#!/usr/bin/env python
"""
Attempt to automatically generate a port for a CPAN module.
"""

import sys, urllib, re, yaml, os, glob, garstowlib

def die(*s):
	print >>sys.stderr, "".join(map(str, s))
	sys.exit(1)

def makeport(package):
	print "Fetching CPAN info for " + package + "...",
	sys.stdout.flush()
	url = "http://search.cpan.org/dist/" + package
	f = urllib.urlopen(url)
	page = f.read()
	f.close()

	# href="/CPAN/authors/id/M/MS/MSCHILLI/Log-Log4perl-1.05.tar.gz">Download<
	m = re.search(r'href="[^"]*/([^"/]*)/([^"/]*)">Download<', page)
	if m is None:
		die("cannot find Download link in page for ", package)
	(author, distfile) = m.group(1, 2)

	m = re.match(r'^(.*)-([0-9._]+)\.tar\.gz$', distfile)
	if m is None:
		die("cannot parse distfile name for ", package, ": ", distfile)
	(n, version) = m.group(1, 2)
	if n != package:
		print "changing package name from " + package + " to " + n
		package = n

	i = page.find("<h2 class=t2>Modules</h2>")
	if i == -1:
		die("cannot find Modules heading in ", package)
	d = page[i:]
	i = d.find(">" + package.replace("-", "::") + "<")
	if i != -1:
		d = d[i:]
	m = re.search(r'<small>([^<]+)&nbsp;</small>', d)
	if m is None:
		print "cannot find description for " + package
		description = "Perl module " + package
	else:
		description = m.group(1)

	print package, author, version

	# href="/src/MSCHILLI/Log-Log4perl-1.05/META.yml">META.yml
	m = re.search(r'href="([^"]*)">META.yml<', page)
	deps = {}
	deps["perl/perl"] = True
	if m is not None:
		print "Fetching META.yml...",
		sys.stdout.flush()
		f = urllib.urlopen(urllib.basejoin(url, m.group(1)))
		meta = yaml.load(f.read())
		f.close()

		print meta

		stowdir = garstowlib.get_stow_dir()
		reqs = meta["requires"]
		if reqs is None:
			reqs = {}
		for dep in reqs.keys():
			if dep == "perl":
				continue
			fn = dep.replace("::", "/") + ".pm"
			installed = []
			for path in ("lib/perl5/*", "lib/perl5/*/*", "lib/perl5/site_perl/*/*"):
				installed += glob.glob(stowdir + "/" + path + "/" + fn)
			if installed == []:
				deps["perl/p5-" + dep.replace("::", "-")] = True
				print "Needs new package " + dep
			else:
				op = garstowlib.get_owning_package(installed[0])
				pn = garstowlib.get_full_package_name(op)
				deps[pn] = True
				print "Needs existing package " + pn

	garname = "p5-" + package
	try:
		os.stat(garname)
	except OSError:
		os.mkdir(garname)

	makefile = "../cpan.mk"

	port = """GARNAME = %s
GARVERSION = %s
CPAN_AUTHOR = %s
LIBDEPS = %s

DESCRIPTION = %s

include %s
""" % (garname, version, author, " ".join(deps.keys()), description.strip(), makefile)
	f = open(garname + "/Makefile", "w")
	f.write(port)
	f.close()

if __name__ == "__main__":
	for package in sys.argv[1:]:
		makeport(package)