# pfwb_thesaurus - thesaurus system
# Copyright (C) 2016  Entr'ouvert
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import psycopg2

from django.conf import settings
from django.core.management.base import BaseCommand, CommandError

from ...models import Term, AlternativeTerm


class Command(BaseCommand):
    def handle(self, *args, **kwargs):
        pgconn = psycopg2.connect(**settings.TABELLIO_DB_SETTINGS)
        cur = pgconn.cursor()

        cur.execute('''SELECT t_thesaurus_term.id,
                              t_thesaurus_term.term,
                              ARRAY(
                                SELECT term
                                  FROM t_thesaurus_term AS t4,
                                       t_thesaurus_rel AS t5
                                 WHERE t4.id = t5.primtermid
                                   AND t5.rel = 'EQ'
                                   AND t5.sectermid = t_thesaurus_term.id) AS eq,
                              (SELECT t2.term FROM t_thesaurus_term AS t2,
                                                   t_thesaurus_rel
                                             WHERE t_thesaurus_rel.primtermid = t_thesaurus_term.id
                                               AND t_thesaurus_rel.rel = 'HN'
                                               AND t2.id = t_thesaurus_rel.sectermid) AS hn,
                              (SELECT t3.term FROM t_thesaurus_term AS t3,
                                                t_thesaurus_rel
                                          WHERE t_thesaurus_rel.primtermid = t_thesaurus_term.id
                                            AND t_thesaurus_rel.rel = 'SN'
                                            AND t3.id = t_thesaurus_rel.sectermid
                                          LIMIT 1) AS sn
                         FROM t_thesaurus_term
                        WHERE EXISTS (
                                 SELECT id
                                   FROM t_thesaurus_rel
                                  WHERE (sectermid = t_thesaurus_term.id
                                         OR primtermid = t_thesaurus_term.id)
                                    AND rel in ('BT', 'RT'))
                                    ''')
        while True:
            row = cur.fetchone()
            if row is None:
                break
            term, created = Term.objects.get_or_create(tabellio_id=row[0])
            term.term = row[1]
            term.historical_note = row[3] or ''
            term.scope_note = row[4] or ''
            current_equivs = set([x.term for x in term.alternativeterm_set.all()])
            new_equivs = set(row[2])
            term.save()
            term.alternativeterm_set.filter(term__in=list(current_equivs - new_equivs)).delete()
            for alt_term in new_equivs - current_equivs:
                alt_term_object = AlternativeTerm(term=alt_term, primary_term=term)
                alt_term_object.save()

        bt_rels = {}
        rt_rels = {}
        cur.execute('''SELECT primtermid, sectermid, rel
                         FROM t_thesaurus_rel
                        WHERE rel IN ('BT', 'RT')
                    ''')
        while True:
            row = cur.fetchone()
            if row is None:
                break
            primtermid, sectermid, rel = row
            if rel == 'BT':
                if not bt_rels.get(primtermid):
                    bt_rels[primtermid] = []
                bt_rels[primtermid].append(sectermid)
            elif rel == 'RT':
                if not rt_rels.get(primtermid):
                    rt_rels[primtermid] = []
                rt_rels[primtermid].append(sectermid)

        for term, broader_term_ids in bt_rels.items():
            term = Term.objects.get(tabellio_id=term)
            broader_terms = Term.objects.filter(tabellio_id__in=broader_term_ids)
            current_set = set([x.id for x in term.broader.all()])
            new_set = set([x.id for x in broader_terms])
            for removed_term in current_set - new_set:
                term.broader.remove(removed_term)
            for added_term in new_set - current_set:
                term.broader.add(added_term)

        for term, related_term_ids in rt_rels.items():
            term = Term.objects.get(tabellio_id=term)
            related_terms = Term.objects.filter(tabellio_id__in=related_term_ids)
            current_set = set([x.id for x in term.related.all()])
            new_set = set([x.id for x in related_terms])
            for removed_term in current_set - new_set:
                term.related.remove(removed_term)
            for added_term in new_set - current_set:
                term.related.add(added_term)

        pgconn.close()