#!/usr/bin/env python
# License of this file:
#  Copy, Modify, Change, Sell it at your will.
#
# There is absolutely no warranty with this file
#
# (C) Copyright 2006 Holger Hans Peter Freyther



def check_dir(name, error):
    """
    Check if the given directory exists, if not error
    is printed and the application is left.
    """
    import os, sys
    import stat
    if not os.path.isdir(name):
        print error
        sys.exit(-1)


def find_packages(dir):
    import os
    contents = os.listdir(dir)
    ipks = []
    for f in contents:
        (root,ext) = os.path.splitext(f)
        if ext == ".ipk":
            ipks.append( f )
    return ipks

def diff_dirs( old_ipks, new_ipks ):
    """
    We will return three lists. The first one will
    contain the files that are only in a, the second
    the files in both directories and the third one
    will
    """
    only_old = [ i for i in old_ipks if i not in new_ipks]
    both     = [ i for i in old_ipks if i in new_ipks ]
    only_new = [ i for i in new_ipks if i not in old_ipks]

    return only_old, both, only_new

def diff_packages( old, new ):
    def compare( name, version, attribute, txt ):
        """
        Compare package with name and version with method
        and print error message
        """
        try:
            left  = getattr( old[package_name][version], 'get_' + attribute )
            right = getattr( new[package_name][version], 'get_' + attribute )
            if not left() == right():
                print txt
        except Exception, e:
            raise e
            print "Error with %s %s and '%s'" % (package_name,version, txt)

    for package_name in old.keys():
        for version in old[package_name].keys():
            print "Comparing %s %s" % (package_name, version)
            compare( package_name, version, 'maintainer', "Maintainer is different" )
            compare( package_name, version, 'architecture', "Architecture is different" )
            compare( package_name, version, 'description', "Description is different" )
            compare( package_name, version, 'depends', "Depends are different" )
            compare( package_name, version, 'provides', "Provides are different" )
            compare( package_name, version, 'conflicts', "Provides are different" )
            compare( package_name, version, 'suggests', "Suggests are different" )
            compare( package_name, version, 'source', "Source is different" )
            compare( package_name, version, 'section', "Section is different" )
            compare( package_name, version, 'file_list', "Filelist is different" )
            compare( package_name, version, 'file_all_list', "Filelist is different" )
            compare( package_name, version, 'md5', "MD5 is different" )

def print_result_start( old, both, new ):
    """
    Print the findings of ipkg-diff
    """
    print "ipkg-diff diff report"
    print "%d packages found" % (len(old)+len(both)+len(new))
    print "# of old/removed packages: %d" % len(old)
    print "# of new packages: %d" % len(new)
    print "# of possible changed packages: %d" % len(both)
    print ""

    if len(old) > 0:
        for i in old:
            print "Vanished ipk: %s" % i

    if len(new) > 0:
        for i in new:
            print "New ipk: %s" % i


def parse_packages(dir, package_names):
    import ipkg, os
    packages = {}

    for package in package_names:
        p = ipkg.Package(os.path.join(dir, package))

        if not p.get_package() in packages:
            packages[p.get_package()] = {}
        packages[p.get_package()][p.get_version()] = p

    return packages


if __name__ == "__main__":
    import os,sys

    # sanity
    if len(sys.argv) != 3:
        print "ipkg-diff OLD NEW"
        sys.exit(-2)

    # check dirs
    check_dir(sys.argv[1], "Source Directory does not exist")
    check_dir(sys.argv[2], "Dest Directory does not exists")

    # find packages
    old_ipks = find_packages(sys.argv[1])
    new_ipks = find_packages(sys.argv[2])

    # find removed and new files
    only_old, both, only_new = diff_dirs( old_ipks, new_ipks )

    # print a summary header
    print_result_start( only_old, both, only_new )

    # start diffing the content by parsing the packages
    print "Loading Content into memory"
    old_packages = parse_packages(sys.argv[1], both )
    new_packages = parse_packages(sys.argv[2], both )

    diff_packages( old_packages, new_packages )