using System.Collections.Generic;
using NUnit.Framework;
using SVSim.BattleNode.Protocol;

namespace SVSim.UnitTests.BattleNode.Integration;

/// <summary>
/// Headless-Conductor milestone tests (M-HC-*). The oracle is a node-native battle:
/// a FIXED master seed + FIXED decks drive the engine's receive path headless, and we
/// assert on engine board-state. By construction the node assigns idx = position in the
/// shuffled order, so the engine's headless draw reproduces the node's draw order.
///
/// Task 1 (M-HC-0a) exit criterion: the engine seats headless (IsReady) in the
/// SVSim.UnitTests process.
///
/// Task 2 (M-HC-0b) exit criterion: a node-generated <c>Deal</c> seats the 3-card hand and a
/// vanilla hand-card <c>Play</c> resolves on ENGINE board state (card left hand, PP dropped
/// by cost, board reflects the play) — driven through the receive CONDUCTOR, not the
/// direct ActionProcessor path the M2-M12 oracles use.
/// </summary>
[TestFixture]
[NonParallelizable]
public class HeadlessConductorTests
{
    [Test]
    public void Harness_seats_engine_headless_and_is_ready()
    {
        using var harness = NodeNativeBattleHarness.Create();

        Assert.That(harness.IsReady, Is.True,
            "Engine must seat headless: EngineGlobalInit ran + both decks seeded. " +
            "If false, the most likely cause is a missing cards.json content link in " +
            "SVSim.UnitTests.csproj (EngineGlobalInit reads AppContext.BaseDirectory/Data/cards.json).");

        // Non-vacuous: a seated engine has live board state for BOTH seats. Reading these off a
        // not-really-set-up engine would throw (Seat() guards on _mgr). Leader life is the headless
        // default (20) before any frame is ingested.
        Assert.That(harness.LeaderLife(playerSeat: true), Is.EqualTo(20), "seat A leader life");
        Assert.That(harness.LeaderLife(playerSeat: false), Is.EqualTo(20), "seat B leader life");
    }

    // The node's BuildDeal opening hand: pos->idx (0,1),(1,2),(2,3). hand == deck idx 1,2,3, i.e.
    // the top 3 of the node-native shuffled deck. Both seats deal the same idx triple.
    private static Dictionary<string, object?> DealBody() => new()
    {
        ["self"] = new List<object?>
        {
            new Dictionary<string, object?> { ["pos"] = 0, ["idx"] = 1 },
            new Dictionary<string, object?> { ["pos"] = 1, ["idx"] = 2 },
            new Dictionary<string, object?> { ["pos"] = 2, ["idx"] = 3 },
        },
        ["oppo"] = new List<object?>
        {
            new Dictionary<string, object?> { ["pos"] = 0, ["idx"] = 1 },
            new Dictionary<string, object?> { ["pos"] = 1, ["idx"] = 2 },
            new Dictionary<string, object?> { ["pos"] = 2, ["idx"] = 3 },
        },
    };

    // A minimal vanilla hand-card play: type 30 == PLAY_HAND; playIdx is the played card's index.
    // No targetList/orderList — a vanilla follower auto-resolves with no selection.
    private static Dictionary<string, object?> PlayBody(int playIdx) => new()
    {
        ["playIdx"] = playIdx,
        ["type"] = 30,
    };

    [Test]
    public void Deal_seats_three_card_hand_headless()
    {
        using var harness = NodeNativeBattleHarness.Create();

        var result = harness.Push(NetworkBattleUri.Deal, DealBody(), isPlayerSeat: true);

        Assert.That(result.Accepted, Is.True, $"Deal rejected: {result.RejectReason}");
        Assert.That(harness.HandCount(playerSeat: true), Is.EqualTo(3),
            "Deal must seat the 3-card opening hand on the player seat.");
    }

    [Test]
    public void Vanilla_play_resolves_on_engine_state_headless()
    {
        // Deck idx 1/2/3 are the top three of the shuffled deck; arrange idx-1 to be a known vanilla
        // follower so the Play assertion is decisive. Put the vanilla follower first; the rest of the
        // default deck (spellboost + vanillas) follows.
        var deck = new List<long> { NodeNativeBattleHarness.VanillaFollowerId };
        deck.AddRange(NodeNativeBattleHarness.DefaultDeck());
        deck = deck.GetRange(0, 30);

        using var harness = NodeNativeBattleHarness.Create(seatADeck: deck);

        var deal = harness.Push(NetworkBattleUri.Deal, DealBody(), isPlayerSeat: true);
        Assert.That(deal.Accepted, Is.True, $"Deal rejected: {deal.RejectReason}");
        Assert.That(harness.HandCount(playerSeat: true), Is.EqualTo(3), "post-Deal hand");

        var ppBefore = harness.Pp(playerSeat: true);
        var handBefore = harness.HandCount(playerSeat: true);
        var boardBefore = harness.BoardCount(playerSeat: true);

        // The played card is at hand index 1 (deck idx 1 -> the first dealt card; engine card Index
        // mirrors deck position+1). The shuffle determines which deck idx-1 maps to; we only need a
        // vanilla follower in the opening hand. Use the first dealt idx.
        var playIdx = harness.PlayerHandCardIndex(0);
        var play = harness.Push(NetworkBattleUri.PlayActions, PlayBody(playIdx), isPlayerSeat: true);

        Assert.That(play.Accepted, Is.True, $"Play rejected: {play.RejectReason}");
        Assert.That(harness.HandCount(playerSeat: true), Is.EqualTo(handBefore - 1),
            "the played card must leave the hand");
        Assert.That(harness.BoardCount(playerSeat: true), Is.EqualTo(boardBefore + 1),
            "a follower play must add one to the board");
        Assert.That(harness.Pp(playerSeat: true), Is.LessThan(ppBefore),
            "PP must drop by the played card's cost");
    }
}