## $Id$

## this module is from quarl's HKN CourseSurvey database.py

'''
Defines database backend library and database table and object relationships.

Example usage:

from Boinc import database, db_mid

# get platform with id 7; will raise exception if no such platform.
p7 = database.Platforms[7]

# get platforms with friendly name "commodore 64"
p_c64 = database.Platforms.find(user_friendly_name="commodore 64")

# delete results of workunit with name "dead.wu", and email their users:
wu_dead = database.Workunits.find(name="dead.wu")[0]
results_dead = database.Results.find(wu=wu_dead)
for result in results_dead:
    print "Removing from db:", result
    os.system("echo oeps | mail %s" % result.host.user.email_addr)
    result.remove()

# multiply the total_credit of each user by 17:
for user in database.Users.find():
    user.total_credit *= 17
    user.commit()

'''

from __future__ import generators
import boinc_path_config
from Boinc import configxml
from Boinc.util import *
import sys, os, weakref
import MySQLdb, MySQLdb.cursors

ID = '$Id$'

boincdb = None

class DatabaseInconsistency(Exception):
    def __init__(self, descript=None, search_table=None, search_kwargs=None):
        self.descript = descript
        self.search_table = search_table
        self.search_kwargs = search_kwargs
        self.search_tree = []
    def __str__(self):
        return ("""** DATABASE INCONSISTENCY **
   %s
   search_table = %s
   search_kwargs = %s
   search_tree = [
%s
   ] """ %(
            self.descript,
            self.search_table,
            self.search_kwargs,
            '\n'.join(
            map(lambda o:"          %s#%s %s"%(o._table.table,o.__dict__.get('id'),o), self.search_tree))
            ))

class Debug:
    def __init__(self):
        self.html = False
    def printline(self,s):
        if self.html:
            print "<!-- ## %s -->"%s
        else:
            print >>sys.stderr, "##", s

debug = Debug()
debug.mysql = not not os.environ.get('BOINC_DEBUG_DB')

def _commit_object(tablename, paramdict, id=None):
    """Takes a tablename, boincdb object, a parameter dict, and an
        optional id.  Puts together the appropriate SQL command to commit
        the object to the database.  Executes it.  Returns the object's
        id."""
    assert(boincdb)
    cursor = boincdb.cursor()
    equalcommands = []
    for key in paramdict.keys():
        value = paramdict[key]
        if value == None:
            minicommand = ''
            continue
        else:
            minicommand = "%s='%s'"%(key,boincdb.escape_string(str(value)))
        equalcommands.append(minicommand)
    if id == None:
        command = 'INSERT INTO %s SET %s' % \
            (tablename, ', '.join(equalcommands))
        #print command, '--', paramdict
        if debug.mysql:
            debug.printline("query: "+command)
        cursor.execute(command)
        id = cursor.insert_id()       #porters note: works w/MySQLdb only
    else:
        command =  "UPDATE %s SET %s WHERE id=%d" % \
            (tablename, ', '.join(equalcommands), id)
        if debug.mysql:
            debug.printline("query: "+command)
        cursor.execute(command)
    cursor.close()
    boincdb.commit()
    return id
def _remove_object(command, id=None):
    """Takes a command string, boincdb object, and optional id.  If an
        id is given, it assembles the SQL command and deletes the object
        from the database.  Does nothing if no id is given."""
    assert(boincdb)
    if id == None:
        pass
    else:
        cursor = boincdb.cursor()
        command =  'DELETE FROM ' + command + \
            ' WHERE id=%d' % id
        if debug.mysql:
            debug.printline("query: "+command)
        cursor.execute(command)
        cursor.close()
        boincdb.commit()
def _select_object(table, searchdict, extra_args="", extra_params=[], select_what=None):
    assert(boincdb)
    parameters = extra_params[:]
    join = None
    if '_join' in searchdict:
        join = searchdict['_join']
        del searchdict['_join']
    if '_extra_params' in searchdict:
        parameters += searchdict['_extra_params']
        del searchdict['_extra_params']
    command = 'SELECT %s from %s'%((select_what or "%s.*"%table) ,table)
    if join:
        command += "," + join
    for (key,value) in searchdict.items():
        # note: if value == 0, we want to look for it.
        if value != None and value != '':
            escaped_value = boincdb.escape_string(str(value))
            if key == 'text':
                parameters.append("instr(%s,'%s')"%(key,escaped_value))
            else:
                parameters.append("%s='%s'"%(key,escaped_value))
    if parameters:
        command += ' WHERE ' + ' AND '.join(parameters)
    if extra_args:
        command += ' ' + extra_args.strip()
    cursor = boincdb.cursor()
    if debug.mysql:
        debug.printline("query: "+command)
    cursor.execute(command)
    return cursor

def _select_object_fetchall(*args, **kwargs):
    cursor = apply(_select_object, args, kwargs)
    results = cursor.fetchall()
    cursor.close()
    return results

def _select_object_iterate(*args, **kwargs):
    cursor = apply(_select_object, args, kwargs)
    while True:
        result = cursor.fetchone()
        if not result: return
        yield result

def _select_count_objects(*args, **kwargs):
    kwargs['select_what'] = 'count(*)'
    cursor = apply(_select_object, args, kwargs)
    result = cursor.fetchone().values()[0]
    cursor.close()
    return result

OBJECT_CACHE_SIZE = 1024

# TODO: use iterators/generators for find()
class DatabaseTable:
    def __init__(self, table, columns, extra_columns=[],
                 select_args = None, sort_results = False):
        self.table        = table
        self.lcolumns     = columns
        self.columns      = list2dict(columns)
        self.extra_columns = list2dict(extra_columns)
        # self.object_class = object_class
        self.select_args  = select_args
        self.sort_results = sort_results
        ## self.objects is a mapping from id->object which weakly references
        ## all current objects from this table.  this guarantees that if a
        ## find() returns a row for which we already created an object in
        ## memory, we return the same one.
        self.objects = weakref.WeakValueDictionary()
        ## self.object_cache is a list of the N most recently retrieved
        ## objects.  its values aren't really used; the list is used to ensure
        ## the strong reference count for self.objects[object] is nonzero to
        ## ensure is lifetime.
        ##
        ## This means if you look up database.Apps[1]: the first lookup does a
        ## MySQL SELECT; afterwards database.Apps[1] is free (only requires a
        ## lookup in database.Apps.objects).  To prevent this object cache
        ## from growing without bound, database.Apps.object is a weak-valued
        ## dictionary.  This means that if no one refers to the object, it is
        ## deleted from the dictionary.  database.Apps.object_cache maintains
        ## a list of the OBJECT_CACHE_SIZE most recent lookups, which forces
        ## their strong reference count.
        self.object_cache = []
        self.defdict = {}
        for key in self.lcolumns:
            if key == 'id':
                self.defdict[key] = None
            elif key.endswith('id'):
                self.defdict[key[:-2]] = None
            elif key.endswith('ids'):
                self.defdict[key[:-3]] = None
            else:
                self.defdict[key] = None

    def _cache(self, object):
        """Maintain up to OBJECT_CACHE_SIZE objects in the object_cache list.

        The object's existence in this cache ensures its strong reference
        count is nonzero, so that it doesn't get implicitly dropped from
        self.objects."""
        if len(self.object_cache) >= OBJECT_CACHE_SIZE:
            self.object_cache = self.object_cache[OBJECT_CACHE_SIZE/2:]
        self.object_cache.append(object)

    def count(self, **kwargs):
        """Return the number of database objects matching keywords.

        Arguments are the same format as find()."""
        if kwargs.keys() == ['id']:
            # looking up by ID only, look in cache first:
            id = kwargs['id']
            if not id:
                return 0
            if id in self.objects:
                return 1
        kwargs = self.dict2database_fields(kwargs)
        return _select_count_objects(self.table, kwargs,
                                     extra_args=self.select_args)

    def find(self, **kwargs):
        """Return a list of database objects matching keywords.

        Allowed keywords are specified by self.columns.

        Objects are cached by ID so repeated lookups are quick.
        """
        if kwargs.keys() == ['id']:
            # looking up by ID only, look in cache first:
            id = kwargs['id']
            if not id:
                return [None]
            try:
                return [self.objects[id]]
            except KeyError:
                pass
            limbo_object = self.object_class(id=None) # prevent possible id recursion
            limbo_object.in_limbo = 1
            self.objects[id] = limbo_object
            self._cache(limbo_object)
        kwargs = self.dict2database_fields(kwargs)
        results = _select_object_fetchall(self.table, kwargs,
                                          extra_args=self.select_args)
        objects = map(self._create_object_from_sql_result, results)
        if self.sort_results:
            objects.sort()
        return objects
    def iterate(self, **kwargs):
        """Same as find(), but using generators.

        No sorting."""
        if kwargs.keys() == ['id']:
            # looking up by ID only, look in cache first:
            id = kwargs['id']
            if not id:
                return
            try:
                yield self.objects[id]
                return
            except KeyError:
                pass
            limbo_object = self.object_class(id=None) # prevent possible id recursion
            limbo_object.in_limbo = 1
            self.objects[id] = limbo_object
            self._cache(limbo_object)
        kwargs = self.dict2database_fields(kwargs)
        for result in _select_object_iterate(self.table, kwargs,
                                             extra_args=self.select_args):
            yield self._create_object_from_sql_result(result)
        return

    def _create_object_from_sql_result(self, result):
        id = result['id']
        try:
            # object already exists in cache?
            object = self.objects[id]
            if 'in_limbo' in object.__dict__:
                # earlier we set the object cache so that we don't recurse;
                # update it now with real values and delete the 'in limbo'
                # flag
                del object.__dict__['in_limbo']
                object.do_init(result)
        except KeyError:
            # create the object - looking up instructors, etc
            object = apply(self.object_class, [], result)
            if object.id:
                self.objects[object.id] = object
                self._cache(object)
        return object
    def find1(self, **kwargs):
        '''Return a single result.  Raises a DatabaseInconsistency if not
        exactly 1 result returned.'''
        objects = apply(self.find, [], kwargs)
        if len(objects) != 1:
            raise DatabaseInconsistency(
                descript="find1: expected 1 result but found %d"%len(objects),
                search_table = self.table,
                search_kwargs = kwargs)
        return objects[0]
    def __getitem__(self, id):
        '''Lookup (possibly cached) object by id.  Returns None if id==None.'''
        return id and self.find1(id=id)
    def objdict2database_fields(self, indict):
        dict = {}
        for key in self.columns:
            if key.endswith('id'):
                obj = indict[key[:-2]]
                dict[key] = obj and obj.id or 0
            else:
                dict[key] = indict[key]
        return dict
    def _valid_query_keys(self):
        return self.columns.keys()+self.extra_columns.keys()+['_join','_extra_params']
    def dict2database_fields(self, indict):
        indict = indict.copy()
        dict = {}
        if 'id' in indict:
            dict['id'] = indict['id']
            del indict['id']
        for key in self._valid_query_keys():
            if key.endswith('id'):
                xkey = key[:-2]
                if xkey in indict:
                    obj = indict[xkey]
                    dict[key] = obj and obj.id
                    del indict[xkey]
            else:
                if key in indict:
                    dict[key] = indict[key]
                    del indict[key]
        if len(indict):
            raise ValueError('Invalid key(s): %s'%indict)
        return dict

class DatabaseObject:
    id_lookups = {} # set near end of file
    def database_fields_to_self(self, dict):
        columns = self._table.columns
        self.__dict__.update(self._table.defdict)  # set defaults to None
        # set this first so that if we get a DatabaseInconsistency we can see
        # the id
        self.id = dict.get('id')
        for (key, value) in dict.items():
            if key == 'id':
                # self.id = value
                continue
            if key or key+'id' in columns:
                if key.endswith('id'):
                    xkey = key[:-2]
                    self.__dict__[xkey] = self.id_lookups[xkey]._table[value]
                else:
                    self.__dict__[key] = value
            else:
                # print '### columns=%s'%columns
                raise ValueError("database '%s' object doesn't take argument '%s'"%(
                    self._table.table, key))

    def do_init(self, kwargs):
        try:
            self.database_fields_to_self(kwargs)
        except DatabaseInconsistency, e:
            e.search_tree.append(self)
            raise
        # if no id then object starts dirty
        self._set_dirty(not self.id)

    def __init__(self, **kwargs):
        self.do_init(kwargs)

    def __eq__(self, other):
        return other!=None and self.id == other.id
    def __ne__(self, other):
        return not (self == other)
    def __hash__(self):
        return self.id or 0

    def _commit_params(self, paramdict):
        """Commits the object to the boincdb database."""
        self.id = _commit_object(self._table.table, paramdict, self.id)

    def commit(self, force=False):
        if force or self._dirty:
            self._commit_params(self._table.objdict2database_fields(self.__dict__))
            self._set_dirty(False)

    def remove(self):
        """Removes the object from the boincdb database."""
        _remove_object(self._table.table, self.id)
        self.id = None

    def dset(self, key, value):
        if self.__dict__[key] != value:
            self.__dict__[key] = value
            self._set_dirty()
    def __setattr__(self, key, value):
        if key in self._table.columns or key+'id' in self._table.columns:
            self.dset(key, value)
        else:
            self.__dict__[key] = value
    def _set_dirty(self, value=True):
        self.__dict__['_dirty'] = value

        # TODO: move this to db_med
    def URL(self):
        """Relative form of absURL()"""
        return make_url_relative(self.absURL())

class Project(DatabaseObject):
    _table = DatabaseTable(
        table = 'project',
        columns = [ 'short_name', 'long_name' ] )

class Platform(DatabaseObject):
    _table = DatabaseTable(
        table = 'platform',
        columns = [ 'create_time',
                    'name',
                    'user_friendly_name' ])

class Platform(DatabaseObject):
    _table = DatabaseTable(
        table = 'platform',
        columns = [ 'create_time',
                    'name',
                    'user_friendly_name' ])

class CoreVersion(DatabaseObject):
    _table = DatabaseTable(
        table = 'core_version',
        columns = [ 'create_time',
                    'version_num',
                    'platformid',
                    'xml_doc',
                    'message',
                    'deprecated' ])

class App(DatabaseObject):
    _table = DatabaseTable(
        table = 'app',
        columns = [ 'create_time',
                    'name',
                    'min_version' ])

class AppVersion(DatabaseObject):
    _table = DatabaseTable(
        table = 'app_version',
        columns = [ 'create_time',
                    'appid',
                    'version_num',
                    'platformid',
                    'xml_doc',
                    'min_core_version',
                    'max_core_version' ])

class User(DatabaseObject):
    _table = DatabaseTable(
        table = 'user',
        columns = [ 'create_time',
                    'email_addr',
                    'name',
                    'authenticator',
                    'country',
                    'postal_code',
                    'total_credit',
                    'expavg_credit',
                    'expavg_time',
                    'global_prefs',
                    'project_prefs',
                    'teamid',
                    'venue',
                    'url',
                    'send_email',
                    'show_hosts',
                    'posts' ])

class Team(DatabaseObject):
    _table = DatabaseTable(
        table = 'team',
        columns = [ 'create_time',
                    'userid',
                    'name',
                    'name_lc',
                    'url',
                    'type',
                    'name_html',
                    'description',
                    'nusers',
                    'country',
                    'total_credit',
                    'expavg_credit' ])

class Host(DatabaseObject):
    _table = DatabaseTable(
        table = 'host',
        columns = [ 'create_time',
                    'userid',
                    'rpc_seqno',
                    'rpc_time',
                    'total_credit',
                    'expavg_credit',
                    'expavg_time',
                    'timezone',
                    'domain_name',
                    'serialnum',
                    'last_ip_addr',
                    'nsame_ip_addr',
                    'on_frac',
                    'connected_frac',
                    'active_frac',
                    'p_ncpus',
                    'p_vendor',
                    'p_model',
                    'p_fpops',
                    'p_iops',
                    'p_membw',
                    'os_name',
                    'os_version',
                    'm_nbytes',
                    'm_cache',
                    'm_swap',
                    'd_total',
                    'd_free',
                    'd_boinc_used_total',
                    'd_boinc_used_project',
                    'd_boinc_max',
                    'n_bwup',
                    'n_bwdown',
                    'credit_per_cpu_sec',
                    'venue',
                    'projects' ])

class Workunit(DatabaseObject):
    _table = DatabaseTable(
        table = 'workunit',
        columns = [ 'create_time',
                    'appid',
                    'name',
                    'xml_doc',
                    'batch',
                    # 'rsc_fpops',
                    # 'rsc_iops',
                    # 'rsc_memory',
                    # 'rsc_disk',
                    'rsc_fpops_est',
                    'rsc_fpops_bound',
                    'rsc_memory_bound',
                    'rsc_disk_bound',
                    'need_validate',
                    'canonical_resultid',
                    'canonical_credit',
                    'transition_time',
                    'delay_bound',
                    'error_mask',
                    'file_delete_state',
                    'assimilate_state',
                    'workseq_next',
                    'opaque',
                    'min_quorum',
                    'target_nresults',
                    'max_error_results',
                    'max_total_results',
                    'max_success_results',
                    'result_template' ])

class Result(DatabaseObject):
    _table = DatabaseTable(
        table = 'result',
        columns = [ 'create_time',
                    'workunitid',
                    'server_state',
                    'outcome',
                    'client_state',
                    'hostid',
                    'report_deadline',
                    'sent_time',
                    'received_time',
                    'name',
                    'cpu_time',
                    'xml_doc_in',
                    'xml_doc_out',
                    'stderr_out',
                    'batch',
                    'file_delete_state',
                    'validate_state',
                    'claimed_credit',
                    'granted_credit',
                    'opaque',
                    'random',
                    'client_version_num' ])

class Workseq(DatabaseObject):
    _table = DatabaseTable(
        table = 'workseq',
        columns = [ 'create_time',
                    'state',
                    'hostid',
                    'wuid_last_done',
                    'wuid_last_sent',
                    'workseqid_master' ])

def _connectp(dbname, user, passwd, host='localhost'):
    """Takes a database name, a username, and password.  Connects to
    SQL server and makes a new Boincdb."""
    global boincdb
    if boincdb:
        raise 'Already connected'
    boincdb = MySQLdb.connect(db=dbname,host=host,user=user,passwd=passwd,
                               cursorclass=MySQLdb.cursors.DictCursor)

# def _connectm(module):
#     _connectp(module.database, module.username, module.password)

# def connect(readonly = False):
#     """Connect if not already connected or if we're adding write permissions"""
#     global boincdb
#     if boincdb:
#         if not readonly and boincdb.readonly:
#             # re-open with write access
#             boincdb.close()
#             boincdb = None
#         else:
#             return 0
#     if readonly:
#         import password_settings_r
#         _connectm(password_settings_r)
#     else:
#         import password_settings
#         _connectm(password_settings)
#     boincdb.readonly = readonly
#     return 1

def connect(config = None):
    """Connect if not already connected, using config values."""
    global boincdb
    if boincdb:
        return 0
    config = config or configxml.default_config().config
    _connectp(config.db_name,
              config.__dict__.get('db_user',''),
              config.__dict__.get('db_passwd', ''))
    return 1

# alias
connect_default_config = connect

def close():
    """Closes the connection to the sql boinc and deletes the Boincdb object."""
    boincdb.close()

database_classes = [ Project,
                     Platform,
                     CoreVersion,
                     App,
                     AppVersion,
                     User,
                     Team,
                     Host,
                     Workunit,
                     Result,
                     Workseq ]

for Class in database_classes:
    # these couldn't be defined earlier because the classes weren't defined yet.
    Class._table.object_class = Class
    DatabaseObject.id_lookups[Class._table.table] = Class

DatabaseObject.id_lookups['canonical_result'] = Result

Projects = Project._table
Platforms = Platform._table
CoreVersions = CoreVersion._table
Apps = App._table
AppVersions = AppVersion._table
Users = User._table
Teams = Team._table
Hosts = Host._table
Workunits = Workunit._table
Results = Result._table
Workseqs = Workseq._table

database_tables = map(lambda c: c._table, database_classes)

# def check_database_consistency():
#     '''Raises DatabaseInconsistency on error.

#     Loads the entire database into memory so will take a while.
#     '''
#     for table in database_tables:
#         print 'Checking', table.table
#         print '   checked', len(table.find())