using System;
using System.Collections.Generic;
using UnityEngine;
using Random = System.Random;

namespace GeometryTD.Core
{
    public static class ShopPriceRuleService
    {
        private static Dictionary<RarityType, DRShopPrice> _shopPriceByRarity;

        public static int ResolveRandomBuyPrice(RarityType rarity, Random random)
        {
            if (!TryFindPriceRow(rarity, out DRShopPrice row) || row == null)
            {
                return 0;
            }

            int min = Mathf.Max(0, row.MinPrice);
            int max = Mathf.Max(min, row.MaxPrice);
            return random != null ? random.Next(min, max + 1) : min;
        }

        public static int ResolveComponentSalePrice(TowerCompItemData component)
        {
            if (component == null)
            {
                return 0;
            }

            return ResolveBasePrice(component.Rarity);
        }

        public static bool TryResolveTowerSalePrice(
            TowerItemData tower,
            BackpackInventoryData inventory,
            out int price)
        {
            price = 0;
            if (tower == null || inventory == null)
            {
                return false;
            }

            if (!TryGetComponentById(inventory.MuzzleComponents, tower.MuzzleComponentInstanceId, out MuzzleCompItemData muzzleComp) ||
                !TryGetComponentById(inventory.BearingComponents, tower.BearingComponentInstanceId, out BearingCompItemData bearingComp) ||
                !TryGetComponentById(inventory.BaseComponents, tower.BaseComponentInstanceId, out BaseCompItemData baseComp))
            {
                return false;
            }

            price = ResolveComponentSalePrice(muzzleComp) +
                    ResolveComponentSalePrice(bearingComp) +
                    ResolveComponentSalePrice(baseComp);
            return price > 0;
        }

        public static int ResolveBasePrice(RarityType rarity)
        {
            if (!TryFindPriceRow(rarity, out DRShopPrice row) || row == null)
            {
                return 0;
            }

            int min = Mathf.Max(0, row.MinPrice);
            int max = Mathf.Max(min, row.MaxPrice);
            return Mathf.RoundToInt((min + max) * 0.5f);
        }

        public static void ClearCache()
        {
            _shopPriceByRarity = null;
        }

        private static bool TryFindPriceRow(RarityType rarity, out DRShopPrice result)
        {
            EnsureShopPriceCache();
            if (_shopPriceByRarity == null)
            {
                result = null;
                return false;
            }

            return _shopPriceByRarity.TryGetValue(rarity, out result);
        }

        private static void EnsureShopPriceCache()
        {
            if (_shopPriceByRarity != null)
            {
                return;
            }

            DRShopPrice[] rows = CoreServiceHub.StaticData?.GetAllShopPrices();
            if (rows == null)
            {
                return;
            }

            Dictionary<RarityType, DRShopPrice> shopPriceByRarity = new Dictionary<RarityType, DRShopPrice>();
            for (int i = 0; i < rows.Length; i++)
            {
                DRShopPrice row = rows[i];
                if (row == null)
                {
                    continue;
                }

                shopPriceByRarity[row.Rarity] = row;
            }

            _shopPriceByRarity = shopPriceByRarity;
        }

        private static bool TryGetComponentById<TComp>(IReadOnlyList<TComp> components, long instanceId, out TComp result)
            where TComp : TowerCompItemData
        {
            result = null;
            if (components == null || instanceId <= 0)
            {
                return false;
            }

            for (int i = 0; i < components.Count; i++)
            {
                TComp component = components[i];
                if (component != null && component.InstanceId == instanceId)
                {
                    result = component;
                    return true;
                }
            }

            return false;
        }
    }
}