aves/lib/model/source/location.dart

110 lines
4.9 KiB
Dart

import 'dart:math';
import 'package:aves/model/availability.dart';
import 'package:aves/model/entry.dart';
import 'package:aves/model/filters/location.dart';
import 'package:aves/model/metadata.dart';
import 'package:aves/model/metadata_db.dart';
import 'package:aves/model/source/collection_source.dart';
import 'package:collection/collection.dart';
import 'package:flutter/foundation.dart';
import 'package:tuple/tuple.dart';
mixin LocationMixin on SourceBase {
static const _commitCountThreshold = 50;
List<String> sortedCountries = List.unmodifiable([]);
List<String> sortedPlaces = List.unmodifiable([]);
Future<void> loadAddresses() async {
final stopwatch = Stopwatch()..start();
final saved = await metadataDb.loadAddresses();
rawEntries.forEach((entry) {
final contentId = entry.contentId;
entry.addressDetails = saved.firstWhere((address) => address.contentId == contentId, orElse: () => null);
});
debugPrint('$runtimeType loadAddresses complete in ${stopwatch.elapsed.inMilliseconds}ms for ${saved.length} entries');
onAddressMetadataChanged();
}
Future<void> locateEntries() async {
if (!(await availability.canGeolocate)) return;
// final stopwatch = Stopwatch()..start();
final byLocated = groupBy<AvesEntry, bool>(rawEntries.where((entry) => entry.hasGps), (entry) => entry.isLocated);
final todo = byLocated[false] ?? [];
if (todo.isEmpty) return;
// geocoder calls take between 150ms and 250ms
// approximation and caching can reduce geocoder usage
// for example, for a set of 2932 entries:
// - 2476 calls (84%) when approximating to 6 decimal places (~10cm - individual humans)
// - 2433 calls (83%) when approximating to 5 decimal places (~1m - individual trees, houses)
// - 2277 calls (78%) when approximating to 4 decimal places (~10m - individual street, large buildings)
// - 1521 calls (52%) when approximating to 3 decimal places (~100m - neighborhood, street)
// - 652 calls (22%) when approximating to 2 decimal places (~1km - town or village)
// cf https://en.wikipedia.org/wiki/Decimal_degrees#Precision
final latLngFactor = pow(10, 2);
Tuple2 approximateLatLng(AvesEntry entry) {
final lat = entry.catalogMetadata?.latitude;
final lng = entry.catalogMetadata?.longitude;
if (lat == null || lng == null) return null;
return Tuple2((lat * latLngFactor).round(), (lng * latLngFactor).round());
}
final knownLocations = <Tuple2, AddressDetails>{};
byLocated[true]?.forEach((entry) => knownLocations.putIfAbsent(approximateLatLng(entry), () => entry.addressDetails));
var progressDone = 0;
final progressTotal = todo.length;
setProgress(done: progressDone, total: progressTotal);
final newAddresses = <AddressDetails>[];
await Future.forEach<AvesEntry>(todo, (entry) async {
final latLng = approximateLatLng(entry);
if (knownLocations.containsKey(latLng)) {
entry.addressDetails = knownLocations[latLng]?.copyWith(contentId: entry.contentId);
} else {
await entry.locate(background: true);
// it is intended to insert `null` if the geocoder failed,
// so that we skip geocoding of following entries with the same coordinates
knownLocations[latLng] = entry.addressDetails;
}
if (entry.isLocated) {
newAddresses.add(entry.addressDetails);
if (newAddresses.length >= _commitCountThreshold) {
await metadataDb.saveAddresses(List.unmodifiable(newAddresses));
onAddressMetadataChanged();
newAddresses.clear();
}
}
setProgress(done: ++progressDone, total: progressTotal);
});
await metadataDb.saveAddresses(List.unmodifiable(newAddresses));
onAddressMetadataChanged();
// debugPrint('$runtimeType locateEntries complete in ${stopwatch.elapsed.inSeconds}s');
}
void onAddressMetadataChanged() {
updateLocations();
eventBus.fire(AddressMetadataChangedEvent());
}
void updateLocations() {
final locations = rawEntries.where((entry) => entry.isLocated).map((entry) => entry.addressDetails).toList();
sortedPlaces = List<String>.unmodifiable(locations.map((address) => address.place).where((s) => s != null && s.isNotEmpty).toSet().toList()..sort(compareAsciiUpperCase));
// the same country code could be found with different country names
// e.g. if the locale changed between geolocating calls
// so we merge countries by code, keeping only one name for each code
final countriesByCode = Map.fromEntries(locations.map((address) => MapEntry(address.countryCode, address.countryName)).where((kv) => kv.key != null && kv.key.isNotEmpty));
sortedCountries = List<String>.unmodifiable(countriesByCode.entries.map((kv) => '${kv.value}${LocationFilter.locationSeparator}${kv.key}').toList()..sort(compareAsciiUpperCase));
invalidateFilterEntryCounts();
eventBus.fire(LocationsChangedEvent());
}
}
class AddressMetadataChangedEvent {}
class LocationsChangedEvent {}