#! /usr/bin/env python2.2
#
#This file contains basic functionality to process Status files
#and assign/compare ebuild levels.
#It is imported by portage.py.
#See also Status.skel for more info
#

import os
from portage_exceptions import *

class StatusError(GenericPortageError):
	"""A very basic one"""
	def __init__ (self,reason=None):
		#this "self" in invocation *is* necessary
		GenericPortageError.__init__(self,reason)


#I'll do the list of status levels. This will allow to do comparisions in an 
#extensible way - so that if there is a decision to change level stucture
#doing that will be a matter of changing few lists only.
#ATTENTION: order is important!!
eStatusList=["unstable","new","confirmed","appr-new","core-new","approved","core"]
#these are the levels as defined in make.conf etc. to be assigned to
#StabilityLevel and rsyncLevel

#the following switches are used in Status files
eStatusSwitches=["unstable","no","yes","core"]

#the order in Status file: confirmed_flag approved_flag - 
#thus "yes no" will correspond to confirmed (and not approved) status

#this one maps unique pairs to corresponding states
#the rest (two "special cases") are processed in the code
eStatusMap={("no","no"):"new",("yes","no"):"confirmed",("no","yes"):"appr-new",
("yes","yes"):"approved",("no","core"):"core-new",("yes","core"):"core"}


#this class will process ebuild Status (single line)
class ebuildStatus:
	def __init__ (self,pkgName,mypkgVR=None,myConf=None,myAppr=None,statusStr=None):
		'''call like: eStatus(pkgName,PVR,Conf,Appr)
		or: eStatus(pkgName,statusStr=str_from_Status_file)'''
		if pkgName:self.pkgName=pkgName
		else:raise StatusError("pkgname missing from ebuildStatus invocation")
		
		#store (PVR,conf,appr) tuple internally
		#generate Status string as necessary
		if mypkgVR and myConf and myAppr:
			self.PVR=mypkgVR
			self.confInd=eStatusSwitches.index(myConf)
			self.apprInd=eStatusSwitches.index(myAppr)
		else:self.setFromStr(statusStr)
		#check validity
		tmp=self.get()

	def get (self):
		"returns status from the eStatusList"
		#check unstable first, then use Map and then check for core
		#ATTN!! the following line relies on "unstable" being 1st in eStatusList
		if (eStatusSwitches[self.confInd]=="unstable") or (eStatusSwitches[self.apprInd]=="unstable"):
			return "unstable"
		ind=(eStatusSwitches[self.confInd],eStatusSwitches[self.apprInd])
		if eStatusMap.has_key(ind):return eStatusMap[ind]
		#now only 3 possible variants left: ("core","core/yes/no")
		#since "core" is not supposed to appear in confirmed field I'll raise an exception
		raise StatusError("unexpected 'core' in confirmedStatus field;  override eStatusClass.get to change this behavior")
			

	def getStatusStr (self):
		"returns string suitable for Status file"
		return " ".join((self.PVR,eStatusSwitches[self.confInd],eStatusSwitches[self.apprInd]))

	def setFromStr (self,myStr):
		"initializes object from Status string"
		try:
			self.PVR,conf,appr=myStr.split()
		except:raise StatusError('''while processing %s:
problematic Status string:  Incorrect number of entries in one of the lines!''' %self.pkgName)
		try:
			self.confInd=eStatusSwitches.index(conf)
			self.apprInd=eStatusSwitches.index(appr)
		except ValueError:raise StatusError('''while processing %s-%s:
problematic Status string:  Incorrect Status entries!''' % (self.pkgName,self.PVR))
		
	def isAllowed (self,StabLevel):
		"returns true if status is greater (more stable) then specified level"
		#StabLevel:eStateList
		return eStatusList.index(StabLevel) <= eStatusList.index(self.get())
	

class pkgStatus(dict):
	'''This will hold info on all ebuilds associated with certain package 
	This class will have properties similar to dictionary
	but can be initialized from the Status file'''

	def __init__(self,pkgDir):
		'''Reads Status file in pkgDir'''
		#This constructor enforces pkgName==PN==dirName
		#that is: ebuild PN part must be the same as dir name in which it resides
		#The enforcement is done by this code only checking dir name
		#thus ebuild having different name will not be found and
		#will assume "new" status per default
		
		self.clear()
		#extract package name
		if pkgDir[-1]=='/':pkgDir=pkgDir[:-1]
		self.pkgName=os.path.basename(pkgDir)
		if os.path.exists(pkgDir+"/Status"):
			StatusLines=file(pkgDir+"/Status","r").readlines()
		else:return
		for line in StatusLines:
			if (line[0]=="#") or (line.strip()==""):continue
			self[line.split()[0]]=ebuildStatus(self.pkgName,statusStr=line)
		
	def __getitem__(self,key):
		"need to override default method to return 'new' status in case of absent key"
		if self.has_key(key):
			return dict(self).get(key)
		else:
			return ebuildStatus(self.pkgName,key,"no","no")