using Unity.Netcode;
using UnityEngine;

/// <summary>
/// Per-avatar network glue on the spawned player. The local owner binds the scene singletons
/// (GameModeManager, cameras) to itself via <see cref="GameModeManager.BindLocalPlayer"/>; remote
/// avatars stop simulating so their transform is driven purely by the NetworkTransform replication.
/// Position-sync milestone: remote avatars still show their mesh/idle pose, just no local control.
/// </summary>
[RequireComponent(typeof(PlayerCharacterController))]
[DisallowMultipleComponent]
public class NetworkPlayerSetup : NetworkBehaviour
{
    [Header("Spawn placement")]
    [Tooltip("All avatars spawn from the same prefab position, so without an offset they stack and shove " +
             "each other on connect. The owner places itself on a ring keyed by its client id (owner-" +
             "authoritative NetworkTransform replicates it). Id 0 (host) stays at the origin; later joiners " +
             "fan out. Spacing between ring slots, in world units. 0 disables placement.")]
    [SerializeField] private float spawnRingRadius = 2.5f;

    [Tooltip("Slots per ring before the radius steps outward, so spacing stays roughly constant as more join.")]
    [SerializeField] private int spawnRingSlots = 8;

    [Tooltip("Role-specific spawn areas, tried FIRST by an owner based on its Role (Hunter uses " +
             "hunterSpawnAreaTag, Hider uses hiderSpawnAreaTag). If a loaded scene holds a GameObject with the " +
             "matching tag, the owner spawns at a random point inside its collider. If this avatar's role area " +
             "is absent it falls back to spawnAreaTag, then to the client-id ring. Empty disables the role lookup.")]
    [SerializeField] private string hunterSpawnAreaTag = "HunterSpawnArea";
    [SerializeField] private string hiderSpawnAreaTag = "HiderSpawnArea";

    [Tooltip("Shared fallback spawn area, used when this avatar's role-specific area (hunter/hiderSpawnAreaTag) " +
             "is not present in any loaded scene. If a loaded scene holds a GameObject with this tag, owners " +
             "spawn at a RANDOM point inside its collider instead of the client-id ring (random scatter already " +
             "prevents the stack-up the ring guards against). Empty disables the lookup. The area collider " +
             "should be convex (a convex MeshCollider or a primitive) so the point is constrained to its actual " +
             "shape, not just its bounding box; a non-convex collider falls back to the bounding box.")]
    [SerializeField] private string spawnAreaTag = "SpawnArea";

    [Tooltip("Metres the spawn is lifted above the spawn area's floor (collider bounds bottom) so the " +
             "CharacterController doesn't start embedded; gravity then settles it. Mirrors the lobby/match " +
             "spawn-centre lift.")]
    [SerializeField] private float spawnAreaGroundLift = 1f;

    // Tries to land a random sample inside the convex footprint before falling back to the bounds centre.
    // The footprint is typically a chunk of its AABB, so a handful of tries hits the inside with near-certainty.
    private const int SpawnAreaSampleAttempts = 24;

    [Header("Role")]
    [Tooltip("Which side this avatar plays. Baked per prefab variant (Hider on the base/Hider prefab, " +
             "Hunter on the Hunter prefab); GameModeManager reads it on spawn to build this role's mode set.")]
    [SerializeField] private PlayerRole role = PlayerRole.Hider;

    [Tooltip("False = lobby/neutral avatar (the base Player prefab) gets the FULL mode set; true = match " +
             "avatar (Hunter/Hider variant) gets only its role's modes. Baked per prefab variant, so the " +
             "mode set follows the spawned avatar with no replicated-phase timing race.")]
    [SerializeField] private bool scopedModes = false;

    /// <summary>The side this avatar plays (Hunter/Hider), baked into the prefab variant.</summary>
    public PlayerRole Role => role;

    /// <summary>True on the match role variants (scope the mode set to <see cref="Role"/>); false on the
    /// neutral lobby Player prefab (full mode set). Baked per prefab variant.</summary>
    public bool ScopedModes => scopedModes;

    // Server-authoritative "this hider has been shot/found". Server-write (a hunter's hit is validated on
    // the server, not by the hider's owner); read by everyone. When it flips true the body is hidden on
    // every client and the owning client drops into free-cam-only spectating. Stays false on hunters/lobby.
    private readonly NetworkVariable<bool> _isFound =
        new NetworkVariable<bool>(false, NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Server);

    /// <summary>True once a hunter has found this hider (replicated). Read by the shoot raycast to skip a
    /// target that is already out of play.</summary>
    public bool IsFound => _isFound.Value;

    private Renderer[] _bodyRenderers; // skinned body mesh(es), toggled by the per-client visibility pass
    private bool _visibilityApplied;
    private bool _lastVisible = true;

    public override void OnNetworkSpawn()
    {
        _bodyRenderers = GetComponentsInChildren<SkinnedMeshRenderer>(true);
        _isFound.OnValueChanged += OnFoundChanged;
        if (_isFound.Value) ApplyFound(); // defensive: an avatar is never normally spawned already-found

        var controller = GetComponent<PlayerCharacterController>();

        if (IsOwner)
        {
            PlaceAtSpawn();

            var manager = FindFirstObjectByType<GameModeManager>(FindObjectsInactive.Include);
            if (manager)
                manager.BindLocalPlayer(controller);
            return;
        }

        // Remote avatar: NetworkTransform owns the transform here, so disable the local
        // simulation (input/movement) and the CharacterController's own depenetration.
        if (controller) controller.enabled = false;
        var cc = GetComponent<CharacterController>();
        if (cc) cc.enabled = false;

        // Owner cleanup: the concealment meter is a per-frame skinned-mesh bake + voxelization +
        // physics overlap whose result only feeds the LOCAL player (HUD / gameplay). A remote avatar's
        // concealment is computed on its own owner's machine, so running it here is pure wasted CPU.
        var concealment = GetComponentInChildren<ConcealmentMeter>(true);
        if (concealment) concealment.enabled = false;

        // NOTE: SkinnedColliderBaker deliberately stays ENABLED on remotes. MeshPainter's stamp replay
        // (ApplyNetworkStamp -> DrawBrushGpu) rasterizes the baker's live, per-frame BakedMesh to map a
        // 3D brush placement into UV space; freezing the bake would mis-map replicated paint onto any
        // non-rest pose. Its bake is the necessary cost of correct remote paint, not wasted work.

        // The rig must keep evaluating even while this body is HIDDEN on the local client. During the hide
        // phase a hider's body is hidden on hunter clients (UpdateVisibility sets renderer.enabled = false),
        // and a remote can also sit off-screen. The avatar's Animator is authored as CullUpdateTransforms,
        // which STOPS writing the bone transforms whenever its renderer isn't visible. PlayerPoseController
        // drives the rig through a PlayableGraph on this Animator and resets un-keyed bones to rest every
        // frame, so a culled Animator leaves the rig frozen at the rest/T-pose. SkinnedColliderBaker then
        // bakes that wrong pose, and any paint stamp replicated during the hidden window lands on the wrong
        // body part - a desync that persists once the body is shown again. Forcing AlwaysAnimate keeps the
        // pose (and thus the baked mesh paint replay rasterizes) correct regardless of visibility. Remote
        // replicas only: an owner is never hidden from its own camera.
        foreach (var anim in GetComponentsInChildren<Animator>(true))
            anim.cullingMode = AnimatorCullingMode.AlwaysAnimate;
    }

    public override void OnNetworkDespawn()
    {
        _isFound.OnValueChanged -= OnFoundChanged;
    }

    /// <summary>Server-only: flag this hider as found by a hunter. Replicates to every client (the body is
    /// hidden for all; the owner drops into free-cam-only spectating). Idempotent.</summary>
    public void ServerMarkFound()
    {
        if (!IsServer || _isFound.Value) return;
        _isFound.Value = true; // OnValueChanged -> ApplyFound on every machine, including this server/host
    }

    private void OnFoundChanged(bool previous, bool current)
    {
        if (current) ApplyFound();
    }

    // A found hider leaves play: the per-client visibility pass hides its body, its baked collider is dropped
    // (so the invisible body neither blocks nor can be hit again), and on the owning client it switches to
    // free-cam-only so the player can still watch the rest of the match. Idempotent.
    private void ApplyFound()
    {
        var baker = GetComponentInChildren<SkinnedColliderBaker>(true);
        if (baker) baker.enabled = false;
        var meshCol = GetComponentInChildren<MeshCollider>(true);
        if (meshCol) meshCol.enabled = false;

        if (IsOwner)
        {
            var controller = GetComponent<PlayerCharacterController>();
            if (controller) controller.enabled = false;
            var cc = GetComponent<CharacterController>();
            if (cc) cc.enabled = false;

            var manager = FindFirstObjectByType<GameModeManager>(FindObjectsInactive.Include);
            if (manager) manager.BindSpectator();
        }
    }

    private void Update() => UpdateVisibility();

    // Per-client visibility: each machine decides whether to render THIS avatar's body from the LOCAL
    // viewer's perspective. A found hider is hidden for everyone; during HIDE, hiders are hidden on hunter
    // clients only (the spec - hunters can't see hiders yet). The local owner's own body is left alone unless
    // found, so this never fights the FirstPersonController's own-body self-hide.
    private void UpdateVisibility()
    {
        bool found = _isFound.Value;
        if (IsOwner && !found) return;

        bool visible = ComputeVisible(found);
        if (_visibilityApplied && visible == _lastVisible) return;

        if (_bodyRenderers != null)
            foreach (var r in _bodyRenderers)
                if (r) r.enabled = visible;

        _lastVisible = visible;
        _visibilityApplied = true;
    }

    private bool ComputeVisible(bool found)
    {
        if (found) return false;

        var match = MatchManager.Instance;
        if (match && match.MatchActive
                  && match.LocalSubPhase == MatchManager.MatchSubPhase.Hide
                  && role == PlayerRole.Hider
                  && LocalViewerIsHunter())
            return false;

        return true;
    }

    // True if THIS machine's local player is a Hunter role variant (so it must not see hiders during hide).
    private static bool LocalViewerIsHunter()
    {
        var nm = NetworkManager.Singleton;
        if (!nm || nm.LocalClient == null) return false;
        var po = nm.LocalClient.PlayerObject;
        if (!po) return false;
        var setup = po.GetComponent<NetworkPlayerSetup>();
        return setup && setup.ScopedModes && setup.Role == PlayerRole.Hunter;
    }

    /// <summary>
    /// Places the freshly-spawned owner. Prefers this avatar's role-specific spawn area (Hunter/Hider tag),
    /// then the shared <see cref="spawnAreaTag"/> area; if a matching area is loaded the owner drops at a
    /// random point inside that collider (designer-authored spawn region). With no area present it falls back
    /// to the deterministic client-id ring. Owner-authoritative either way - the NetworkTransform replicates
    /// the result, and PlayerCharacterController captures it on its first Update as the kill-plane rescue target.
    /// </summary>
    private void PlaceAtSpawn()
    {
        if (TryGetSpawnArea(out Collider area))
            PlaceRandomlyInArea(area);
        else
            PlaceOnSpawnRing();
    }

    // Resolves the spawn-area collider for this avatar: the Role-specific area (Hunter/Hider) takes priority,
    // then the shared spawnAreaTag area; a miss on both leaves it to the caller's client-id ring fallback.
    private bool TryGetSpawnArea(out Collider area)
    {
        string roleTag = role == PlayerRole.Hunter ? hunterSpawnAreaTag : hiderSpawnAreaTag;
        return TryFindAreaByTag(roleTag, out area) || TryFindAreaByTag(spawnAreaTag, out area);
    }

    // Finds a collider tagged 'tag' in any loaded scene, if present. FindWithTag throws when the tag is
    // undefined (e.g. stripped from a build), so it is guarded - a missing/undefined tag just means "not here".
    private static bool TryFindAreaByTag(string tag, out Collider area)
    {
        area = null;
        if (string.IsNullOrEmpty(tag)) return false;

        GameObject go;
        try { go = GameObject.FindWithTag(tag); }
        catch (UnityException) { return false; }

        if (!go) return false;
        area = go.GetComponent<Collider>();
        return area;
    }

    /// <summary>
    /// Drops the owner at a random point inside the spawn-area collider. X/Z are sampled within the
    /// collider's footprint (rejection-sampled against the convex shape so the irregular outline is honoured,
    /// not just its bounding box); Y sits a touch above the area floor so gravity settles the avatar onto the
    /// ground. The CharacterController is toggled around the move because it otherwise overrides direct
    /// transform writes (same pattern as <see cref="PlaceOnSpawnRing"/>).
    /// </summary>
    private void PlaceRandomlyInArea(Collider area)
    {
        Bounds b = area.bounds;
        bool convex = SupportsClosestPoint(area);

        Vector3 pick = b.center;
        for (int i = 0; i < SpawnAreaSampleAttempts; i++)
        {
            Vector3 p = new Vector3(Random.Range(b.min.x, b.max.x), b.center.y, Random.Range(b.min.z, b.max.z));
            // ClosestPoint returns the input unchanged when it lies inside a convex collider, so an unchanged
            // sample is a point within the real (possibly non-box) footprint.
            if (!convex || (area.ClosestPoint(p) - p).sqrMagnitude <= 1e-6f)
            {
                pick = p;
                break;
            }
        }

        Vector3 target = new Vector3(pick.x, b.min.y + spawnAreaGroundLift, pick.z);

        var cc = GetComponent<CharacterController>();
        bool reenable = cc && cc.enabled;
        if (cc) cc.enabled = false;
        transform.position = target;
        if (cc) cc.enabled = reenable;
    }

    // Collider.ClosestPoint only constrains to the real shape for primitives and CONVEX mesh colliders;
    // a non-convex mesh returns the input unchanged (no containment info), so we fall back to its AABB.
    private static bool SupportsClosestPoint(Collider c)
    {
        return !(c is MeshCollider mc) || mc.convex;
    }

    /// <summary>
    /// Offsets the freshly-spawned owner onto a deterministic ring keyed by its client id so avatars
    /// don't pile up at the shared prefab spawn point. Id 0 (the host) keeps the origin so single-player
    /// "host alone" is unchanged; every later joiner takes the next ring slot, stepping the radius out
    /// once a ring fills. Only X/Z are shifted (gravity settles Y), and the CharacterController is toggled
    /// around the move because it otherwise overrides direct transform writes. Owner-authoritative, so the
    /// NetworkTransform replicates the placement outward.
    /// </summary>
    private void PlaceOnSpawnRing()
    {
        if (spawnRingRadius <= 0f || spawnRingSlots < 1) return;

        ulong id = OwnerClientId;
        if (id == 0) return; // host stays centered

        ulong k = id - 1;
        int ring = (int)(k / (ulong)spawnRingSlots);
        int slot = (int)(k % (ulong)spawnRingSlots);

        float radius = spawnRingRadius * (ring + 1);
        // Half-slot stagger per ring so outer slots don't line up radially with inner ones.
        float angle = (slot / (float)spawnRingSlots + ring * 0.5f / spawnRingSlots) * Mathf.PI * 2f;
        Vector3 offset = new Vector3(Mathf.Cos(angle), 0f, Mathf.Sin(angle)) * radius;

        var cc = GetComponent<CharacterController>();
        bool reenable = cc && cc.enabled;
        if (cc) cc.enabled = false;
        transform.position += offset;
        if (cc) cc.enabled = reenable;
    }
}