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

from garstowlib.makeport import *
from garstowlib.packages import get_scripts_dir, get_stow_dir
from garstowlib.utils import memoised, parse_version
import os, sys, re, glob, subprocess

archive_url = "http://hackage.haskell.org/packages/archive/"
ignore_packages = [
	"HOC",
	"HOC-AppKit",
	"HOC-Foundation",
	"Win32",
	"special-functors",
	]

@memoised
def get_ghc_packages():
	"""Get a list of packages that GHC ships with (and we thus don't need
	to bother listing as explicit dependencies)."""
	ghcdir = glob.glob(get_stow_dir() + "/packages/ghc/lib/*")[0]
	package_re = re.compile(r'^(.*)-[0-9.]+$')
	return [m.group(1) for m in map(package_re.match, os.listdir(ghcdir))
	                   if m is not None]

def parse_cabal_file(cabal_file):
	"""Parse a Cabal file using the Haskell helper program."""
	cmd = ["runhaskell", get_scripts_dir() + "/HsPortHelper.hs", cabal_file]
	output = subprocess.Popen(cmd, stdout = subprocess.PIPE).communicate()[0]
	return output.rstrip().split("\n")

def make_garname(cabal_name):
	"""Convert a Cabal name into a GARstow package name."""
	if cabal_name in ("cairo", "gconf", "gio", "glade", "glib", "gnomevfs", "gtk", "gtkglext", "gtksourceview2", "mozembed", "soegtk", "svgcairo"):
		return "gtk2hs"
	else:
		return "hs-" + cabal_name

def list_http_dir(url):
	"""Return a list of files and subdirectories from an HTTP directory listing.
	This is a bit of a hack, but it'll probably work in most cases."""

	# Make sure we have a trailing /, and remove duplicated ones (except ://).
	url = re.sub(r'([^:])/+', r'\1/', url + "/")

	# Run links, and extract URLs from its output (which will include a
	# complete list of links).
	entries = []
	f = subprocess.Popen(["links", "-dump", url], stdout = subprocess.PIPE).stdout
	for l in f.readlines():
		l = l.rstrip()
		for u in re.findall(r'(http://[^"\']+)', l):
			if u.startswith(url):
				entry = u[len(url):]
				if entry.endswith("/"):
					entry = entry[:-1]
				if not entry.startswith("?"):
					entries.append(entry)
	f.close()

	return entries

def make_cabal_port(cabal_name):
	if cabal_name.startswith("hs-"):
		cabal_name = cabal_name[3:]

	version_prefix = ""
	m = re.match(r'^(.*)-([0-9.]+)$', cabal_name)
	if m is not None:
		(cabal_name, version_prefix) = m.group(1, 2)

	garname = make_garname(cabal_name)
	if version_prefix != "":
		garname += "-" + version_prefix
	if garname.startswith("hs-"):
		shortname = garname[3:]
		if os.access(shortname, os.F_OK):
			garname = shortname
	print "Making port " + garname + " for " + cabal_name + "..."

	if version_prefix != "":
		version_prefix += "."

	# Find the latest version of the package.
	# There should be a "latest" symlink in hackage_dir, but (as of May
	# 2009) many packages don't have that, or have it pointing to the wrong
	# version.
	hackage_dir = archive_url + cabal_name + "/"
	versions = [(parse_version(v), v)
	            for v in list_http_dir(hackage_dir)
	            if re.match(r'^[0-9]', v) is not None
	               and v.startswith(version_prefix)]
	versions.sort()
	if versions == []:
		print "No versions found!"
		sys.exit(1)
	garversion = versions[-1][1]
	print "  Using version: " + garversion

	# Grab and parse the Cabal file.
	cabal_file_url = hackage_dir + garversion + "/" + cabal_name + ".cabal"
	tmpfn = "/tmp/make-hs-port.%d" % os.getpid()
	subprocess.call(["wget", "-q", "-O", tmpfn, cabal_file_url])
	parsed = parse_cabal_file(tmpfn)
	os.unlink(tmpfn)

	(description, home_url, cabal_deps) = parsed
	if home_url == "":
		home_url = None

	# Work out the dependencies (or a good approximation).
	deps = cabal_deps.split()
	ghc_packages = get_ghc_packages()
	need_deps = set(deps) - set(ghc_packages) - set(ignore_packages)
	libdeps = " ".join(["haskell/" + make_garname(dep) for dep in need_deps])
	if libdeps == "":
		libdeps = None

	lines = [
		VarLine("GARNAME", garname),
		VarLine("GARVERSION", garversion, mode = "update"),
		]
	if version_prefix != "":
		lines += [VarLine("UPSTREAMNAME", cabal_name, mode = "update")]
	lines += [
		VarLine("LIBDEPS", libdeps, mode = "merge-deps"),
		BlankLine(),
		VarLine("DESCRIPTION", description, mode = "update"),
		VarLine("HOME_URL", home_url, mode = "update"),
		BlankLine(),
		IncludeLine("../haskell.mk"),
		]

	update_portfile(garname + "/Makefile", lines)

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