using System.Text.Json;
using RadicadeServer.RecNet.Avatar;
using RadicadeServer.RecNet.Enums.Players.Avatar;
using RadicadeServer.RecNet.Enums.Store;
using RadicadeServer.Utils;
using Xunit;

namespace RadicadeServer.Tests;

/// <summary>
/// What a completion pays once the player owns everything the activity hands out. The reward can no
/// longer be a first-time one, so it becomes a reacquisition: a selection of ordinary items for a
/// map game, a non-rare consumable for a quest.
/// </summary>
public class RroReacquisitionTests
{
    private static string ShippedCatalogueJson() =>
        File.ReadAllText(Path.Combine(AppContext.BaseDirectory, "Fixtures", "2022-avatar.json"));

    private static string ConsumableCatalogueJson() => JsonSerializer.Serialize(new List<ConsumableItem>
    {
        new() { ConsumableItemDesc = "consumable-a", FriendlyName = "Consumable A", Rarity = Rarity.Common },
        new() { ConsumableItemDesc = "consumable-b", FriendlyName = "Consumable B", Rarity = Rarity.Uncommon },
    });

    private static LevelUpRewardPool.Pool ConsumablePool() => new()
    {
        Consumables = ["consumable-a", "consumable-b"]
    };

    // ---------------------------------------------------------------------------------
    // The repeat is filed under its own context
    // ---------------------------------------------------------------------------------

    [Fact]
    public void ARepeatIsFiledUnderTheReacquisitionContext()
    {
        // Not under the activity's own context: the client has to be able to tell a duplicate from
        // a first-time reward.
        Assert.Equal(20, (int)RroRewardPools.ReacquisitionContext);
        Assert.Equal(GiftContext.Reacquisition, RroRewardPools.ReacquisitionContext);
        Assert.False(RroRewardPools.IsDeprecated(RroRewardPools.ReacquisitionContext));
    }

    // ---------------------------------------------------------------------------------
    // A map game offers a selection of ordinary items
    // ---------------------------------------------------------------------------------

    [Fact]
    public void AMapGameOffersASelectionOfOrdinaryItems()
    {
        var drops = RroRewardPools.BuildFallbackDrops(
            selection: true, owned: null, random: new Random(4), catalogueJson: ShippedCatalogueJson());

        Assert.Equal(3, drops.Count);
        Assert.Equal(3, drops.Select(x => x.AvatarItemDesc).Distinct(StringComparer.Ordinal).Count());
        Assert.All(drops, drop => Assert.Equal(GiftContext.Reacquisition, drop.Context));
        Assert.All(drops, drop => Assert.Equal(20, drop.GiftContext));
        Assert.All(drops, drop => Assert.Contains(drop.Rarity, new[] { Rarity.Uncommon, Rarity.Rare }));
    }

    [Fact]
    public void TheOrdinaryPoolIsTheTwoLowestRaritiesAndNothingDenied()
    {
        var json = ShippedCatalogueJson();
        var pool = RroRewardPools.ReacquisitionPool(json);

        // The shipped scale is 2/3/4/5 stars as rarity 10/20/30/50; the ordinary tiers are the two
        // lowest, which is a few hundred items rather than the whole catalogue.
        Assert.True(pool.Count > 300, $"only {pool.Count} ordinary items");
        Assert.All(pool, item => Assert.Contains(item.Rarity, new[] { 10, 20 }));
        Assert.All(pool, item => Assert.False(LevelUpRewardPool.IsAlwaysDenied(item)));
        Assert.All(pool, item => Assert.False(string.IsNullOrWhiteSpace(item.AvatarItemDesc)));
        Assert.All(pool, item => Assert.False(item.IsBaseAvatarItem));
    }

    [Fact]
    public void TheGenericPoolIsNotAnotherActivitysRewardList()
    {
        // A dodgeball clear must not offer a Crimson Cauldron piece as a consolation prize: nothing
        // from any reward set belongs in the generic draw.
        var json = ShippedCatalogueJson();
        var pool = RroRewardPools.ReacquisitionPool(json);

        Assert.All(pool, item => Assert.False(RroRewardPools.IsRewardSetItem(item),
            $"{item.FriendlyName} is a reward-set item and should not be offered generically"));
        Assert.All(pool, item => Assert.DoesNotContain("Witch Hunter", item.FriendlyName, StringComparison.OrdinalIgnoreCase));
        Assert.All(pool, item => Assert.DoesNotContain("Angler", item.FriendlyName, StringComparison.OrdinalIgnoreCase));
        Assert.All(pool, item => Assert.DoesNotContain("Knight", item.FriendlyName, StringComparison.OrdinalIgnoreCase));

        // And the ordinary items a player actually saw are still eligible.
        Assert.Contains(pool, item => item.FriendlyName == "Turtleneck (White)");
        Assert.Contains(pool, item => item.FriendlyName == "Bike Gloves (Blue)");
    }

    [Fact]
    public void TheFilterCatchesRewardItemsThePoolsDoNot()
    {
        // The pools only name the colours a rank pays. A colour they do not name is still that
        // activity's item and must not leak into a generic reward either.
        Assert.True(RroRewardPools.IsRewardSetItem(new AvatarItem { FriendlyName = "Stunt Singlet (Pink)" }));
        Assert.True(RroRewardPools.IsRewardSetItem(new AvatarItem { FriendlyName = "Wizard Robes (Green)" }));
        Assert.True(RroRewardPools.IsRewardSetItem(new AvatarItem { FriendlyName = "Runner Harness (Orange)" }));
        Assert.True(RroRewardPools.IsRewardSetItem(new AvatarItem { FriendlyName = "Angler Hat (Gray)" }));

        Assert.False(RroRewardPools.IsRewardSetItem(new AvatarItem { FriendlyName = "Turtleneck (White)" }));
        Assert.False(RroRewardPools.IsRewardSetItem(new AvatarItem { FriendlyName = "Bike Gloves (Blue)" }));
    }

    [Fact]
    public void AnItemBoxCarriesNoCurrencyType()
    {
        var json = ShippedCatalogueJson();
        var quest = RroRewardPools.BuildGift(GiftContext.Quest_Goblin_A, null, new Random(1), json);
        Assert.NotNull(quest);
        Assert.Equal(CurrencyType.Invalid, quest!.CurrencyType);

        var reacquired = RroRewardPools.BuildFallbackDrops(true, null, new Random(1), json);
        Assert.All(reacquired, drop => Assert.Equal(CurrencyType.Invalid, drop.CurrencyType));
        Assert.All(reacquired, drop => Assert.Equal(0, drop.Currency));
    }

    [Fact]
    public void TheSelectionOpensUpTheCatalogueBeforeItRepeats()
    {
        // The point of preferring what is unowned: a player who has finished Golden Trophy should be
        // offered something they have never had, not one of the two pieces they already own.
        var json = ShippedCatalogueJson();
        var pool = RroRewardPools.ReacquisitionPool(json);
        var keep = pool.Take(2).ToList();
        var owned = pool.Skip(2)
            .Select(x => LevelUpRewardPool.OwnershipKey(x.AvatarItemDesc))
            .ToHashSet(StringComparer.OrdinalIgnoreCase);

        var drops = RroRewardPools.BuildFallbackDrops(true, owned, new Random(6), json);

        Assert.Equal(2, drops.Count);
        var expected = keep.Select(x => x.AvatarItemDesc).ToHashSet(StringComparer.Ordinal);
        Assert.All(drops, drop => Assert.Contains(drop.AvatarItemDesc, expected));
    }

    [Fact]
    public void APlayerWhoOwnsEverythingIsStillOfferedASelection()
    {
        // A repeat has to terminate: once the catalogue itself is owned, the draw repeats rather
        // than leaving the player with nothing.
        var json = ShippedCatalogueJson();
        var owned = RroRewardPools.ReacquisitionPool(json)
            .Select(x => LevelUpRewardPool.OwnershipKey(x.AvatarItemDesc))
            .ToHashSet(StringComparer.OrdinalIgnoreCase);

        var drops = RroRewardPools.BuildFallbackDrops(true, owned, new Random(8), json);
        Assert.Equal(3, drops.Count);
        Assert.Equal(3, drops.Select(x => x.AvatarItemDesc).Distinct(StringComparer.Ordinal).Count());
    }

    // ---------------------------------------------------------------------------------
    // A quest is handed a consumable instead
    // ---------------------------------------------------------------------------------

    [Fact]
    public void AQuestIsHandedANonRareConsumableInsteadOfAChoice()
    {
        var drops = RroRewardPools.BuildFallbackDrops(
            selection: false,
            owned: null,
            random: new Random(2),
            catalogueJson: ShippedCatalogueJson(),
            consumableCatalogJson: ConsumableCatalogueJson(),
            consumablePool: ConsumablePool());

        Assert.Single(drops);
        Assert.False(string.IsNullOrWhiteSpace(drops[0].ConsumableItemDesc));
        Assert.True(string.IsNullOrWhiteSpace(drops[0].AvatarItemDesc));
        Assert.Equal(GiftContext.Reacquisition, drops[0].Context);
        Assert.Equal(0, drops[0].Currency);
        Assert.Equal(0, drops[0].Xp);
    }

    [Fact]
    public void TheConsumablePrefersOneThePlayerDoesNotHave()
    {
        var owned = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
        {
            LevelUpRewardPool.OwnershipKey(ConsumableCatalog.ToClientDesc("consumable-a"))
        };

        var gift = RroRewardPools.BuildFallbackConsumable(
            owned, new Random(3), ConsumableCatalogueJson(), ConsumablePool());

        Assert.NotNull(gift);
        Assert.Equal(ConsumableCatalog.ToClientDesc("consumable-b"), gift!.ConsumableItemDesc);
    }

    [Fact]
    public void AnExhaustedConsumablePoolStillPaysOne()
    {
        var owned = new[] { "consumable-a", "consumable-b" }
            .Select(x => LevelUpRewardPool.OwnershipKey(ConsumableCatalog.ToClientDesc(x)))
            .ToHashSet(StringComparer.OrdinalIgnoreCase);

        var gift = RroRewardPools.BuildFallbackConsumable(
            owned, new Random(3), ConsumableCatalogueJson(), ConsumablePool());

        Assert.NotNull(gift);
        Assert.Equal(GiftContext.Reacquisition, gift!.Context);
    }

    [Fact]
    public void WithNothingToDrawFromTheFallbackIsEmptyRatherThanAWrongItem()
    {
        // An empty consumable catalogue leaves the caller to its token fallback. It must not reach
        // for an ordinary item here: a quest is not a selection.
        Assert.Null(RroRewardPools.BuildFallbackConsumable(null, new Random(1), "[]", new LevelUpRewardPool.Pool()));
        Assert.Empty(RroRewardPools.BuildFallbackDrops(
            selection: false, owned: null, random: new Random(1),
            consumableCatalogJson: "[]", consumablePool: new LevelUpRewardPool.Pool()));

        // And a catalogue that cannot satisfy the ordinary tiers yields no selection.
        Assert.Empty(RroRewardPools.BuildFallbackDrops(
            selection: true, owned: null, random: new Random(1), catalogueJson: "[]"));
    }

    // ---------------------------------------------------------------------------------
    // A completion whose own pool cannot pay still offers items, with tokens as one of them
    // ---------------------------------------------------------------------------------

    [Fact]
    public void AStuntRunnerCompletionPaysItsOwnItems()
    {
        // The reward request for a finished Stunt Runner run arrives after the player has left the
        // room, so the room the visit was recorded against names the Rec Center rather than the
        // activity. The context the client claims is what names it, and the consumable the client
        // files a run with nothing new to give under belongs to the same activity, not to tokens.
        Assert.Equal("StuntRunner", RroRewardPools.RoomForContext(GiftContext.StuntRunner_TheMainEvent_C));
        Assert.Equal("StuntRunner", RroRewardPools.RoomForContext(GiftContext.StuntRunner_TheMainEvent_SS));
        Assert.Equal("StuntRunner", RroRewardPools.RoomForContext(GiftContext.StuntRunner_TheMainEvent_Consumable));
        Assert.True(RroRewardPools.IsRewardActivity("StuntRunner"));

        // A quest's pool is served by rank, and a consumable is no rank: the activity's lowest rank
        // is what answers it.
        Assert.True(RroRewardPools.TryFloorContext("StuntRunner", out var floor));
        Assert.Equal(GiftContext.StuntRunner_TheMainEvent_C, floor);

        var drops = RroRewardPools.BuildDrops(GiftContext.StuntRunner_TheMainEvent_C,
            selection: false, owned: null, random: new Random(3), catalogueJson: ShippedCatalogueJson());

        var box = Assert.Single(drops);
        Assert.False(string.IsNullOrWhiteSpace(box.AvatarItemDesc));
        // An item is not a token box: the run pays a Stunt Runner item, never the token package.
        Assert.Equal(CurrencyType.Invalid, box.CurrencyType);
        Assert.Equal(0, box.Currency);
    }

    [Fact]
    public void ACompletionNothingOwnOfItsOwnCanPayIsNotPaidInTokensAlone()
    {
        // Rec Royale's Season 1 rewards came from the Frontier Pass, which is not implemented, so a
        // completed match used to be handed the token package as its whole reward.
        var drops = RroRewardPools.BuildFallbackSelection(random: new Random(6), catalogueJson: ShippedCatalogueJson());

        Assert.Equal(RroRewardPools.SelectionSize, drops.Count);
        Assert.Equal(RroRewardPools.SelectionSize,
            drops.Count(drop => !string.IsNullOrWhiteSpace(drop.AvatarItemDesc)));

        // An item box is an item: none of them is a token box with an item's name on it.
        Assert.All(drops, drop => Assert.Equal(0, drop.Currency));
        Assert.All(drops, drop => Assert.Equal(CurrencyType.Invalid, drop.CurrencyType));
    }

    /// <summary>
    /// The token box used to be in EVERY fallback selection - a fixed one-in-three chance of being
    /// handed tokens on a completion that had nothing of its own left to give - which is what "I keep
    /// getting these" was. It is now the draw, and this is the draw's own budget.
    /// </summary>
    [Fact]
    public void TheTokenBoxIsTheExceptionInAFallbackSelection()
    {
        var json = ShippedCatalogueJson();
        var withTokens = 0;
        const int draws = 400;

        for (var seed = 1; seed <= draws; seed++)
        {
            var drops = RroRewardPools.BuildFallbackSelection(random: new Random(seed), catalogueJson: json);
            Assert.Equal(RroRewardPools.SelectionSize, drops.Count);
            if (drops.Any(drop => drop.CurrencyType == CurrencyType.RecCenterTokens)) withTokens++;
        }

        Assert.True(withTokens > 0, "the token option is never offered at all");
        Assert.True(withTokens < draws / 4,
            $"the token option is in {withTokens} of {draws} selections; it is meant to be the exception");
    }

    [Fact]
    public void TheTokenBoxIsTitledWithTheAmountItHolds()
    {
        var tokens = RroRewardPools.TokenGift(GiftContext.GameRewards_Tokens, RroRewardPools.CompletionTokenAmount);

        // Every token box used to be called "Rec Center Tokens" whatever it carried, so a 50 and a
        // 150 looked like the same reward twice; the amount is the title now.
        Assert.Equal("50 Tokens", tokens.FriendlyName);
        Assert.Equal(50, tokens.Currency);
        Assert.Equal(CurrencyType.RecCenterTokens, tokens.CurrencyType);
        Assert.Equal("200 Tokens", RroRewardPools.TokenGift(GiftContext.GameRewards_Tokens, 200).FriendlyName);
    }

    [Fact]
    public void TheTokenBoxFillsTheSlotTheOrdinaryPoolCannot()
    {
        // A catalogue with two ordinary items cannot fill a three-box selection, so the slot it
        // cannot fill is the token option rather than a short selection.
        var drops = RroRewardPools.BuildFallbackSelection(random: new Random(1), catalogueJson: TwoItemCatalogueJson());

        Assert.Equal(RroRewardPools.SelectionSize, drops.Count);
        var tokens = Assert.Single(drops, drop => drop.CurrencyType == CurrencyType.RecCenterTokens);
        Assert.Equal(RroRewardPools.CompletionTokenAmount, tokens.Currency);
        Assert.Equal("50 Tokens", tokens.FriendlyName);
        Assert.Equal(GiftContext.GameRewards_Tokens, tokens.Context);
    }

    [Fact]
    public void ACatalogueWithNothingOrdinaryStillPaysTheTokenOption()
    {
        var drops = RroRewardPools.BuildFallbackSelection(random: new Random(1), catalogueJson: "[]");

        // Nothing to offer but tokens, so tokens it is - the caller's own token package is the same
        // answer, and this only has to be the one box rather than a failure.
        var tokens = Assert.Single(drops);
        Assert.Equal(CurrencyType.RecCenterTokens, tokens.CurrencyType);
        Assert.Equal("50 Tokens", tokens.FriendlyName);
    }

    /// <summary>Two ordinary items, which is what a selection of three cannot be filled from.</summary>
    private static string TwoItemCatalogueJson() => JsonSerializer.Serialize(new List<AvatarItem>
    {
        new()
        {
            AvatarItemDesc = "aa11,bb22", FriendlyName = "Plain Shirt (Grey)", Rarity = 10,
            AvatarItemId = 1, CreatedAt = new DateTime(2020, 1, 1, 0, 0, 0, DateTimeKind.Utc)
        },
        new()
        {
            AvatarItemDesc = "cc33,dd44", FriendlyName = "Plain Hat (Grey)", Rarity = 20,
            AvatarItemId = 2, CreatedAt = new DateTime(2020, 1, 1, 0, 0, 0, DateTimeKind.Utc)
        },
    });
}