import 'dart:collection';

import 'package:collection/collection.dart';
import 'package:jadb/_data_ingestion/jmdict/objects.dart';
import 'package:jadb/table_names/jmdict.dart';
import 'package:sqflite_common/sqlite_api.dart';

class ResolvedXref {
  Entry entry;
  bool ambiguous;

  ResolvedXref(this.entry, this.ambiguous);
}

ResolvedXref resolveXref(
  SplayTreeMap<String, Set<Entry>> entriesByKanji,
  SplayTreeMap<String, Set<Entry>> entriesByReading,
  XRefParts xref,
) {
  List<Entry> candidateEntries = switch ((xref.kanjiRef, xref.readingRef)) {
    (null, null) => throw Exception(
      'Xref $xref has no kanji or reading reference',
    ),
    (final String k, null) => entriesByKanji[k]!.toList(),
    (null, final String r) => entriesByReading[r]!.toList(),
    (final String k, final String r) =>
      entriesByKanji[k]!.intersection(entriesByReading[r]!).toList(),
  };

  // Filter out entries that don't have the number of senses specified in the xref
  if (xref.senseOrderNum != null) {
    candidateEntries.retainWhere(
      (entry) => entry.senses.length >= xref.senseOrderNum!,
    );
  }

  // If the xref has a reading ref but no kanji ref, and there are multiple
  // entries to choose from, prefer entries with empty kanji readings
  // if possible.
  if (xref.kanjiRef == null &&
      xref.readingRef != null &&
      candidateEntries.length > 1) {
    final candidatesWithEmptyKanji = candidateEntries
        .where((entry) => entry.kanji.isEmpty)
        .toList();

    if (candidatesWithEmptyKanji.isNotEmpty) {
      candidateEntries = candidatesWithEmptyKanji;
    }
  }

  // Having more senses is a cheap way to choose the most likely correct
  // entry in case there are multiple candidates left.
  candidateEntries.sortBy<num>((entry) => entry.senses.length);

  if (candidateEntries.isEmpty) {
    throw Exception(
      'SKIPPING: Xref $xref has ${candidateEntries.length} entries, '
      'kanjiRef: ${xref.kanjiRef}, readingRef: ${xref.readingRef}, '
      'senseOrderNum: ${xref.senseOrderNum}',
    );
  } else if (candidateEntries.length > 1) {
    print(
      'WARNING: Xref $xref has ${candidateEntries.length} entries, '
      'kanjiRef: ${xref.kanjiRef}, readingRef: ${xref.readingRef}, '
      'senseOrderNum: ${xref.senseOrderNum}',
    );
    return ResolvedXref(candidateEntries.first, true);
  } else {
    return ResolvedXref(candidateEntries.first, false);
  }
}

Future<void> seedJMDictData(List<Entry> entries, Database db) async {
  print('  [JMdict] Batch 1 - Kanji and readings');
  Batch b = db.batch();

  int elementId = 0;
  for (final e in entries) {
    b.insert(JMdictTableNames.entry, e.sqlValue);

    for (final k in e.kanji) {
      elementId++;
      b.insert(
        JMdictTableNames.kanjiElement,
        k.sqlValue..addAll({'entryId': e.entryId, 'elementId': elementId}),
      );

      for (final i in k.info) {
        b.insert(JMdictTableNames.kanjiInfo, {
          'elementId': elementId,
          'info': i,
        });
      }
    }

    for (final r in e.readings) {
      elementId++;
      b.insert(
        JMdictTableNames.readingElement,
        r.sqlValue..addAll({'entryId': e.entryId, 'elementId': elementId}),
      );

      for (final i in r.info) {
        b.insert(JMdictTableNames.readingInfo, {
          'elementId': elementId,
          'info': i,
        });
      }
      for (final res in r.restrictions) {
        b.insert(JMdictTableNames.readingRestriction, {
          'elementId': elementId,
          'restriction': res,
        });
      }
    }
  }

  await b.commit(noResult: true);

  print('  [JMdict] Batch 2 - Senses');
  b = db.batch();

  for (final e in entries) {
    for (final s in e.senses) {
      b.insert(
        JMdictTableNames.sense,
        s.sqlValue..addAll({'entryId': e.entryId}),
      );
      for (final d in s.dialects) {
        b.insert(JMdictTableNames.senseDialect, {
          'senseId': s.senseId,
          'dialect': d,
        });
      }
      for (final f in s.fields) {
        b.insert(JMdictTableNames.senseField, {
          'senseId': s.senseId,
          'field': f,
        });
      }
      for (final i in s.info) {
        b.insert(JMdictTableNames.senseInfo, {'senseId': s.senseId, 'info': i});
      }
      for (final m in s.misc) {
        b.insert(JMdictTableNames.senseMisc, {'senseId': s.senseId, 'misc': m});
      }
      for (final p in s.pos) {
        b.insert(JMdictTableNames.sensePOS, {'senseId': s.senseId, 'pos': p});
      }
      for (final rk in s.restrictedToKanji) {
        b.insert(JMdictTableNames.senseRestrictedToKanji, {
          'entryId': e.entryId,
          'senseId': s.senseId,
          'kanji': rk,
        });
      }
      for (final rr in s.restrictedToReading) {
        b.insert(JMdictTableNames.senseRestrictedToReading, {
          'entryId': e.entryId,
          'senseId': s.senseId,
          'reading': rr,
        });
      }
      for (final ls in s.languageSource) {
        b.insert(
          JMdictTableNames.senseLanguageSource,
          ls.sqlValue..addAll({'senseId': s.senseId}),
        );
      }
      for (final g in s.glossary) {
        b.insert(
          JMdictTableNames.senseGlossary,
          g.sqlValue..addAll({'senseId': s.senseId}),
        );
      }
    }
  }

  await b.commit(noResult: true);

  print('  [JMdict] Building xref trees');
  final SplayTreeMap<String, Set<Entry>> entriesByKanji = SplayTreeMap();

  for (final entry in entries) {
    for (final kanji in entry.kanji) {
      if (entriesByKanji.containsKey(kanji.reading)) {
        entriesByKanji.update(kanji.reading, (list) => list..add(entry));
      } else {
        entriesByKanji.putIfAbsent(kanji.reading, () => {entry});
      }
    }
  }
  final SplayTreeMap<String, Set<Entry>> entriesByReading = SplayTreeMap();
  for (final entry in entries) {
    for (final reading in entry.readings) {
      if (entriesByReading.containsKey(reading.reading)) {
        entriesByReading.update(reading.reading, (list) => list..add(entry));
      } else {
        entriesByReading.putIfAbsent(reading.reading, () => {entry});
      }
    }
  }

  print('  [JMdict] Batch 3 - Xrefs');
  b = db.batch();

  for (final e in entries) {
    for (final s in e.senses) {
      for (final xref in s.seeAlso) {
        final resolvedEntry = resolveXref(
          entriesByKanji,
          entriesByReading,
          xref,
        );

        b.insert(JMdictTableNames.senseSeeAlso, {
          'senseId': s.senseId,
          'xrefEntryId': resolvedEntry.entry.entryId,
          'seeAlsoKanji': xref.kanjiRef,
          'seeAlsoReading': xref.readingRef,
          'seeAlsoSense': xref.senseOrderNum,
          'ambiguous': resolvedEntry.ambiguous,
        });
      }

      for (final ant in s.antonyms) {
        final resolvedEntry = resolveXref(
          entriesByKanji,
          entriesByReading,
          ant,
        );

        b.insert(JMdictTableNames.senseAntonyms, {
          'senseId': s.senseId,
          'xrefEntryId': resolvedEntry.entry.entryId,
          'antonymKanji': ant.kanjiRef,
          'antonymReading': ant.readingRef,
          'antonymSense': ant.senseOrderNum,
          'ambiguous': resolvedEntry.ambiguous,
        });
      }
    }
  }

  await b.commit(noResult: true);
}