using TMPro;
using UnityEngine;
using UnityEngine.UI;

namespace UI
{
    [RequireComponent(typeof(VerticalLayoutGroup))]
    public class MessageAligner : MonoBehaviour
    {
        [Header("Bubble")]
        public Image bubbleBackground;
        public Sprite playerBubbleSprite;
        public Sprite aiBubbleSprite;
        public Color playerColor = new Color(0.2f, 0.6f, 1f);
        public Color aiColor = new Color(0.2f, 0.2f, 0.2f);
        public Color playerTextColor = Color.white;
        public Color aiTextColor = Color.white;

        [Header("Avatar Row")]
        public HorizontalLayoutGroup rowLayout;
        public GameObject avatarObject;
        public Image avatarImage;
        public Sprite playerAvatarSprite;
        public Sprite aiAvatarSprite;
        public Color playerAvatarColor = Color.white;
        public Color aiAvatarColor = Color.white;
        public bool showPlayerAvatar = true;
        public bool showAiAvatar = true;
        public float rowHorizontalPadding = 20f;
        public float rowSpacingWhenAvatarVisible = 14f;
        public float rowSpacingWhenAvatarHidden = 0f;
        public float rowMinHeight = 80f;

        [Header("Layout")]
        [Tooltip("Hard cap for bubble width before wrapping kicks in.")]
        public float maxBubbleWidth = 1000f;
        public bool clampToViewportWidth = true;
        [Range(0.1f, 1f)] public float viewportWidthRatio = 0.7f;

        private TextMeshProUGUI textComponent;
        private Sprite fallbackBubbleSprite;
        private Sprite fallbackAvatarSprite;
        private bool lastIsPlayer;

        private void Awake()
        {
            ResolveReferences();
            CacheFallbacks();
        }

        private void OnValidate()
        {
            ResolveReferences();
            CacheFallbacks();
        }

        public void SetAlignment(bool isPlayer)
        {
            lastIsPlayer = isPlayer;

            ResolveReferences();
            CacheFallbacks();

            ApplyRootLayout();
            ApplyAvatarStyle(isPlayer);
            ApplyRowLayout(isPlayer);
            ApplyBubbleStyle(isPlayer);
            ApplyTextStyle(isPlayer);
            ApplyWidthLimit();
            RebuildLayout();
        }

        public void Reapply()
        {
            SetAlignment(lastIsPlayer);
        }

        private void ResolveReferences()
        {
            if (bubbleBackground == null)
            {
                TextMeshProUGUI tmp = GetComponentInChildren<TextMeshProUGUI>(true);
                if (tmp != null)
                {
                    bubbleBackground = tmp.GetComponentInParent<Image>();
                }
            }

            if (bubbleBackground != null && textComponent == null)
            {
                textComponent = bubbleBackground.GetComponentInChildren<TextMeshProUGUI>(true);
            }

            if (rowLayout == null && bubbleBackground != null && bubbleBackground.transform.parent != null)
            {
                rowLayout = bubbleBackground.transform.parent.GetComponent<HorizontalLayoutGroup>();
            }

            if (avatarObject == null && rowLayout != null)
            {
                foreach (Transform child in rowLayout.transform)
                {
                    if (bubbleBackground == null || child.gameObject != bubbleBackground.gameObject)
                    {
                        avatarObject = child.gameObject;
                        break;
                    }
                }
            }

            if (avatarImage == null && avatarObject != null)
            {
                avatarImage = avatarObject.GetComponent<Image>();
            }
        }

        private void CacheFallbacks()
        {
            if (bubbleBackground != null)
            {
                if (fallbackBubbleSprite == null)
                {
                    fallbackBubbleSprite = bubbleBackground.sprite;
                }

                if (aiBubbleSprite == null) aiBubbleSprite = fallbackBubbleSprite;
                if (playerBubbleSprite == null) playerBubbleSprite = fallbackBubbleSprite;
            }

            if (avatarImage != null)
            {
                if (fallbackAvatarSprite == null)
                {
                    fallbackAvatarSprite = avatarImage.sprite;
                }

                if (aiAvatarSprite == null) aiAvatarSprite = fallbackAvatarSprite;
                if (playerAvatarSprite == null) playerAvatarSprite = fallbackAvatarSprite;
            }
        }

        private void ApplyRootLayout()
        {
            VerticalLayoutGroup layoutGroup = GetComponent<VerticalLayoutGroup>();
            if (layoutGroup == null)
            {
                return;
            }

            int horizontalPadding = Mathf.RoundToInt(Mathf.Max(0f, rowHorizontalPadding));

            layoutGroup.childControlWidth = true;
            layoutGroup.childForceExpandWidth = true;
            layoutGroup.childControlHeight = true;
            layoutGroup.childForceExpandHeight = false;
            layoutGroup.childAlignment = TextAnchor.UpperLeft;
            layoutGroup.padding.left = horizontalPadding;
            layoutGroup.padding.right = horizontalPadding;
        }

        private void ApplyRowLayout(bool isPlayer)
        {
            if (rowLayout == null)
            {
                return;
            }

            LayoutElement rowElement = rowLayout.GetComponent<LayoutElement>();
            if (rowElement == null)
            {
                rowElement = rowLayout.gameObject.AddComponent<LayoutElement>();
            }

            rowElement.flexibleWidth = 1f;
            if (rowMinHeight > 0f)
            {
                rowElement.minHeight = rowMinHeight;
            }

            bool avatarVisible = avatarObject != null && avatarObject.activeSelf;

            rowLayout.childAlignment = isPlayer ? TextAnchor.LowerRight : TextAnchor.LowerLeft;
            rowLayout.reverseArrangement = isPlayer && avatarVisible;
            rowLayout.spacing = avatarVisible ? rowSpacingWhenAvatarVisible : rowSpacingWhenAvatarHidden;
            rowLayout.childControlWidth = false;
            rowLayout.childControlHeight = false;
            rowLayout.childForceExpandWidth = false;
            rowLayout.childForceExpandHeight = false;
        }

        private void ApplyAvatarStyle(bool isPlayer)
        {
            bool shouldShowAvatar = isPlayer ? showPlayerAvatar : showAiAvatar;

            if (avatarObject != null)
            {
                avatarObject.SetActive(shouldShowAvatar);
            }

            if (!shouldShowAvatar || avatarImage == null)
            {
                return;
            }

            avatarImage.sprite = ResolveAvatarSprite(isPlayer);
            avatarImage.color = isPlayer ? playerAvatarColor : aiAvatarColor;
            avatarImage.preserveAspect = true;
        }

        private void ApplyBubbleStyle(bool isPlayer)
        {
            if (bubbleBackground == null)
            {
                return;
            }

            bubbleBackground.sprite = ResolveBubbleSprite(isPlayer);
            bubbleBackground.color = isPlayer ? playerColor : aiColor;
        }

        private void ApplyTextStyle(bool isPlayer)
        {
            if (textComponent == null)
            {
                return;
            }

            textComponent.color = isPlayer ? playerTextColor : aiTextColor;
        }

        private void ApplyWidthLimit()
        {
            if (textComponent == null)
            {
                return;
            }

            float effectiveMaxWidth = maxBubbleWidth;
            if (clampToViewportWidth)
            {
                float viewportWidth = GetViewportWidth();
                if (viewportWidth > 0f)
                {
                    float viewportMaxWidth = viewportWidth * viewportWidthRatio;
                    if (viewportMaxWidth > 0f)
                    {
                        effectiveMaxWidth = effectiveMaxWidth <= 0f
                            ? viewportMaxWidth
                            : Mathf.Min(effectiveMaxWidth, viewportMaxWidth);
                    }
                }
            }

            LayoutElement textLayout = textComponent.GetComponent<LayoutElement>();
            if (textLayout == null)
            {
                textLayout = textComponent.gameObject.AddComponent<LayoutElement>();
            }

            Vector2 preferredSize =
                textComponent.GetPreferredValues(textComponent.text, float.PositiveInfinity, float.PositiveInfinity);

            if (effectiveMaxWidth > 0f && preferredSize.x > effectiveMaxWidth)
            {
                textLayout.enabled = true;
                textLayout.preferredWidth = effectiveMaxWidth;
            }
            else
            {
                textLayout.enabled = false;
            }
        }

        private Sprite ResolveBubbleSprite(bool isPlayer)
        {
            if (isPlayer)
            {
                if (playerBubbleSprite != null) return playerBubbleSprite;
                if (aiBubbleSprite != null) return aiBubbleSprite;
            }
            else
            {
                if (aiBubbleSprite != null) return aiBubbleSprite;
                if (playerBubbleSprite != null) return playerBubbleSprite;
            }

            return fallbackBubbleSprite;
        }

        private Sprite ResolveAvatarSprite(bool isPlayer)
        {
            if (isPlayer)
            {
                if (playerAvatarSprite != null) return playerAvatarSprite;
                if (aiAvatarSprite != null) return aiAvatarSprite;
            }
            else
            {
                if (aiAvatarSprite != null) return aiAvatarSprite;
                if (playerAvatarSprite != null) return playerAvatarSprite;
            }

            return fallbackAvatarSprite;
        }

        private void RebuildLayout()
        {
            if (rowLayout != null)
            {
                LayoutRebuilder.ForceRebuildLayoutImmediate(rowLayout.GetComponent<RectTransform>());
            }

            LayoutRebuilder.ForceRebuildLayoutImmediate(GetComponent<RectTransform>());

            RectTransform parentRt = transform.parent as RectTransform;
            if (parentRt != null)
            {
                LayoutRebuilder.ForceRebuildLayoutImmediate(parentRt);
            }
        }

        private float GetViewportWidth()
        {
            ScrollRect scrollRect = GetComponentInParent<ScrollRect>();
            if (scrollRect != null)
            {
                RectTransform viewport = scrollRect.viewport != null
                    ? scrollRect.viewport
                    : scrollRect.GetComponent<RectTransform>();
                if (viewport != null) return viewport.rect.width;
            }

            RectTransform parentRt = transform.parent as RectTransform;
            if (parentRt != null) return parentRt.rect.width;

            return 0f;
        }
    }
}