#!/usr/bin/env python

# Encoding: iso-8859-1

# vim: tw=80 ts=4 sw=4 noet

# -----------------------------------------------------------------------------

# Project   : Basic Darcs to Mercurial conversion script

#

# *** DEPRECATED. Use the convert extension instead. This script will

# *** be removed soon.

#

# -----------------------------------------------------------------------------

# Authors   : Sebastien Pierre                           <sebastien@xprima.com>

#             TK Soh                                      <teekaysoh@gmail.com>

# -----------------------------------------------------------------------------

# Creation  : 24-May-2006

# -----------------------------------------------------------------------------

import os, sys

import tempfile

import xml.dom.minidom as xml_dom

from time import strptime, mktime

import re

DARCS_REPO = None

HG_REPO    = None

USAGE = """\

%s DARCSREPO HGREPO [SKIP]

    Converts the given Darcs repository to a new Mercurial repository. The given

    HGREPO must not exist, as it will be created and filled up (this will avoid

    overwriting valuable data.

    In case an error occurs within the process, you can resume the process by

    giving the last successfuly applied change number.

""" % (os.path.basename(sys.argv[0]))

# ------------------------------------------------------------------------------

#

# Utilities

#

# ------------------------------------------------------------------------------

def cmd(text, path=None, silent=False):

	"""Executes a command, in the given directory (if any), and returns the

	command result as a string."""

	cwd = None

	if path:

		path = os.path.abspath(path)

		cwd  = os.getcwd()

		os.chdir(path)

	if not silent: print "> ", text

	res = os.popen(text).read()

	if path:

		os.chdir(cwd)

	return res

def writefile(path, data):

	"""Writes the given data into the given file."""

	f = file(path, "w") ; f.write(data)  ; f.close()

def error( *args ):

	sys.stderr.write("ERROR: ")

	for a in args: sys.stderr.write(str(a))

	sys.stderr.write("\n")

	sys.stderr.write("You can make manual fixes if necessary and then resume by"

	" giving the last changeset number")

	sys.exit(-1)

# ------------------------------------------------------------------------------

#

# Darcs interface

#

# ------------------------------------------------------------------------------

def darcs_changes(darcsRepo):

	"""Gets the changes list from the given darcs repository. This returns the

	chronological list of changes as (change name, change summary)."""

	changes    = cmd("darcs changes --reverse --xml-output", darcsRepo)

	doc        = xml_dom.parseString(changes)

	for patch_node in doc.childNodes[0].childNodes:

		name = filter(lambda n: n.nodeName == "name", patch_node.childNodes)

		comm = filter(lambda n: n.nodeName == "comment", patch_node.childNodes)

		if not name:continue

		else: name = name[0].childNodes[0].data

		if not comm: comm = ""

		else: comm = comm[0].childNodes[0].data

		author = patch_node.getAttribute("author")

		date   = patch_node.getAttribute("date")

		chash  = os.path.splitext(patch_node.getAttribute("hash"))[0]

		yield author, date, name, chash, comm

def darcs_tip(darcs_repo):

	changes = cmd("darcs changes",darcs_repo,silent=True)

	changes = filter(lambda l: l.strip().startswith("* "), changes.split("\n"))

	return len(changes)

def darcs_pull(hg_repo, darcs_repo, chash):

	old_tip = darcs_tip(darcs_repo)

	res     = cmd("darcs pull \"%s\" --all --match=\"hash %s\"" % (darcs_repo, chash), hg_repo)

	if re.search('^We have conflicts in the following files:$', res, re.MULTILINE):

		print "Trying to revert files to work around conflict..."

		rev_res = cmd ("darcs revert --all", hg_repo)

		print rev_res

	print res

	new_tip = darcs_tip(darcs_repo)

	if not new_tip != old_tip + 1:

		error("Darcs pull did not work as expected: " + res)

def darcs_changes_summary(darcs_repo, chash):

	"""Gets the changes from the darcs summary. This returns the chronological

	list of changes as (change_type, args). Eg. ('add_file', 'foo.txt') or

	('move', ['foo.txt','bar.txt'])."""

	change = cmd("darcs changes --summary --xml-output --match=\"hash %s\"" % (chash), darcs_repo)

	doc = xml_dom.parseString(change)

	for patch_node in doc.childNodes[0].childNodes:

		summary_nodes = filter(lambda n: n.nodeName == "summary" and n.nodeType == n.ELEMENT_NODE, patch_node.childNodes)

		for summary_node in summary_nodes:

			change_nodes = filter(lambda n: n.nodeType == n.ELEMENT_NODE, summary_node.childNodes)

			if len(change_nodes) == 0:

				name = filter(lambda n: n.nodeName == "name", patch_node.childNodes)

				if not name:

					error("Darcs patch has an empty summary node and no name: " + patch_node.toxml())

				name = name[0].childNodes[0].data.strip()

				(tag, sub_count) = re.subn('^TAG ', '', name, 1)

				if sub_count != 1:

					error("Darcs patch has an empty summary node but doesn't look like a tag: " + patch_node.toxml());

			for change_node in change_nodes:

				change = change_node.nodeName

				if change == 'modify_file':

					yield change, change_node.childNodes[0].data.strip()

				elif change == 'add_file':

					yield change, change_node.childNodes[0].data.strip()

				elif change == 'remove_file':

					yield change, change_node.childNodes[0].data.strip()

				elif change == 'add_directory':

					yield change, change_node.childNodes[0].data.strip()

				elif change == 'remove_directory':

					yield change, change_node.childNodes[0].data.strip()

				elif change == 'move':

					yield change, (change_node.getAttribute('from'), change_node.getAttribute('to'))

				else:

					error('Problem parsing summary xml: Unexpected element: ' + change_node.toxml())

# ------------------------------------------------------------------------------

#

# Mercurial interface

#

# ------------------------------------------------------------------------------

def hg_commit( hg_repo, text, author, date ):

	fd, tmpfile = tempfile.mkstemp(prefix="darcs2hg_")

	writefile(tmpfile, text)

	old_tip = hg_tip(hg_repo)

	cmd("hg add -X _darcs", hg_repo)

	cmd("hg remove -X _darcs --after", hg_repo)

	res = cmd("hg commit -l %s -u \"%s\" -d \"%s 0\""  % (tmpfile, author, date), hg_repo)

	os.close(fd)

	os.unlink(tmpfile)

	new_tip = hg_tip(hg_repo)

	if not new_tip == old_tip + 1:

		# Sometimes we may have empty commits, we simply skip them

		if res.strip().lower().find("nothing changed") != -1:

			pass

		else:

			error("Mercurial commit did not work as expected: " + res)

def hg_tip( hg_repo ):

	"""Returns the latest local revision number in the given repository."""

	tip = cmd("hg tip", hg_repo, silent=True)

	tip = tip.split("\n")[0].split(":")[1].strip()

	return int(tip)

def hg_rename( hg_repo, from_file, to_file ):

	cmd("hg rename --after \"%s\" \"%s\"" % (from_file, to_file), hg_repo);

def hg_tag ( hg_repo, text, author, date ):

	old_tip = hg_tip(hg_repo)

	res = cmd("hg tag -u \"%s\" -d \"%s 0\" \"%s\""	 % (author, date, text), hg_repo)

	new_tip = hg_tip(hg_repo)

	if not new_tip == old_tip + 1:

		error("Mercurial tag did not work as expected: " + res)

def hg_handle_change( hg_repo, author, date, change, arg ):

	"""Processes a change event as output by darcs_changes_summary. These

	consist of file move/rename/add/delete commands."""

	if change == 'modify_file':

		pass

	elif change == 'add_file':

		pass

	elif change =='remove_file':

		pass

	elif change == 'add_directory':

		pass

	elif change == 'remove_directory':

		pass

	elif change == 'move':

		hg_rename(hg_repo, arg[0], arg[1])

	elif change == 'tag':

		hg_tag(hg_repo, arg, author, date)

	else:

		error('Unknown change type ' + change + ': ' + arg)

# ------------------------------------------------------------------------------

#

# Main

#

# ------------------------------------------------------------------------------

if __name__ == "__main__":

	args = sys.argv[1:]

	# We parse the arguments

	if len(args)   == 2:

		darcs_repo = os.path.abspath(args[0])

		hg_repo    = os.path.abspath(args[1])

		skip       = None

	elif len(args) == 3:

		darcs_repo = os.path.abspath(args[0])

		hg_repo    = os.path.abspath(args[1])

		skip       = int(args[2])

	else:

		print USAGE

		sys.exit(-1)

	print 'This command is deprecated.  Use the convert extension instead.'

	# Initializes the target repo

	if not os.path.isdir(darcs_repo + "/_darcs"):

		print "No darcs directory found at: " + darcs_repo

		sys.exit(-1)

	if not os.path.isdir(hg_repo):

		os.mkdir(hg_repo)

	elif skip == None:

		print "Given HG repository must not exist when no SKIP is specified."

		sys.exit(-1)

	if skip == None:

		cmd("hg init \"%s\"" % (hg_repo))

		cmd("darcs initialize", hg_repo)

	# Get the changes from the Darcs repository

	change_number = 0

	for author, date, summary, chash, description in darcs_changes(darcs_repo):

		print "== changeset", change_number,

		if skip != None and change_number <= skip:

			print "(skipping)"

		else:

			text = summary + "\n" + description

			# The commit hash has a date like 20021020201112

			# --------------------------------YYYYMMDDHHMMSS

			date = chash.split("-")[0]

			epoch = int(mktime(strptime(date, '%Y%m%d%H%M%S')))

			darcs_pull(hg_repo, darcs_repo, chash)

			for change, arg in darcs_changes_summary(darcs_repo, chash):

				hg_handle_change(hg_repo, author, epoch, change, arg)

			hg_commit(hg_repo, text, author, epoch)

		change_number += 1

	print "Darcs repository (_darcs) was not deleted. You can keep or remove it."

# EOF