import 'package:flutter_test/flutter_test.dart';
import 'package:pluriwave/modelos/preset_ecualizador.dart';
import 'package:pluriwave/servicios/servicio_presets_personalizados.dart';
import 'package:shared_preferences/shared_preferences.dart';

/// WU13 task 13.2 — persistence for user-named custom EQ presets.
///
/// Design ADR-5 hazard box: this lives in its OWN file and OWN
/// SharedPreferences key (`eq_custom_presets_v1`), deliberately separate
/// from `ServicioEcualizador` — that file has an empty-`git diff` success
/// criterion for this change, so persistence for custom presets must never
/// be added there.
void main() {
  setUp(() {
    SharedPreferences.setMockInitialValues({});
  });

  test('listar returns an empty list when nothing was saved yet', () async {
    final prefs = await SharedPreferences.getInstance();
    final servicio = ServicioPresetsPersonalizados(prefs: prefs);

    expect(await servicio.listar(), isEmpty);
  });

  test('guardar then listar round-trips a named custom preset', () async {
    final prefs = await SharedPreferences.getInstance();
    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
    // Not `const`: PresetEcualizador's constructor asserts `bandas.length
    // == 5`, and `List.length` is not constant-foldable in an assert here
    // (same const-eval limitation the branch already hit for
    // `DateTime(...)` fixtures in WU9) — the model's own static presets
    // (e.g. `PresetEcualizador.flat`) are declared `final`, not `const`,
    // for the same reason.
    final preset = PresetEcualizador(
      nombre: 'Mi preset',
      bandas: [1.0, -2.0, 3.0, -4.0, 5.0],
    );

    await servicio.guardar(preset);
    final guardados = await servicio.listar();

    expect(guardados, hasLength(1));
    expect(guardados.single, equals(preset));
  });

  test('guardar persists under its OWN SharedPreferences key', () async {
    final prefs = await SharedPreferences.getInstance();
    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
    final preset = PresetEcualizador(nombre: 'Otro', bandas: [0, 0, 0, 0, 0]);

    await servicio.guardar(preset);

    expect(prefs.getString('eq_custom_presets_v1'), isNotNull);
  });

  test('guardar with a repeated name replaces the previous entry', () async {
    final prefs = await SharedPreferences.getInstance();
    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
    final v1 = PresetEcualizador(nombre: 'Mismo', bandas: [1, 1, 1, 1, 1]);
    final v2 = PresetEcualizador(nombre: 'Mismo', bandas: [2, 2, 2, 2, 2]);

    await servicio.guardar(v1);
    await servicio.guardar(v2);
    final guardados = await servicio.listar();

    expect(guardados, hasLength(1));
    expect(guardados.single.bandas, equals(v2.bandas));
  });

  test('guardar preserves insertion order across multiple presets', () async {
    final prefs = await SharedPreferences.getInstance();
    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
    final primero = PresetEcualizador(
      nombre: 'Primero',
      bandas: [0, 0, 0, 0, 0],
    );
    final segundo = PresetEcualizador(
      nombre: 'Segundo',
      bandas: [0, 0, 0, 0, 0],
    );

    await servicio.guardar(primero);
    await servicio.guardar(segundo);
    final guardados = await servicio.listar();

    expect(guardados.map((p) => p.nombre).toList(), ['Primero', 'Segundo']);
  });

  test('eliminar removes the named preset only', () async {
    final prefs = await SharedPreferences.getInstance();
    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
    final conservar = PresetEcualizador(
      nombre: 'Conservar',
      bandas: [0, 0, 0, 0, 0],
    );
    final borrar = PresetEcualizador(nombre: 'Borrar', bandas: [0, 0, 0, 0, 0]);
    await servicio.guardar(conservar);
    await servicio.guardar(borrar);

    await servicio.eliminar('Borrar');
    final guardados = await servicio.listar();

    expect(guardados, hasLength(1));
    expect(guardados.single.nombre, equals('Conservar'));
  });

  test('eliminar on an unknown name is a safe no-op', () async {
    final prefs = await SharedPreferences.getInstance();
    final servicio = ServicioPresetsPersonalizados(prefs: prefs);

    await servicio.eliminar('no existe');

    expect(await servicio.listar(), isEmpty);
  });

  test(
    'a corrupt top-level payload degrades to an empty list, never throws',
    () async {
      final prefs = await SharedPreferences.getInstance();
      await prefs.setString('eq_custom_presets_v1', 'not valid json{{{');
      final servicio = ServicioPresetsPersonalizados(prefs: prefs);

      await expectLater(servicio.listar(), completion(isEmpty));
    },
  );
}