefix

    if prefix != "":

        print "%s%s" % (prefix, changes[4].replace('\n', nlprefix).strip())

    else:

        print changes[4]

def catfile(args, ui, repo):

    doptions = {}

    opts = [('s', 'stdin', None, 'stdin')]

    args = fancyopts.fancyopts(args, opts, doptions,

                               'hg cat-file type sha1')

    # in stdin mode, every line except the commit is prefixed with two

    # spaces.  This way the our caller can find the commit without magic

    # strings

    #

    prefix = ""

    if doptions['stdin']:

        try:

            (type, r) = raw_input().split(' ');

            prefix = "  "

        except EOFError:

            return

    else:

        if len(args) < 2:

            help()

            sys.exit(1)

        type = args[0]

        r = args[1]

    while r:

        if type != "commit":

            sys.stderr.write("aborting hg cat-file only understands commits\n")

            sys.exit(1);

        n = repo.changelog.lookup(r)

        catcommit(repo, n, prefix)

        if doptions['stdin']:

            try:

                (type, r) = raw_input().split(' ');

            except EOFError:

                break

        else:

            break

# git rev-tree is a confusing thing.  You can supply a number of

# commit sha1s on the command line, and it walks the commit history

# telling you which commits are reachable from the supplied ones via

# a bitmask based on arg position.

# you can specify a commit to stop at by starting the sha1 with ^

def revtree(args, repo):

    # calculate and return the reachability bitmask for sha

    def is_reachable(ar, reachable, sha):

        if len(ar) == 0:

            return 1

        mask = 0

        for i in range(len(ar)):

            if sha in reachable[i]:

                mask |= 1 << i

        return mask

    reachable = []

    stop_sha1 = []

    want_sha1 = []

    # figure out which commits they are asking for and which ones they

    # want us to stop on

    for i in range(len(args)):

        if args[i].count('^'):

            s = args[i].split('^')[1]

            stop_sha1.append(repo.changelog.lookup(s))

            want_sha1.append(s)

        elif args[i] != 'HEAD':

            want_sha1.append(args[i])

    # calculate the graph for the supplied commits

    for i in range(len(want_sha1)):

        reachable.append({});

        n = repo.changelog.lookup(want_sha1[i]);

        visit = [n];

        reachable[i][n] = 1

        while visit:

            n = visit.pop(0)

            if n in stop_sha1:

                break

            for p in repo.changelog.parents(n):

                if p not in reachable[i]:

                    reachable[i][p] = 1

                    visit.append(p)

                if p in stop_sha1:

                    break

    # walk the repository looking for commits that are in our

    # reachability graph

    for i in range(repo.changelog.count()):

        n = repo.changelog.node(i)

        mask = is_reachable(want_sha1, reachable, n)

        if mask:

            changes = repo.changelog.read(n)

            (p1, p2) = repo.changelog.parents(n)

            (h, h1, h2) = map(hg.hex, (n, p1, p2))

            (i1, i2) = map(repo.changelog.rev, (p1, p2))

            date = changes[2].split(' ')[0]

            print "%s %s:%s" % (date, h, mask),

            mask = is_reachable(want_sha1, reachable, p1)

            if i1 != -1 and mask > 0:

                print "%s:%s " % (h1, mask),

            mask = is_reachable(want_sha1, reachable, p2)

            if i2 != -1 and mask > 0:

                print "%s:%s " % (h2, mask),

            print ""

# git rev-list tries to order things by date, and has the ability to stop

# at a given commit without walking the whole repo.  TODO add the stop

# parameter

def revlist(args, repo):

    doptions = {}

    opts = [('c', 'commit', None, 'commit')]

    args = fancyopts.fancyopts(args, opts, doptions,

                               'hg rev-list')

    for i in range(repo.changelog.count()):

        n = repo.changelog.node(i)

        print hg.hex(n)

        if doptions['commit']:

            catcommit(repo, n, '  ')

def catchterm(*args):

    raise SignalInterrupt

def help():

    sys.stderr.write("commands:\n")

    sys.stderr.write("  hgit cat-file [type] sha1\n")

    sys.stderr.write("  hgit diff-tree [-p] [-r] sha1 sha1\n")

    sys.stderr.write("  hgit rev-tree [sha1 ... [^stop sha1]]\n")

    sys.stderr.write("  hgit rev-list [-c]\n")

cmd = sys.argv[1]

args = sys.argv[2:]

u = ui.ui()

signal.signal(signal.SIGTERM, catchterm)

repo = hg.repository(ui = u)

if cmd == "diff-tree":

    difftree(args, repo)

elif cmd == "cat-file":

    catfile(args, ui, repo)

elif cmd == "rev-tree":

    revtree(args, repo)

elif cmd == "rev-list":

    revlist(args, repo)

elif cmd == "help":

    help()

else:

    if cmd: sys.stderr.write("unknown command\n\n")

    help()

    sys.exit(1)

sys.exit(0)