using Microsoft.Extensions.DependencyInjection;
using NeonSprawl.Server.Game.Quests;
using NeonSprawl.Server.Tests;
using Xunit;

namespace NeonSprawl.Server.Tests.Game.Quests;

public sealed class QuestStateOperationsTests
{
    private const string PlayerId = "dev-local-1";
    private const string UnknownPlayerId = "unknown-player-xyz";
    private const string GatherQuestId = PrototypeE7M1QuestCatalogRules.GatherIntroQuestId;
    private const string RefineQuestId = PrototypeE7M1QuestCatalogRules.RefineIntroQuestId;
    private const string CombatQuestId = PrototypeE7M1QuestCatalogRules.CombatIntroQuestId;
    private const string ChainQuestId = PrototypeE7M1QuestCatalogRules.ChainQuestId;
    private const string ChainObjectiveId = PrototypeE7M1QuestCatalogRules.ChainFirstObjectiveId;

    [Fact]
    public async Task TryAccept_ShouldActivateGatherIntro_WhenNotStarted()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);

        // Act
        var result = QuestStateOperations.TryAccept(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.True(result.Success);
        Assert.Null(result.ReasonCode);
        Assert.NotNull(result.Snapshot);
        Assert.Equal(QuestProgressStatus.Active, result.Snapshot!.Status);
        Assert.Equal(0, result.Snapshot.CurrentStepIndex);
    }

    [Fact]
    public async Task TryAccept_ShouldDenyPrerequisiteIncomplete_WhenRefineIntroBeforeGatherComplete()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);

        // Act
        var result = QuestStateOperations.TryAccept(
            PlayerId,
            RefineQuestId,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.PrerequisiteIncomplete, result.ReasonCode);
        Assert.Null(result.Snapshot);
    }

    [Fact]
    public async Task TryAccept_ShouldSucceedRefineIntro_WhenGatherIntroCompleted()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);
        var timeProvider = TimeProvider.System;
        Assert.True(QuestStateOperations.TryAccept(PlayerId, GatherQuestId, deps.QuestRegistry, deps.ProgressStore).Success);
        Assert.True(QuestStateOperations.TryMarkComplete(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore,
            timeProvider).Success);

        // Act
        var result = QuestStateOperations.TryAccept(
            PlayerId,
            RefineQuestId,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.True(result.Success);
        Assert.Null(result.ReasonCode);
        Assert.Equal(QuestProgressStatus.Active, result.Snapshot!.Status);
    }

    [Fact]
    public async Task TryAccept_ShouldDenyUnknownQuest_WhenQuestIdNotInCatalog()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);

        // Act
        var result = QuestStateOperations.TryAccept(
            PlayerId,
            "prototype_quest_missing",
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.UnknownQuest, result.ReasonCode);
    }

    [Fact]
    public async Task TryAccept_ShouldDenyAlreadyActive_WhenQuestAlreadyAccepted()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);
        Assert.True(QuestStateOperations.TryAccept(PlayerId, GatherQuestId, deps.QuestRegistry, deps.ProgressStore).Success);

        // Act
        var result = QuestStateOperations.TryAccept(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.AlreadyActive, result.ReasonCode);
        Assert.NotNull(result.Snapshot);
        Assert.Equal(QuestProgressStatus.Active, result.Snapshot!.Status);
    }

    [Fact]
    public async Task TryAccept_ShouldDenyAlreadyCompleted_WhenQuestAlreadyCompleted()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);
        var timeProvider = TimeProvider.System;
        Assert.True(QuestStateOperations.TryAccept(PlayerId, GatherQuestId, deps.QuestRegistry, deps.ProgressStore).Success);
        Assert.True(QuestStateOperations.TryMarkComplete(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore,
            timeProvider).Success);

        // Act
        var result = QuestStateOperations.TryAccept(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.AlreadyCompleted, result.ReasonCode);
        Assert.Equal(QuestProgressStatus.Completed, result.Snapshot!.Status);
    }

    [Fact]
    public async Task TryAccept_ShouldDenyUnknownPlayer_WhenPlayerNotInStore()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);

        // Act
        var result = QuestStateOperations.TryAccept(
            UnknownPlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.UnknownPlayer, result.ReasonCode);
    }

    [Fact]
    public async Task TryAdvanceStep_ShouldAdvanceChainQuestAndClearCounters()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);
        var timeProvider = TimeProvider.System;
        AcceptAndComplete(deps, GatherQuestId, timeProvider);
        AcceptAndComplete(deps, RefineQuestId, timeProvider);
        AcceptAndComplete(deps, CombatQuestId, timeProvider);
        Assert.True(QuestStateOperations.TryAccept(PlayerId, ChainQuestId, deps.QuestRegistry, deps.ProgressStore).Success);
        Assert.True(deps.ProgressStore.TryUpdateObjectiveCounter(PlayerId, ChainQuestId, ChainObjectiveId, 5, out _));

        // Act
        var result = QuestStateOperations.TryAdvanceStep(
            PlayerId,
            ChainQuestId,
            1,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.True(result.Success);
        Assert.Null(result.ReasonCode);
        Assert.Equal(1, result.Snapshot!.CurrentStepIndex);
        Assert.Empty(result.Snapshot.ObjectiveCounters);
    }

    [Theory]
    [InlineData(0)]
    [InlineData(4)]
    public async Task TryAdvanceStep_ShouldDenyInvalidStepIndex_WhenIndexNotIncreasingOrPastLastStep(int newStepIndex)
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);
        var timeProvider = TimeProvider.System;
        AcceptAndComplete(deps, GatherQuestId, timeProvider);
        AcceptAndComplete(deps, RefineQuestId, timeProvider);
        AcceptAndComplete(deps, CombatQuestId, timeProvider);
        Assert.True(QuestStateOperations.TryAccept(PlayerId, ChainQuestId, deps.QuestRegistry, deps.ProgressStore).Success);

        // Act
        var result = QuestStateOperations.TryAdvanceStep(
            PlayerId,
            ChainQuestId,
            newStepIndex,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.InvalidStepIndex, result.ReasonCode);
    }

    [Fact]
    public async Task TryAdvanceStep_ShouldDenyUnknownQuest_WhenQuestIdNotInCatalog()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);

        // Act
        var result = QuestStateOperations.TryAdvanceStep(
            PlayerId,
            "prototype_quest_missing",
            1,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.UnknownQuest, result.ReasonCode);
    }

    [Fact]
    public async Task TryMarkComplete_ShouldDenyUnknownQuest_WhenQuestIdNotInCatalog()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);

        // Act
        var result = QuestStateOperations.TryMarkComplete(
            PlayerId,
            "prototype_quest_missing",
            deps.QuestRegistry,
            deps.ProgressStore,
            TimeProvider.System);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.UnknownQuest, result.ReasonCode);
    }

    [Fact]
    public async Task TryAdvanceStep_ShouldDenyNotActive_WhenQuestNotAccepted()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);

        // Act
        var result = QuestStateOperations.TryAdvanceStep(
            PlayerId,
            GatherQuestId,
            1,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.NotActive, result.ReasonCode);
    }

    [Fact]
    public async Task TryAdvanceStep_ShouldDenyAlreadyCompleted_WhenQuestCompleted()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);
        var timeProvider = TimeProvider.System;
        Assert.True(QuestStateOperations.TryAccept(PlayerId, GatherQuestId, deps.QuestRegistry, deps.ProgressStore).Success);
        Assert.True(QuestStateOperations.TryMarkComplete(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore,
            timeProvider).Success);

        // Act
        var result = QuestStateOperations.TryAdvanceStep(
            PlayerId,
            GatherQuestId,
            1,
            deps.QuestRegistry,
            deps.ProgressStore);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.AlreadyCompleted, result.ReasonCode);
    }

    [Fact]
    public async Task TryMarkComplete_ShouldBeIdempotentAtOperationsLayer()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);
        var timeProvider = TimeProvider.System;
        Assert.True(QuestStateOperations.TryAccept(PlayerId, GatherQuestId, deps.QuestRegistry, deps.ProgressStore).Success);

        // Act
        var first = QuestStateOperations.TryMarkComplete(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore,
            timeProvider);
        var second = QuestStateOperations.TryMarkComplete(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore,
            timeProvider);

        // Assert
        Assert.True(first.Success);
        Assert.Null(first.ReasonCode);
        Assert.NotNull(first.Snapshot!.CompletedAt);
        Assert.True(second.Success);
        Assert.Null(second.ReasonCode);
        Assert.Equal(first.Snapshot.CompletedAt, second.Snapshot!.CompletedAt);
        Assert.Equal(QuestProgressStatus.Completed, second.Snapshot.Status);
    }

    [Fact]
    public async Task TryMarkComplete_ShouldDenyNotActive_WhenQuestNeverAccepted()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);
        var timeProvider = TimeProvider.System;

        // Act
        var result = QuestStateOperations.TryMarkComplete(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore,
            timeProvider);

        // Assert
        Assert.False(result.Success);
        Assert.Equal(QuestStateReasonCodes.NotActive, result.ReasonCode);
    }

    [Fact]
    public async Task Host_ShouldResolveRegistryAndStore_ForQuestStateOperations()
    {
        // Arrange
        await using var factory = new InMemoryWebApplicationFactory();
        var deps = ResolveDependencies(factory);

        // Act
        var accept = QuestStateOperations.TryAccept(PlayerId, GatherQuestId, deps.QuestRegistry, deps.ProgressStore);
        var complete = QuestStateOperations.TryMarkComplete(
            PlayerId,
            GatherQuestId,
            deps.QuestRegistry,
            deps.ProgressStore,
            TimeProvider.System);

        // Assert
        Assert.True(accept.Success);
        Assert.True(complete.Success);
        Assert.Equal(QuestProgressStatus.Completed, complete.Snapshot!.Status);
    }

    private static void AcceptAndComplete(
        (IQuestDefinitionRegistry QuestRegistry, IPlayerQuestStateStore ProgressStore) deps,
        string questId,
        TimeProvider timeProvider)
    {
        Assert.True(QuestStateOperations.TryAccept(PlayerId, questId, deps.QuestRegistry, deps.ProgressStore).Success);
        Assert.True(QuestStateOperations.TryMarkComplete(
            PlayerId,
            questId,
            deps.QuestRegistry,
            deps.ProgressStore,
            timeProvider).Success);
    }

    private static (IQuestDefinitionRegistry QuestRegistry, IPlayerQuestStateStore ProgressStore) ResolveDependencies(
        InMemoryWebApplicationFactory factory)
    {
        var services = factory.Services;
        return (
            services.GetRequiredService<IQuestDefinitionRegistry>(),
            services.GetRequiredService<IPlayerQuestStateStore>());
    }
}