using System;
using System.Collections.Generic;
using Bogatyri.World;
using NUnit.Framework;

// Тесты модулей без Unity-сцены. Запуск: Window -> General -> Test Runner -> EditMode -> Run All.
// Список тестов, которые команда решила добавить (план от 19.10.2026), -- в Docs/Modules/README.md.
public class ModuleTests
{
    [SetUp]
    public void ResetCore()
    {
        GameServices.Clear();
        EventBus.Clear();
        SaveRegistry.Clear();
    }

    // ---------------- Армия: один солдат не может быть в двух местах ----------------

    [Test]
    public void ArmyMath_TakeProportional_NeverDoubleCountsOrLosesSoldiers()
    {
        var rnd = new Random(1);
        for (int run = 0; run < 2000; run++)
        {
            var troops = new int[4];
            int total = 0;
            for (int i = 0; i < 4; i++) { troops[i] = rnd.Next(0, 50); total += troops[i]; }
            if (total == 0) continue;

            int count = rnd.Next(1, total + 1);
            int[] taken = ArmyMath.TakeProportional(troops, count);

            int sum = 0;
            for (int i = 0; i < 4; i++)
            {
                Assert.That(taken[i], Is.InRange(0, troops[i]), "нельзя взять больше, чем есть в типе");
                sum += taken[i];
            }
            Assert.AreEqual(count, sum, "в поход уходит ровно столько, сколько просили");
        }
    }

    [Test]
    public void ArmyMath_TakeMoreThanExists_ReturnsNull()
    {
        Assert.IsNull(ArmyMath.TakeProportional(new[] { 1, 1, 0, 0 }, 3));
    }

    [Test]
    public void ArmyMath_SplitSurvivors_ReturnsExactlySurvivors()
    {
        int[] back = ArmyMath.SplitSurvivors(new[] { 10, 5, 0, 1 }, 9);
        int sum = 0;
        foreach (var b in back) { Assert.GreaterOrEqual(b, 0); sum += b; }
        Assert.AreEqual(9, sum);
    }

    // ---------------- Боевая система ----------------

    [Test]
    public void Battle_MoreSoldiersWins_TieGoesToDefender()
    {
        var battle = new BattleSystem();
        Assert.IsTrue(battle.Resolve(new BattleRequest { Attackers = 30, Defenders = 20 }).Victory);
        Assert.IsFalse(battle.Resolve(new BattleRequest { Attackers = 20, Defenders = 20 }).Victory);
        Assert.AreEqual(20, battle.Resolve(new BattleRequest { Attackers = 30, Defenders = 20 }).Survivors);
    }

    // ---------------- Глобальный мир: поход до конца, в том числе офлайн ----------------

    [Test]
    public void World_MarchResolvesAndReturns_EvenAfterLongOffline()
    {
        var world = new WorldSimulation(WorldMapLayout.CreateDefault(), new BattleSystem());
        MarchData march = world.StartMarch("p", WorldMapLayout.PlayerCityId, WorldMapLayout.BossCastleId, 30, 0, out string error);
        Assert.IsNotNull(march, error);

        var events = new List<WorldEvent>();
        world.Advance(3_600_000, events); // игра была закрыта час

        Assert.AreEqual(2, events.Count, "бой и возвращение за один вызов");
        Assert.AreEqual(WorldEventType.BattleResolved, events[0].Type);
        Assert.AreEqual(WorldEventType.MarchReturned, events[1].Type);
        Assert.AreEqual(0, world.Marches.Count);
    }

    // ---------------- Ядро ----------------

    [Test]
    public void EventBus_FailingSubscriberDoesNotBreakOthers()
    {
        int delivered = 0;
        Exception caught = null;
        EventBus.OnHandlerError = e => caught = e;
        EventBus.Subscribe<MarchReturnedEvent>(_ => throw new InvalidOperationException("boom"));
        EventBus.Subscribe<MarchReturnedEvent>(_ => delivered++);

        EventBus.Publish(new MarchReturnedEvent { Survivors = 5 });

        Assert.AreEqual(1, delivered);
        Assert.IsNotNull(caught);
    }

    [Test]
    public void GameServices_MissingModule_ThrowsClearError()
    {
        Assert.Throws<InvalidOperationException>(() => GameServices.Get<IArmy>());
        Assert.IsFalse(GameServices.TryGet(out IArmy _));
    }
}