import { NextRequest } from 'next/server';
import { getInvoiceWithItems, getCompanyConfig, getBankDetails } from '@/lib/invoice';
import { initializeDatabase } from '@/lib/database';
import jsPDF from 'jspdf';
import { readFileSync, existsSync, writeFileSync, mkdirSync } from 'fs';
import path from 'path';

export async function GET(request: NextRequest, { params }: { params: { id: string } }) {
    await initializeDatabase();
    const invoiceId = Number(params.id);
    const pdfDir = path.join(process.cwd(), 'public', 'invoices');
    const pdfPath = path.join(pdfDir, `invoice-${invoiceId}.pdf`);
    if (existsSync(pdfPath)) {
        const pdfBuffer = readFileSync(pdfPath);
        return new Response(pdfBuffer, {
            status: 200,
            headers: {
                'Content-Type': 'application/pdf',
                'Content-Disposition': `attachment; filename=invoice-${invoiceId}.pdf`,
                'Content-Length': String(pdfBuffer.length),
            },
        });
    } else {
        // Regenerate PDF if not found
        const invoiceData = await getInvoiceWithItems(invoiceId);
        if (!invoiceData) {
            return new Response('Invoice not found', { status: 404 });
        }
        const company = await getCompanyConfig();
        const bank = await getBankDetails();
        // Load logo as base64 (prefer company_logo if present)
        let logoBase64 = '';
        // Fix company config type if it's an array or RowDataPacket[]
        const companyData = Array.isArray(company) ? company[0] : company;
        // If companyData is a RowDataPacket, convert to plain object
        const plainCompany = (companyData && typeof companyData.toJSON === 'function') ? companyData.toJSON() : companyData;
        // Calculate logo size to fit max height 50px and max width 160px, preserving aspect ratio
        let logoWidth = 200, logoHeight = 50;
        try {
            let logoPath = '';
            if (companyData?.company_logo) {
                let logoRelPath = companyData.company_logo.replace(/^\/+/, '')
                if (!logoRelPath.startsWith('uploads/')) {
                    logoRelPath = 'uploads/' + logoRelPath;
                }
                logoPath = path.join(process.cwd(), 'public', logoRelPath);
            } else {
                logoPath = path.join(process.cwd(), 'public', 'logo.png');
            }
            const logoBuffer = readFileSync(logoPath);
            logoBase64 = logoBuffer.toString('base64');
        } catch (e) {
            console.error('Logo read error:', e);
        }
        const doc = new jsPDF({ unit: 'pt', format: 'a4' });
        let imageType = 'PNG';
        if (plainCompany?.company_logo && plainCompany.company_logo.match(/\.svg$/i)) {
            imageType = 'SVG';
        } else if (plainCompany?.company_logo && plainCompany.company_logo.match(/\.jpg$|\.jpeg$/i)) {
            imageType = 'JPEG';
        }
        if (logoBase64) {
            // Place logo on the left, vertically aligned with company info
            doc.addImage(`data:image/${imageType.toLowerCase()};base64,${logoBase64}`, imageType, 40, 30, logoWidth, logoHeight);
        }
        doc.setFontSize(16);
        doc.setFont('helvetica', 'bold');
        doc.text(plainCompany?.name || 'Company Name', 425, 45, { maxWidth: 160, align: 'right' });
        doc.setFontSize(8);
        doc.setFont('helvetica', 'normal');
        doc.text('a web & mobile dev company', 550, 50, { maxWidth: 160, align: 'right' });
        doc.setFontSize(10);
        doc.setFont('helvetica', 'normal');
        let companyAddress = (plainCompany?.address || '').replace(/\n|\r/g, ', ');
        doc.text(companyAddress, 525, 70, { maxWidth: 300, align: 'right' });
        doc.text(plainCompany?.contact || '', 400, 80, { maxWidth: 300, align: 'right' });
        doc.text(plainCompany?.email || '', 400, 90, { maxWidth: 300, align: 'right' });
        doc.text('GSTIN-23XXXXXPS9604H1Z1', 535, 90, { maxWidth: 300, align: 'right' });

        doc.setFontSize(13);
        doc.setFont('helvetica', 'bold');
        doc.text('Software Service Invoice', 200, 125);
        doc.setFont('helvetica', 'normal');
        doc.setFontSize(10);
        // Draw a line as separation
        doc.setLineWidth(0.5);
        doc.line(30, 130, 570, 130);

        // --- Bill To Block ---
        let billToY = 150;
        doc.setFont('helvetica', 'normal');
        doc.text('Bill To', 40, billToY);
        doc.setFont('helvetica', 'bold');
        let billToYNext = billToY + 10;
        // 1. Client company name
        if (invoiceData.invoice.client_company_name) {
            // billToYNext += 15;
            doc.text(invoiceData.invoice.client_company_name, 40, billToYNext);
        }
        doc.setFont('helvetica', 'normal');
        // 2. Client address (split into lines)
        const addressLines = (invoiceData.invoice.client_address || '').split(/\r?\n/);
        for (const line of addressLines) {
            billToYNext += 15;
            doc.text(line.trim(), 40, billToYNext, { maxWidth: 250 });
        }

        // 3. KA and Email for client
        billToYNext += 15;
        doc.setFont('helvetica', 'bold');
        doc.text(`KA: ${invoiceData.invoice.client_name} /`, 40, billToYNext, { maxWidth: 250 });
        doc.setFont('helvetica', 'normal');
        doc.text(`Email: ${invoiceData.invoice.client_email}`, 150, billToYNext, { maxWidth: 250 });


        // --- End Bill To Block ---
        // Remove company KA from Bill To, move to footer (already present in footer section below)
        // --- Remove double border: only draw one outer border at the end ---
        let infoY_pdf = 150;
        doc.setFont('helvetica', 'normal');
        doc.text('Date', 350, infoY_pdf);
        doc.setFont('helvetica', 'bold');
        doc.text(new Date(invoiceData.invoice.invoice_date).toLocaleDateString(), 450, infoY_pdf);
        infoY_pdf += 15;
        doc.setFont('helvetica', 'normal');
        doc.text('Invoice No.', 350, infoY_pdf);
        doc.setFont('helvetica', 'bold');
        doc.text(invoiceData.invoice.invoice_number, 450, infoY_pdf);
        infoY_pdf += 15;
        doc.setFont('helvetica', 'normal');
        doc.text('Period', 350, infoY_pdf);
        doc.setFont('helvetica', 'bold');
        doc.text(invoiceData.invoice.period || '', 450, infoY_pdf);
        infoY_pdf += 15;
        doc.setFont('helvetica', 'normal');
        doc.text('Term', 350, infoY_pdf);
        doc.setFont('helvetica', 'bold');
        doc.text(invoiceData.invoice.term || '', 450, infoY_pdf);
        infoY_pdf += 15;
        doc.setFont('helvetica', 'normal');
        doc.text('Project code', 350, infoY_pdf);
        doc.setFont('helvetica', 'bold');
        doc.text(invoiceData.invoice.project_code || '', 450, infoY_pdf);
        let y = Math.max(billToYNext + 60, infoY_pdf + 20);

        // Draw a line as separation
        doc.setLineWidth(0.5);
        doc.line(30, 240, 570, 240);

        doc.setFontSize(11);
        doc.setFont('helvetica', 'bold');

        doc.text('Description', 45, y);
        doc.text('Rate', 300, y, { align: 'center' });
        doc.text('Amount (USD)', 400, y, { align: 'right' });
        // Draw Rate sub-columns
        doc.setFont('helvetica', 'bold');
        doc.text('Base', 250, y + 15, { align: 'center' });
        doc.text('Unit', 350, y + 15, { align: 'center' });
        // Draw a line as separation
        doc.setLineWidth(0.5);
        doc.line(30, 270, 570, 270);
        // Draw header lines
        doc.setLineWidth(0.5);
        //doc.line(40, y + 5, 550, y + 5); // under main header
        // doc.line(220, y, 220, y + 30); // left border of Rate
        // doc.line(380, y, 380, y + 30); // right border of Rate
        //  doc.line(300, y + 5, 300, y + 30); // between Base and Unit
        //   doc.line(40, y + 30, 550, y + 30); // under sub-header
        y += 40;
        doc.setFontSize(10);
        doc.setFont('helvetica', 'normal');
        // Fix: ensure items are always InvoiceItem[]
        const items = Array.isArray(invoiceData.items) ? (invoiceData.items as any[]) : [];
        items.forEach((item: any, idx: number) => {
            doc.text(`${idx + 1}. ${item.description || ''}`, 45, y);
            doc.text(String(item.base_rate ?? ''), 250, y, { align: 'center', maxWidth: 50 });
            doc.text(String(item.unit ?? ''), 350, y, { align: 'center', maxWidth: 30 });
            doc.text(String(item.amount ?? ''), 480, y, { align: 'right', maxWidth: 60 });
            //doc.setDrawColor(220);            
            y += 18;
        });
        if (invoiceData.invoice.payment_charges && Number(invoiceData.invoice.payment_charges) > 0) {
            doc.setFont('helvetica', 'bold');
            doc.text('Payment Transfer Charges', 45, y);
            doc.setFont('helvetica', 'normal');
            doc.text('35', 250, y, { align: 'center' });
            doc.text('1.00', 350, y, { align: 'center' });
            doc.text(String(invoiceData.invoice.payment_charges), 480, y, { align: 'right' });
            //doc.setDrawColor(220);

            y += 18;
        }
        y += 10;
        doc.getLineWidth(0.5);
        doc.line(30, y, 570, y); // horizontal line
        doc.setFont('helvetica', 'bold');
        doc.setFontSize(12);
        doc.text('Net Balance Due', 300, y);
        doc.text(String(invoiceData.invoice.total), 400, y, { align: 'right' });
        doc.text('USD', 480, y, { align: 'right' });
        doc.setFont('helvetica', 'normal');
        y += 30;
        doc.setFontSize(9);
        if (plainCompany?.hsn_sac) {
            doc.text(`HSN / SAC: ${plainCompany.hsn_sac}`, 45, y);
        }
        doc.text('SUPPLY/MENT FOR EXPORT UNDER LUT WITHOUT PAYMENT OF INTEGRATED TAX', 200, y);
        y += 30;
        doc.setFontSize(10);
        doc.setFont('helvetica', 'bold');
        doc.text('We appreciate your business, thank you', 45, y);
        y += 15;
        doc.setFont('helvetica', 'normal');
        doc.text(`KA: ${plainCompany?.admin_name || ''}, ${plainCompany?.admin_department || ''}`, 45, y);
        y += 15;
        doc.text('Please wire as per bank details below & send SWIFT / bank advisory to ' + (plainCompany?.email || ''), 45, y, { maxWidth: 500 });
        y += 15;
        doc.setFont('helvetica', 'bold');
        doc.text('For credit to', 45, y);
        doc.setFont('helvetica', 'normal');
        doc.text(`${plainCompany?.name || ''}, ${plainCompany?.address || ''}`, 120, y, { maxWidth: 350 });
        y += 15;
        doc.setFont('helvetica', 'bold');
        doc.text('Account with', 45, y);
        doc.setFont('helvetica', 'normal');
        doc.text(bank?.bank_name || '', 120, y);
        y += 15;
        doc.setFont('helvetica', 'bold');
        doc.text('Bank/Branch address', 45, y);
        doc.setFont('helvetica', 'normal');
        doc.text(bank?.bank_address || '', 150, y);
        y += 15;
        doc.setFont('helvetica', 'bold');
        doc.text('SWIFT', 45, y);
        doc.setFont('helvetica', 'normal');
        doc.text(bank?.swift_code || '', 120, y);
        y += 15;
        doc.setFont('helvetica', 'bold');
        doc.text('IFSC CODE', 45, y);
        doc.setFont('helvetica', 'normal');
        doc.text(bank?.ifsc_code || '', 120, y);
        y += 15;
        doc.setFont('helvetica', 'bold');
        doc.text('Bank Wire Charges', 45, y);
        doc.setFont('helvetica', 'normal');
        doc.text('On client side', 150, y);
        y += 20;
        doc.setFontSize(8);
        doc.setFont('helvetica', 'italic');
        doc.text('Late payments charges, if paid later than 7days per terms, @ 1.5% monthly interest or USD 35, whichever is greater', 45, y, { maxWidth: 500 });
        // Draw a visible border around the entire invoice content (outer box) ONCE at the end
        doc.setDrawColor(30, 30, 30); // dark border
        doc.setLineWidth(2);
        // (x, y, width, height) - adjust as needed to fit all content
        doc.rect(30, 20, 540, y + 180, 'S');
        // Output PDF and save to disk
        const pdf = doc.output('arraybuffer');
        const pdfBuffer = Buffer.from(new Uint8Array(pdf));
        mkdirSync(pdfDir, { recursive: true });
        writeFileSync(pdfPath, new Uint8Array(pdfBuffer));
        // Serve the file
        return new Response(pdfBuffer, {
            status: 200,
            headers: {
                'Content-Type': 'application/pdf',
                'Content-Disposition': `attachment; filename=invoice-${invoiceId}.pdf`,
                'Content-Length': String(pdfBuffer.length),
            },
        });
    }
}