import os
import errno
from fnmatch import fnmatch
from gzip import GzipFile
from debian_bundle import deb822
from operator import itemgetter
import difflib

from DiffGzHandler import DiffGzHandler

class Archive:
  def __init__(self, dir, suitefilter=None, pkgfilter=None):
    self.root = None
    self.distsdir = None
    self.pkgs = {}

    self.root = dir
    self.distsdir = os.sep.join([dir, "dists"])
    for s in self.parsesuites(filter=suitefilter):
      print "suite: ",s
      self.addsuite(s)
      for c in self.parsecomponents(s):
        print "\tcomponent:",c
        self.addcomponent(s,c)
        for p in self.parsesourcepackages(s,c,filter=pkgfilter):
          print "\t\tpackage:",p
          self.addsourcepackage(s,c,p)

  def addsuite(self, suite):
    self.pkgs[suite] = {}

  def suites(self, filter=None):
    return sorted(self.pkgs.iterkeys())

  def parsesuites(self, filter=None):
    slist = os.listdir(self.distsdir)
    if filter:
      slist = set(filter).intersection(set(slist))
    for s in sorted(slist):
      yield s

  def addcomponent(self, suite, component):
    self.pkgs[suite][component] = {}

  def components(self, suite):
    return sorted(self.pkgs[suite].iterkeys())

  def parsecomponents(self, suite):
    f = file(self.distsdir + os.sep + os.sep.join([suite, "Release"]))
    rel = deb822.Release(f)
    for comp in rel['Components'].split(' '):
      yield comp

  def addsourcepackage(self, suite, component, package):
    self.pkgs[suite][component][package.name] = package

  def sourcepackages(self, suite, component, filter=None, namesonly=False):
    if not namesonly:
      return sorted(self.pkgs[suite][component].itervalues())
    else:
      namer = lambda x: x.name
      return sorted(map(namer, self.pkgs[suite][component].itervalues()))

  def parsesourcepackages(self, suite, component, filter=None):
    sfile=os.sep.join([self.distsdir,suite,component,"/source/Sources.gz"])
    k = itemgetter('Package')
    fdict = {}
    if filter:
      for name in filter:
        fdict[name] = True
    for ent in sorted(deb822.Sources.iter_paragraphs(GzipFile(sfile)), key=k):
      if filter and not fdict.has_key(ent['Package']):
        continue
      else:
        yield SourcePackage(ent)

  def __str__(self):
    return "Archive rooted at "+self.root

class ArchiveDiffer:
  def diffsuites(self,a,b):
    return difflib.ndiff(a.suites(), b.suites())

  def diffcomponents(self,a,b, suite):
    return difflib.ndiff(a.components(suite), b.components(suite))

  def diffsourcepackages(self,a,b, suite, component):
    return difflib.ndiff(a.sourcepackages(suite, component, namesonly=True),
                         b.sourcepackages(suite, component, namesonly=True))

# XXX maybe there's a better place/way for this
def getidx(letter):
  name = str(letter)
  if len(name) < 4 or name[0:3] != "lib":
    return name[0]
  else:
    return name[0:4]

class SourcePackage:
  def __init__(self, info):
    self.diffgz_name = None
    self.diffgz_size = None
    self.diffgz_md5sum = None
    self.diffgz = None
    self.type = "Native"
    self.name = info['Package']  
    self.format = info['Format']  
    self.loc = info['Directory']  
    self.version = info['Version']  
    self.idx = getidx(self)

    for f in info['Files']:
      if fnmatch(f['name'], '*.diff.gz'):
        self.diffgz_name=f['name']
        self.diffgz_size=f['size']
        self.diffgz_md5sum=f['md5sum']
        self.type = "Debian-diff"

  def __str__(self):
    return self.name

class MasterIndex:
  def __init__(self):
    self.pkgcounts = {}

  def add(self, name):
    idx = getidx(name)
    if not self.pkgcounts.has_key(idx):
      self.pkgcounts[idx] = 1
    else:
      self.pkgcounts[idx] += 1

  def indices(self):
    for k,v in sorted(self.pkgcounts.iteritems()):
      yield (k,v)
 
class SourcePackageIndex:
  def __init__(self):
    self.pkgs = {}

  def ins(self, srcpkg, rel):
    if not self.pkgs.has_key(srcpkg.idx):
      self.pkgs[srcpkg.idx] = {}
    if not self.pkgs[srcpkg.idx].has_key(srcpkg.name):
      self.pkgs[srcpkg.idx][srcpkg.name] = {}
    if not self.pkgs[srcpkg.idx][srcpkg.name].has_key(rel):
      self.pkgs[srcpkg.idx][srcpkg.name][rel] = srcpkg

  def getletter(self, letter):
    return self.pkgs[getidx(letter)]

  def indices(self):
    for k,v in sorted(self.pkgs.iteritems()):
      yield (k,v)

# basic module tests
if __name__ == "__main__":
  import Conf
  import sys
  import copy
  a = Archive(sys.argv[1], suitefilter=["etch"])
  b = copy.deepcopy(a)
  b.addsuite("lenny")
  b.addcomponent("etch", "something")
  class x:
    def __init__(self,name):
      self.name=name
  b.addsourcepackage("etch","main",x("foo"))
  print "suite diff"
  print "\n".join( ArchiveDiffer().diffsuites(a,b) )
  print "component diff"
  print "\n".join( ArchiveDiffer().diffcomponents(a,b,"etch") )
  print "package diff"
  print "\n".join( ArchiveDiffer().diffsourcepackages(a,b,"etch","main") )