<?php
require_once __DIR__ . '/../db/config.php';
require_once '/usr/share/php/tcpdf/tcpdf.php';

// Extend TCPDF with custom Header and Footer
class MYPDF extends TCPDF {
    public function Header() {
        $this->SetFont('helvetica', 'B', 20);
        $this->Cell(0, 15, 'CRM PRO DOCUMENT', 0, false, 'L', 0, '', 0, false, 'M', 'M');
        $this->Ln(10);
        $this->SetFont('helvetica', '', 10);
        $this->Cell(0, 10, 'Your Trusted Partner in Education', 0, false, 'L', 0, '', 0, false, 'M', 'M');
        $this->Line(10, 30, 200, 30);
    }

    public function Footer() {
        $this->SetY(-15);
        $this->SetFont('helvetica', 'I', 8);
        $this->Cell(0, 10, 'Page '.$this->getAliasNumPage().'/'.$this->getAliasNbPages(), 0, false, 'C', 0, '', 0, false, 'T', 'M');
    }
}

class DocumentService {
    
    public static function generateQuotationPDF($id, $dest = 'I') {
        $stmt = db()->prepare("SELECT q.*, c.name as customer_name, c.email as customer_email, c.phone as customer_phone, c.address as customer_address 
                  FROM quotations q 
                  JOIN customers c ON q.customer_id = c.id 
                  WHERE q.id = ? AND q.deleted_at IS NULL");
        $stmt->execute([$id]);
        $quotation = $stmt->fetch();

        if (!$quotation) return null;

        $stmt = db()->prepare("SELECT qi.*, p.name as product_name 
                  FROM quotation_items qi 
                  JOIN products p ON qi.product_id = p.id 
                  WHERE qi.quotation_id = ?");
        $stmt->execute([$id]);
        $items = $stmt->fetchAll();

        $pdf = new MYPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, true, 'UTF-8', false);
        $pdf->SetCreator(PDF_CREATOR);
        $pdf->SetAuthor('CRM PRO');
        $pdf->SetTitle('Quotation ' . $quotation['quotation_number']);
        $pdf->SetMargins(PDF_MARGIN_LEFT, 40, PDF_MARGIN_RIGHT);
        $pdf->SetHeaderMargin(PDF_MARGIN_HEADER);
        $pdf->SetFooterMargin(PDF_MARGIN_FOOTER);
        $pdf->SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);
        $pdf->SetFont('helvetica', '', 10);
        $pdf->AddPage();

        $html = self::buildHtml($quotation, $items, 'Quotation');
        $pdf->writeHTML($html, true, false, true, false, '');

        return $pdf->Output('Quotation_' . $quotation['quotation_number'] . '.pdf', $dest);
    }

    public static function generateInvoicePDF($id, $dest = 'I') {
        $stmt = db()->prepare("SELECT i.*, c.name as customer_name, c.email as customer_email, c.phone as customer_phone, c.address as customer_address 
                  FROM invoices i 
                  JOIN customers c ON i.customer_id = c.id 
                  WHERE i.id = ? AND i.deleted_at IS NULL");
        $stmt->execute([$id]);
        $invoice = $stmt->fetch();

        if (!$invoice) return null;

        $stmt = db()->prepare("SELECT ii.*, p.name as product_name 
                  FROM invoice_items ii 
                  JOIN products p ON ii.product_id = p.id 
                  WHERE ii.invoice_id = ?");
        $stmt->execute([$id]);
        $items = $stmt->fetchAll();

        $pdf = new MYPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, true, 'UTF-8', false);
        $pdf->SetCreator(PDF_CREATOR);
        $pdf->SetAuthor('CRM PRO');
        $pdf->SetTitle('Invoice ' . $invoice['invoice_number']);
        $pdf->SetMargins(PDF_MARGIN_LEFT, 40, PDF_MARGIN_RIGHT);
        $pdf->SetHeaderMargin(PDF_MARGIN_HEADER);
        $pdf->SetFooterMargin(PDF_MARGIN_FOOTER);
        $pdf->SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);
        $pdf->SetFont('helvetica', '', 10);
        $pdf->AddPage();

        $html = self::buildHtml($invoice, $items, 'Invoice');
        $pdf->writeHTML($html, true, false, true, false, '');

        return $pdf->Output('Invoice_' . $invoice['invoice_number'] . '.pdf', $dest);
    }

    private static function buildHtml($doc, $items, $type) {
        $number_key = ($type == 'Quotation') ? 'quotation_number' : 'invoice_number';
        $date_key = 'issue_date';
        $expiry_key = ($type == 'Quotation') ? 'expiry_date' : 'due_date';
        $expiry_label = ($type == 'Quotation') ? 'Expiry' : 'Due Date';

        $html = '
        <table cellpadding="5">
            <tr>
                <td width="50%">
                    <strong>Bill To:</strong><br>
                    ' . e($doc['customer_name']) . '<br>
                    ' . nl2br(e($doc['customer_address'])) . '<br>
                    Email: ' . e($doc['customer_email']) . '<br>
                    Phone: ' . e($doc['customer_phone']) . '
                </td>
                <td width="50%" align="right">
                    <strong>' . $type . ' Details:</strong><br>
                    Number: ' . e($doc[$number_key]) . '<br>
                    Date: ' . date('M d, Y', strtotime($doc[$date_key])) . '<br>
                    ' . $expiry_label . ': ' . date('M d, Y', strtotime($doc[$expiry_key])) . '<br>
                    Status: ' . e($doc['status']) . '
                </td>
            </tr>
        </table>
        <br><br>
        <table border="1" cellpadding="5">
            <thead>
                <tr style="background-color: #f2f2f2; font-weight: bold;">
                    <th width="50%">Product/Service Description</th>
                    <th width="10%" align="center">Qty</th>
                    <th width="20%" align="right">Unit Price</th>
                    <th width="20%" align="right">Total</th>
                </tr>
            </thead>
            <tbody>';

        foreach ($items as $item) {
            $html .= '
                <tr>
                    <td>' . e($item['product_name']) . '</td>
                    <td align="center">' . number_format($item['quantity'], 2) . '</td>
                    <td align="right">' . format_currency($item['unit_price']) . '</td>
                    <td align="right">' . format_currency($item['total_price']) . '</td>
                </tr>';
        }

        $html .= '
            </tbody>
        </table>
        <br><br>
        <table cellpadding="5">
            <tr>
                <td width="60%">
                    <strong>Notes:</strong><br>
                    ' . nl2br(e($doc['notes'])) . '
                </td>
                <td width="40%">
                    <table cellpadding="2">
                        <tr>
                            <td><strong>Subtotal:</strong></td>
                            <td align="right">' . format_currency($doc['subtotal']) . '</td>
                        </tr>
                        <tr>
                            <td><strong>Tax (10%):</strong></td>
                            <td align="right">' . format_currency($doc['tax_amount']) . '</td>
                        </tr>
                        <tr style="font-size: 12pt; font-weight: bold;">
                            <td><strong>Total:</strong></td>
                            <td align="right">' . format_currency($doc['total_amount']) . '</td>
                        </tr>
                    </table>
                </td>
            </tr>
        </table>';
        return $html;
    }
}