#!/usr/bin/env python

"""Helper for cutting Python releases.

This script creates a compressed tar file named Webware-VER.tar.gz
in the parent directory of Webware. The package can be built either
from a live SVN workspace or from a tag in the SVN repository.

The live SVN workspace will be used if you call the script without
any arguments, like that:

  > bin/ReleaseHelper.py

Since the release will be created from the files in the live workspace,
it should be clean and up to date and not have had install.py run on it,
or your distro will end up with generated docs. However, the versions
should have been set with the bin/setversion script.

The workspace will not be touched in the process.

The version number for the release tarball is taken from
Webware/Properties.py like you would expect.

Instead of using the workspace, you can also export the release directly
from a SVN tag in the repository, for instance:

  > bin/ReleaseHelper.py tag=Release-0.9b3

This will export the SVN files tagged with Release-0_9b3 and build the
tarball Webware-0.9b3.tar.gz in Webware's parent directory.

This means the release will match exactly what is in the SVN,
reducing the risk of local changes, modified files, or new files
which are not in SVN from showing up in the release.

This script only works on Posix. Releases are not created on Windows
because permissions and EOLs can be problematic for other platforms.

For more information, see the Release Procedures in the Webware docs.

"""

import os, sys, time


class ReleaseHelper:

	def main(self):
		self.writeHello()
		self.checkPlatform()
		self.readArgs()
		self.build_release()

	def build_release(self):
		"""Prepare a release by using the SVN export approach.

		This is used when a tag name is specified on the command line, like

			> bin/ReleaseHelper.py tag=Release-0.9b3

		This will export the SVN files tagged with Release-0_9b3 and build the
		tarball Webware-0.9b3.tar.gz in your parent directory.

		This means the release will match exactly what is in the SVN,
		and reduces the risk of local changes, modified files, or new
		files which are not in SVN from showing up in the release.

		"""

		url = self.args.get('url', ' http://svn.w4py.org/Webware/tags')

		tag = self.args.get('tag', None)
		if tag:
			print "Creating tarball from tag %s ..." % tag
		else:
			print "Creating tarball from current workspace..."

		# the location of this script:
		progPath = os.path.join(os.getcwd(), sys.argv[0])
		# we assume this script is located in Webware/bin/
		webwarePath = os.path.dirname(os.path.dirname(progPath))
		# make the Webware directory our current directory
		self.chdir(webwarePath)
		# the tarball will land in its parent directory:
		tarDir = os.pardir

		if webwarePath not in sys.path:
			sys.path.insert(1, webwarePath)
		from MiscUtils.PropertiesObject import PropertiesObject

		target = 'ReleaseHelper-Export'
		if os.path.exists(target):
			print "There is incomplete ReleaseHelper data in:", target
			print "Please remove this directory."
			return 1

		cleanup = [target]

		if tag:
			source = '%s/%s' % (url, tag)
		else:
			source = '.'

		try:
			self.run('svn export -q %s %s' % (source, target))
			if not os.path.exists(target):
				print "Unable to export from %r" % source
				if tag:
					print "Perhaps the tag %r does not exist." % tag
				self.error()
			propertiesFile = os.path.join(target, 'Properties.py')
			if not os.path.exists(propertiesFile):
				self.error('Properties.py not found.')
			props = PropertiesObject(propertiesFile)
			if props.get('name', None) != 'Webware for Python':
				self.error('This is not a Webware package.')
			ver = props['versionString']

			print "Webware version is:", ver

			if not tag:
				# timestamp for time of release used to in versioning the file
				year, month, day = time.localtime(time.time())[:3]
				datestamp = "%04d%02d%02d" % (year,month,day)
				# drop leading 2 digits from year. (Ok, itn's not Y2K but it
				# is short and unique in a narrow time range of 100 years.)
				datestamp = datestamp[2:]
				ver = ver + "-" + datestamp
				print "Packaged release will be:", ver

			pkgDir = "Webware-%s" % ver

			if os.path.exists(pkgDir):
				self.error("%s is in the way, please remove it." % pkgDir)

			# rename the target to the pkgDir so the extracted parent
			# directory from the tarball will be unique to this package.
			self.run("mv %s %s" % (target, pkgDir))

			cleanup.append(pkgDir)

			pkgName = os.path.join(pkgDir + ".tar.gz")

			# cleanup .cvs files
			self.run("find %s -name '.cvs*' -exec rm {} \;" % pkgDir)

			# We could cleanup any other files not part of this release here.
			# (For instance, we could create releases without documentation).

			# We could also create additional files to be part of this release
			# without being part of the repository, for instance documentation
			# that is automatically created from markup.

			pkgPath = os.path.join(tarDir, pkgName)

			if os.path.exists(pkgPath):
				self.error("%s is in the way, please remove it." % pkgPath)

			self.run('tar -czf %s %s' % (pkgPath, pkgDir))

			if not os.path.exists(pkgPath):
				self.error('Could not create tarball.')

		finally: # Clean up
			for path in cleanup:
				if os.path.exists(path):
					self.run('rm -rf ' + path)

		print
		print "file:", pkgName
		print "dir:", os.path.abspath(tarDir)
		print "size:", os.path.getsize(pkgPath), 'Bytes'
		print
		print 'Success.'
		print

	def writeHello(self):
		print
		print 'Webware for Python'
		print 'Release Helper'
		print

	def checkPlatform(self):
		if os.name != 'posix':
			print 'This script only runs on Posix. Your op sys is %s.' % os.name
			print 'Webware release are always created on Posix machines.'
			print 'These releases work on both Posix and MS Windows.'
			self.error()

	def readArgs(self):
		args = {}
		for arg in sys.argv[1:]:
			try:
				name, value = arg.split('=', 1)
			except ValueError:
				self.error('Invalid argument: %s' % arg)
			args[name] = value
		self.args = args

	def error(self, msg=''):
		if msg:
			print 'ERROR: %s' % msg
		sys.exit(1)

	def chdir(self, path):
		print 'cmd> chdir %s' % path
		os.chdir(path)

	def run(self, cmd):
		"""Runs an arbitrary Unix command."""
		print 'cmd>', cmd
		results = os.popen(cmd).read()
		if results:
			print results


if __name__=='__main__':
	ReleaseHelper().main()
