# Copyright 2005 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id: $

import os.path,string,re
from portage_util import grabfile,writemsg

class use_desc:
	""" A simple class to access the use.desc and use.local.desc files. """
	def __init__(self,portdir):
		# Initialize use_desc.desc dictionnary from profiles/use.desc
		use_desc_path=os.path.join(portdir,"profiles/use.desc")
		if not os.access(use_desc_path, os.R_OK):
			raise Exception, "use_desc: Can't read "+use_desc_path
		use_desc_lines=grabfile(use_desc_path)
		self.desc={}
		use_desc_re=re.compile('^\s*(?P<flag>[\w\-\+\.]+)\s+-\s*(?P<desc>.+)\s*$')
		for myline in use_desc_lines:
			mymatch=use_desc_re.match(myline)
			if not mymatch:
				writemsg("--- Invalid use.desc entry:\n")
				writemsg("--- "+myline+"\n")
				continue
			(myflag,mydesc)=(mymatch.group("flag"),mymatch.group("desc"))
			if myflag in self.desc:
				writemsg("--- USE flag \""+myflag+"\" has several descriptions in use.desc.\n")
				continue
			self.desc[myflag]=mydesc
		# Initialize use_desc.local_desc dictionnary from profiles/use.local.desc
		use_local_desc_path=os.path.join(portdir,"profiles/use.local.desc")
		if not os.access(use_local_desc_path, os.R_OK):
			raise Exception, "use_desc: Can't read "+use_local_desc_path
		use_local_desc_lines=grabfile(use_local_desc_path)
		self.local_desc={}
		use_local_desc_re=re.compile('^\s*(?P<pkg>[\w\-\+/]+):(?P<flag>[\w\-\+\.]+)\s+-\s*(?P<desc>.+)\s*$')
		for myline in use_local_desc_lines:
			mymatch=use_local_desc_re.match(myline)
			if not mymatch:
				writemsg("--- Invalid use.local.desc entry:\n")
				writemsg("--- "+myline+"\n")
				continue
			(mypkg,myflag,mydesc)=(mymatch.group("pkg"),mymatch.group("flag"),mymatch.group("desc"))
			if mypkg not in self.local_desc:
				self.local_desc[mypkg]={}
			if myflag in self.local_desc[mypkg]:
				writemsg("--- USE flag \""+myflag+"\" has several descriptions for package "+mypkg+" in use.local.desc.\n")
				continue
			self.local_desc[mypkg][myflag]=mydesc
		# Initialize use_desc.local_flag_to_pkgs, a "local flag -> list of pkgs" dictionnary.
		# (may be useful for some repoman checks, but i'm not sure yet)
		self.local_flag_to_pkgs={}
		for mypkg in self.local_desc:
			for myflag in self.local_desc[mypkg]:
				if myflag not in self.local_flag_to_pkgs:
					self.local_flag_to_pkgs[myflag]=[]
				self.local_flag_to_pkgs[myflag].append(mypkg)

	def get_local_desc(self,flag,pkg):
		""" Returns flag description only if it is 
		a local flag for this pkg. """
		if pkg in self.local_desc \
		   and flag in self.local_desc[pkg]:
			return self.local_desc[pkg][flag]
		return None

	def get_special_desc(self,flag,pkg):
		""" Returns flag description only if it is 
		a global flag overridden for this pkg. """
		if flag not in self.desc:
			return None
		return self.get_local_desc(flag,pkg)

	def get_global_desc(self,flag,pkg):
		""" Returns flag description only if it is a global 
		flag which is not overridden in use.local.desc. """
		if pkg in self.local_desc and flag in self.local_desc[pkg]:
			return None
		if flag in self.desc:
			return self.desc[flag]
		return None

	def get_desc(self,flag,pkg=None):
		""" Returns flag description. With the optionnal pkg 
		parameter, try to find a local description first. """
		if pkg and pkg in self.local_desc and flag in self.local_desc[pkg]:
			return self.local_desc[pkg][flag]
		if flag in self.desc:
			return self.desc[flag]
		return None

	def get_pkg_flags_desc(self,flagslist,pkg,level="all",mark_local=False):
		""" Returns a dictionnary of flags descriptions for a given package.
		The optional level parameter can be "all", "global", "local" or "special",
		and defaults to "all". Optionnaly, if mark_local is set, the keys from
		use.local.desc will be "cat/pkg:flag" instead of simply "flag". """
		desc_dict={}
		remaningflags=[]
		# Get descriptions from use.local.desc first:
		if level != "global":
			get_method=self.get_local_desc
			if level == "special":
				get_method=self.get_special_desc
			for myflag in flagslist:
				mydesc=get_method(myflag,pkg)
				if mydesc:
					if mark_local: desc_dict[pkg+":"+myflag]=mydesc
					else: desc_dict[myflag]=mydesc
				else: remaningflags.append(myflag)
		# Then get descriptions from use.desc if in "all" or "global" mode:
		if level == "global": remaningflags=flagslist
		if level in ("all","global"):
			for myflag in remaningflags:
				if myflag in self.desc:
					desc_dict[myflag]=self.desc[myflag]
		return desc_dict

	def get_all_special_flags(self):
		""" This helper function returns a "local flag -> cat/pkg -> description"
		dictionnary of dictionnaries of flags that also have a description in use.desc.
		May be useful to advice some use.local.desc cleanups. """
		my_dict={}
		for myflag in self.local_flag_to_pkgs:
			if myflag in self.desc:
				my_dict[myflag]={}
				for mypkg in self.local_flag_to_pkgs[myflag]:
					my_dict[myflag][mypkg] = self.local_desc[mypkg][myflag]
		return my_dict

	def get_multiple_local_flags(self,multiplicity=2):
		""" This helper function returns a "local flag -> cat/pkg -> description"
		dictionnary of dictionnaries of flags that are local to several packages.
		The optionnal multiplicity parameter (integer >= 2) is a bound on the 
		number of occurences required to be in the result. May be useful to advice
		some local->global flags moves. """
		my_dict={}
		if multiplicity < 2: multiplicity=2
		for myflag in self.local_flag_to_pkgs:
			if myflag in self.desc: continue
			if len(self.local_flag_to_pkgs[myflag]) >= multiplicity:
				my_dict[myflag]={}
				for mypkg in self.local_flag_to_pkgs[myflag]:
					my_dict[myflag][mypkg] = self.local_desc[mypkg][myflag]
		return my_dict