using UnityEngine;
using UnityEngine.UI;
using TMPro;
using DG.Tweening;
using System;
using System.Collections.Generic;
using Ashwild.Inventory;

namespace Ashwild.Crafting
{
    /// <summary>
    /// Pure crafting view: shows the recipe list, the detail panel and the craft button.
    /// It knows nothing about the player or the crafting logic — CraftingManager drives it and
    /// passes in the player-dependent queries (can-craft, item-count) and the craft action as
    /// delegates. The UI never reaches back into the player or the manager.
    /// </summary>
    public class CraftingUI : MonoBehaviour
    {
        #region Serialized Fields

        [Header("Recipe List (Left)")]
        [SerializeField] private Transform recipeListContainer;
        [SerializeField] private GameObject recipeButtonPrefab;

        [Header("Detail Panel (Right)")]
        [SerializeField] private GameObject detailPanel;
        [SerializeField] private Image resultIcon;
        [SerializeField] private TextMeshProUGUI resultNameText;
        [SerializeField] private TextMeshProUGUI resultQuantityText;
        [SerializeField] private Transform ingredientContainer;
        [SerializeField] private GameObject ingredientSlotPrefab;
        [SerializeField] private Button craftButton;

        [Header("Craft Feedback")]
        [SerializeField] private float punchScale = 0.15f;
        [SerializeField] private float punchDuration = 0.3f;

        #endregion

        #region State

        private Func<CraftingRecipe, int, bool> canCraftQuery;
        private Func<ItemData, int> countItemQuery;
        private Func<CraftingRecipe, int, bool> craftRequest;
        private readonly List<RecipeButtonUI> recipeButtons = new List<RecipeButtonUI>();
        private readonly List<GameObject> ingredientInstances = new List<GameObject>();
        private RecipeButtonUI selectedButton;
        private Tweener punchTween;
        private bool built;

        #endregion

        #region Public API

        /// <summary>
        /// Builds the recipe buttons (once) and wires the manager-owned queries/action. Safe to
        /// call again later to re-point the delegates; it then simply refreshes the display.
        /// </summary>
        public void Build(CraftingRecipe[] recipes, Func<CraftingRecipe, int, bool> canCraft, Func<ItemData, int> countItem, Func<CraftingRecipe, int, bool> craft)
        {
            canCraftQuery = canCraft;
            countItemQuery = countItem;
            craftRequest = craft;

            if (!built)
            {
                for (int i = 0; i < recipes.Length; i++)
                {
                    GameObject btnGO = Instantiate(recipeButtonPrefab, recipeListContainer);
                    RecipeButtonUI btn = btnGO.GetComponent<RecipeButtonUI>();
                    btn.Initialize(recipes[i], OnRecipeSelected, OnCountChanged);
                    recipeButtons.Add(btn);
                }

                craftButton.onClick.AddListener(OnCraftClicked);
                detailPanel.SetActive(false);
                built = true;
            }

            Refresh();
        }

        /// <summary>
        /// Recomputes craftability for every recipe button and refreshes the open detail.
        /// Called by the manager whenever the local player's inventory changes.
        /// </summary>
        public void Refresh()
        {
            if (!built) return;

            for (int i = 0; i < recipeButtons.Count; i++)
            {
                RecipeButtonUI btn = recipeButtons[i];
                bool canCraft = canCraftQuery != null && canCraftQuery(btn.Recipe, btn.CraftCount);
                btn.UpdateCraftability(canCraft);
            }

            if (selectedButton != null)
                RefreshDetail();
        }

        #endregion

        #region Unity Lifecycle

        /// <summary>
        /// Kills the feedback tween so it never targets a destroyed button.
        /// </summary>
        private void OnDestroy()
        {
            punchTween?.Kill();
        }

        #endregion

        #region Event Handlers

        /// <summary>
        /// Selects a recipe and opens its detail panel.
        /// </summary>
        private void OnRecipeSelected(RecipeButtonUI button)
        {
            if (selectedButton == button) return;

            if (selectedButton != null)
                selectedButton.SetSelected(false);

            selectedButton = button;
            selectedButton.SetSelected(true);

            detailPanel.SetActive(true);
            RefreshDetail();
        }

        /// <summary>
        /// Refreshes the detail panel when the selected recipe's craft count changes.
        /// </summary>
        private void OnCountChanged(RecipeButtonUI button)
        {
            if (button == selectedButton)
                RefreshDetail();
        }

        /// <summary>
        /// Asks the manager to craft the selected recipe and plays feedback on success.
        /// </summary>
        private void OnCraftClicked()
        {
            if (selectedButton == null || craftRequest == null) return;

            if (craftRequest(selectedButton.Recipe, selectedButton.CraftCount))
            {
                punchTween?.Kill();
                punchTween = craftButton.transform.DOPunchScale(Vector3.one * punchScale, punchDuration, 5, 0.5f)
                    .SetUpdate(true);

                selectedButton.ResetCount();
            }
        }

        #endregion

        #region Internal Helpers

        /// <summary>
        /// Renders the detail panel (result + ingredient slots) for the selected recipe,
        /// using the manager-provided item-count query to show what the player owns.
        /// </summary>
        private void RefreshDetail()
        {
            CraftingRecipe recipe = selectedButton.Recipe;
            int count = selectedButton.CraftCount;

            // Result info
            resultIcon.sprite = recipe.Icon;
            resultNameText.text = recipe.RecipeName;
            int totalResult = recipe.ResultQuantity * count;
            bool showQty = totalResult > 1;
            resultQuantityText.gameObject.SetActive(showQty);
            if (showQty)
                resultQuantityText.text = "x" + totalResult;

            // Clear old ingredients
            foreach (GameObject go in ingredientInstances)
                Destroy(go);
            ingredientInstances.Clear();

            // Create ingredient slots
            bool canCraft = true;
            CraftingIngredient[] ingredients = recipe.Ingredients;
            for (int i = 0; i < ingredients.Length; i++)
            {
                GameObject slotGO = Instantiate(ingredientSlotPrefab, ingredientContainer);
                IngredientSlotUI slotUI = slotGO.GetComponent<IngredientSlotUI>();

                int required = ingredients[i].quantity * count;
                int playerHas = countItemQuery != null ? countItemQuery(ingredients[i].item) : 0;
                slotUI.Setup(ingredients[i].item, required, playerHas);

                if (playerHas < required)
                    canCraft = false;

                ingredientInstances.Add(slotGO);
            }

            craftButton.interactable = canCraft;
        }

        #endregion
    }
}