#!/usr/bin/python3
#
# LOW LEVEL example how to deal with the depcache
#
# you probably do not want to use this low level code and use
# the high level "apt" interface instead that can do all this
# but with a nicer API

import apt_pkg
from progress import TextFetchProgress

from apt.progress.text import OpProgress

# init
apt_pkg.init()

progress = OpProgress()
cache = apt_pkg.Cache(progress)
print("Available packages: %s " % cache.package_count)

print("Fetching")
progress = TextFetchProgress()
source = apt_pkg.SourceList()
cache.update(progress, source)

iter = cache["base-config"]
print("example package iter: %s" % iter)

# get depcache
print("\n\n depcache")
depcache = apt_pkg.DepCache(cache)
depcache.read_pinfile()
print("got a depcache: %s " % depcache)
print("Marked for install: %s " % depcache.inst_count)

print("\n\n Reinit")
depcache.init(progress)

# sys.exit()

# get a canidate version
ver = depcache.get_candidate_ver(iter)
print("Candidate version: %s " % ver)

print("\n\nQuerry interface")
print(f"{iter.name}.is_upgradable(): {depcache.is_upgradable(iter)}")

print("\nMarking interface")
print("Marking '%s' for install" % iter.name)
depcache.mark_install(iter)
print("Install count: %s " % depcache.inst_count)
print(f"{iter.name}.marked_install(): {depcache.marked_install(iter)}")
print(f"{iter.name}.marked_upgrade(): {depcache.marked_upgrade(iter)}")
print(f"{iter.name}.marked_delete(): {depcache.marked_delete(iter)}")

print("Marking %s for delete" % iter.name)
depcache.mark_delete(iter)
print("del_count: %s " % depcache.del_count)
print(f"{iter.name}.marked_delete(): {depcache.marked_delete(iter)}")

iter = cache["apt"]
print("\nMarking '%s' for install" % iter.name)
depcache.mark_install(iter)
print("Install count: %s " % depcache.inst_count)
print(f"{iter.name}.marked_install(): {depcache.marked_install(iter)}")
print(f"{iter.name}.marked_upgrade(): {depcache.marked_upgrade(iter)}")
print(f"{iter.name}.marked_delete(): {depcache.marked_delete(iter)}")

print("Marking %s for keep" % iter.name)
depcache.mark_keep(iter)
print("Install: %s " % depcache.inst_count)

iter = cache["python-apt"]
print("\nMarking '%s' for install" % iter.name)
depcache.mark_install(iter)
print("Install: %s " % depcache.inst_count)
print("Broken count: %s" % depcache.broken_count)
print("fix_broken() ")
depcache.fix_broken()
print("Broken count: %s" % depcache.broken_count)

print("\nPerforming upgrade")
depcache.upgrade()
print("Keep: %s " % depcache.keep_count)
print("Install: %s " % depcache.inst_count)
print("Delete: %s " % depcache.del_count)
print("usr_size: %s " % apt_pkg.size_to_str(depcache.usr_size))
print("deb_size: %s " % apt_pkg.size_to_str(depcache.deb_size))

for pkg in cache.packages:
    if (
        pkg.current_ver is not None
        and not depcache.marked_install(pkg)
        and depcache.is_upgradable(pkg)
    ):
        print("upgrade didn't upgrade (kept): %s" % pkg.name)

print("\nPerforming Distupgrade")
depcache.upgrade(True)
print("Keep: %s " % depcache.keep_count)
print("Install: %s " % depcache.inst_count)
print("Delete: %s " % depcache.del_count)
print("usr_size: %s " % apt_pkg.size_to_str(depcache.usr_size))
print("deb_size: %s " % apt_pkg.size_to_str(depcache.deb_size))

# overview about what would happen
for pkg in cache.packages:
    if depcache.marked_install(pkg):
        if pkg.current_ver is not None:
            print("Marked upgrade: %s " % pkg.name)
        else:
            print("Marked install: %s" % pkg.name)
    elif depcache.marked_delete(pkg):
        print("Marked delete: %s" % pkg.name)
    elif depcache.marked_keep(pkg):
        print("Marked keep: %s" % pkg.name)