import jsPDF from 'jspdf';
import autoTable from 'jspdf-autotable';
import { Transaction, PattiExpenses } from '../types';

export const formatINR = (v: number | string | null | undefined) => {
    const numeric = typeof v === 'number' ? v : Number(v);
    return `₹${(Number.isFinite(numeric) ? numeric : 0).toFixed(2)}`;
};
export const formatDate = (dateStr: string) => {
    const date = new Date(dateStr);
    return date.toLocaleDateString('en-IN', { day: '2-digit', month: '2-digit', year: 'numeric' });
};

const getPaymentModeLabel = (mode: string): string => {
    switch (mode.toLowerCase()) {
        case 'cash': return 'रोख (Cash)';
        case 'online': return 'ऑनलाइन (Online)';
        case 'cheque': return 'चेक (Cheque)';
        default: return mode;
    }
};

export const generateInvoicePDFDoc = (transaction: Transaction): jsPDF => {
    const doc = new jsPDF({
        orientation: 'portrait',
        unit: 'mm',
        format: 'a5'
    });

    // Calculate totals - handle both regular and Patti expense formats
    const isPatti = (transaction as any).bill_type === 'patti_jawaak' || (transaction as any).bill_type === 'patti_awaak';
    const isMixed = !!(transaction as any).is_mixed;
    const billTypeLabel = isMixed ? 'M' : (isPatti ? 'P' : 'R');
    const pattiExp = (transaction as any).expenses as PattiExpenses | undefined;

    const subtotal = transaction.subtotal || 0;
    const packing = isPatti && pattiExp ? (pattiExp.packing || 0) : (transaction.expenses?.poti_amount || 0);
    const cess = isPatti && pattiExp ? (pattiExp.godown || 0) : (transaction.expenses?.cess_amount || 0);
    const adat = isPatti && pattiExp ? (pattiExp.commission || 0) : (transaction.expenses?.adat_amount || 0);
    const hamali = isPatti && pattiExp
        ? ((pattiExp.hamali || 0))
        : ((transaction.expenses?.hamali_amount || 0) + (transaction.expenses?.packaging_hamali_amount || 0));
    const gaadiBharni = isPatti && pattiExp ? (pattiExp.gaadi_bhade || 0) : (transaction.expenses?.gaadi_bharni || 0);
    const otherExpenses = (isPatti && pattiExp ? pattiExp.other_expenses : transaction.expenses?.other_expenses) || 0;
    const grandTotal = transaction.total_amount || (subtotal + packing + cess + adat + hamali + gaadiBharni + otherExpenses);

    // NO GROUPING - each item shown separately (client requirement)
    const displayItems = transaction.items;

    // === INVOICE HEADER ===
    doc.setFontSize(24);
    doc.setFont('helvetica', 'bold');
    doc.text('INVOICE', 14, 20);

    // Bill No and Date on right
    doc.setFontSize(14);
    doc.setFont('helvetica', 'bold');
    doc.text(`Bill No: ${transaction.bill_number}`, 140, 15, { align: 'right' });
    
    doc.setFontSize(12);
    doc.setFont('helvetica', 'normal');
    doc.text(`Date: ${formatDate(transaction.bill_date)} (${billTypeLabel})`, 140, 22, { align: 'right' });

    // Header line
    doc.setLineWidth(2);
    doc.line(14, 28, 140, 28);

    // === PARTY SECTION — CENTERED ===
    const partyPhone = (transaction as any).party_phone;
    const actualPayments = (transaction.payments || []).filter((p: any) => p.mode !== 'due' && p.mode !== 'Due');
    const actualPaidAmount = actualPayments.reduce((sum: number, p: any) => sum + p.amount, 0);
    const calculatedDue = grandTotal - actualPaidAmount;
    const isPartial = actualPaidAmount > 0 && calculatedDue > 0;

    doc.setTextColor(0, 0, 0);
    doc.setFontSize(22);
    doc.setFont('helvetica', 'bold');
    
    // Center logic
    const partyNameText = transaction.party_name || '-';
    const payMethodText = (!isPartial && calculatedDue <= 0 && transaction.payment_method) ? ` (${transaction.payment_method})` : '';
    const fullText = partyNameText + payMethodText;
    
    doc.text(fullText, 74, 38, { align: 'center' });

    if (partyPhone) {
        doc.setFontSize(11);
        doc.setFont('helvetica', 'normal');
        doc.setTextColor(85, 85, 85);
        doc.text(`Mob: ${partyPhone}`, 74, 43, { align: 'center' });
        doc.setTextColor(0, 0, 0);
    }

    let nextY = 48;

    // === ITEMS TABLE — NO GROUPING ===
    const tableData = displayItems.map((item: any, idx: number) => {
        const potiWeights = Array.isArray(item.poti_weights) ? item.poti_weights.join(', ') : (typeof item.poti_weights === 'string' ? item.poti_weights : '-');
        const amount = (item.net_weight || 0) * (item.rate_per_kg || 0);
        const lotLabel = item.lot_number ? ` (${item.lot_number})` : '';
        return [
            idx + 1,
            `${item.mirchi_name || '-'}${lotLabel}\nWeights: ${potiWeights}`,
            item.poti_count || 0,
            (item.net_weight || 0).toFixed(2),
            formatINR(item.rate_per_kg),
            formatINR(amount)
        ];
    });

    autoTable(doc, {
        startY: nextY,
        head: [['#', 'मिरची', 'पोती', 'वजन', 'दर', 'एकूण']],
        body: tableData,
        theme: 'grid',
        styles: { fontSize: 10, cellPadding: 4, lineWidth: 0.5, lineColor: [0, 0, 0] },
        headStyles: { fillColor: [255, 255, 255], textColor: [0, 0, 0], fontStyle: 'bold', fontSize: 12 },
        bodyStyles: { textColor: [0, 0, 0] },
        columnStyles: {
            0: { halign: 'center', cellWidth: 10 },
            1: { halign: 'left', cellWidth: 45 },
            2: { halign: 'center', cellWidth: 15 },
            3: { halign: 'center', cellWidth: 20 },
            4: { halign: 'right', cellWidth: 20 },
            5: { halign: 'right', cellWidth: 22 }
        }
    });

    const finalY = (doc as any).lastAutoTable.finalY + 10;

    // === SUMMARY TABLE (Right side) ===
    const summaryData: string[][] = [];
    summaryData.push(['पॅकिंग', formatINR(packing)]);
    summaryData.push(['एकूण', formatINR(subtotal + packing)]);
    if (cess > 0) summaryData.push(['सेस', formatINR(cess)]);
    if (adat > 0) summaryData.push(['अडत', formatINR(adat)]);
    if (hamali > 0) summaryData.push(['हमाली', formatINR(hamali)]);
    if (gaadiBharni > 0) summaryData.push(['गाडी भाडे', formatINR(gaadiBharni)]);
    if (otherExpenses > 0) summaryData.push(['इतर खर्च', formatINR(otherExpenses)]);
    summaryData.push(['पूर्ण रक्कम', formatINR(grandTotal)]);

    // === PAYMENT SUMMARY — WITH PAYMENT MODE ===
    const actualPay = (transaction.payments || []).filter((p: any) => p.mode !== 'due' && p.mode !== 'Due');
    const actualP = actualPay.reduce((sum: number, p: any) => sum + p.amount, 0);
    const calcDue = grandTotal - actualP;
    const isP = actualP > 0 && calcDue > 0;

    if (actualPay.length > 0) {
        summaryData.push([isP ? 'जमा (Partial)' : 'जमा', formatINR(actualP)]);
        actualPay.forEach((p: any) => {
            summaryData.push([`${getPaymentModeLabel(p.mode)} ${p.reference ? `(${p.reference})` : ''}`, formatINR(p.amount)]);
        });
    } else {
        summaryData.push(['जमा', formatINR(0)]);
    }

    if (calcDue > 0) {
        summaryData.push(['येणे बाकी', formatINR(calcDue)]);
    }

    autoTable(doc, {
        startY: finalY,
        body: summaryData,
        theme: 'grid',
        styles: { fontSize: 10, cellPadding: 3, lineWidth: 0.5, lineColor: [200, 200, 200], font: 'NotoSansDevanagari' },
        bodyStyles: { textColor: [0, 0, 0] },
        columnStyles: {
            0: { halign: 'left', cellWidth: 35 },
            1: { halign: 'right', cellWidth: 30 }
        },
        margin: { left: 85 }
    });

    return doc;
};

// shareInvoiceToWhatsApp is now handled exclusively in invoiceUtils.ts