using System.Collections.Immutable;
using CardGame.Core;

var cardsDir = ResolveContent("cards");
var packsDir = ResolveContent("packs");
var catalog = CardJson.LoadCatalog(cardsDir);
var packs = PackJson.LoadDirectory(packsDir);
var seed = ParseSeed(args);
var auto = args.Any(a => a is "--auto" or "-a");
var runMode = args.Any(a => a is "--run" or "-r");
var fights = ParseFights(args);

if (runMode)
{
    RunFull(seed, auto, fights, catalog, packs);
}
else
{
    RunSingleBattle(seed, auto, catalog);
}

static void RunSingleBattle(ulong seed, bool auto, IReadOnlyDictionary<string, CardDefinition> catalog)
{
    var state = MatchSetup.CreateStartingBattle(seed, catalog, shuffle: true);
    Console.WriteLine($"Card Roguelike CLI combat  seed={seed}  auto={auto}");
    Console.WriteLine("Commands: number = choose action, a = auto-step, q = quit");
    _ = PlayBattle(state, auto, playerIsHuman: !auto);
}

static void RunFull(
    ulong seed,
    bool auto,
    int fightCount,
    IReadOnlyDictionary<string, CardDefinition> catalog,
    IReadOnlyList<PackDefinition> packs)
{
    var run = RunProgress.Start(seed, catalog);
    Console.WriteLine($"Card Roguelike CLI full run  seed={seed}  fights={fightCount}  auto={auto}");
    Console.WriteLine("Between fights: reward draft → Holder → simple upgrade → next fight.");
    Console.WriteLine($"Starting owned={run.Owned.Count}");

    for (var i = 0; i < fightCount; i++)
    {
        run.FightIndex = i;
        Console.WriteLine();
        Console.WriteLine($"===== Fight {i + 1}/{fightCount}  owned={run.Owned.Count}  heal={run.Stats.HealReceived} atk={run.Stats.AttacksDeclared} =====");
        var state = MatchSetup.CreateFromRun(run, catalog, shuffle: true);
        state = PlayBattle(state, auto, playerIsHuman: !auto);
        if (!state.IsOver)
        {
            Console.WriteLine("Battle stopped early; run aborted.");
            return;
        }

        run.SyncStatsFrom(state, 0);
        if (state.WinnerIndex != 0)
        {
            Console.WriteLine($"Defeat on fight {i + 1}. Wins={run.Wins}");
            return;
        }

        run.Wins++;
        Console.WriteLine($"Victory. Wins={run.Wins}");
        if (i + 1 >= fightCount)
        {
            break;
        }

        OfferReward(run, state, catalog, packs, auto);
        OfferUpgrade(run, catalog, auto);
    }

    Console.WriteLine();
    Console.WriteLine($"Run complete. Wins={run.Wins}/{fightCount} owned={run.Owned.Count}");
}

static GameState PlayBattle(GameState state, bool forceAuto, bool playerIsHuman)
{
    PrintState(state);
    var steps = 0;
    const int maxActions = 200;
    while (!state.IsOver && steps < maxActions)
    {
        var legal = RulesEngine.GetLegalActions(state);
        if (legal.IsDefaultOrEmpty)
        {
            break;
        }

        GameAction action;
        var autoNow = forceAuto || state.ActivePlayerIndex == 1 || !playerIsHuman;
        if (autoNow)
        {
            action = TurnBeamSearch.ChooseWithTrace(state, legal).Action;
            Console.WriteLine($">> P{state.ActivePlayerIndex} {Describe(state, action)}");
        }
        else
        {
            PrintActions(state, legal);
            Console.Write("P0> ");
            var line = Console.ReadLine();
            if (line is null || line.Equals("q", StringComparison.OrdinalIgnoreCase))
            {
                break;
            }

            if (line.Equals("a", StringComparison.OrdinalIgnoreCase))
            {
                action = TurnBeamSearch.ChooseWithTrace(state, legal).Action;
                Console.WriteLine($">> P0 {Describe(state, action)}");
            }
            else if (int.TryParse(line, out var index) && index >= 1 && index <= legal.Length)
            {
                action = legal[index - 1];
            }
            else
            {
                Console.WriteLine("Invalid input.");
                continue;
            }
        }

        state = RulesEngine.Execute(state, action);
        steps++;
        PrintState(state);
    }

    if (state.IsOver)
    {
        Console.WriteLine($"Winner=P{state.WinnerIndex} turns={state.TurnNumber} P0={state.Players[0].Life} P1={state.Players[1].Life}");
    }
    else
    {
        Console.WriteLine($"Stopped turns={state.TurnNumber} P0={state.Players[0].Life} P1={state.Players[1].Life}");
    }

    return state;
}

static void OfferReward(
    RunProgress run,
    GameState battle,
    IReadOnlyDictionary<string, CardDefinition> catalog,
    IReadOnlyList<PackDefinition> packs,
    bool auto)
{
    var pool = RunRewards.ActivePool(battle, 0, packs);
    var offer = RunRewards.RollOffer(run.Rng, pool, RunProgress.RewardChoices);
    Console.WriteLine();
    Console.WriteLine($"Reward pool size={pool.Count} unlocked packs={Packs.Unlocked(battle, 0, packs).Count}");
    if (offer.Count == 0)
    {
        Console.WriteLine("No reward cards available.");
        return;
    }

    for (var i = 0; i < offer.Count; i++)
    {
        var id = offer[i];
        var name = catalog.TryGetValue(id, out var def) ? def.Name : id;
        Console.WriteLine($"  {i + 1}. {name} ({id})");
    }

    Console.WriteLine("  0. Skip reward");

    var pick = auto ? 1 : ReadIndex("Reward>", 0, offer.Count);
    if (pick <= 0)
    {
        Console.WriteLine("Skipped reward.");
        return;
    }

    var cardId = offer[pick - 1];
    if (!catalog.TryGetValue(cardId, out var chosen))
    {
        Console.WriteLine($"Missing card '{cardId}'.");
        return;
    }

    if (run.Owned.Count >= RunProgress.MaxOwned)
    {
        Console.WriteLine($"Owned at max ({RunProgress.MaxOwned}). Choose a card to remove:");
        PrintOwned(run, catalog);
        var remove = auto ? 0 : ReadIndex("Remove>", 0, run.Owned.Count - 1);
        if (auto)
        {
            remove = run.Owned.Count - 1;
        }

        RunRewards.RemoveAt(run, remove);
        Console.WriteLine($"Removed index {remove}.");
    }

    var holders = RunRewards.HolderChoices(cardId);
    string holder;
    if (holders.Count == 1)
    {
        holder = holders[0];
    }
    else if (auto)
    {
        holder = holders[0];
    }
    else
    {
        Console.WriteLine("Assign Holder:");
        for (var i = 0; i < holders.Count; i++)
        {
            Console.WriteLine($"  {i + 1}. {holders[i]}");
        }

        var h = ReadIndex("Holder>", 1, holders.Count);
        holder = holders[h - 1];
    }

    RunRewards.AddCard(run, chosen, holder);
    Console.WriteLine($"Added {chosen.Name} holder={holder.Split('.').Last()} owned={run.Owned.Count}");
}

static void OfferUpgrade(RunProgress run, IReadOnlyDictionary<string, CardDefinition> catalog, bool auto)
{
    Console.WriteLine();
    Console.WriteLine("Upgrade one owned card (or skip):");
    PrintOwned(run, catalog);
    Console.WriteLine("  -1. Skip upgrade");

    int cardIndex;
    if (auto)
    {
        cardIndex = -1;
        for (var i = 0; i < run.Owned.Count; i++)
        {
            var o = run.Owned[i];
            if (!catalog.TryGetValue(o.DefinitionId, out var d))
            {
                continue;
            }

            if (RunRewards.LegalUpgrades(o, d).Any(u => u != SimpleUpgrade.Skip))
            {
                cardIndex = i;
                break;
            }
        }
    }
    else
    {
        cardIndex = ReadIndex("Card# (-1 skip)>", -1, run.Owned.Count - 1);
    }

    if (cardIndex < 0)
    {
        Console.WriteLine(auto ? "Auto: skipped upgrade." : "Skipped upgrade.");
        return;
    }

    var card = run.Owned[cardIndex];
    if (!catalog.TryGetValue(card.DefinitionId, out var def))
    {
        Console.WriteLine("Missing definition.");
        return;
    }

    var legal = RunRewards.LegalUpgrades(card, def);
    for (var i = 0; i < legal.Count; i++)
    {
        Console.WriteLine($"  {i + 1}. {legal[i]}");
    }

    int upIndex;
    if (auto)
    {
        upIndex = 0;
        for (var i = 0; i < legal.Count; i++)
        {
            if (legal[i] != SimpleUpgrade.Skip)
            {
                upIndex = i;
                break;
            }
        }
    }
    else
    {
        upIndex = ReadIndex("Upgrade>", 1, legal.Count) - 1;
    }

    var upgrade = legal[upIndex];
    RunRewards.ApplyUpgrade(card, def, upgrade);
    Console.WriteLine($"Applied {upgrade} → {DescribeOwned(card, def)}");
}

static void PrintOwned(RunProgress run, IReadOnlyDictionary<string, CardDefinition> catalog)
{
    for (var i = 0; i < run.Owned.Count; i++)
    {
        var o = run.Owned[i];
        catalog.TryGetValue(o.DefinitionId, out var def);
        Console.WriteLine($"  {i}. {DescribeOwned(o, def)}");
    }
}

static string DescribeOwned(OwnedCard o, CardDefinition? def)
{
    var name = def?.Name ?? o.DefinitionId;
    var body = def?.Type == CardType.Creature || def?.Type == CardType.FieldCard
        ? $" {o.Attack}/{o.Health}"
        : "";
    return $"{name}({o.Cost}){body}[{o.HolderId.Split('.').Last()}]";
}

static int ReadIndex(string prompt, int min, int max)
{
    while (true)
    {
        Console.Write(prompt + " ");
        var line = Console.ReadLine();
        if (line is not null && int.TryParse(line, out var n) && n >= min && n <= max)
        {
            return n;
        }

        Console.WriteLine($"Enter {min}..{max}");
    }
}

static string ResolveContent(string folder)
{
    var path = Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "content", folder));
    if (!Directory.Exists(path))
    {
        path = Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "..", "..", "..", "..", "..", "content", folder));
    }

    return path;
}

static ulong ParseSeed(string[] args)
{
    for (var i = 0; i < args.Length - 1; i++)
    {
        if (args[i] is "--seed" or "-s" && ulong.TryParse(args[i + 1], out var seed))
        {
            return seed;
        }
    }

    return 20261006UL;
}

static int ParseFights(string[] args)
{
    for (var i = 0; i < args.Length - 1; i++)
    {
        if (args[i] is "--fights" or "-f" && int.TryParse(args[i + 1], out var n) && n > 0)
        {
            return n;
        }
    }

    return RunProgress.DefaultFightCount;
}

static void PrintState(GameState state)
{
    Console.WriteLine();
    Console.WriteLine(
        $"--- turn {state.TurnNumber} active=P{state.ActivePlayerIndex}  P0={state.Players[0].Life}hp/{state.Players[0].Energy}e  P1={state.Players[1].Life}hp/{state.Players[1].Energy}e ---");
    PrintZone("P0 hand", state.Players[0].Hand, state);
    PrintZone("P1 hand", state.Players[1].Hand, state);
    Console.WriteLine("Board:");
    foreach (var e in state.Board)
    {
        Console.WriteLine("  " + DescribeEntity(state, e));
    }

    Console.WriteLine($"P0 deck={state.Players[0].Deck.Count} gy={state.Players[0].Graveyard.Count} | P1 deck={state.Players[1].Deck.Count} gy={state.Players[1].Graveyard.Count}");
}

static void PrintZone(string title, List<Entity> cards, GameState state)
{
    Console.WriteLine(title + ": " + string.Join(", ", cards.Select(c => ShortCard(state, c))));
}

static void PrintActions(GameState state, ImmutableArray<GameAction> legal)
{
    Console.WriteLine("Legal:");
    for (var i = 0; i < legal.Length; i++)
    {
        Console.WriteLine($"  {i + 1}. {Describe(state, legal[i])}");
    }
}

static string Describe(GameState state, GameAction action) =>
    action switch
    {
        PlayCardAction play =>
            $"Play {ShortCard(state, state.Find(play.CardId)!)}"
            + (play.Target is null ? "" : $" -> {DescribeTarget(state, play.Target)}")
            + (play.Target2 is null ? "" : $" & {DescribeTarget(state, play.Target2)}"),
        AttackAction attack =>
            $"Attack {ShortCard(state, state.Find(attack.AttackerId)!)} -> {DescribeTarget(state, attack.Target)}",
        ActivateAction act =>
            $"Activate {ShortCard(state, state.Find(act.SourceId)!)}"
            + (act.Target is null ? "" : $" -> {DescribeTarget(state, act.Target)}"),
        EndTurnAction => "EndTurn",
        _ => action.ToString() ?? "action"
    };

static string DescribeTarget(GameState state, TargetRef target) =>
    target switch
    {
        PlayerTarget p => $"P{p.PlayerIndex}",
        EntityTarget e => ShortCard(state, state.Find(e.Id)!),
        _ => "?"
    };

static string ShortCard(GameState state, Entity e)
{
    var atk = e.Definition.Type == CardType.Creature ? state.EffectiveAttack(e) : e.Attack;
    return e.Definition.Type switch
    {
        CardType.Creature => $"{e.Id}:{e.Definition.Name}({e.Cost}) {atk}/{e.Health}[{e.HolderId.Split('.').Last()}]",
        CardType.FieldCard => $"{e.Id}:{e.Definition.Name} CD{e.Countdown}{(e.IsSystem ? "*" : "")}",
        _ => $"{e.Id}:{e.Definition.Name}({e.Cost})"
    };
}

static string DescribeEntity(GameState state, Entity e) =>
    $"P{e.ControllerIndex} {ShortCard(state, e)} atkLeft={e.AttacksRemaining} actLeft={e.ActivatesRemaining}";