using UnityEngine;
using System.Collections.Generic;

/// <summary>
/// Height scaling for GKC player characters.
/// NEW APPROACH: Instead of scaling COM/capsule/camera/IK down, 
/// simply SCALES THE MODEL UP (or down) to match GKC's standard character height.
/// This way capsule, camera, IK, weapons, ground detection — everything stays at 
/// GKC default values and just works. Only the model transform changes.
/// </summary>
public class characterHeightScaler : MonoBehaviour
{
    [Header ("Auto-Detect Settings")]
    [Space]

    [Tooltip ("When enabled, the system automatically measures your FBX model height " +
              "and scales it to match the GKC standard height. No manual slider needed.")]
    public bool autoDetectHeight = true;

    [Tooltip ("The standard/reference height in Unity units for the default GKC character. " +
              "Typically 1.8 units (average humanoid).")]
    public float gkcStandardHeight = 1.8f;

    [Tooltip ("The detected height of the current FBX model in Unity units (before scaling).")]
    public float detectedModelHeight;

    [Tooltip ("The calculated model scale to match GKC standard height.\n" +
              "= gkcStandardHeight / detectedModelHeight")]
    public float modelScaleMultiplier = 1.0f;

    [Space]
    [Header ("Manual Scale (when Auto-Detect is OFF)")]
    [Space]

    [Range (0.3f, 3.0f)]
    [Tooltip ("Manual scale multiplier for the model. Used only when autoDetectHeight is OFF.")]
    public float characterHeightScale = 1.0f;

    public float minHeightScale = 0.3f;
    public float maxHeightScale = 3.0f;

    [Space]
    [Header ("State")]
    [Space]

    public bool heightBaseValuesCaptured;
    public bool showDebugLog;

    [Space]
    [Header ("Captured Base Values")]
    [Space]

    public Vector3 baseModelLocalScale;
    public Vector3 baseModelLocalPosition;
    public Transform modelTransform;

    [Tooltip ("Small vertical offset to fine-tune foot alignment (in Unity units). " +
              "Positive = raise model, Negative = lower model.")]
    public float footAlignmentOffset = 0.0f;


    // Internal references
    playerComponentsManager componentsManager;
    playerController playerControllerManager;
    IKSystem IKManager;
    IKFootSystem IKFootManager;
    Transform COMTransform;


    // ==================== AUTO-DETECT HEIGHT ====================

    /// <summary>
    /// Measures the FBX model height using multiple methods.
    /// Returns the height in Unity units.
    /// </summary>
    public float detectModelHeight (GameObject model)
    {
        if (model == null) {
            Debug.LogWarning ("characterHeightScaler: No model provided for height detection.");
            return gkcStandardHeight;
        }

        float measuredHeight = 0f;
        string method = "none";

        Animator animator = model.GetComponentInChildren<Animator> ();

        // --- Method 1: Animator humanoid bones (head to foot) ---
        if (animator != null && animator.isHuman && animator.avatar != null && animator.avatar.isHuman) {
            Transform head = animator.GetBoneTransform (HumanBodyBones.Head);
            Transform leftFoot = animator.GetBoneTransform (HumanBodyBones.LeftFoot);
            Transform rightFoot = animator.GetBoneTransform (HumanBodyBones.RightFoot);

            if (head != null && (leftFoot != null || rightFoot != null)) {
                Transform foot = leftFoot != null ? leftFoot : rightFoot;
                measuredHeight = head.position.y - foot.position.y;

                // Head bone is at eye level, add ~10% for top of head
                measuredHeight *= 1.1f;
                method = "Animator bones (head-to-foot)";
            }
        }

        // --- Method 2: Animator humanScale ---
        if (measuredHeight <= 0.01f && animator != null && animator.isHuman) {
            measuredHeight = animator.humanScale * 1.8f;
            method = "Animator humanScale";
        }

        // --- Method 3: SkinnedMeshRenderer bounds ---
        if (measuredHeight <= 0.01f) {
            SkinnedMeshRenderer[] skinnedRenderers = model.GetComponentsInChildren<SkinnedMeshRenderer> ();

            if (skinnedRenderers.Length > 0) {
                Bounds combinedBounds = new Bounds (skinnedRenderers [0].bounds.center, Vector3.zero);

                for (int i = 0; i < skinnedRenderers.Length; i++) {
                    combinedBounds.Encapsulate (skinnedRenderers [i].bounds);
                }

                measuredHeight = combinedBounds.size.y;
                method = "SkinnedMeshRenderer bounds";
            }
        }

        // --- Method 4: Regular Renderer bounds ---
        if (measuredHeight <= 0.01f) {
            Renderer[] renderers = model.GetComponentsInChildren<Renderer> ();

            if (renderers.Length > 0) {
                Bounds combinedBounds = new Bounds (renderers [0].bounds.center, Vector3.zero);

                for (int i = 0; i < renderers.Length; i++) {
                    combinedBounds.Encapsulate (renderers [i].bounds);
                }

                measuredHeight = combinedBounds.size.y;
                method = "Renderer bounds";
            }
        }

        // --- Fallback ---
        if (measuredHeight <= 0.01f) {
            measuredHeight = gkcStandardHeight;
            method = "fallback (assuming standard)";
        }

        if (showDebugLog) {
            Debug.Log ("characterHeightScaler: DETECT '" + method + "'"
                + " | measured=" + measuredHeight.ToString ("F3")
                + " | standard=" + gkcStandardHeight.ToString ("F3"));
        }

        return measuredHeight;
    }


    /// <summary>
    /// Auto-detects model height and calculates the scale multiplier 
    /// to make the model match GKC standard height.
    /// scale = gkcStandardHeight / detectedModelHeight
    /// </summary>
    public float autoDetectAndSetScale ()
    {
        resolveModelTransform ();

        if (modelTransform == null) {
            Debug.LogWarning ("characterHeightScaler: Cannot auto-detect — no model transform found.");
            return 1.0f;
        }

        detectedModelHeight = detectModelHeight (modelTransform.gameObject);

        if (detectedModelHeight > 0.01f) {
            modelScaleMultiplier = gkcStandardHeight / detectedModelHeight;
            modelScaleMultiplier = Mathf.Clamp (modelScaleMultiplier, minHeightScale, maxHeightScale);
        } else {
            modelScaleMultiplier = 1.0f;
        }

        characterHeightScale = modelScaleMultiplier;

        if (showDebugLog) {
            Debug.Log ("characterHeightScaler: AUTO-DETECT RESULT"
                + " | modelHeight=" + detectedModelHeight.ToString ("F3")
                + " | standardHeight=" + gkcStandardHeight.ToString ("F3")
                + " | scaleMultiplier=" + modelScaleMultiplier.ToString ("F3")
                + " (model will be scaled UP by " + modelScaleMultiplier.ToString ("F2") + "x)");
        }

        return modelScaleMultiplier;
    }


    /// <summary>
    /// Full automatic: capture base values, detect height, scale model, align feet.
    /// </summary>
    public void autoDetectAndApply ()
    {
        captureBaseValues ();
        autoDetectAndSetScale ();
        applyHeightScale ();

        if (showDebugLog) {
            Debug.Log ("characterHeightScaler: FULL AUTO complete."
                + " Model scaled " + characterHeightScale.ToString ("F3") + "x"
                + " (from " + detectedModelHeight.ToString ("F3")
                + "m to ~" + gkcStandardHeight.ToString ("F3") + "m)");
        }
    }


    // ==================== CAPTURE / APPLY / RESET ====================

    /// <summary>
    /// Captures the model's current localScale and localPosition as the base (unscaled) values.
    /// Call after building the character, before applying any scale.
    /// </summary>
    public void captureBaseValues ()
    {
        resolveReferences ();

        resolveModelTransform ();

        if (modelTransform != null) {
            baseModelLocalScale = modelTransform.localScale;
            baseModelLocalPosition = modelTransform.localPosition;
        }

        heightBaseValuesCaptured = true;
        characterHeightScale = 1.0f;
        modelScaleMultiplier = 1.0f;

        if (showDebugLog) {
            Debug.Log ("characterHeightScaler: CAPTURED"
                + " | model='" + (modelTransform != null ? modelTransform.name : "NULL") + "'"
                + " | baseScale=" + baseModelLocalScale
                + " | basePos=" + baseModelLocalPosition);
        }

        updateComponent ();
    }


    /// <summary>
    /// Scales the model transform to match GKC standard height.
    /// No COM, capsule, camera, IK, or weapon changes needed —
    /// those all stay at GKC default values since we're fitting the model to the system,
    /// not the system to the model.
    /// </summary>
    public void applyHeightScale ()
    {
        if (!heightBaseValuesCaptured) {
            Debug.LogWarning ("characterHeightScaler: No base values captured. Click 'Capture Base Values' first.");
            return;
        }

        resolveReferences ();

        float scale = characterHeightScale;

        if (showDebugLog) {
            Debug.Log ("characterHeightScaler: ===== APPLYING MODEL SCALE = " + scale.ToString ("F3") + "x =====");
        }

        // 1. Scale the model
        if (modelTransform != null) {
            modelTransform.localScale = baseModelLocalScale * scale;

            if (showDebugLog) {
                Debug.Log ("  [Model] '" + modelTransform.name + "' localScale = " + modelTransform.localScale);
            }
        }

        // 2. Align feet to ground (model origin may not be at feet)
        alignFeetToGround ();

        // 3. Recalculate IK foot initial values (bone positions changed due to model scale)
        if (IKFootManager != null) {
            IKFootManager.calculateInitialFootValues ();

            if (showDebugLog) {
                Debug.Log ("  [IKFoot] Recalculated initial foot values");
            }
        }

        updateComponent ();
        markComponentsDirty ();

        if (showDebugLog) {
            Debug.Log ("characterHeightScaler: ===== APPLY COMPLETE =====");
        }
    }


    /// <summary>
    /// After scaling the model, ensure feet are aligned with ground level.
    /// Measures the lowest foot bone Y (or mesh bottom) and adjusts model localPosition.
    /// </summary>
    void alignFeetToGround ()
    {
        if (modelTransform == null) {
            return;
        }

        Animator animator = modelTransform.GetComponentInChildren<Animator> ();

        float footWorldY = float.MaxValue;
        bool footFound = false;

        // Try humanoid foot bones (LeftToes / RightToes first, then LeftFoot / RightFoot)
        if (animator != null && animator.isHuman) {
            Transform leftToes = animator.GetBoneTransform (HumanBodyBones.LeftToes);
            Transform rightToes = animator.GetBoneTransform (HumanBodyBones.RightToes);
            Transform leftFoot = animator.GetBoneTransform (HumanBodyBones.LeftFoot);
            Transform rightFoot = animator.GetBoneTransform (HumanBodyBones.RightFoot);

            // Prefer toes (closest to ground), fall back to foot bone
            if (leftToes != null || rightToes != null) {
                if (leftToes != null) footWorldY = Mathf.Min (footWorldY, leftToes.position.y);
                if (rightToes != null) footWorldY = Mathf.Min (footWorldY, rightToes.position.y);
                footFound = true;
            } else if (leftFoot != null || rightFoot != null) {
                if (leftFoot != null) footWorldY = Mathf.Min (footWorldY, leftFoot.position.y);
                if (rightFoot != null) footWorldY = Mathf.Min (footWorldY, rightFoot.position.y);
                footFound = true;
            }
        }

        // Fallback: SkinnedMeshRenderer bounds bottom
        if (!footFound) {
            SkinnedMeshRenderer[] renderers = modelTransform.GetComponentsInChildren<SkinnedMeshRenderer> ();

            if (renderers.Length > 0) {
                Bounds combinedBounds = renderers [0].bounds;

                for (int i = 1; i < renderers.Length; i++) {
                    combinedBounds.Encapsulate (renderers [i].bounds);
                }

                footWorldY = combinedBounds.min.y;
                footFound = true;
            }
        }

        if (!footFound) {
            if (showDebugLog) {
                Debug.LogWarning ("characterHeightScaler: Could not find foot bones or renderers for alignment.");
            }

            return;
        }

        // Ground level = Player Controller transform.position.y (capsule bottom)
        float groundWorldY = transform.position.y;

        float offsetY = footWorldY - groundWorldY;

        if (showDebugLog) {
            Debug.Log ("  [FootAlign] footWorldY=" + footWorldY.ToString ("F4")
                + " groundY=" + groundWorldY.ToString ("F4")
                + " offset=" + offsetY.ToString ("F4")
                + " userAdjust=" + footAlignmentOffset.ToString ("F4"));
        }

        // Adjust model localPosition to put feet on ground + user fine-tune offset
        if (Mathf.Abs (offsetY) > 0.005f || Mathf.Abs (footAlignmentOffset) > 0.001f) {
            Vector3 modelPos = modelTransform.localPosition;
            modelPos.y = baseModelLocalPosition.y - offsetY + footAlignmentOffset;
            modelTransform.localPosition = modelPos;

            if (showDebugLog) {
                Debug.Log ("  [FootAlign] model localPos.y = " + modelPos.y.ToString ("F4"));
            }
        }
    }


    /// <summary>
    /// Resets model to original scale and position (1:1 with FBX import).
    /// </summary>
    public void resetHeightScale ()
    {
        if (modelTransform != null) {
            modelTransform.localScale = baseModelLocalScale;
            modelTransform.localPosition = baseModelLocalPosition;
        }

        characterHeightScale = 1.0f;
        modelScaleMultiplier = 1.0f;

        if (IKFootManager != null) {
            IKFootManager.calculateInitialFootValues ();
        }

        updateComponent ();
        markComponentsDirty ();
    }


    // ==================== INTERNAL ====================

    void resolveReferences ()
    {
        if (componentsManager == null) {
            GameObject playerObject = null;

            buildPlayer builder = GetComponent<buildPlayer> ();

            if (builder != null) {
                playerObject = builder.player;
            }

            if (playerObject == null) {
                playerObject = transform.root.gameObject;
            }

            componentsManager = playerObject.GetComponent<playerComponentsManager> ();
        }

        if (componentsManager != null) {
            if (playerControllerManager == null) {
                playerControllerManager = componentsManager.getPlayerController ();
            }

            if (IKManager == null) {
                IKManager = componentsManager.getIKSystem ();
            }

            if (IKFootManager == null) {
                IKFootManager = GetComponentInChildren<IKFootSystem> ();
            }

            if (COMTransform == null && IKManager != null) {
                COMTransform = IKManager.getIKBodyCOM ();
            }
        }

        resolveModelTransform ();
    }


    void resolveModelTransform ()
    {
        if (modelTransform == null) {
            buildPlayer builder = GetComponent<buildPlayer> ();

            if (builder != null && builder.currentCharacterModel != null) {
                modelTransform = builder.currentCharacterModel.transform;
            }
        }
    }


    void markComponentsDirty ()
    {
#if UNITY_EDITOR
        if (modelTransform != null) {
            UnityEditor.EditorUtility.SetDirty (modelTransform);
            UnityEditor.EditorUtility.SetDirty (modelTransform.gameObject);
        }

        if (IKFootManager != null) {
            UnityEditor.EditorUtility.SetDirty (IKFootManager);
        }

        UnityEditor.EditorUtility.SetDirty (this);
#endif
    }


    void updateComponent ()
    {
#if UNITY_EDITOR
        UnityEditor.EditorUtility.SetDirty (this);
#endif
    }
}