#!/usr/bin/python3
# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright (c) 2013 TrilioData, Inc.
# All Rights Reserved.

# Interactive shell based on Django:
#
# Copyright (c) 2005, the Lawrence Journal-World
# All rights reserved.
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# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
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#     1. Redistributions of source code must retain the above copyright notice,
#        this list of conditions and the following disclaimer.
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#     2. Redistributions in binary form must reproduce the above copyright
#        notice, this list of conditions and the following disclaimer in the
#        documentation and/or other materials provided with the distribution.
#
#     3. Neither the name of Django nor the names of its contributors may be
#        used to endorse or promote products derived from this software without
#        specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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"""
  CLI interface for workloadmgr management.
"""

import os
import sys
import uuid


from sqlalchemy import create_engine, MetaData, Table
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker


# If ../workloadmgr/__init__.py exists, add ../ to Python search path, so that
# it will override what happens to be installed in /usr/(local/)lib/python...
POSSIBLE_TOPDIR = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
                                                os.pardir,
                                                os.pardir))
if os.path.exists(os.path.join(POSSIBLE_TOPDIR, 'workloadmgr', '__init__.py')):
    sys.path.insert(0, POSSIBLE_TOPDIR)

from workloadmgr.openstack.common import gettextutils
gettextutils.install('workloadmgr')

from oslo.config import cfg

from workloadmgr import context
from workloadmgr import db
from workloadmgr.db import migration
from workloadmgr import exception
from workloadmgr import flags
from workloadmgr.openstack.common import log as logging
from workloadmgr.openstack.common import rpc
from workloadmgr.openstack.common import uuidutils
from workloadmgr import utils
from workloadmgr import version
from taskflow.persistence import backends as taskflow_backend

FLAGS = flags.FLAGS


# Decorators for actions
def args(*args, **kwargs):
    def _decorator(func):
        func.__dict__.setdefault('args', []).insert(0, (args, kwargs))
        return func
    return _decorator


def param2id(object_id):
    """Helper function to convert various id types to internal id.
    args: [object_id], e.g. 'wlm-0000000a' or 'wlm-0000000a' or '10'
    """
    if uuidutils.is_uuid_like(object_id):
        return object_id
    elif '-' in object_id:
        # FIXME(ja): mapping occurs in nova?
        pass
    else:
        return int(object_id)


class ShellCommands(object):
    def bpython(self):
        """Runs a bpython shell.

        Falls back to Ipython/python shell if unavailable"""
        self.run('bpython')

    def ipython(self):
        """Runs an Ipython shell.

        Falls back to Python shell if unavailable"""
        self.run('ipython')

    def python(self):
        """Runs a python shell.

        Falls back to Python shell if unavailable"""
        self.run('python')

    @args('--shell', dest="shell",
          metavar='<bpython|ipython|python>',
          help='Python shell')
    def run(self, shell=None):
        """Runs a Python interactive interpreter."""
        if not shell:
            shell = 'bpython'

        if shell == 'bpython':
            try:
                import bpython
                bpython.embed()
            except ImportError:
                shell = 'ipython'
        if shell == 'ipython':
            try:
                import IPython
                # Explicitly pass an empty list as arguments, because
                # otherwise IPython would use sys.argv from this script.
                shell = IPython.Shell.IPShell(argv=[])
                shell.mainloop()
            except ImportError:
                shell = 'python'

        if shell == 'python':
            import code
            try:
                # Try activating rlcompleter, because it's handy.
                import readline
            except ImportError:
                pass
            else:
                # We don't have to wrap the following import in a 'try',
                # because we already know 'readline' was imported successfully.
                import rlcompleter
                readline.parse_and_bind("tab:complete")
            code.interact()

    @args('--path', required=True, help='Script path')
    def script(self, path):
        """Runs the script from the specifed path with flags set properly.
        arguments: path"""
        exec(compile(open(path).read(), path, 'exec'), locals(), globals())


def _db_error(caught_exception):
    print caught_exception
    print _("The above error may show that the database has not "
            "been created.\nPlease create a database using "
            "'workloadmgr-manage db sync' before running this command.")
    exit(1)


class HostCommands(object):
    """List hosts."""

    @args('zone', nargs='?', default=None,
          help='Availability Zone (default: %(default)s)')
    def list(self, zone=None):
        """Show a list of all physical hosts. Filter by zone.
        args: [zone]"""
        print "%-25s\t%-15s" % (_('host'),
                                _('zone'))
        ctxt = context.get_admin_context()
        services = db.service_get_all(ctxt)
        if zone:
            services = [s for s in services if s['availability_zone'] == zone]
        hosts = []
        for srv in services:
            if not [h for h in hosts if h['host'] == srv['host']]:
                hosts.append(srv)

        for h in hosts:
            print "%-25s\t%-15s" % (h['host'], h['availability_zone'])


class DbCommands(object):
    """Class for managing the database."""

    def __init__(self):
        pass

    @args('connection', nargs='?', default=None,
          help='Database connection')
    @args('version', nargs='?', default=None,
          help='Database version')
    def sync(self, connection, version=None):
        """Sync the database up to the most recent version."""

        # workloadmgr database
        ret = migration.db_sync(version)

        # add taskflow tables to workloadmgr database
        backend = taskflow_backend.fetch({'connection': connection})
        ret = backend.get_connection().upgrade()

        return ret

    def version(self):
        """Print the current database version."""
        print migration.db_version()


class VersionCommands(object):
    """Class for exposing the codebase version."""

    def __init__(self):
        pass

    def list(self):
        print(version.version_string())

    def __call__(self):
        self.list()


class ConfigCommands(object):
    """Class for exposing the flags defined by flag_file(s)."""

    def __init__(self):
        pass

    def list(self):
        for key, value in FLAGS.iteritems():
            if value is not None:
                print '%s = %s' % (key, value)


class GetLogCommands(object):
    """Get logging information."""

    def errors(self):
        """Get all of the errors from the log files."""
        error_found = 0
        if FLAGS.log_dir:
            logs = [x for x in os.listdir(FLAGS.log_dir) if x.endswith('.log')]
            for file in logs:
                log_file = os.path.join(FLAGS.log_dir, file)
                lines = [line.strip() for line in open(log_file, "r")]
                lines.reverse()
                print_name = 0
                for index, line in enumerate(lines):
                    if line.find(" ERROR ") > 0:
                        error_found += 1
                        if print_name == 0:
                            print log_file + ":-"
                            print_name = 1
                        print "Line %d : %s" % (len(lines) - index, line)
        if error_found == 0:
            print "No errors in logfiles!"

    @args('num_entries', nargs='?', type=int, default=10,
          help='Number of entries to list (default: %(default)d)')
    def syslog(self, num_entries=10):
        """Get <num_entries> of the workloadmgr syslog events."""
        entries = int(num_entries)
        count = 0
        log_file = ''
        if os.path.exists('/var/log/syslog'):
            log_file = '/var/log/syslog'
        elif os.path.exists('/var/log/messages'):
            log_file = '/var/log/messages'
        else:
            print "Unable to find system log file!"
            sys.exit(1)
        lines = [line.strip() for line in open(log_file, "r")]
        lines.reverse()
        print "Last %s workloadmgr syslog entries:-" % (entries)
        for line in lines:
            if line.find("workloadmgr") > 0:
                count += 1
                print "%s" % (line)
            if count == entries:
                break

        if count == 0:
            print "No workloadmgr entries in syslog!"


class ServiceCommands(object):
    """Methods for managing services."""

    def list(self):
        """Show a list of all workloadmgr services."""
        ctxt = context.get_admin_context()
        services = db.service_get_all(ctxt)
        print_format = "%-16s %-36s %-16s %-10s %-5s %-10s"
        print print_format % (
            _('Binary'),
            _('Host'),
            _('Zone'),
            _('Status'),
            _('State'),
            _('Updated At'))
        for svc in services:
            alive = utils.service_is_up(svc)
            art = ":-)" if alive else "XXX"
            status = 'enabled'
            if svc['disabled']:
                status = 'disabled'
            print print_format % (svc['binary'], svc['host'].partition('.')[0],
                                  svc['availability_zone'], status, art,
                                  svc['updated_at'])


CATEGORIES = {
    'config': ConfigCommands,
    'db': DbCommands,
    'host': HostCommands,
    'logs': GetLogCommands,
    'service': ServiceCommands,
    'shell': ShellCommands,
    'version': VersionCommands,
}


def methods_of(obj):
    """Get all callable methods of an object that don't start with underscore
    returns a list of tuples of the form (method_name, method)"""
    result = []
    for i in dir(obj):
        if callable(getattr(obj, i)) and not i.startswith('_'):
            result.append((i, getattr(obj, i)))
    return result


def add_command_parsers(subparsers):
    for category in CATEGORIES:
        command_object = CATEGORIES[category]()

        parser = subparsers.add_parser(category)
        parser.set_defaults(command_object=command_object)

        category_subparsers = parser.add_subparsers(dest='action')

        for (action, action_fn) in methods_of(command_object):
            parser = category_subparsers.add_parser(action)

            action_kwargs = []
            for args, kwargs in getattr(action_fn, 'args', []):
                parser.add_argument(*args, **kwargs)

            parser.set_defaults(action_fn=action_fn)
            parser.set_defaults(action_kwargs=action_kwargs)


category_opt = cfg.SubCommandOpt('category',
                                 title='Command categories',
                                 handler=add_command_parsers)


def get_arg_string(args):
    arg = None
    if args[0] == '-':
        # (Note)zhiteng: args starts with FLAGS.oparser.prefix_chars
        # is optional args. Notice that cfg module takes care of
        # actual ArgParser so prefix_chars is always '-'.
        if args[1] == '-':
            # This is long optional arg
            arg = args[2:]
        else:
            arg = args[3:]
    else:
        arg = args

    return arg


def fetch_func_args(func):
    fn_args = []
    for args, kwargs in getattr(func, 'args', []):
        arg = get_arg_string(args[0])
        fn_args.append(getattr(FLAGS.category, arg))

    return fn_args


def main():
    """Parse options and call the appropriate class/method."""
    FLAGS.register_cli_opt(category_opt)
    script_name = sys.argv[0]
    if len(sys.argv) < 2:
        print(_("\nOpenStack WorkloadMgr version: %(version)s\n") %
              {'version': version.version_string()})
        print script_name + " category action [<args>]"
        print _("Available categories:")
        for category in CATEGORIES:
            print "\t%s" % category
        sys.exit(2)

    try:
        flags.parse_args(sys.argv)
        logging.setup("workloadmgr")
    except cfg.ConfigFilesNotFoundError:
        cfgfile = FLAGS.config_file[-1] if FLAGS.config_file else None
        if cfgfile and not os.access(cfgfile, os.R_OK):
            st = os.stat(cfgfile)
            print _("Could not read %s. Re-running with sudo") % cfgfile
            try:
                os.execvp('sudo', ['sudo', '-u', '#%s' % st.st_uid] + sys.argv)
            except Exception:
                print _('sudo failed, continuing as if nothing happened')

        print _('Please re-run workloadmgr-manage as root.')
        sys.exit(2)

    fn = FLAGS.category.action_fn

    fn_args = fetch_func_args(fn)
    fn(*fn_args)


if __name__ == '__main__':
    main()