/**
 * invoice-modal.js — Invoice create/edit modal
 * Uses shared item-editor for accordion items
 * 
 * Features:
 * - Auto-sets tax-exempt based on customer's taxable flag
 * - Recurring invoice support (monthly/yearly)
 */
import { addItem, getItems, resetItemCounter } from '../utils/item-editor.js';
import { setDefaultDate, showSpinner, hideSpinner } from '../utils/helpers.js';

let currentInvoiceId = null;
let qboLaborRate = null;

export async function loadLaborRate() {
    try {
        const response = await fetch('/api/qbo/labor-rate');
        const data = await response.json();
        if (data.rate) {
            qboLaborRate = data.rate;
            console.log(`💰 Labor Rate geladen: $${qboLaborRate}`);
        }
    } catch (e) {
        console.log('Labor Rate konnte nicht geladen werden.');
    }
}

export function getLaborRate() { return qboLaborRate; }

/**
 * Auto-set tax exempt based on customer's taxable flag
 */
function applyCustomerTaxStatus(customerId) {
    const allCust = window.getCustomers ? window.getCustomers() : (window.customers || []);
    const customer = allCust.find(c => c.id === parseInt(customerId));
    if (customer) {
        const cb = document.getElementById('invoice-tax-exempt');
        if (cb) {
            cb.checked = (customer.taxable === false);
            updateInvoiceTotals();
        }
    }
}

export async function openInvoiceModal(invoiceId = null) {
    currentInvoiceId = invoiceId;
    if (invoiceId) {
        await loadInvoiceForEdit(invoiceId);
    } else {
        prepareNewInvoice();
    }
    document.getElementById('invoice-modal').classList.add('active');
}

export function closeInvoiceModal() {
    document.getElementById('invoice-modal').classList.remove('active');
    currentInvoiceId = null;
}

async function loadInvoiceForEdit(invoiceId) {
    document.getElementById('invoice-modal-title').textContent = 'Edit Invoice';
    const response = await fetch(`/api/invoices/${invoiceId}`);
    const data = await response.json();

    // Set customer in Alpine component
    const allCust = window.getCustomers ? window.getCustomers() : (window.customers || []);
    const customer = allCust.find(c => c.id === data.invoice.customer_id);
    if (customer) {
        const customerInput = document.querySelector('#invoice-modal input[placeholder="Search customer..."]');
        if (customerInput) {
            customerInput.value = customer.name;
            customerInput.dispatchEvent(new Event('input'));
            const alpineData = Alpine.$data(customerInput.closest('[x-data]'));
            if (alpineData) {
                alpineData.search = customer.name;
                alpineData.selectedId = customer.id;
                alpineData.selectedName = customer.name;
            }
        }
    }

    document.getElementById('invoice-number').value = data.invoice.invoice_number || '';
    document.getElementById('invoice-customer').value = data.invoice.customer_id;
    document.getElementById('invoice-date').value = data.invoice.invoice_date.split('T')[0];
    document.getElementById('invoice-terms').value = data.invoice.terms;
    document.getElementById('invoice-authorization').value = data.invoice.auth_code || '';
    document.getElementById('invoice-tax-exempt').checked = data.invoice.tax_exempt;
    document.getElementById('invoice-bill-to-name').value = data.invoice.bill_to_name || '';

    const sendDateEl = document.getElementById('invoice-send-date');
    if (sendDateEl) {
        sendDateEl.value = data.invoice.scheduled_send_date
            ? data.invoice.scheduled_send_date.split('T')[0] : '';
    }

    // Recurring fields
    const recurringCb = document.getElementById('invoice-recurring');
    const recurringInterval = document.getElementById('invoice-recurring-interval');
    const recurringGroup = document.getElementById('invoice-recurring-group');
    if (recurringCb) {
        recurringCb.checked = data.invoice.is_recurring || false;
        if (recurringInterval) recurringInterval.value = data.invoice.recurring_interval || 'monthly';
        if (recurringGroup) recurringGroup.style.display = data.invoice.is_recurring ? 'block' : 'none';
    }

    // Load items
    document.getElementById('invoice-items').innerHTML = '';
    resetItemCounter();
    data.items.forEach(item => {
        addItem('invoice-items', { item, type: 'invoice', laborRate: qboLaborRate, onUpdate: updateInvoiceTotals });
    });
    updateInvoiceTotals();
}

function prepareNewInvoice() {
    document.getElementById('invoice-modal-title').textContent = 'New Invoice';
    document.getElementById('invoice-form').reset();
    document.getElementById('invoice-items').innerHTML = '';
    document.getElementById('invoice-terms').value = 'Net 30';
    document.getElementById('invoice-number').value = '';
    document.getElementById('invoice-send-date').value = '';

    // Reset recurring
    const recurringCb = document.getElementById('invoice-recurring');
    const recurringGroup = document.getElementById('invoice-recurring-group');
    if (recurringCb) recurringCb.checked = false;
    if (recurringGroup) recurringGroup.style.display = 'none';

    resetItemCounter();
    setDefaultDate();
    addItem('invoice-items', { type: 'invoice', laborRate: qboLaborRate, onUpdate: updateInvoiceTotals });
}

export function addInvoiceItem(item = null) {
    addItem('invoice-items', { item, type: 'invoice', laborRate: qboLaborRate, onUpdate: updateInvoiceTotals });
}

export function updateInvoiceTotals() {
    const items = getItems('invoice-items');
    const taxExempt = document.getElementById('invoice-tax-exempt').checked;
    let subtotal = 0;
    items.forEach(item => {
        const amount = parseFloat(item.amount.replace(/[$,]/g, '')) || 0;
        subtotal += amount;
    });
    const taxAmount = taxExempt ? 0 : (subtotal * 8.25 / 100);
    const total = subtotal + taxAmount;
    document.getElementById('invoice-subtotal').textContent = `$${subtotal.toFixed(2)}`;
    document.getElementById('invoice-tax').textContent = taxExempt ? '$0.00' : `$${taxAmount.toFixed(2)}`;
    document.getElementById('invoice-total').textContent = `$${total.toFixed(2)}`;
    document.getElementById('invoice-tax-row').style.display = taxExempt ? 'none' : 'block';
}

export async function handleInvoiceSubmit(e) {
    e.preventDefault();
    const isRecurring = document.getElementById('invoice-recurring')?.checked || false;
    const recurringInterval = isRecurring
        ? (document.getElementById('invoice-recurring-interval')?.value || 'monthly') : null;

    const data = {
        invoice_number: document.getElementById('invoice-number').value || null,
        customer_id: document.getElementById('invoice-customer').value,
        invoice_date: document.getElementById('invoice-date').value,
        terms: document.getElementById('invoice-terms').value,
        auth_code: document.getElementById('invoice-authorization').value,
        tax_exempt: document.getElementById('invoice-tax-exempt').checked,
        scheduled_send_date: document.getElementById('invoice-send-date')?.value || null,
        bill_to_name: document.getElementById('invoice-bill-to-name')?.value || null,
        is_recurring: isRecurring,
        recurring_interval: recurringInterval,
        items: getItems('invoice-items')
    };

    if (!data.customer_id) { alert('Please select a customer.'); return; }
    if (!data.items || data.items.length === 0) { alert('Please add at least one item.'); return; }

    const invoiceId = currentInvoiceId;
    const url = invoiceId ? `/api/invoices/${invoiceId}` : '/api/invoices';
    const method = invoiceId ? 'PUT' : 'POST';
    showSpinner(invoiceId ? 'Saving invoice & syncing QBO...' : 'Creating invoice & exporting to QBO...');

    try {
        const response = await fetch(url, { method, headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(data) });
        const result = await response.json();
        if (response.ok) {
            closeInvoiceModal();
            if (result.qbo_doc_number) console.log(`✅ Invoice saved & exported to QBO: #${result.qbo_doc_number}`);
            else if (result.qbo_synced) console.log('✅ Invoice saved & synced to QBO');
            else console.log('✅ Invoice saved locally (QBO sync pending)');
            if (window.invoiceView) window.invoiceView.loadInvoices();
        } else {
            alert(`Error: ${result.error}`);
        }
    } catch (error) {
        console.error('Error:', error);
        alert('Error saving invoice');
    } finally {
        hideSpinner();
    }
}

export function initInvoiceModal() {
    const form = document.getElementById('invoice-form');
    if (form) form.addEventListener('submit', handleInvoiceSubmit);

    const taxExempt = document.getElementById('invoice-tax-exempt');
    if (taxExempt) taxExempt.addEventListener('change', updateInvoiceTotals);

    // Recurring toggle
    const recurringCb = document.getElementById('invoice-recurring');
    const recurringGroup = document.getElementById('invoice-recurring-group');
    if (recurringCb && recurringGroup) {
        recurringCb.addEventListener('change', () => {
            recurringGroup.style.display = recurringCb.checked ? 'block' : 'none';
        });
    }

    // Watch for customer selection → auto-set tax exempt (only for new invoices)
    const customerHidden = document.getElementById('invoice-customer');
    if (customerHidden) {
        const observer = new MutationObserver(() => {
            // Only auto-apply when creating new (not editing existing)
            if (!currentInvoiceId && customerHidden.value) {
                applyCustomerTaxStatus(customerHidden.value);
            }
        });
        observer.observe(customerHidden, { attributes: true, attributeFilter: ['value'] });
    }
}

window.openInvoiceModal = openInvoiceModal;
window.closeInvoiceModal = closeInvoiceModal;
window.addInvoiceItem = addInvoiceItem;