using Wizard.Battle.Phase;
using Wizard.Battle.Recovery;
using Wizard.Battle.Replay;
using Wizard.Battle.Resource;
using Wizard.Battle.View.Vfx;
using Wizard.BattleMgr;

namespace SVSim.BattleEngine.Tests
{
    // Initializes the global engine state a headless battle assumes exists. In the real client this
    // is populated from /load/index at login; here we author the minimum the resolution path reads.
    public static class HeadlessEngineEnv
    {
        // Simplest zero-skill vanilla follower in cards.json: neutral (clan 0), cost 1, 1/2, no skill.
        public const int FollowerId = 100011010;

        // M3 next-hardest deterministic card: a fixed-damage spell. 900124030 is an ELF (clan 1, matches
        // PlayerClassId) cost-3 spell whose sole skill is `when_play` `damage=3` to `card_type=class`
        // (the enemy leader) — auto-targeted (no select_count), no RNG. Deterministic burn to the face.
        public const int SpellId = 900124030;

        private static bool _done;

        public static void EnsureInitialized()
        {
            if (_done) return;
            // Wizard.Data.Load: static /load/index snapshot. The ctor's CreateBackgroundId reads
            // Data.Load.data._userTutorial (LoadDetail self-inits _userTutorial). Suppress VFX too.
            Wizard.Data.Load = new Load { data = new LoadDetail() };
            // CardParameter(CardCSVData) reads Data.Crossover.RestrictedCard for deck-limit calc;
            // an empty Crossover returns the default count (no restriction). Private setter -> reflect.
            typeof(Wizard.Data).GetProperty("Crossover",
                System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.Public)
                .SetValue(null, new Wizard.Crossover());
            BattleManagerBase.IsForecast = true;
            // CardMaster must be non-null before construction (the leader/class card looks up id 0).
            // Load the M2 vanilla follower + the M3 fixed-damage spell so each oracle can create +
            // look up its real stats.
            HeadlessCardMaster.Load(FollowerId, SpellId);
            // Master reference data (class-character list) for leader/class card resolution.
            HeadlessMasterData.Install();
            // Player/enemy leaders (chara ids must map to a ClassCharacterMasterData in Master).
            // Set the backing fields directly: the public SetPlayerCharaId() also pulls MyRotation/
            // AvatarBattle info (more null statics) which the resolution path doesn't need (the
            // TryGet* accessors are null-tolerant).
            var dm = GameMgr.GetIns().GetDataMgr();
            SetField(dm, "_playerCharaId", HeadlessMasterData.PlayerCharaId);
            SetField(dm, "_enemyCharaId", HeadlessMasterData.EnemyCharaId);
            _done = true;
        }

        // Seed each leader's starting life on a freshly-constructed mgr. The engine does this in
        // BattleManagerBase.SetupInitialGameState -> InitializeClassLife (InitBaseMaxLife per leader),
        // but the full SetupInitialGameState also cascades into rotation/avatar/turn-panel UI init
        // that is irrelevant (and hostile) to a headless resolution test, so apply just the
        // InitializeClassLife subset. Without this a leader's BaseMaxLife defaults to 0 — which reads
        // as already-dead/game-over and silently blocks any card play (the M2 follower oracle never
        // noticed because it only asserted leader life *unchanged*, and 0 == 0).
        public const int DefaultLeaderLife = 20;

        public static void InitLeaderLife(BattleManagerBase mgr, int life = DefaultLeaderLife)
        {
            ((ClassBattleCardBase)mgr.BattlePlayer.Class).InitBaseMaxLife(life);
            ((ClassBattleCardBase)mgr.BattleEnemy.Class).InitBaseMaxLife(life);
        }

        private static void SetField(object obj, string name, object value)
        {
            var f = obj.GetType().GetField(name,
                System.Reflection.BindingFlags.Instance |
                System.Reflection.BindingFlags.NonPublic |
                System.Reflection.BindingFlags.Public);
            if (f == null) throw new System.InvalidOperationException(
                $"{obj.GetType().Name} has no field '{name}'");
            f.SetValue(obj, value);
        }
    }

    // Test-side replica of the engine's own StandardBattleMgrContentsCreator (the practice/solo
    // init path: GameMgr.cs:244 `new SingleBattleMgr(new StandardBattleMgrContentsCreator(null, null))`).
    // Authored here (not copied) so we control the seed deterministically; uses the real engine
    // managers verbatim. The real StandardBattleMgrContentsCreator + SingleBattlePhaseCreator were
    // cut from the M1 copy set (entry-point constructors), so we reproduce them minimally.
    public sealed class HeadlessContentsCreator : IBattleMgrContentsCreator
    {
        public int RandomSeed => 12345; // fixed; vanilla follower has no RNG so value is irrelevant

        // No-op managers (vs the practice path's file-backed SingleBattleRecoveryRecordManager):
        // the ctor's FirstRecoverySetting/FirstReplaySetting dereference these, and recovery/replay
        // recording is irrelevant to the M2 oracle, so use the engine's own null implementations.
        public IRecoveryManager RecoveryManager { get; } = new NullRecoveryManager();
        public IRecoveryRecordManager RecoveryRecordManager { get; } = new NullRecoveryRecordManager();
        public IReplayRecordManager ReplayRecordManager { get; } = new NullReplayRecordManager();

        public IBattleResourceMgr CreateResourceMgr() => new BattleResourceMgr();
        public VfxMgr CreateVfxMgr() => new VfxMgr();
        public IPhaseCreator CreatePhaseCreator(BattleManagerBase battleMgr) =>
            new HeadlessPhaseCreator(battleMgr);
    }

    // Equivalent of the engine's SingleBattlePhaseCreator: inherits PhaseCreatorBase wholesale.
    public sealed class HeadlessPhaseCreator : PhaseCreatorBase
    {
        public HeadlessPhaseCreator(BattleManagerBase battleMgr) : base(battleMgr) { }
    }
}