lodel2_mirror/leobject/datasources/ledatasourcesql.py

#-*- coding: utf-8 -*-

import pymysql

import leobject
from leobject.datasources.dummy import DummyDatasource
from leobject.leobject import REL_SUB, REL_SUP

from leobject.letype import LeType

from mosql.db import Database, all_to_dicts, one_to_dict
from mosql.query import select, insert, update, delete, join
from mosql.util import raw, or_
import mosql.mysql

from DataSource.MySQL.MySQL import MySQL


## MySQL DataSource for LeObject
class LeDataSourceSQL(DummyDatasource):

    RELATIONS_POSITIONS_FIELDS = {REL_SUP: 'superior_id', REL_SUB: 'subordinate_id'}

    def __init__(self, module=pymysql, conn_args=None):
        super(LeDataSourceSQL, self).__init__()
        self.module = module
        self.datasource_utils = MySQL
        if conn_args is None:
            conn_args = self.datasource_utils.connections['default']
        self.connection = Database(self.module, host=conn_args['host'], user=conn_args['user'], passwd=conn_args['passwd'], db=conn_args['db'])

    ## @brief inserts a new object
    # @param letype LeType
    # @param leclass LeClass
    # @param datas dict : dictionnary of field:value pairs to save
    # @return int : lodel_id of the created object
    # @todo add the returning clause and the insertion in "object"
    def insert(self, letype, leclass, datas):
        if isinstance(datas, list):
            res = list()
            for data in datas:
                res.append(self.insert(letype, leclass, data))
            return res
        elif isinstance(datas, dict):

            with self.connection as cur:
                object_datas = {'class_id': leclass._class_id, 'type_id': letype._type_id}
                if cur.execute(insert(self.datasource_utils.objects_table_name, object_datas)) != 1:
                    raise RuntimeError('SQL error')

                if cur.execute('SELECT last_insert_id() as lodel_id') != 1:
                    raise RuntimeError('SQL error')

                lodel_id, = cur.fetchone()

                datas[self.datasource_utils.field_lodel_id] = lodel_id
                query_table_name = self.datasource_utils.get_table_name_from_class(leclass.__name__)
                query = insert(query_table_name, datas)

                if cur.execute(query) != 1:
                    raise RuntimeError('SQL error')

            return lodel_id

    ## @brief search for a collection of objects
    # @param leclass LeClass
    # @param letype LeType
    # @field_list list
    # @param filters list : list of tuples formatted as (FIELD, OPERATOR, VALUE)
    # @param relation_filters list : list of tuples formatted as (('superior'|'subordinate', FIELD), OPERATOR, VALUE)
    # @return list
    def get(self, leclass, letype, field_list, filters, relational_filters=None):

        query_table_name = self.datasource_utils.get_table_name_from_class(leclass.__name__)
        where_filters = self._prepare_filters(filters, query_table_name)
        join_fields = {}

        if relational_filters is not None and len(relational_filters) > 0:
            rel_filters = self._prepare_rel_filters(relational_filters)
            for rel_filter in rel_filters:
                # join condition
                relation_table_join_field = "%s.%s" % (self.datasource_utils.relations_table_name, self.RELATIONS_POSITIONS_FIELDS[rel_filter['position']])
                query_table_join_field = "%s.%s" % (query_table_name, self.datasource_utils.field_lodel_id)
                join_fields[query_table_join_field] = relation_table_join_field
                # Adding "where" filters
                where_filters['%s.%s' % (self.datasource_utils.relations_table_name, self.datasource_utils.relations_field_nature)] = rel_filter['nature']
                where_filters[rel_filter['condition_key']] = rel_filter['condition_value']

            # building the query
            query = select(query_table_name, where=where_filters, select=field_list, joins=join(self.datasource_utils.relations_table_name, join_fields))
        else:
            query = select(query_table_name, where=where_filters, select=field_list)

        # Executing the query
        with self.connection as cur:
            results = all_to_dicts(cur.execute(query))

        return results

    ## @brief delete an existing object
    # @param letype LeType
    # @param leclass LeClass
    # @param filters list : list of tuples formatted as (FIELD, OPERATOR, VALUE)
    # @param relational_filters list : list of tuples formatted as (('superior'|'subordinate', FIELD), OPERATOR, VALUE)
    # @return bool : True on success
    def delete(self, letype, leclass, filters, relational_filters):
        query_table_name = self.datasource_utils.get_table_name_from_class(leclass.__name__)
        prep_filters = self._prepare_filters(filters, query_table_name)
        prep_rel_filters = self._prepare_rel_filters(relational_filters)

        if len(prep_rel_filters) > 0:
            query = "DELETE %s FROM " % query_table_name

            for prep_rel_filter in prep_rel_filters:
                query += "%s INNER JOIN %s ON (%s.%s = %s.%s)" % (
                    self.datasource_utils.relations_table_name,
                    query_table_name,
                    self.datasource_utils.relations_table_name,
                    prep_rel_filter['position'],
                    query_table_name,
                    self.datasource_utils.field_lodel_id
                )

                if prep_rel_filter['condition_key'][0] is not None:
                    prep_filters[("%s.%s" % (self.datasource_utils.relations_table_name, prep_rel_filter['condition_key'][0]), prep_rel_filter['condition_key'][1])] = prep_rel_filter['condition_value']

            if prep_filters is not None and len(prep_filters) > 0:
                query += " WHERE "
                filter_counter = 0
                for filter_item in prep_filters:
                    if filter_counter > 1:
                        query += " AND "
                    query += "%s %s %s" % (filter_item[0][0], filter_item[0][1], filter_item[1])
        else:
            query = delete(query_table_name, filters)

        query_delete_from_object = delete(self.datasource_utils.objects_table_name, {'lodel_id': filters['lodel_id']})
        with self.connection as cur:
            cur.execute(query)
            cur.execute(query_delete_from_object)

        return True

    ## @brief update an existing object's data
    # @param letype LeType
    # @param leclass LeClass
    # @param  filters list : list of tuples formatted as (FIELD, OPERATOR, VALUE)
    # @param rel_filters list : list of tuples formatted as (('superior'|'subordinate', FIELD), OPERATOR, VALUE)
    # @param data dict
    # @return bool
    # @todo prendre en compte les rel_filters
    def update(self, letype, leclass, filters, rel_filters, data):

        query_table_name = self.datasource_utils.get_table_name_from_class(leclass.__name__)
        where_filters = filters
        set_data = data

        prepared_rel_filters = self._prepare_rel_filters(rel_filters)

        # Building the query
        query = update(table=query_table_name, where=where_filters, set=set_data)
        # Executing the query
        with self.connection as cur:
            cur.execute(query)
        return True

    ## @brief prepares the relational filters
    # @params rel_filters : (("superior"|"subordinate"), operator, value)
    # @return list
    def _prepare_rel_filters(self, rel_filters):
        prepared_rel_filters = []

        if rel_filters is not None and len(rel_filters) > 0:
            for rel_filter in rel_filters:
                rel_filter_dict = {
                    'position': REL_SUB if rel_filter[0][0] == REL_SUP else REL_SUB,
                    'nature': rel_filter[0][1],
                    'condition_key': (self.RELATIONS_POSITIONS_FIELDS[rel_filter[0][0]], rel_filter[1]),
                    'condition_value': rel_filter[2]
                }
                prepared_rel_filters.append(rel_filter_dict)

        return prepared_rel_filters

    ## @brief prepares the filters to be used by the mosql library's functions
    # @params filters : (FIELD, OPERATOR, VALUE) tuples
    # @return dict : Dictionnary with (FIELD, OPERATOR):VALUE style elements
    def _prepare_filters(self, filters, tablename=None):
        prepared_filters = {}
        if filters is not None and len(filters) > 0:
            for filter_item in filters:
                if '.' in filter_item[0]:
                    prepared_filter_key = (filter_item[0], filter_item[1])
                else:
                    prepared_filter_key = ("%s.%s" % (tablename, filter_item[0]), filter_item[1])
                prepared_filter_value = filter_item[2]
                prepared_filters[prepared_filter_key] = prepared_filter_value

        return prepared_filters


    ## @brief Make a relation between 2 LeType
    # @note rel2type relations. Superior is the LeType from the EmClass and subordinate the LeType for the EmType
    # @param lesup LeType : LeType child class instance that is from the EmClass containing the rel2type field
    # @param lesub LeType : LeType child class instance that is from the EmType linked by the rel2type field ( @ref EditorialModel.fieldtypes.rel2type.EmFieldType.rel_to_type_id )
    # @return The relation_id if success else return False
    def add_related(self, lesup, lesub, rank, **rel_attr):
        with self.connection as cur:
            #First step : relation table insert
            sql = insert(MySQL.relations_table_name,{
                        'id_sup': lesup.lodel_id, 
                        'id_sub': lesub.lodel_id,
                        'rank': 0, #default value that will be set latter
                    })
            cur.execute(sql)
            relation_id = cur.lastrowid


            if len(rel_attr) > 0:
                #There is some relation attribute to add in another table
                attr_table = get_r2t2table_name(lesup._leclass.__name__, lesub.__class__.__name__)
                rel_attr['id_relation'] = relation_id
                sql = insert(attr_table, rel_attr)
                cur.execute(sql)
        self._set_relation_rank(id_relation, rank)
        return relation_id
    
    ## @brief Set the rank of a relation identified by its ID
    # @param id_relation int : relation ID
    # @param rank int|str : 'first', 'last', or an integer value
    # @throw ValueError if rank is not valid
    # @throw leobject.leobject.LeObjectQueryError if id_relation don't exists
    def set_relation_rank(self, id_relation, rank):
        self._check_rank(rank)
        self._set_relation_rank(id_relation, rank)

        

    ## @brief Set the rank of a relation identified by its ID
    #
    # @note this solution is not the more efficient solution but it
    # garantee that ranks are continuous and starts at 1
    # @warning there is no way to fail on rank parameters even giving very bad parameters, if you want a method that may fail on rank use set_relation_rank() instead
    # @param id_relation int : relation ID
    # @param rank int|str : 'first', 'last', or an integer value
    # @throw leobject.leobject.LeObjectQueryError if id_relation don't exists
    def _set_relation_rank(self, id_relation, rank):
        ret = self.get_relation(id_relation, no_attr = True)
        if not ret:
            raise leobject.leobject.LeObjectQueryError("No relation with id_relation = %d"%id_relation)
        lesup = ret['lesup']
        lesub = ret['lesup']
        cur_rank = ret['rank']
        rank = 1 if rank == 'first' or rank < 1 else rank
        if cur_rank == rank:
            return True

        relations = self.get_related(lesup, lesub.__class__, get_sub=True)

        if not isinstance(rank, int) or rank > len(relations):
            rank = len(relations)
            if cur_rank == rank:
                return True
        
        #insert the relation at the good position
        our_relation = relations.pop(cur_rank)
        relations.insert(our_relation, rank)

        #gathering (relation_id, new_rank)
        rdatas = [ (attrs['relation_id'], new_rank+1) for new_rank,(sup, sub, attrs) in enumerate(relations) ]
        sql = insert(MySQL.relations_table_name, columns=(MySQL.relations_pkname, 'rank'), values = rdatas, on_duplicate_key_update={'rank',mosql.util.raw('VALUES(`rank`)')})

    
    ## @brief Check a rank value
    # @param rank int | str : Can be an integer >= 1 , 'first' or 'last'
    # @throw ValueError if the rank is not valid
    def _check_rank(self, rank):
        if isinstance(rank, str) and rank != 'first' and rank != 'last':
            raise ValueError("Invalid rank value : %s"%rank)
        elif isinstance(rank, int) and rank < 1:
            raise ValueError("Invalid rank value : %d"%rank)
        else:
            raise ValueError("Invalid rank type : %s"%type(rank))
    
    ## @brief Link two object given a relation nature, depth and rank
    # @param lesup LeObject : a LeObject
    # @param lesub LeObject : a LeObject
    # @param nature str|None : The relation nature or None if rel2type
    # @param rank int : a rank
    def add_relation(self, lesup, lesub, nature=None, depth=None, rank=None, **rel_attr):
        if len(rel_attr) > 0 and nature is not None:
            #not a rel2type but have some relation attribute
            raise AttributeError("No relation attributes allowed for non rel2type relations")

        with self.connection as cur:
            sql = insert(self.datasource_utils.relations_table_name, {'id_sup': lesup.lodel_id, 'id_sub': lesub.lodel_id, 'nature': nature, 'rank': rank, 'depth': depth})
            if cur.execute(sql) != 1:
                raise RuntimeError("Unknow SQL error")

            if len(rel_attr) > 0:
                #a relation table exists
                cur.execute('SELECT last_insert_id()')
                relation_id, = cur.fetchone()
                raise NotImplementedError()

        return True
    
    ## @brief Delete a rel2type relation
    # @warning this method may not be efficient
    # @param id_relation int : The relation identifier
    # @return bool
    def del_relation(self, id_relation):
        with self.connection as cur:
            pk_where = {MySQL.relations_pkname:id_relation}
            if not MySQL.fk_on_delete_cascade and len(lesup._linked_types[lesub.__class__]) > 0:
                #Delete the row in the relation attribute table
                ret = self.get_relation(id_relation, no_attr = False)
                lesup = ret['lesup']
                lesub = ret['lesub']
                sql = delete(MySQL.relations_table_name, pk_where)
                if cur.execute(sql) != 1:
                    raise RuntimeError("Unknown SQL Error")
            sql = delete(MySQL.relations_table_name, pk_where)
            if cur.execute(sql) != 1:
                raise RuntimeError("Unknown SQL Error")

        return True
    
    ## @brief Fetch a relation
    # @param id_relation int : The relation identifier
    # @param no_attr bool : If true dont fetch rel_attr
    # @return a dict{'id_relation':.., 'lesup':.., 'lesub':..,'rank':.., 'depth':.., #if not none#'nature':.., #if exists#'dict_attr':..>}
    #
    # @todo TESTS
    def get_relation(self, id_relation, no_attr = False):
        relation = dict()
        with self.connection as cur:
            sql = select(MySQL.relation_table_name, {MySQL.relations_pkname: id_relation})
            if cur.execute(sql) != 1:
                raise RuntimeError("Unknow SQL error")
            res = all_to_dicts(cur)
            if len(res) == 0:
                return False
            if len(res) > 1:
                raise RuntimeError("When selecting on primary key, get more than one result. Bailout")

            if res['nature'] != None:
                raise ValueError("The relation with id %d is not a rel2type relation"%id_relation)

            leobj = leobject.lefactory.LeFactory.leobj_from_name('LeObject')
            lesup = leobj.uid2leobj(res['id_sup'])
            lesub = leobj.uid2leobj(res['id_sub'])

            relation['id_relation'] = res['id_relation']
            relation['lesup'] = lesup
            relation['lesub'] = lesub
            relation['rank'] = rank
            relation['depth'] = depth
            if not (res['nature'] is None):
                relation['nature'] = res['nature']
            
            if not no_attr and res['nature'] is None and len(lesup._linked_types[lesub.__class__]) != 0:
                #Fetch relation attributes
                rel_attr_table = MySQL.get_r2t2table_name(lesup.__class__.__name__, lesub.__class__.__name__)
                sql = select(MySQL.rel_attr_table, {MySQL.relations_pkname: id_relation})
                if cur.execute(sql) != 1:
                    raise RuntimeError("Unknow SQL error")

                res = all_to_dicts(cur)
                if len(res) == 0:
                    #Here raising a warning and adding empty (or default) attributes will be better
                    raise RuntimeError("This relation should have attributes but none found !!!")
                if len(res) > 1:
                    raise RuntimeError("When selecting on primary key, get more than one result. Bailout")
                attrs = res[0]
            relation['rel_attr'] = attrs

            return relation

    ## @brief Fetch all relations concerning an object (rel2type relations)
    # @param leo LeType : LeType child instance
    # @return a list of tuple (lesup, lesub, dict_attr)
    def get_relations(self, leo):

        sql = select(self.datasource_utils.relations_table_name, where=or_(({'id_sub':leo.lodel_id},{'id_sup':leo.lodel_id})))

        with self.connection as cur:
            results = all_to_dicts(cur.execute(sql))

        relations = []
        for result in results:
            id_sup = result['id_sup']
            id_sub = result['id_sub']

            del result['id_sup']
            del result['id_sub']
            rel_attr = result

            relations.append((id_sup, id_sub, rel_attr))

        return relations

    ## @brief Add a superior to a LeObject
    # @note in the MySQL version the method will have a depth=None argument to allow reccursive calls to add all the path to the root with corresponding depth
    # @param lesup LeType : superior LeType child class instance
    # @param lesub LeType : subordinate LeType child class instance
    # @param nature str : A relation nature @ref EditorialModel.classtypesa
    # @param rank int : The rank of this relation
    # @param depth None|int : The depth of the relation (used to make reccursive calls in order to link with all superiors)
    # @return The relation ID or False if fails
    def add_superior(self, lesup, lesub, nature, rank, depth=None):

        params = {'id_sup': lesup.lodel_id,'id_sub': lesub.lodel_id,'nature': nature,'rank': rank}
        if depth is not None:
            params['depth'] = depth


        sql_insert = insert(self.datasource_utils.relations_table_name, params)
        with self.connection as cur:
            if cur.execute(sql_insert) != 1:
                return False

            cur.execute('SELECT last_insert_id()')
            relation_id, = cur.fetchone()

        return relation_id

    ## @brief Fetch a superiors list ordered by depth for a LeType
    # @param lesub LeType : subordinate LeType child class instance
    # @param nature str : A relation nature @ref EditorialModel.classtypes
    # @return A list of LeType ordered by depth (the first is the direct superior)
    def get_superiors(self, lesub, nature):

        sql = select(
            self.datasource_utils.relations_table_name,
            columns=('id_sup',),
            where={'id_sub': lesub.lodel_id, 'nature': nature},
            order_by=('depth desc',)
        )

        result = []
        with self.connection as cur:
            results = all_to_dicts(cur.execute(sql))

        superiors = [LeType(result['id_sup']) for result in results]

        return superiors
    
    ## @brief Fetch the list of the subordinates given a nature
    # @param lesup LeType : superior LeType child class instance
    # @param nature str : A relation nature @ref EditorialModel.classtypes
    # @return A list of LeType ordered by rank that are subordinates of lesup in a "nature" relation
    def get_subordinates(self, lesup, nature):
        with self.connection as cur:
            id_sup = lesup.lodel_id if isinstance(lesup, leobject.letype.LeType) else MySQL.leroot_lodel_id
            sql = select(
                MySQL.relations_table_name,
                columns=('id_sup',),
                where={'id_sup': id_sup, 'nature': nature},
                order_by=('rank',)
            )
            cur.execut(sql)
            res = all_to_dicts(cur)

            return [LeType(r['id_sup']) for r in res]