# DistUpgradeView.py
#
#  Copyright (c) 2004,2005 Canonical
#
#  Author: Michael Vogt <michael.vogt@ubuntu.com>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License as
#  published by the Free Software Foundation; either version 2 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
#  USA

import apt
import apt_pkg
import logging
import locale
import time
import sys
import os
import pty
import select
import subprocess
import copy
import apt.progress

from configparser import NoSectionError, NoOptionError
from subprocess import PIPE, Popen

from .DistUpgradeView import DistUpgradeView, InstallProgress, AcquireProgress
from .telemetry import get as get_telemetry
from .DistUpgradeConfigParser import DistUpgradeConfig


class NonInteractiveAcquireProgress(AcquireProgress):
    def update_status(self, uri, descr, shortDescr, status):
        AcquireProgress.update_status(self, uri, descr, shortDescr, status)
        #logging.debug("Fetch: updateStatus %s %s" % (uri, status))
        if status == apt_pkg.STAT_DONE:
            print("fetched %s (%.2f/100) at %sb/s" % (
                uri, self.percent, apt_pkg.size_to_str(int(self.current_cps))))
            if sys.stdout.isatty():
                sys.stdout.flush()


class NonInteractiveInstallProgress(InstallProgress):
    """
    Non-interactive version of the install progress class

    This ensures that conffile prompts are handled and that
    hanging scripts are killed after a (long) timeout via ctrl-c
    """

    def __init__(self, logdir):
        InstallProgress.__init__(self)
        logging.debug("setting up environ for non-interactive use")
        if "DEBIAN_FRONTEND" not in os.environ:
            os.environ["DEBIAN_FRONTEND"] = "noninteractive"
        os.environ["APT_LISTCHANGES_FRONTEND"] = "none"
        os.environ["RELEASE_UPGRADER_NO_APPORT"] = "1"
        self.config = DistUpgradeConfig(".")
        self.logdir = logdir
        self.install_run_number = 0
        try:
            if self.config.getWithDefault("NonInteractive","ForceOverwrite", False):
                apt_pkg.config.set("DPkg::Options::","--force-overwrite")
        except (NoSectionError, NoOptionError):
            pass
        # more debug
        #apt_pkg.config.set("Debug::pkgOrderList","true")
        #apt_pkg.config.set("Debug::pkgDPkgPM","true")
        # default to 2400 sec timeout
        self.timeout = 2400
        try:
            self.timeout = self.config.getint("NonInteractive","TerminalTimeout")
        except Exception:
            pass

    def error(self, pkg, errormsg):
        logging.error("got a error from dpkg for pkg: '%s': '%s'" % (pkg, errormsg))
        # check if re-run of maintainer script is requested
        if not self.config.getWithDefault(
            "NonInteractive","DebugBrokenScripts", False):
            return
        # re-run maintainer script with sh -x/perl debug to get a better
        # idea what went wrong
        #
        # FIXME: this is just a approximation for now, we also need
        #        to pass:
        #        - a version after remove (if upgrade to new version)
        #
        #        not everything is a shell or perl script
        #
        # if the new preinst fails, its not yet in /var/lib/dpkg/info
        # so this is inaccurate as well
        environ = copy.copy(os.environ)
        environ["PYCENTRAL"] = "debug"
        cmd = []

        # find what maintainer script failed
        if "post-installation" in errormsg:
            prefix = "/var/lib/dpkg/info/"
            name = "postinst"
            argument = "configure"
            maintainer_script = "%s/%s.%s" % (prefix, pkg, name)
        elif "pre-installation" in errormsg:
            prefix = "/var/lib/dpkg/tmp.ci/"
            #prefix = "/var/lib/dpkg/info/"
            name = "preinst"
            argument = "install"
            maintainer_script = "%s/%s" % (prefix, name)
        elif "pre-removal" in errormsg:
            prefix = "/var/lib/dpkg/info/"
            name = "prerm"
            argument = "remove"
            maintainer_script = "%s/%s.%s" % (prefix, pkg, name)
        elif "post-removal" in errormsg:
            prefix = "/var/lib/dpkg/info/"
            name = "postrm"
            argument = "remove"
            maintainer_script = "%s/%s.%s" % (prefix, pkg, name)
        else:
            print("UNKNOWN (trigger?) dpkg/script failure for %s (%s) " % (pkg, errormsg))
            return

        # find out about the interpreter
        if not os.path.exists(maintainer_script):
            logging.error("can not find failed maintainer script '%s' " % maintainer_script)
            return
        with open(maintainer_script) as f:
            interp = f.readline()[2:].strip().split()[0]
        if ("bash" in interp) or ("/bin/sh" in interp):
            debug_opts = ["-ex"]
        elif ("perl" in interp):
            debug_opts = ["-d"]
            environ["PERLDB_OPTS"] = "AutoTrace NonStop"
        else:
            logging.warning("unknown interpreter: '%s'" % interp)

        # check if debconf is used and fiddle a bit more if it is
        with open(maintainer_script) as f:
            maintainer_script_text = f.read()
        if ". /usr/share/debconf/confmodule" in maintainer_script_text:
            environ["DEBCONF_DEBUG"] = "developer"
            environ["DEBIAN_HAS_FRONTEND"] = "1"
            interp = "/usr/share/debconf/frontend"
            debug_opts = ["sh","-ex"]

        # build command
        cmd.append(interp)
        cmd.extend(debug_opts)
        cmd.append(maintainer_script)
        cmd.append(argument)

        # check if we need to pass a version
        if name == "postinst":
            version = Popen("dpkg-query -s %s|grep ^Config-Version" % pkg,
                            shell=True, stdout=PIPE,
                            universal_newlines=True).communicate()[0]
            if version:
                cmd.append(version.split(":",1)[1].strip())
        elif name == "preinst":
            pkg = os.path.basename(pkg)
            pkg = pkg.split("_")[0]
            version = Popen("dpkg-query -s %s|grep ^Version" % pkg,
                            shell=True, stdout=PIPE,
                            universal_newlines=True).communicate()[0]
            if version:
                cmd.append(version.split(":",1)[1].strip())

        logging.debug("re-running '%s' (%s)" % (cmd, environ))
        ret = subprocess.call(cmd, env=environ)
        logging.debug("%s script returned: %s" % (name,ret))

    def conffile(self, current, new):
        logging.warning("got a conffile-prompt from dpkg for file: '%s'" %
                        current)
        # looks like we have a race here *sometimes*
        time.sleep(5)
        try:
          # don't overwrite
          os.write(self.master_fd, b"n\n")
          logging.warning("replied no to the conffile-prompt for file: '%s'" %
                          current)
        except Exception as e:
          logging.error("error '%s' when trying to write to the conffile"%e)

    def start_update(self):
        InstallProgress.start_update(self)
        self.last_activity = time.time()
        progress_log = self.config.getWithDefault("NonInteractive","DpkgProgressLog", False)
        if progress_log:
            fullpath = os.path.join(self.logdir, "dpkg-progress.%s.log" % self.install_run_number)
            logging.debug("writing dpkg progress log to '%s'" % fullpath)
            self.dpkg_progress_log = open(fullpath, "w")
        else:
            self.dpkg_progress_log = open(os.devnull, "w")
        self.dpkg_progress_log.write("%s: Start\n" % time.time())
    def finish_update(self):
        InstallProgress.finish_update(self)
        self.dpkg_progress_log.write("%s: Finished\n" % time.time())
        self.dpkg_progress_log.close()
        self.install_run_number += 1
    def status_change(self, pkg, percent, status_str):
        self.dpkg_progress_log.write("%s:%s:%s:%s\n" % (time.time(),
                                                        percent,
                                                        pkg,
                                                        status_str))
    def update_interface(self):
        InstallProgress.update_interface(self)
        if self.statusfd == None:
            return
        if (self.last_activity + self.timeout) < time.time():
            logging.warning("no activity %s seconds (%s) - sending ctrl-c" % (
                    self.timeout, self.status))
            # ctrl-c
            os.write(self.master_fd,chr(3))
        # read master fd and write to stdout so that terminal output
        # actualy works
        res = select.select([self.master_fd],[],[],0.1)
        while len(res[0]) > 0:
           self.last_activity = time.time()
           try:
               s = os.read(self.master_fd, 1)
               sys.stdout.write("%s" % s.decode(
                    locale.getpreferredencoding(), errors='ignore'))
           except OSError:
               # happens after we are finished because the fd is closed
               return
           res = select.select([self.master_fd],[],[],0.1)
        sys.stdout.flush()


    def fork(self):
        logging.debug("doing a pty.fork()")
        # some maintainer scripts fail without
        os.environ["TERM"] = "dumb"
        # unset PAGER so that we can do "diff" in the dpkg prompt
        os.environ["PAGER"] = "true"
        (self.pid, self.master_fd) = pty.fork()
        if self.pid != 0:
            logging.debug("pid is: %s" % self.pid)
        return self.pid


class DistUpgradeViewNonInteractive(DistUpgradeView):
    " non-interactive version of the upgrade view "
    def __init__(self, datadir=None, logdir=None):
        DistUpgradeView.__init__(self)
        get_telemetry().set_updater_type('NonInteractive')
        self.config = DistUpgradeConfig(".")
        self._acquireProgress = NonInteractiveAcquireProgress()
        self._installProgress = NonInteractiveInstallProgress(logdir)
        self._opProgress = apt.progress.base.OpProgress()
        sys.__excepthook__ = self.excepthook
    def excepthook(self, type, value, tb):
        " on uncaught exceptions -> print error and reboot "
        import traceback
        logging.exception("got exception '%s': %s " % (type, value))
        lines = traceback.format_exception(type, value, tb)
        logging.error("not handled exception:\n%s" % "".join(lines))
        #sys.excepthook(type, value, tb)
        self.confirmRestart()
    def getOpCacheProgress(self):
        " return a OpProgress() subclass for the given graphic"
        return self._opProgress
    def getAcquireProgress(self):
        " return an acquire progress object "
        return self._acquireProgress
    def getInstallProgress(self, cache=None):
        " return a install progress object "
        return self._installProgress
    def updateStatus(self, msg):
        """ update the current status of the distUpgrade based
            on the current view
        """
        pass
    def setStep(self, step):
        """ we have 5 steps current for a upgrade:
        1. Analyzing the system
        2. Updating repository information
        3. Performing the upgrade
        4. Post upgrade stuff
        5. Complete
        """
        super(DistUpgradeViewNonInteractive, self).setStep(step)
        pass
    def confirmChanges(self, summary, changes, downloadSize,
                       actions=None, removal_bold=True):
        DistUpgradeView.confirmChanges(self, summary, changes,
                                       downloadSize, actions)
        logging.debug("toinstall: '%s'" % [p.name for p in self.toInstall])
        logging.debug("toupgrade: '%s'" % [p.name for p in self.toUpgrade])
        logging.debug("toremove: '%s'" % [p.name for p in self.toRemove])
        return True
    def askYesNoQuestion(self, summary, msg, default='No'):
        " ask a Yes/No question and return True on 'Yes' "
        # if this gets enabled upgrades over ssh with the non-interactive
        # frontend will no longer work
        #if default.lower() == "no":
        #    return False
        return True
    def askCancelContinueQuestion(self, summary, msg, default='Cancel'):
        return True
    def confirmRestart(self):
        " generic ask about the restart, can be overridden "
        logging.debug("confirmRestart() called")
        # rebooting here makes sense if we run e.g. in qemu
        return self.config.getWithDefault("NonInteractive","RealReboot", False)
    def error(self, summary, msg, extended_msg=None):
        " display a error "
        logging.error("%s %s (%s)" % (summary, msg, extended_msg))
    def abort(self):
        logging.error("view.abort called")
