using System.Collections.Immutable;

namespace CardGame.Core;

public sealed class RunStats
{
    public int HealReceived { get; set; }
    public int AttacksDeclared { get; set; }
    public int FriendlyDestroyed { get; set; }
    public int FatigueTicks { get; set; }
    public Dictionary<string, int> KillsByTag { get; } = new(StringComparer.Ordinal);

    public int Kills(string tag) => KillsByTag.GetValueOrDefault(tag);

    public RunStats Clone()
    {
        var copy = new RunStats
        {
            HealReceived = HealReceived,
            AttacksDeclared = AttacksDeclared,
            FriendlyDestroyed = FriendlyDestroyed,
            FatigueTicks = FatigueTicks
        };
        foreach (var (key, value) in KillsByTag)
        {
            copy.KillsByTag[key] = value;
        }

        return copy;
    }
}

public enum PackConditionKind
{
    HealReceivedAtLeast,
    AttacksAtLeast,
    FriendlyDestroyedAtLeast,
    FatigueAtLeast,
    DeckTagAtLeast,
    KillTagAtLeast
}

public sealed record PackCondition(PackConditionKind Kind, int Amount = 0, string? Tag = null);

public sealed record PackDefinition(
    string Id,
    string Name,
    bool Base,
    ImmutableArray<string> CoreActions,
    ImmutableArray<string> Cards,
    ImmutableArray<PackCondition> AllOf);

public static class Packs
{
    public static bool IsUnlocked(GameState state, int playerIndex, PackDefinition pack)
    {
        if (pack.Base)
        {
            return true;
        }

        return pack.AllOf.All(c => Met(state, playerIndex, c));
    }

    public static IReadOnlyList<PackDefinition> Unlocked(GameState state, int playerIndex, IEnumerable<PackDefinition> catalog) =>
        catalog.Where(p => IsUnlocked(state, playerIndex, p)).ToList();

    public static int CountTag(GameState state, int playerIndex, string tag)
    {
        var player = state.Players[playerIndex];
        return player.Deck.Concat(player.Hand).Concat(player.Graveyard)
            .Concat(state.Board.Where(e => e.ControllerIndex == playerIndex))
            .Count(e => e.Definition.HasTag(tag));
    }

    private static bool Met(GameState state, int playerIndex, PackCondition condition)
    {
        var run = state.Players[playerIndex].Run;
        return condition.Kind switch
        {
            PackConditionKind.HealReceivedAtLeast => run.HealReceived >= condition.Amount,
            PackConditionKind.AttacksAtLeast => run.AttacksDeclared >= condition.Amount,
            PackConditionKind.FriendlyDestroyedAtLeast => run.FriendlyDestroyed >= condition.Amount,
            PackConditionKind.FatigueAtLeast => run.FatigueTicks >= condition.Amount,
            PackConditionKind.DeckTagAtLeast => CountTag(state, playerIndex, condition.Tag ?? "") >= condition.Amount,
            PackConditionKind.KillTagAtLeast => run.Kills(condition.Tag ?? "") >= condition.Amount,
            _ => false
        };
    }
}