using UnityEngine;

namespace BrewMonster
{
    /// <summary>
    /// Shared static helpers used by ElsePlayerPortraitCapture and HostPlayerPortraitCapture.
    /// </summary>
    public static class PortraitCaptureUtils
    {
        private static readonly string[] HeadBoneNames =
        {
            "Bip01 Head", "Bip001 Head", "head", "Head", "Bone_Head", "HEAD"
        };

        // ──────────────────────────────────────────────────────────────────────────────
        // Model / bone search
        // ──────────────────────────────────────────────────────────────────────────────

        /// <summary>
        /// Returns the root transform of the visual model inside <paramref name="playerRoot"/>.
        /// Tries to find the first child that owns a SkinnedMeshRenderer; falls back to the
        /// root itself if a SkinnedMeshRenderer is found anywhere in the hierarchy.
        /// </summary>
        public static Transform FindVisualModelRoot(Transform playerRoot)
        {
            if (playerRoot == null) return null;

            // Walk immediate children first — model root is usually a direct child
            for (int i = 0; i < playerRoot.childCount; i++)
            {
                var child = playerRoot.GetChild(i);
                if (child.GetComponentInChildren<SkinnedMeshRenderer>() != null)
                    return child;
            }

            // Fallback: if the root itself contains a SMR, use it
            if (playerRoot.GetComponentInChildren<SkinnedMeshRenderer>() != null)
                return playerRoot;

            return null;
        }

        /// <summary>
        /// Searches <paramref name="modelRoot"/>'s hierarchy for a head bone by common name patterns.
        /// </summary>
        public static Transform FindHeadBone(Transform modelRoot)
        {
            if (modelRoot == null) return null;
            foreach (var boneName in HeadBoneNames)
            {
                var bone = FindChildByName(modelRoot, boneName);
                if (bone != null) return bone;
            }
            return null;
        }

        /// <summary>Recursive depth-first search for a child transform by exact name.</summary>
        public static Transform FindChildByName(Transform root, string name)
        {
            if (root.name == name) return root;
            for (int i = 0; i < root.childCount; i++)
            {
                var result = FindChildByName(root.GetChild(i), name);
                if (result != null) return result;
            }
            return null;
        }

        // ──────────────────────────────────────────────────────────────────────────────
        // Clone setup
        // ──────────────────────────────────────────────────────────────────────────────

        /// <summary>
        /// Strips non-visual components from a cloned GameObject so it becomes a lightweight
        /// render-only puppet. Keeps Animator so idle animations continue to play.
        /// </summary>
        public static void CleanupCloneComponents(GameObject go)
        {
            foreach (var col in go.GetComponentsInChildren<Collider>(true))
                Object.Destroy(col);

            foreach (var rb in go.GetComponentsInChildren<Rigidbody>(true))
                Object.Destroy(rb);

            foreach (var mb in go.GetComponentsInChildren<MonoBehaviour>(true))
            {
                if (mb is Animator) continue;
                Object.Destroy(mb);
            }
        }

        /// <summary>Recursively sets the layer of <paramref name="go"/> and all its children.</summary>
        public static void SetLayerRecursive(GameObject go, int layer)
        {
            go.layer = layer;
            foreach (Transform child in go.transform)
                SetLayerRecursive(child.gameObject, layer);
        }

        // ──────────────────────────────────────────────────────────────────────────────
        // Camera / RenderTexture factories
        // ──────────────────────────────────────────────────────────────────────────────

        /// <summary>
        /// Creates a Camera child GameObject under <paramref name="parent"/> whose culling mask
        /// covers only <paramref name="portraitLayer"/>. Camera starts disabled.
        /// </summary>
        public static Camera CreatePortraitCamera(Transform parent, string goName, int portraitLayer, float fov)
        {
            var camGO = new GameObject(goName);
            camGO.transform.SetParent(parent, false);

            var cam = camGO.AddComponent<Camera>();
            cam.cullingMask = 1 << portraitLayer;
            cam.clearFlags = CameraClearFlags.SolidColor;
            cam.backgroundColor = Color.clear;
            cam.fieldOfView = fov;
            cam.nearClipPlane = 0.1f;
            cam.farClipPlane = 200f;
            cam.enabled = false;
            return cam;
        }

        /// <summary>
        /// Creates a 256×256 ARGB32 RenderTexture and wires it to <paramref name="cam"/> if provided.
        /// </summary>
        public static RenderTexture CreatePortraitRT(string rtName, Camera cam)
        {
            var rt = new RenderTexture(256, 256, 16, RenderTextureFormat.ARGB32)
            {
                name = rtName,
                antiAliasing = 1
            };
            rt.Create();
            if (cam != null) cam.targetTexture = rt;
            return rt;
        }
    }
}