#!/usr/bin/python -tt
# First Aid Kit - diagnostic and repair tool for Linux
# Copyright (C) 2007 Joel Granados <jgranado@redhat.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., 675 Mass Ave, Cambridge, MA 02139, USA.

import getopt, sys, os, os.path, pickle, logging

from pyfirstaidkit import Config
from pyfirstaidkit import reporting
from pyfirstaidkit import initLogger
from pyfirstaidkit.plugins import PluginSystem
from pyfirstaidkit.dependency import Dependencies
from pyfirstaidkit.utils.backup import FileBackupStore

def usage(name):
    print("""Usage:
%s [opts] <plugins>
                        - Executes the revert function of the listed plugins.
                          If the plugin name has a space use quotation marks
                          ("")

opts:
    -P <path>           - add different plugin path  it can be used more than
                          once.
    -c <config file>    - location of the config file
    --dir=BACK_UP_DIR   - The directory where the backups are.  The user
                          must specify this option.
    --all               - When "all" option is passed, revert ignores the
                          list of plugins and tries to revert everything
                          present in directory.
""") % (name,)

def revert(backup, plugin, report):
    """ use the plugin revert function with the backup object stored in path.

    backup - BackupPersistent object.
    plugin - The plugin class.
    report - the reporting object.
    """

    # We try to execute the plugin revert function.
    try:
        plugink = plugin.get_plugin()
        plugink.revert(backup, report)
    except:
        Logger.warning("FAK Revert: An Error has occured whle executing the " \
                "revert function for plugin %s/" % plugin)


def findPluginIdPath(plugin):
    pluginid = plugin.__name__.split('.')[-1:][0]
    pluginpath = os.path.join(Config.revert.dir, pluginid)
    if os.path.isdir(pluginpath):
        retval = (pluginid, pluginpath)
    else:

        pluginid = plugin.getBackupId()
        pluginpath = os.path.join(Config.revert.dir, pluginid)
        if os.path.isdir(pluginpath):
            retval =  (pluginid, pluginpath)
        else:
            Logger.warning("FAK Revert: No backup directory was found " \
                    "for %s." % plugin.__name__)
        retval = (None, None)

        # FIXME: if there is a change of the namespace for the current
        # plugin being different from the namespace of the same plugin
        # but called from firstaidkit, we should include a check for this.

    return retval

if __name__ == "__main__":
    try:
        (opts, vars) = getopt.getopt(sys.argv[1:], "c:P", \
                ["all", "dir=", "plugin-path=", "config="])
    except Exception, e:
        print("\nError parsing the argument line: ",e,"\n")
        usage(sys.argv[0])
        sys.exit(1)

    for (o, val) in opts:
        if o == "--dir":
            if os.path.isdir(val):
                Config.revert.dir = val
            else:
                print("%s is not a valid directory." % val)
                usage(sys.argv[0])
                sys.exit(1)
        elif o == "--all":
            Config.revert.all = "True"

        elif o in ("-P", "--plugin-path"):
            if not os.path.isdir(val):
                print("%s is not a valid directory."% val)
                usage(sys.argv[0])
                sys.exit(1)
            Config.set("paths", val.strip("/"), val)

        elif o in ("-c", "--config"):
            Config.read(val)



    # FIXME: implement the use of quotation marks.
    plugins = vars

    if len(plugins) == 0 and Config.revert.all == "False":
        print("You must give a list of plugins after the optiosn.  Or " \
                "the --all options so the plugin list gets ignored.")
        usage(sys.argv[0])
        sys.exit(1)

    if len(Config.revert.dir) == 0:
        print("You must specify a directory.")
        usage(sys.argv[0])
        sys.exit(1)



    # Modify the logging a little
    Config.log.filename = "/var/log/firstaidkitrevert.log"
    Config.log.fallbacks = \
            "firstaidkitrevert.log,/tmp/firstaidkitrevert.log,/dev/null"
    Config.log.method = "stdout"

    # initialize log for plugin system.
    fallbacks = Config.log.fallbacks.split(",")
    for lfile in fallbacks:
        try:
            initLogger(Config)
            break
        except Exception, e:
            if lfile != fallbacks[len(fallbacks)-1]:
                Config.log.filename = lfile
                continue
            else:
                print(e)
                usage(sys.argv[0])
                sys.exit(1)
    Logger = logging.getLogger("firstaidkit")
    report = reporting.Reports(maxsize = 1, round = True)

    # initialize the plugin system.
    class Taskr(object):
        def continuing(self):
            return True
        
    try:
        ps = PluginSystem(report, Dependencies(), interpret = Taskr())
    except:
        Logger.critical("FAK Revert: An error has occured while creating " \
                "the Plugin system.")
        sys.exit(1)

    if Config.revert.all == "True":
        plugins = ps.list()

    # we execute the revert for all plugins passed by the user.
    for plugin in plugins:
        (id, path) = findPluginIdPath(ps._plugins[plugin])
        if id is None or path is None:
            Logger.warning("FAK Revert: Revert found no backup object " \
                    "for %s" % plugin)
        else:
            # We create the backup persistent object bpo before passing it to
            # the revert function.
            bpo = FileBackupStore.BackupPersistent(id, path, reverting = True)
            bpo.loadMeta()
            revert(bpo, ps._plugins[plugin], report)