// static/js/cart.js

import { getAuthHeaders, handleApiError } from './utils.js';

document.addEventListener('DOMContentLoaded', async () => {
    try {
        const token = localStorage.getItem('token');
        if (!token) {
            window.location.href = '/login.html';
            return;
        }

        const response = await fetch('/api/cart', {
            headers: getAuthHeaders()
        });
        
        if (!response.ok) throw new Error('Błąd ładowania koszyka');
        const cartItems = await response.json();
        renderCart(cartItems);

    } catch (error) {
        handleApiError(error, 'Nie udało się załadować koszyka');
    }
});

function renderCart(cartItems) {
    const container = document.getElementById('cart-items');
    container.innerHTML = '';

    if (cartItems.length === 0) {
        container.innerHTML = '<p class="text-center">Twój koszyk jest pusty</p>';
        return;
    }

    let totalCartValue = 0;

    cartItems.forEach(item => {
        const price = parseFloat(item.cena);
        const itemTotal = price * item.quantity;
        totalCartValue += itemTotal;

        const itemHTML = `
            <div class="col-12 mb-4 cart-item">
                <div class="card dark-card">
                    <div class="row g-0">
                        <div class="col-md-4 text-center p-3 cart-item-image">
                            <img src="${item.obraz_url}" 
                                 class="img-fluid rounded" 
                                 alt="${item.tytul}"
                                 style="max-height: 200px;">
                        </div>
                        <div class="col-md-8 cart-item-details">
                            <div class="card-body h-100 d-flex flex-column">
                                <div>
                                    <h5 class="card-title cart-item-title">${item.tytul}</h5>
                                    <p class="card-text cart-item-author">${item.autor}</p>
                                </div>
                                
                                <div class="d-flex flex-wrap gap-3 mb-2 cart-item-info mt-auto">
                                    <div class="d-flex flex-column flex-grow-1">
                                        <span class="fw-bold cart-item-price">Cena jednostkowa</span>
                                        <span class="fs-5">${price.toFixed(2)} PLN</span>
                                    </div>
                                    
                                    <div class="d-flex flex-column">
                                        <span class="fw-bold">Ilość</span>
                                        <div class="d-flex align-items-center gap-2">
                                            <span class="fs-5 badge bg-dark rounded-pill">${item.quantity}</span>
                                        </div>
                                    </div>
                                    
                                    <div class="d-flex flex-column">
                                        <span class="fw-bold cart-item-total">Suma</span>
                                        <span class="fs-5 text-warning">${itemTotal.toFixed(2)} PLN</span>
                                    </div>
                                </div>
                                
                                <div class="mt-3">
                                    <div class="btn-group w-100" role="group">
                                        <button class="btn btn-sm btn-outline-secondary decrease-quantity flex-grow-1" 
                                                data-book-id="${item.book_id}">
                                            <i class="bi bi-dash"></i> Zmniejsz ilość
                                        </button>
                                        <button class="btn btn-sm btn-outline-danger remove-from-cart cart-remove-btn flex-grow-1" 
                                                data-book-id="${item.book_id}">
                                            <i class="bi bi-trash"></i> Usuń
                                        </button>
                                    </div>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        `;
        container.insertAdjacentHTML('beforeend', itemHTML);
    });

    // Suma całkowita
    const totalHTML = `
        <div class="col-12 mt-4">
            <div class="card dark-card p-4">
                <div class="d-flex justify-content-between align-items-center">
                    <h2 class="mb-0">Suma całkowita</h2>
                    <h2 class="mb-0 total-cart-value">${totalCartValue.toFixed(2)} PLN</h2>
                </div>
            </div>
        </div>
    `;
    container.insertAdjacentHTML('beforeend', totalHTML);

    // Obsługa przycisków
    document.querySelectorAll('.decrease-quantity').forEach(button => {
        button.addEventListener('click', function() {
            const bookId = this.dataset.bookId;
            updateCartItemQuantity(bookId, 'decrease');
        });
    });

    document.querySelectorAll('.remove-from-cart').forEach(button => {
        button.addEventListener('click', function() {
            const bookId = this.dataset.bookId;
            updateCartItemQuantity(bookId, 'remove');
        });
    });

    // Finalizacja zamówienia
    document.getElementById('checkoutBtn')?.addEventListener('click', handleCheckout);
}

async function updateCartItemQuantity(bookId, action) {
    try {
        const token = localStorage.getItem('token');
        if (!token) {
            window.location.href = '/login.html';
            return;
        }

        let method, endpoint;
        if (action === 'decrease') {
            endpoint = `/api/decrease-cart-item/${bookId}`;
            method = 'POST';
        } else {
            endpoint = `/api/remove-from-cart/${bookId}`;
            method = 'DELETE';
        }

        const response = await fetch(endpoint, {
            method,
            headers: getAuthHeaders()
        });

        if (!response.ok) throw new Error('Błąd aktualizacji koszyka');
        location.reload();
    } catch (error) {
        handleApiError(error);
    }
}

async function handleCheckout() {
    try {
        const token = localStorage.getItem('token');
        if (!token) {
            window.location.href = '/login.html';
            return;
        }

        // Pobierz zawartość koszyka
        const cartResponse = await fetch('/api/cart', {
            headers: getAuthHeaders()
        });
        if (!cartResponse.ok) throw new Error('Błąd pobierania koszyka');
        const cartItems = await cartResponse.json();

        // Wyślij zamówienie
        const response = await fetch('/api/checkout', {
            method: 'POST',
            headers: getAuthHeaders(),
            body: JSON.stringify({
                items: cartItems.map(item => ({
                    book_id: item.book_id,
                    quantity: item.quantity
                })),
                total: cartItems.reduce((sum, item) => 
                    sum + (parseFloat(item.cena) * item.quantity), 0)
            })
        });

        if (!response.ok) throw new Error('Błąd podczas składania zamówienia');
        window.location.href = '/thankyou.html';
    } catch (error) {
        handleApiError(error, 'Nie udało się złożyć zamówienia');
    }
}