"use client";

import { useState, useMemo, useCallback } from "react";
import { useProduct } from "./useProduct";
import type { Product } from "@/lib/api/product";
import type { ProductVariant } from "@/components/ecommerce/productDetail/ProductDetailCard";
import type { ExtendedCartItem } from "./useCart";

interface ProductImage {
    src: string;
    alt: string;
}

interface ProductMeta {
    salePrice?: string;
    ribbon?: string;
    inventoryStatus?: string;
    inventoryQuantity?: number;
    sku?: string;
}

export function useProductDetail(productId: string) {
    const { product, isLoading, error } = useProduct(productId);
    const [selectedQuantity, setSelectedQuantity] = useState(1);
    const [selectedVariants, setSelectedVariants] = useState<Record<string, string>>({});

    const images = useMemo<ProductImage[]>(() => {
        if (!product) return [];

        if (product.images && product.images.length > 0) {
            return product.images.map((src, index) => ({
                src,
                alt: product.imageAlt || `${product.name} - Image ${index + 1}`,
            }));
        }
        return [{
            src: product.imageSrc,
            alt: product.imageAlt || product.name,
        }];
    }, [product]);

    const meta = useMemo<ProductMeta>(() => {
        if (!product?.metadata) return {};

        const metadata = product.metadata;

        let salePrice: string | undefined;
        const onSaleValue = metadata.onSale;
        const onSale = String(onSaleValue) === "true" || onSaleValue === 1 || String(onSaleValue) === "1";
        const salePriceValue = metadata.salePrice;

        if (onSale && salePriceValue !== undefined && salePriceValue !== null) {
            if (typeof salePriceValue === 'number') {
                salePrice = `$${salePriceValue.toFixed(2)}`;
            } else {
                const salePriceStr = String(salePriceValue);
                salePrice = salePriceStr.startsWith('$') ? salePriceStr : `$${salePriceStr}`;
            }
        }

        let inventoryQuantity: number | undefined;
        if (metadata.inventoryQuantity !== undefined) {
            const qty = metadata.inventoryQuantity;
            inventoryQuantity = typeof qty === 'number' ? qty : parseInt(String(qty), 10);
        }

        return {
            salePrice,
            ribbon: metadata.ribbon ? String(metadata.ribbon) : undefined,
            inventoryStatus: metadata.inventoryStatus ? String(metadata.inventoryStatus) : undefined,
            inventoryQuantity,
            sku: metadata.sku ? String(metadata.sku) : undefined,
        };
    }, [product]);

    const variants = useMemo<ProductVariant[]>(() => {
        if (!product) return [];

        const variantList: ProductVariant[] = [];

        if (product.metadata?.variantOptions) {
            try {
                const variantOptionsStr = String(product.metadata.variantOptions);
                const parsedOptions = JSON.parse(variantOptionsStr);

                if (Array.isArray(parsedOptions)) {
                    parsedOptions.forEach((option: any) => {
                        if (option.name && option.values) {
                            const values = typeof option.values === 'string'
                                ? option.values.split(',').map((v: string) => v.trim())
                                : Array.isArray(option.values)
                                    ? option.values.map((v: any) => String(v).trim())
                                    : [String(option.values)];

                            if (values.length > 0) {
                                const optionLabel = option.name;
                                const currentSelected = selectedVariants[optionLabel] || values[0];

                                variantList.push({
                                    label: optionLabel,
                                    options: values,
                                    selected: currentSelected,
                                    onChange: (value) => {
                                        setSelectedVariants((prev) => ({
                                            ...prev,
                                            [optionLabel]: value,
                                        }));
                                    },
                                });
                            }
                        }
                    });
                }
            } catch (error) {
                console.warn("Failed to parse variantOptions:", error);
            }
        }

        if (variantList.length === 0 && product.brand) {
            variantList.push({
                label: "Brand",
                options: [product.brand],
                selected: product.brand,
                onChange: () => { },
            });
        }

        if (variantList.length === 0 && product.variant) {
            const variantOptions = product.variant.includes('/')
                ? product.variant.split('/').map(v => v.trim())
                : [product.variant];

            const variantLabel = "Variant";
            const currentSelected = selectedVariants[variantLabel] || variantOptions[0];

            variantList.push({
                label: variantLabel,
                options: variantOptions,
                selected: currentSelected,
                onChange: (value) => {
                    setSelectedVariants((prev) => ({
                        ...prev,
                        [variantLabel]: value,
                    }));
                },
            });
        }

        return variantList;
    }, [product, selectedVariants]);

    const quantityVariant = useMemo<ProductVariant>(() => ({
        label: "Quantity",
        options: Array.from({ length: 10 }, (_, i) => String(i + 1)),
        selected: String(selectedQuantity),
        onChange: (value) => setSelectedQuantity(parseInt(value, 10)),
    }), [selectedQuantity]);

    const createCartItem = useCallback((): ExtendedCartItem | null => {
        if (!product) return null;

        const variantStrings = Object.entries(selectedVariants).map(
            ([label, value]) => `${label}: ${value}`
        );

        if (variantStrings.length === 0 && product.variant) {
            variantStrings.push(`Variant: ${product.variant}`);
        }

        const variantId = Object.values(selectedVariants).join('-') || 'default';

        return {
            id: `${product.id}-${variantId}-${selectedQuantity}`,
            productId: product.id,
            name: product.name,
            variants: variantStrings,
            price: product.price,
            quantity: selectedQuantity,
            imageSrc: product.imageSrc,
            imageAlt: product.imageAlt || product.name,
        };
    }, [product, selectedVariants, selectedQuantity]);

    return {
        product,
        isLoading,
        error,
        images,
        meta,
        variants,
        quantityVariant,
        selectedQuantity,
        selectedVariants,
        createCartItem,
    };
}