#!/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)