using UnityEngine;

namespace SmartAction.Patch;

/// <summary>
/// Verification instrumentation for the movement patches.
///
/// These postfixes run on every movement query for every entity in the raid, so nothing here
/// may allocate or log on the hot path. Counters are plain increments; the periodic flush is
/// gated behind a call counter so Time.unscaledTime is read once per ~4096 calls rather than
/// per call. Disable via the "Diagnostics" config entry once the design is trusted.
/// </summary>
internal static class Diagnostics
{
    internal static bool Enabled;

    private const int TickGate = 4096;
    private const float FlushIntervalSeconds = 30f;

    // Guard outcomes — the multiplayer-safety evidence.
    internal static long LocalCalls;
    internal static long NonLocalCalls;
    internal static long NullPlayerCalls;

    // Patch outcomes.
    internal static long WalkLifted;
    internal static long WalkHeldByObstacle;

    private static int _tick;
    private static float _nextFlush;

    // One-shot announcements, so the first occurrence of each interesting event is visible
    // immediately instead of waiting up to 30s for a flush.
    private static bool _saidWalkLift;
    private static bool _saidWalkObstacle;
    private static bool _saidNullPlayer;

    internal static void OnceWalkLifted()
    {
        if (_saidWalkLift) return;
        _saidWalkLift = true;
        Plugin.Log.LogInfo("[diag] CanWalk LIFTED (HealingLegs) — first occurrence");
    }

    internal static void OnceWalkHeldByObstacle()
    {
        if (_saidWalkObstacle) return;
        _saidWalkObstacle = true;
        Plugin.Log.LogInfo("[diag] CanWalk HELD by obstacle check — first occurrence "
                           + "(this is the CanMove() guard upstream's transpiler dropped)");
    }

    internal static void OnceNullPlayer()
    {
        if (_saidNullPlayer) return;
        _saidNullPlayer = true;
        Plugin.Log.LogWarning("[diag] MovementContext._player was NULL — guard handled it without throwing. "
                              + "This is the predicted NRE case; it is being absorbed correctly.");
    }

    /// <summary>Called from the guard. Cheap on all but 1-in-4096 calls.</summary>
    internal static void Tick()
    {
        if (++_tick < TickGate) return;
        _tick = 0;

        var now = Time.unscaledTime;
        if (now < _nextFlush) return;
        _nextFlush = now + FlushIntervalSeconds;

        Flush();
    }

    internal static void Flush()
    {
        Plugin.Log.LogInfo(
            $"[diag] guard: local={LocalCalls} nonLocal={NonLocalCalls} nullPlayer={NullPlayerCalls} | "
            + $"walk: lifted={WalkLifted} heldByObstacle={WalkHeldByObstacle}");

        if (NonLocalCalls == 0)
        {
            Plugin.Log.LogWarning("[diag] nonLocal=0 — no bot/remote MovementContext has been seen yet. "
                                  + "Either you are not in a raid with AI, or the postfixes are not firing "
                                  + "for other entities. The guard is unproven until this is non-zero.");
        }
    }
}