# helper.py
# Copyright (C) 2008, 2009 Michael Trier (mtrier@gmail.com) and contributors
#
# This module is part of GitPython and is released under
# the BSD License: http://www.opensource.org/licenses/bsd-license.php

import os
import sys
from git import Repo, Remote, GitCommandError
from unittest import TestCase
import tempfile
import shutil
import cStringIO

from base import (
					maketemp,
					rorepo_dir
				)


__all__ = (
			'StringProcessAdapter', 'GlobalsItemDeletorMetaCls', 
			'with_rw_repo', 'with_rw_and_rw_remote_repo', 'TestBase', 'TestCase', 
		)


	
#{ Adapters 
	
class StringProcessAdapter(object):
	"""Allows to use strings as Process object as returned by SubProcess.Popen.
	Its tailored to work with the test system only"""
	
	def __init__(self, input_string):
		self.stdout = cStringIO.StringIO(input_string)
		self.stderr = cStringIO.StringIO()
		
	def wait(self):
		return 0
		
	poll = wait
	
#} END adapters

#{ Decorators 

def _rmtree_onerror(osremove, fullpath, exec_info):
	"""
	Handle the case on windows that read-only files cannot be deleted by 
	os.remove by setting it to mode 777, then retry deletion.
	"""
	if os.name != 'nt' or osremove is not os.remove:
		raise
		
	os.chmod(fullpath, 0777)
	os.remove(fullpath)

def with_rw_repo(working_tree_ref, bare=False):
	"""
	Same as with_bare_repo, but clones the rorepo as non-bare repository, checking 
	out the working tree at the given working_tree_ref.
	
	This repository type is more costly due to the working copy checkout.
	
	To make working with relative paths easier, the cwd will be set to the working 
	dir of the repository.
	"""
	assert isinstance(working_tree_ref, basestring), "Decorator requires ref name for working tree checkout"
	def argument_passer(func):
		def repo_creator(self):
			prefix = 'non_'
			if bare:
				prefix = ''
			#END handle prefix
			repo_dir = maketemp("%sbare_%s" % (prefix, func.__name__))
			rw_repo = self.rorepo.clone(repo_dir, shared=True, bare=bare, n=True)
			
			rw_repo.head.commit = rw_repo.commit(working_tree_ref)
			if not bare:
				rw_repo.head.reference.checkout()
			# END handle checkout
			
			prev_cwd = os.getcwd()
			os.chdir(rw_repo.working_dir)
			try:
				try:
					return func(self, rw_repo)
				except:
					print >> sys.stderr, "Keeping repo after failure: %s" % repo_dir
					repo_dir = None
					raise
			finally:
				os.chdir(prev_cwd)
				rw_repo.git.clear_cache()
				if repo_dir is not None:
					shutil.rmtree(repo_dir, onerror=_rmtree_onerror)
				# END rm test repo if possible
			# END cleanup
		# END rw repo creator
		repo_creator.__name__ = func.__name__
		return repo_creator
	# END argument passer
	return argument_passer
	
def with_rw_and_rw_remote_repo(working_tree_ref):
	"""
	Same as with_rw_repo, but also provides a writable remote repository from which the
	rw_repo has been forked as well as a handle for a git-daemon that may be started to 
	run the remote_repo.
	The remote repository was cloned as bare repository from the rorepo, wheras 
	the rw repo has a working tree and was cloned from the remote repository.
	
	remote_repo has two remotes: origin and daemon_origin. One uses a local url, 
	the other uses a server url. The daemon setup must be done on system level 
	and should be an inetd service that serves tempdir.gettempdir() and all 
	directories in it.
	
	The following scetch demonstrates this::
	 rorepo ---<bare clone>---> rw_remote_repo ---<clone>---> rw_repo
	
	The test case needs to support the following signature::
		def case(self, rw_repo, rw_remote_repo)
		
	This setup allows you to test push and pull scenarios and hooks nicely.
	
	See working dir info in with_rw_repo
	"""
	assert isinstance(working_tree_ref, basestring), "Decorator requires ref name for working tree checkout"
	def argument_passer(func):
		def remote_repo_creator(self):
			remote_repo_dir = maketemp("remote_repo_%s" % func.__name__)
			repo_dir = maketemp("remote_clone_non_bare_repo")
			
			rw_remote_repo = self.rorepo.clone(remote_repo_dir, shared=True, bare=True)
			rw_repo = rw_remote_repo.clone(repo_dir, shared=True, bare=False, n=True)		# recursive alternates info ?
			rw_repo.head.commit = working_tree_ref
			rw_repo.head.reference.checkout()
			
			# prepare for git-daemon
			rw_remote_repo.daemon_export = True
			
			# this thing is just annoying !
			crw = rw_remote_repo.config_writer()
			section = "daemon"
			try:
				crw.add_section(section)
			except Exception:
				pass
			crw.set(section, "receivepack", True)
			# release lock
			del(crw)
			
			# initialize the remote - first do it as local remote and pull, then 
			# we change the url to point to the daemon. The daemon should be started
			# by the user, not by us
			d_remote = Remote.create(rw_repo, "daemon_origin", remote_repo_dir)
			d_remote.fetch()
			remote_repo_url = "git://localhost%s" % remote_repo_dir
			
			d_remote.config_writer.set('url', remote_repo_url)
			
			# try to list remotes to diagnoes whether the server is up
			try:
				rw_repo.git.ls_remote(d_remote)
			except GitCommandError,e:
				print str(e)
				if os.name == 'nt':
					raise AssertionError('git-daemon needs to run this test, but windows does not have one. Otherwise, run: git-daemon "%s"'%tempfile.gettempdir()) 
				else:
					raise AssertionError('Please start a git-daemon to run this test, execute: git-daemon "%s"'%tempfile.gettempdir())
			
			# adjust working dir
			prev_cwd = os.getcwd()
			os.chdir(rw_repo.working_dir)
			try:
				return func(self, rw_repo, rw_remote_repo)
			finally:
				os.chdir(prev_cwd)
				rw_repo.git.clear_cache()
				rw_remote_repo.git.clear_cache()
				shutil.rmtree(repo_dir, onerror=_rmtree_onerror)
				shutil.rmtree(remote_repo_dir, onerror=_rmtree_onerror)
			# END cleanup
		# END bare repo creator
		remote_repo_creator.__name__ = func.__name__
		return remote_repo_creator
		# END remote repo creator
	# END argument parsser
	
	return argument_passer
	
#} END decorators

#{ Meta Classes
class GlobalsItemDeletorMetaCls(type):
	"""Utiltiy to prevent the RepoBase to be picked up by nose as the metacls
	will delete the instance from the globals"""
	#{ Configuration
	# Set this to a string name of the module to delete
	ModuleToDelete = None
	#} END configuration
	
	def __new__(metacls, name, bases, clsdict):
		assert metacls.ModuleToDelete is not None, "Invalid metaclass configuration"
		new_type = super(GlobalsItemDeletorMetaCls, metacls).__new__(metacls, name, bases, clsdict)
		if name != metacls.ModuleToDelete:
			mod = __import__(new_type.__module__, globals(), locals(), new_type.__module__)
			delattr(mod, metacls.ModuleToDelete)
		#END handle deletion
		return new_type
	
#} END meta classes
	
class TestBase(TestCase):
	"""
	Base Class providing default functionality to all tests such as:
	- Utility functions provided by the TestCase base of the unittest method such as::
		self.fail("todo")
		self.failUnlessRaises(...)
	"""
	
	@classmethod
	def setUpAll(cls):
		"""This method is only called to provide the most basic functionality
		Subclasses may just override it or implement it differently"""
		cls.rorepo = Repo(rorepo_dir())
	
	def _make_file(self, rela_path, data, repo=None):
		"""
		Create a file at the given path relative to our repository, filled
		with the given data. Returns absolute path to created file.
		"""
		repo = repo or self.rorepo
		abs_path = os.path.join(repo.working_tree_dir, rela_path)
		fp = open(abs_path, "w")
		fp.write(data)
		fp.close()
		return abs_path
