import glob
import os
import re
import rpm
import sys

ts = rpm.TransactionSet()

packages = []
for arg in sys.argv[1:]:
	packages += glob.glob(arg)

erlang_provides = {}
erlang_requires = {}

package_names = []
package_headers = {}

##
## Custom tweaks begins here
##

# These packages should be marked as noarch
package_noarch = [
		"emacs-erlang",
		"emacs-erlang-el",
		"erlang-doc",
		"xemacs-erlang",
		"xemacs-erlang-el"]

# These are additional Requires which cannot be picked up automatically (yet).
# TODO these should be added automatically
package_additional_requires = {
		"emacs-erlang": ["emacs-common-erlang = %{version}-%{release}", "emacs(bin) >= %{_emacs_version}" ],
		"emacs-erlang-el": ["emacs-erlang = %{version}-%{release}"],
		"erlang-dialyzer": ["graphviz"],
		"erlang-erl_interface": ["%{name}-erts%{?_isa} = %{version}-%{release}"],
		# This library (lksctp-tools) is dlopened so it can't be picked
		# up automatically by the RPM dependency checker
		"erlang-erts": ["lksctp-tools"],
		"erlang-gs": ["tk"],
		# Stores files/links in /usr/share/java so has to depend on jpackage-utils
		"erlang-ic": ["jpackage-utils"],
		# Stores files/links in /usr/share/java so has to depend on jpackage-utils
		"erlang-jinterface": ["%{name}-erts%{?_isa} = %{version}-%{release}", "jpackage-utils"],
		"erlang-wx": ["mesa-libGL", "mesa-libGLU"],
		"xemacs-erlang": ["emacs-common-erlang = %{version}-%{release}", "xemacs(bin) >= %{_xemacs_version}"],
		"xemacs-erlang-el": ["xemacs-erlang = %{version}-%{release}"]
		}

package_additional_buildrequires = {
		"emacs-erlang": ["emacs", "emacs-el"],
		"erlang-crypto": ["openssl-devel"],
		"erlang-diameter": ["ed"],

		# BEWARE. No fop for EPEL5, and only for x86/x86_64 in EPEL6,
		# so we cannot regenerate docs here. (Un)Fortunately we dropped
		# support for EPEL6 and older versions.
		# FIXME add bootstrap condition first.
		"erlang-doc": ["fop", "libxslt"],

		"erlang-erts": ["lksctp-tools-devel", "m4", "ncurses-devel", "zlib-devel"],
		"erlang-gs": ["tcl-devel", "tk-devel"],

		# in EPEL6 on arches different from %{ix86} x86_64 we have to
		# use java-devel-gcj, so technically this requirement makes it
		# impossible to build Java support there. (Un)Fortunately we
		# already dropped full support for EPEL6 and older versions.
		"erlang-ic": ["java-devel"],
		"erlang-jinterface": ["java-devel"],

		"erlang-odbc": ["unixODBC-devel"],
		"erlang-wx": ["wxGTK-devel"],
		"xemacs-erlang": ["xemacs", "xemacs-packages-extra-el"],
		}

package_additional_obsoletes = {
		"erlang-erts": [
			"erlang-appmon",
			"erlang-docbuilder",
			"erlang-inviso",
			"erlang-pman",
			"erlang-toolbar",
			"erlang-tv"],
		}

##
## Custom tweaks ends here
##

# To match 'erlang(asn1ct_eval_ext:transform_to_EXTERNAL1994/1)'
prog = re.compile("^erlang(.*:.*/\d+)")
rpmmask = re.compile(".*\.rpm")

# iterate over all rpms
for package in sorted([p for p in packages if rpmmask.match(p)]):

	# A tricky part. We are processing packages, rebuilt with
	# %{__erlang_provides_requires}. Otherwise we won't get information
	# about imports/exports (until we learn how to parse Erlang BEAM file
	# headers with Python.
	fd = os.open(package, os.O_RDONLY)
	h = ts.hdrFromFdno(fd)
	os.close(fd)

	rpm_name = h[rpm.RPMTAG_NAME]

	# Let's calculate provides
	# We'll create dictionary to speedup future use
	# FIXME duplicate provides
	local_provides = [p for p in h[rpm.RPMTAG_PROVIDENAME] if prog.match(p)]
	erlang_provides.update({k: rpm_name for k in local_provides})

	# Let's calculate requires
	erlang_requires.update({rpm_name: [r for r in h[rpm.RPMTAG_REQUIRENAME] if prog.match(r) and not r in local_provides]})

	package_headers.update({rpm_name: h})

	package_names.append(rpm_name)

namemask = re.compile("^erlang-[a-zA-Z0-9_]*$")

print "### BEGIN OF AUTOGENERATED LIST ###"
print ""

for name in package_names:
	h = package_headers[name]

	if name == "erlang-doc":
		# Additional ifdef just for this sub-package (see below)
		print "%if %{with doc}"

	if namemask.match(name):
		print "%%package %s" % name.replace("erlang-", "")
	else:
		print "%%package -n %s" % name

	print "Summary: %s" % h[rpm.RPMTAG_SUMMARY]
	print "Group: %s" % h[rpm.RPMTAG_GROUP]

	rawdeps = [erlang_provides.get(r, "Error: missing requires: %s" % r) for r in erlang_requires[name]]

	deps = set()
	dependency_add = deps.add
	[x for x in rawdeps if not (x in deps or dependency_add(x))]

	# Additional BuildRequires (if any):
	for br in package_additional_buildrequires.get(name, []):
		print "BuildRequires: %s" % br

	# Add basic autogenerated Requires:
	for r in sorted(deps):
		#Requires: %{name}-stdlib%{?_isa} = %{version}-%{release}
		print "Requires: %s%%{?_isa} = %%{version}-%%{release}" % r.replace("erlang-", "%{name}-")

	# Add custom additional Requires (if any):
	for r in package_additional_requires.get(name, []):
		print "Requires: %s" % r

	# Add custom additional Obsoletes (if any):
	for os in package_additional_obsoletes.get(name, []):
		print "Obsoletes: %s" % os

	if name in package_noarch:
		print "BuildArch: noarch"

	print ""
	if namemask.match(name):
		print "%%description %s" % name.replace("erlang-", "")
	else:
		print "%%description -n %s" % name
	print "%s" % h[rpm.RPMTAG_DESCRIPTION]

	if name == "erlang-doc":
		# Additional ifdef just for this sub-package (see above)
		print "%endif"

	print ""

print "### END OF AUTOGENERATED LIST ###"