#!/usr/bin/env python
# Authors: Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2008  Red Hat
# see file 'COPYING' for use and warranty information
#
# 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; version 2 only
#
# 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
#

# Documentation can be found at http://freeipa.org/page/LdapUpdate

# TODO
# save undo files?

UPDATES_DIR="/usr/share/ipa/updates/"

import sys
try:
    from optparse import OptionParser
    from ipaserver import ipaldap
    from ipa import entity, ipaerror, ipautil, config
    from ipaserver import installutils
    import ldap
    import logging
    import re
    import krbV
    import platform
    import shlex
    import time
    import random
    import os
    import fnmatch
except ImportError:
    print >> sys.stderr, """\
There was a problem importing one of the required Python modules. The
error was:

    %s
""" % sys.exc_value
    sys.exit(1)

# global variable
sub_dict = {}
live_run = True

class BadSyntax(Exception):
    def __init__(self, value):
        self.value = value
    def __str__(self):
        return repr(self.value)

def parse_options():
    usage = "%prog [options] input_file(s)\n"
    usage += "%prog [options]\n"
    parser = OptionParser(usage=usage, formatter=config.IPAFormatter())

    parser.add_option("-d", "--debug", action="store_true", dest="debug",
                      help="Display debugging information about the update(s)")
    parser.add_option("-t", "--test", action="store_true", dest="test",
                      help="Run through the update without changing anything")
    parser.add_option("-y", dest="password",
                      help="File containing the Directory Manager password")

    config.add_standard_options(parser)
    options, args = parser.parse_args()

    config.init_config(options)

    return options, args

def get_dirman_password(fqdn):
    """Prompt the user for the Directory Manager password and verify its
       correctness.
    """
    password = installutils.read_password("Directory Manager", confirm=False, validate=False)

    # Try out the password
    try:
        conn = ipaldap.IPAdmin(fqdn)
        conn.do_simple_bind(bindpw=password)
        conn.unbind()
    except ldap.CONNECT_ERROR, e:
        sys.exit("\nUnable to connect to LDAP server %s" % fqdn)
    except ldap.SERVER_DOWN, e:
        sys.exit("\nUnable to connect to LDAP server %s" % fqdn)
    except ldap.INVALID_CREDENTIALS, e :
        sys.exit("\nThe password provided is incorrect for LDAP server %s" % fqdn)

    return password

def detail_error(detail):
    """IPA returns two errors back. One a generic one indicating the broad
       problem and a detailed message back as well which should have come
       from LDAP. This function will parse that into a human-readable string.
    """
    msg = ""
    desc = detail[0].get('desc')
    info = detail[0].get('info')

    if desc:
        msg = desc
        if info:
            msg = msg + " " + info

    return msg

def identify_arch():
    """On multi-arch systems some libraries may be in /lib64, /usr/lib64, etc.
       Determine if a suffix is needed based on the current architecture.
    """
    arch = platform.platform()

    if arch == "x86_64":
        return "64"
    else:
        return ""

def template_str(s):
    global sub_dict

    try:
        return ipautil.template_str(s, sub_dict)
    except KeyError, e:
        raise BadSyntax("Unknown template keyword %s" % e)

def remove_quotes(line):
    """Remove leading and trailng double or single quotes"""
    if line.startswith('"'):
        line = line[1:]
    if line.endswith('"'):
        line = line[:-1]
    if line.startswith("'"):
        line = line[1:]
    if line.endswith("'"):
        line = line[:-1]

    return line

def parse_values(line):
    """Parse a comma-separated string into separate values and convert them
       into a list. This should handle quoted-strings with embedded commas
    """
    lexer = shlex.shlex(line)
    lexer.wordchars = lexer.wordchars + ".()-"
    l = []
    v = ""
    for token in lexer:
        if token != ',':
            if v:
                v = v + " " + token
            else:
                v = token
        else:
            l.append(remove_quotes(v))
            v = ""

    l.append(remove_quotes(v))

    return l

def read_file(filename):
    if filename == '-':
        fd = sys.stdin
    else:
        fd = open(filename)
    text = fd.readlines()
    if fd != sys.stdin: fd.close()
    return text

def entry_to_entity(ent):
    """Tne Entry class is a bare LDAP entry. The Entity class has a lot more
       helper functions that we need, so convert to dict and then to Entity.
    """
    entry = dict(ent.data)
    entry['dn'] = ent.dn
    for key,value in entry.iteritems():
        if isinstance(value,list) or isinstance(value,tuple):
            if len(value) == 0:
                entry[key] = ''
            elif len(value) == 1:
                entry[key] = value[0]
    return entity.Entity(entry)

def combine_updates(dn_list, all_updates, update):
    """Combine a new update with the list of total updates

       Updates are stored in 2 lists:
           dn_list: contains a unique list of DNs in the updates
           all_updates: the actual updates that need to be applied

       We want to apply the updates from the shortest to the longest
       path so if new child and parent entries are in different updates
       we can be sure the parent gets written first. This also lets
       us apply any schema first since it is in the very short cn=schema.
    """
    dn = update.get('dn')
    dns = ldap.explode_dn(dn.lower())
    l = len(dns)
    if dn_list.get(l):
        if dn not in dn_list[l]:
            dn_list[l].append(dn)
    else:
        dn_list[l] = [dn]
    if not all_updates.get(dn):
        all_updates[dn] = update
        return all_updates

    e = all_updates[dn]
    e['updates'] = e['updates'] + update['updates']

    all_updates[dn] = e

    return all_updates

def parse_update_file(conn, data, all_updates, dn_list):
    """Parse the update file into a dictonary of lists and apply the update
       for each DN in the file."""
    valid_keywords = ["default", "add", "remove", "only"]
    update = {}
    dn = None
    lcount = 0
    for line in data:
        # Strip out \n and extra white space
        lcount = lcount + 1

        # skip comments and empty lines
        line = line.rstrip()
        if line.startswith('#') or line == '': continue

        if line.lower().startswith('dn:'):
            if dn is not None:
                all_updates = combine_updates(dn_list, all_updates, update)

            update = {}
            dn = line[3:].strip()
            update['dn'] = template_str(dn)
        else:
            if dn is None:
                raise BadSyntax, "dn is not defined in the update"

            if line.startswith(' '):
                v = d[len(d) - 1]
                v = v + " " + line.strip()
                d[len(d) - 1] = v
                update[index] = d
                continue
            line = line.strip()
            values = line.split(':', 2)
            if len(values) != 3:
                raise BadSyntax, "Bad formatting on line %d: %s" % (lcount,line)

            index = values[0].strip().lower()

            if index not in valid_keywords:
                raise BadSyntax, "Unknown keyword %s" % index

            attr = values[1].strip()
            value = values[2].strip()
            value = template_str(value)

            new_value = ""
            if index == "default":
                new_value = attr + ":" + value
            else:
                new_value = index + ":" + attr + ":" + value
                index = "updates"

            d = update.get(index, [])

            d.append(new_value)

            update[index] = d

    if dn is not None:
        all_updates = combine_updates(dn_list, all_updates, update)

    return (all_updates, dn_list)

def create_index_task(conn, attribute):
    """Create a task to update an index for an attribute"""
    global live_run

    r = random.SystemRandom()

    # Refresh the time to make uniqueness more probable. Add on some
    # randomness for good measure.
    sub_dict['TIME'] = int(time.time()) + r.randint(0,10000)

    cn = template_str("indextask_$TIME")
    dn = "cn=%s, cn=index, cn=tasks, cn=config" % cn

    e = ipaldap.Entry(dn)

    e.setValues('objectClass', ['top', 'extensibleObject'])
    e.setValue('cn', cn)
    e.setValue('nsInstance', 'userRoot')
    e.setValues('nsIndexAttribute', attribute)

    logging.info("Creating task to index attribute: %s", attribute)
    logging.debug("Task id: %s", dn)

    if live_run:
        conn.addEntry(e.dn, e.toTupleList())

    return dn

def monitor_index_task(conn, dn):
    """Give a task DN monitor it and wait until it has completed (or failed)"""
    global live_run

    if not live_run:
        # If not doing this live there is nothing to monitor
        return

    # Pause for a moment to give the task time to be created
    time.sleep(1)

    attrlist = ['nstaskstatus', 'nstaskexitcode']
    entry = None
    done = False

    while not done:
        try:
            entry = conn.getEntry(dn, ldap.SCOPE_BASE, "(objectclass=*)", attrlist)
        except ipaerror.exception_for(ipaerror.LDAP_NOT_FOUND):
            logging.error("Task not found: %s", dn)
            return
        except ipaerror.exception_for(ipaerror.LDAP_DATABASE_ERROR), e:
            logging.error("Task lookup failure %s: %s", e, detail_error(e.detail))
            return

        status = entry.getValue('nstaskstatus')
        if status is None:
            # task doesn't have a status yet
            time.sleep(1)
            continue

        if status.lower().find("finished") > -1:
            logging.info("Indexing finished")
            done = True

        logging.debug("Indexing in progress")
        time.sleep(1)

    return

def create_default_entry(dn, default):
    """Create the default entry from the values provided.

       The return type is entity.Entity
    """
    entry = ipaldap.Entry(dn)

    if not default:
        # This means that the entire entry needs to be created with add
        return entry_to_entity(entry)

    for line in default:
        # We already do syntax-parsing so this is safe
        (k, v) = line.split(':',1)
        e = entry.getValues(k)
        if e:
            # multi-valued attribute
            e = list(e)
            e.append(v)
        else:
            e = v
        entry.setValues(k, e)

    return entry_to_entity(entry)

def get_entry(conn, dn):
    """Retrieve an object from LDAP.

       The return type is ipaldap.Entry
    """
    searchfilter="objectclass=*"
    sattrs = ["*"]
    scope = ldap.SCOPE_BASE

    return conn.getList(dn, scope, searchfilter, sattrs)

def apply_updates(dn, updates, entry):
    """updates is a list of changes to apply
       entry is the thing to apply them to

       returns the modified entry
    """
    if not updates:
        return entry

    only = {}
    for u in updates:
        # We already do syntax-parsing so this is safe
        (utype, k, values) = u.split(':',2)

        values = parse_values(values)

        e = entry.getValues(k)
        if not isinstance(e, list):
            if e is None:
                e = []
            else:
                e = [e]

        for v in values:
            if utype == 'remove':
                logging.debug("remove: '%s' from %s, current value %s", v, k, e)
                try:
                    e.remove(v)
                except ValueError:
                    logging.warn("remove: '%s' not in %s", v, k)
                    pass
                entry.setValues(k, e)
                logging.debug('remove: updated value %s', e)
            elif utype == 'add':
                logging.debug("add: '%s' to %s, current value %s", v, k, e)
                # Remove it, ignoring errors so we can blindly add it later
                try:
                    e.remove(v)
                except ValueError:
                    pass
                e.append(v)
                logging.debug('add: updated value %s', e)
                entry.setValues(k, e)
            elif utype == 'only':
                logging.debug("only: set %s to '%s', current value %s", k, v, e)
                if only.get(k):
                    e.append(v)
                else:
                    e = v
                    only[k] = True
                entry.setValues(k, e)
                logging.debug('only: updated value %s', e)

            print_entity(entry)

    return entry

def print_entity(e, message=None):
    """The entity object currently lacks a str() method"""
    logging.debug("---------------------------------------------")
    if message:
        logging.debug("%s", message)
    logging.debug("dn: " + e.dn)
    attr = e.attrList()
    for a in attr:
        value = e.getValues(a)
        if isinstance(value,str):
            logging.debug(a + ": " + value)
        else:
            logging.debug(a + ": ")
            for l in value:
                logging.debug("\t" + l)

def update_record(conn, update):
    global live_run

    found = False

    new_entry = create_default_entry(update.get('dn'),
                                         update.get('default'))

    try:
        e = get_entry(conn, new_entry.dn)
        if len(e) > 1:
            # we should only ever get back one entry
            raise BadSyntax, "More than 1 entry returned on a dn search!? %s" % new_entry.dn
        entry = entry_to_entity(e[0])
        found = True
        logging.info("Updating existing entry: %s", entry.dn)
    except ipaerror.exception_for(ipaerror.LDAP_NOT_FOUND):
        # Doesn't exist, start with the default entry
        entry = new_entry
        logging.info("New entry: %s", entry.dn)
    except ipaerror.exception_for(ipaerror.LDAP_DATABASE_ERROR):
        # Doesn't exist, start with the default entry
        entry = new_entry
        logging.info("New entry, using default value: %s", entry.dn)

    print_entity(entry)

    # Bring this entry up to date
    entry = apply_updates(entry.dn, update.get('updates'), entry)

    print_entity(entry, "Final value")

    if not found:
        # New entries get their orig_data set to the entry itself. We want to
        # empty that so that everything appears new when generating the
        # modlist
        # entry.orig_data = {}
        try:
            if live_run:
                conn.addEntry(entry.dn, entry.toTupleList())
        except Exception, e:
            logging.error("Add failure %s: %s", e, detail_error(e.detail))
    else:
        # Update LDAP
        try:
            logging.debug("%s" % conn.generateModList(entry.origDataDict(), entry.toDict()))
            if live_run:
                conn.updateEntry(entry.dn, entry.origDataDict(), entry.toDict())
            logging.info("Done")
        except ipaerror.exception_for(ipaerror.LDAP_EMPTY_MODLIST), e:
            logging.info("Entry already up-to-date")
        except ipaerror.exception_for(ipaerror.LDAP_DATABASE_ERROR), e:
            logging.error("Update failed: %s: %s", e, detail_error(e.detail))

        if ("cn=index" in entry.dn and
            "cn=userRoot" in entry.dn):
            id = create_index_task(conn, entry.cn)
            monitor_index_task(conn, id)
    return

def get_all_files(root, recursive=False):
    """Get all update files"""
    f = []
    for path, subdirs, files in os.walk(root):
        for name in files:
            if fnmatch.fnmatch(name, "*.update"):
                f.append(os.path.join(path, name))
        if not recursive:
            break
    return f

def main():
    global sub_dict, live_run
    loglevel = logging.INFO

    options, args = parse_options()
    if options.debug:
        loglevel = logging.DEBUG
    if options.test:
        live_run = False

    logging.basicConfig(level=loglevel,
                        format='%(levelname)s %(message)s')

    try:
        krbctx = krbV.default_context()
    except krbV.Krb5Error, e:
        print "Unable to get default kerberos realm: %s" % e[1]
        sys.exit(1)

    fqdn = installutils.get_fqdn()
    if fqdn is None:
        print "Unable to determine hostname"
        sys.exit(1)

    domain = ipautil.get_domain_name()
    libarch = identify_arch()
    suffix = ipautil.realm_to_suffix(krbctx.default_realm)

    sub_dict = { "REALM" : krbctx.default_realm, "FQDN": fqdn,
                 "DOMAIN" : domain, "SUFFIX" : suffix,
                 "LIBARCH" : libarch, "TIME" : int(time.time()) }

    dirman_password = ""
    if options.password:
        pw = read_file(options.password)
        dirman_password = pw[0].strip()
    else:
        dirman_password = get_dirman_password(fqdn)

    files=[]
    if len(args) < 1:
        files = get_all_files(UPDATES_DIR)
    else:
        files = args

    conn = None
    try:
        conn = ipaldap.IPAdmin(fqdn)
        conn.do_simple_bind(bindpw=dirman_password)
        all_updates = {}
        dn_list = {}
        for f in files:
            try:
                logging.info("Parsing file %s" % f)
                data = read_file(f)
            except Exception, e:
                print e
                sys.exit(1)

            (all_updates, dn_list) = parse_update_file(conn, data, all_updates, dn_list)

        sortedkeys = dn_list.keys()
        sortedkeys.sort()
        for k in sortedkeys:
            for dn in dn_list[k]:
                update_record(conn, all_updates[dn])
    finally:
        if conn: conn.unbind()

    return

try:
    if __name__ == "__main__":
        sys.exit(main())
except BadSyntax, e:
    print "There is a syntax error in this update file:"
    print "  %s" % e
    sys.exit(1)
except SystemExit, e:
    sys.exit(e)
except KeyboardInterrupt, e:
    sys.exit(1)