# Copyright 2007 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id$

__all__ = ["SETPREFIX", "get_boolean", "SetConfigError",
	"SetConfig", "load_default_config"]

import os
from ConfigParser import SafeConfigParser, NoOptionError
from portage import load_mod
from portage.const import USER_CONFIG_PATH, GLOBAL_CONFIG_PATH
from portage.exception import PackageSetNotFound

SETPREFIX = "@"

def get_boolean(options, name, default):
	if not name in options:
		return default
	elif options[name].lower() in ("1", "yes", "on", "true"):
		return True
	elif options[name].lower() in ("0", "no", "off", "false"):
		return False
	else:
		raise SetConfigError("invalid value '%s' for option '%s'" % (options[name], name))

class SetConfigError(Exception):
	pass

class SetConfig(object):
	def __init__(self, paths, settings, trees):
		self._parser = SafeConfigParser()
		self._parser.read(paths)
		self.errors = []
		self.psets = {}
		self.trees = trees
		self.settings = settings
		self._parsed = False
		self.active = []

	def update(self, setname, options):
		parser = self._parser
		self.errors = []
		if not setname in self.psets:
			options["name"] = setname
			options["world-candidate"] = "False"
			
			# for the unlikely case that there is already a section with the requested setname
			import random
			while setname in parser.sections():
				setname = "%08d" % random.randint(0, 10**10)
			
			parser.add_section(setname)
			for k, v in options.items():
				parser.set(setname, k, v)
		else:
			section = self.psets[setname].creator
			if parser.has_option(section, "multiset") and \
				parser.getboolean(section, "multiset"):
				self.errors.append("Invalid request to reconfigure set '%s' generated by multiset section '%s'" % (setname, section))
				return
			for k, v in options.items():
				parser.set(section, k, v)
		self._parse(update=True)

	def _parse(self, update=False):
		if self._parsed and not update:
			return
		parser = self._parser
		for sname in parser.sections():
			# find classname for current section, default to file based sets
			if not parser.has_option(sname, "class"):
				classname = "portage.sets.files.StaticFileSet"
			else:
				classname = parser.get(sname, "class")
			
			# try to import the specified class
			try:
				setclass = load_mod(classname)
			except (ImportError, AttributeError):
				try:
					setclass = load_mod("portage.sets."+classname)
				except (ImportError, AttributeError):
					self.errors.append("Could not import '%s' for section '%s'" % (classname, sname))
					continue
			# prepare option dict for the current section
			optdict = {}
			for oname in parser.options(sname):
				optdict[oname] = parser.get(sname, oname)
			
			# create single or multiple instances of the given class depending on configuration
			if parser.has_option(sname, "multiset") and \
				parser.getboolean(sname, "multiset"):
				if hasattr(setclass, "multiBuilder"):
					newsets = {}
					try:
						newsets = setclass.multiBuilder(optdict, self.settings, self.trees)
					except SetConfigError, e:
						self.errors.append("Configuration error in section '%s': %s" % (sname, str(e)))
						continue
					for x in newsets:
						if x in self.psets and not update:
							self.errors.append("Redefinition of set '%s' (sections: '%s', '%s')" % (x, self.psets[x].creator, sname))
						newsets[x].creator = sname
						if parser.has_option(sname, "world-candidate") and \
							not parser.getboolean(sname, "world-candidate"):
							newsets[x].world_candidate = False
					self.psets.update(newsets)
				else:
					self.errors.append("Section '%s' is configured as multiset, but '%s' doesn't support that configuration" % (sname, classname))
					continue
			else:
				try:
					setname = parser.get(sname, "name")
				except NoOptionError:
					setname = sname
				if setname in self.psets and not update:
					self.errors.append("Redefinition of set '%s' (sections: '%s', '%s')" % (setname, self.psets[setname].creator, sname))
				if hasattr(setclass, "singleBuilder"):
					try:
						self.psets[setname] = setclass.singleBuilder(optdict, self.settings, self.trees)
						self.psets[setname].creator = sname
						if parser.has_option(sname, "world-candidate") and \
							not parser.getboolean(sname, "world-candidate"):
							self.psets[setname].world_candidate = False
					except SetConfigError, e:
						self.errors.append("Configuration error in section '%s': %s" % (sname, str(e)))
						continue
				else:
					self.errors.append("'%s' does not support individual set creation, section '%s' must be configured as multiset" % (classname, sname))
					continue
		self._parsed = True
	
	def getSets(self):
		self._parse()
		return self.psets.copy()

	def getSetAtoms(self, setname, ignorelist=None):
		"""
		This raises PackageSetNotFound if the give setname does not exist.
		"""
		self._parse()
		try:
			myset = self.psets[setname]
		except KeyError:
			raise PackageSetNotFound(setname)
		myatoms = myset.getAtoms()
		parser = self._parser
		extend = set()
		remove = set()
		intersect = set()
		
		if ignorelist is None:
			ignorelist = set()
		if not setname in ignorelist:
			if parser.has_option(myset.creator, "extend"):
				extend.update(parser.get(myset.creator, "extend").split())
			if parser.has_option(myset.creator, "remove"):
				remove.update(parser.get(myset.creator, "remove").split())
			if parser.has_option(myset.creator, "intersect"):
				intersect.update(parser.get(myset.creator, "intersect").split())
						
		ignorelist.add(setname)
		for n in myset.getNonAtoms():
			if n.startswith(SETPREFIX):
				s = n[len(SETPREFIX):]
				if s in self.psets:
					extend.add(n[len(SETPREFIX):])
				else:
					raise PackageSetNotFound(s)

		for s in ignorelist:
			extend.discard(s)
			remove.discard(s)
			intersect.discard(s)
		
		for s in extend:
			myatoms.update(self.getSetAtoms(s, ignorelist=ignorelist))
		for s in remove:
			myatoms.difference_update(self.getSetAtoms(s, ignorelist=ignorelist))
		for s in intersect:
			myatoms.intersection_update(self.getSetAtoms(s, ignorelist=ignorelist))

		return myatoms

def load_default_config(settings, trees):
	setconfigpaths = [os.path.join(GLOBAL_CONFIG_PATH, "sets.conf")]
	setconfigpaths.append(os.path.join(settings["PORTDIR"], "sets.conf"))
	setconfigpaths += [os.path.join(x, "sets.conf") for x in settings["PORTDIR_OVERLAY"].split()]
	setconfigpaths.append(os.path.join(settings["PORTAGE_CONFIGROOT"],
		USER_CONFIG_PATH.lstrip(os.path.sep), "sets.conf"))
	return SetConfig(setconfigpaths, settings, trees)

# adhoc test code
if __name__ == "__main__":
	import portage
	sc = load_default_config(portage.settings, portage.db["/"])
	l, e = sc.getSets()
	for x in l:
		print x+":"
		print "DESCRIPTION = %s" % l[x].getMetadata("Description")
		for n in sorted(l[x].getAtoms()):
			print "- "+n
		print