from functools import partial

from yams.constraints import UniqueConstraint

from cubicweb.schema import PURE_VIRTUAL_RTYPES

from cubicweb.server.schema2sql import build_index_name, check_constraint

sql = partial(sql, ask_confirm=False)

source = repo.system_source

helper = source.dbhelper

# drop all relations primary keys

for table, cstr in sql('''

    SELECT DISTINCT tc.table_name, tc.constraint_name

    FROM information_schema.table_constraints tc,

         information_schema.key_column_usage kc

    WHERE tc.constraint_type IN 'PRIMARY KEY'

          AND kc.table_name = tc.table_name

          AND kc.table_name LIKE '%\_relation'

          AND kc.table_schema = tc.table_schema

          AND kc.constraint_name = tc.constraint_name;

'''):

    sql('ALTER TABLE %s DROP CONSTRAINT' % (table, cstr))

for table, cstr in sql("""

    SELECT DISTINCT table_name, constraint_name FROM information_schema.constraint_column_usage

    WHERE table_name LIKE 'cw\_%' AND constraint_name LIKE '%\_key'"""):

    sql("ALTER TABLE %(table)s DROP CONSTRAINT %(cstr)s" % locals())

for rschema in schema.relations():

    if rschema.rule or rschema in PURE_VIRTUAL_RTYPES:

        continue

    if rschema.final or rschema.inlined:

        for rdef in rschema.rdefs.values():

            table = 'cw_{0}'.format(rdef.subject)

            column = 'cw_{0}'.format(rdef.rtype)

            if any(isinstance(cstr, UniqueConstraint) for cstr in rdef.constraints):

                old_name = '%s_%s_key' % (table.lower(), column.lower())

                sql('ALTER TABLE %s DROP CONSTRAINT %s' % (table, old_name))

                source.create_index(cnx, table, column, unique=True)

            if rschema.inlined or rdef.indexed:

                old_name = '%s_%s_idx' % (table.lower(), column.lower())

                sql('DROP INDEX IF EXISTS %s' % old_name)

                source.create_index(cnx, table, column)

    else:

        table = '{0}_relation'.format(rschema)

        sql('ALTER TABLE %s ADD CONSTRAINT %s PRIMARY KEY(eid_from, eid_to)'

            % (table, build_index_name(table, ['eid_from', 'eid_to'], 'key_')))

        for column in ('from', 'to'):

            sql('DROP INDEX IF EXISTS %s_%s_idx' % (table, column))

            sql('CREATE INDEX %s ON %s(eid_%s);'

                % (build_index_name(table, ['eid_' + column], 'idx_'), table, column))

# we changed constraint serialization, which also changes their name

for table, cstr in sql("""

    SELECT DISTINCT table_name, constraint_name FROM information_schema.constraint_column_usage

    WHERE constraint_name LIKE 'cstr%'"""):

    sql("ALTER TABLE %(table)s DROP CONSTRAINT %(cstr)s" % locals())

for cwconstraint in rql('Any C WHERE R constrained_by C').entities():

    cwrdef = cwconstraint.reverse_constrained_by[0]

    rdef = cwrdef.yams_schema()

    cstr = rdef.constraint_by_eid(cwconstraint.eid)

    with cnx.deny_all_hooks_but():

        cwconstraint.cw_set(value=unicode(cstr.serialize()))

    if cstr.type() not in ('BoundaryConstraint', 'IntervalBoundConstraint',

                           'StaticVocabularyConstraint'):

        # These cannot be translate into backend CHECK.

        continue

    cstrname, check = check_constraint(rdef, cstr, helper, prefix='cw_')

    args = {'e': rdef.subject.type, 'c': cstrname, 'v': check}

    sql('ALTER TABLE cw_%(e)s ADD CONSTRAINT %(c)s CHECK(%(v)s)' % args)

commit()

if 'identity_relation' in helper.list_tables(cnx.cnxset.cu):

    sql('DROP TABLE identity_relation')