<?php

namespace App\Libraries;

use App\Models\ClientModel;
use App\Models\LeadsModel;
use App\Models\RFQModel;
use Mpdf\Mpdf;
use Mpdf\Output\Destination;

/**
 * Builds the GMC Quote Comparison Report PDF:
 * cover (client) + static front + dynamic QCR pages + static back.
 */
class GmcQcrPdfService
{
    public const GMC_POLICY_TYPE_IDS = [2, 3, 4, 5];

    private const PAGE_W_MM = 338.6667; // 960 pt
    private const PAGE_H_MM = 190.5;    // 540 pt
    private const ROWS_PER_PAGE = 18;
    private const COLS_PER_PAGE = 5;

    private RFQModel $rfqModel;
    private LeadsModel $leadsModel;
    private ClientModel $clientModel;

    public function __construct(?RFQModel $rfqModel = null, ?LeadsModel $leadsModel = null, ?ClientModel $clientModel = null)
    {
        $this->rfqModel    = $rfqModel ?? new RFQModel();
        $this->leadsModel  = $leadsModel ?? new LeadsModel();
        $this->clientModel = $clientModel ?? new ClientModel();
    }

    public static function isGmc(int $policyTypeId): bool
    {
        return in_array($policyTypeId, self::GMC_POLICY_TYPE_IDS, true);
    }

    /**
     * @return array{status:bool,message:string,file_name?:string,file_path?:string,download_name?:string}
     */
    /**
     * @param int $leadId
     * @param array|null $selectedProposals If provided, only include these proposal names
     */
    public function generate(int $leadId, ?array $selectedProposals = null): array
    {
        $lead = $this->leadsModel
            ->select('leads.*, policy_type.policy_type, policy_type.long_name')
            ->join('policy_type', 'leads.policy_type_id = policy_type.id', 'left')
            ->where('leads.id', $leadId)
            ->where('leads.is_active', 1)
            ->first();

        if (! $lead) {
            return ['status' => false, 'message' => 'Opportunity not found'];
        }

        if (! self::isGmc((int) ($lead['policy_type_id'] ?? 0))) {
            return ['status' => false, 'message' => 'GMC QCR PDF is only available for GMC policies'];
        }

        // Primary: explicit QCR row (type=2)
        $rfq = $this->rfqModel
            ->where('lead_id', $leadId)
            ->where('type', 2)
            ->where('is_active', 1)
            ->orderBy('id', 'desc')
            ->first();

        // Fallback: some older leads/pages show latest active RFQ row on QCR view.
        // If explicit QCR is missing, use latest active saved table JSON.
        if (! $rfq || empty($rfq['json'])) {
            $rfq = $this->rfqModel
                ->where('lead_id', $leadId)
                ->where('is_active', 1)
                ->orderBy('id', 'desc')
                ->first();
        }

        if (! $rfq || empty($rfq['json'])) {
            return ['status' => false, 'message' => 'No saved proposal table data found. Please save this page first.'];
        }

        $qcrJson = json_decode($rfq['json'], true);
        if (! is_array($qcrJson) || empty($qcrJson['table_data'])) {
            return ['status' => false, 'message' => 'QCR data is invalid or empty'];
        }

        $clientName = trim((string) ($lead['client_name'] ?? 'Client'));
        $logoPath  = $this->resolveClientLogoPath((int) ($lead['client_id'] ?? 0));
        $nhanceLogo = ROOTPATH . 'public/assets/images/Nhance-Logo-Final.png';

        $coveragePages = $this->buildCoveragePages($qcrJson, $selectedProposals);
        $premiumSections = $this->buildPremiumSections($qcrJson, $selectedProposals);

        if (empty($coveragePages) && empty($premiumSections)) {
            return ['status' => false, 'message' => 'No QCR-enabled proposals found to include in the PDF'];
        }

        $frontPdf = ROOTPATH . 'public/assets/qcr_gmc/static_front.pdf';
        $backPdf  = ROOTPATH . 'public/assets/qcr_gmc/static_back.pdf';
        if (! is_file($frontPdf) || ! is_file($backPdf)) {
            return ['status' => false, 'message' => 'Static GMC QCR template PDFs are missing'];
        }

        $tempDir = rtrim(WRITEPATH, '/\\') . DIRECTORY_SEPARATOR . 'cache' . DIRECTORY_SEPARATOR . 'gmc_qcr_mpdf';
        if (! is_dir($tempDir)) {
            @mkdir($tempDir, 0775, true);
        }
        $mpdfNested = $tempDir . DIRECTORY_SEPARATOR . 'mpdf';
        if (! is_dir($mpdfNested)) {
            @mkdir($mpdfNested, 0775, true);
        }

        $outDir = rtrim(WRITEPATH, '/\\') . DIRECTORY_SEPARATOR . 'uploads' . DIRECTORY_SEPARATOR . 'qcr_pdf' . DIRECTORY_SEPARATOR;
        if (! is_dir($outDir)) {
            @mkdir($outDir, 0775, true);
        }

        $safeClient = preg_replace('/[^A-Za-z0-9_\- ]+/', '', $clientName) ?: 'Client';
        $safeClient = trim(preg_replace('/\s+/', ' ', $safeClient));
        $downloadName = $safeClient . ' GMC Quote comparison.-' . date('d-F-Y') . '.pdf';
        $storedName   = 'gmc_qcr_' . $leadId . '_' . time() . '_' . bin2hex(random_bytes(3)) . '.pdf';
        $outPath      = $outDir . $storedName;

        try {
            $mpdf = new Mpdf([
                'tempDir'      => $tempDir,
                'mode'         => 'utf-8',
                'format'       => [self::PAGE_W_MM, self::PAGE_H_MM],
                'orientation'  => 'P',
                'margin_left'  => 0,
                'margin_right' => 0,
                'margin_top'   => 0,
                'margin_bottom'=> 0,
            ]);

            // 1) Cover
            $mpdf->AddPageByArray($this->pageArray());
            $mpdf->WriteHTML($this->renderCoverHtml($clientName, $logoPath, $nhanceLogo));

            // 2) Static front (pages 2–7 from master)
            $this->importPdfPages($mpdf, $frontPdf, $tempDir);

            // 3) Dynamic coverage pages — one set per proposal (Quote Asked only)
            foreach ($coveragePages as $page) {
                $rowChunks = array_chunk($page['rows'], self::ROWS_PER_PAGE);
                foreach ($rowChunks as $chunkIdx => $chunk) {
                    $mpdf->AddPageByArray($this->pageArray());
                    $mpdf->WriteHTML($this->renderCoverageHtml(
                        $page['title'],
                        $chunk,
                        $nhanceLogo,
                        $chunkIdx === 0
                    ));
                }
            }

            // 4) Quote Comparison — insurers with premium data
            if (! empty($premiumSections)) {
                $mpdf->AddPageByArray($this->pageArray());
                $mpdf->WriteHTML($this->renderPremiumHtml($premiumSections, $nhanceLogo));
            }

            // 5) Static back (last 3)
            $this->importPdfPages($mpdf, $backPdf, $tempDir);

            $mpdf->Output($outPath, Destination::FILE);
        } catch (\Throwable $e) {
            log_message('error', 'GmcQcrPdfService::generate failed | lead_id=' . $leadId . ' | ' . $e->getMessage());
            return ['status' => false, 'message' => 'PDF generation failed: ' . $e->getMessage()];
        }

        if (! is_file($outPath)) {
            return ['status' => false, 'message' => 'PDF file was not created'];
        }

        $this->persistGeneratedPath($lead, $storedName, $downloadName);

        return [
            'status'         => true,
            'message'        => 'GMC QCR PDF generated successfully',
            'file_name'      => $storedName,
            'file_path'      => $outPath,
            'download_name'  => $downloadName,
        ];
    }

    /**
     * @return array{status:bool,message:string,file_path?:string,download_name?:string}
     */
    public function resolveDownload(int $leadId): array
    {
        $lead = $this->leadsModel->where('id', $leadId)->where('is_active', 1)->first();
        if (! $lead) {
            return ['status' => false, 'message' => 'Opportunity not found'];
        }
        if (! self::isGmc((int) ($lead['policy_type_id'] ?? 0))) {
            return ['status' => false, 'message' => 'GMC QCR PDF is only available for GMC policies'];
        }

        $misc = [];
        if (! empty($lead['misc'])) {
            $decoded = json_decode($lead['misc'], true);
            if (is_array($decoded)) {
                $misc = $decoded;
            }
        }

        $storedName   = $misc['gmc_qcr_pdf'] ?? null;
        $downloadName = $misc['gmc_qcr_pdf_download_name'] ?? null;
        if (! $storedName) {
            return ['status' => false, 'message' => 'No generated PDF found. Please click Generate first.'];
        }

        $path = rtrim(WRITEPATH, '/\\') . DIRECTORY_SEPARATOR . 'uploads' . DIRECTORY_SEPARATOR . 'qcr_pdf' . DIRECTORY_SEPARATOR . $storedName;
        if (! is_file($path)) {
            return ['status' => false, 'message' => 'Generated PDF file is missing. Please Generate again.'];
        }

        if (! $downloadName) {
            $clientName = trim((string) ($lead['client_name'] ?? 'Client'));
            $downloadName = $clientName . ' GMC Quote comparison.-' . date('d-F-Y') . '.pdf';
        }

        return [
            'status'        => true,
            'message'       => 'OK',
            'file_path'     => $path,
            'download_name' => $downloadName,
        ];
    }

    private function pageArray(): array
    {
        return [
            'orientation'  => 'P',
            'sheet-size'   => [self::PAGE_W_MM, self::PAGE_H_MM],
            'margin-left'  => 0,
            'margin-right' => 0,
            'margin-top'   => 0,
            'margin-bottom'=> 0,
        ];
    }

    private function resolveClientLogoPath(int $clientId): ?string
    {
        if ($clientId <= 0) {
            return null;
        }
        $client = $this->clientModel->select('client_logo')->where('id', $clientId)->where('is_active', 1)->first();
        if (empty($client['client_logo'])) {
            return null;
        }
        $path = ROOTPATH . 'public/uploads/logo/' . $client['client_logo'];
        return is_file($path) ? $path : null;
    }

    /**
     * Build one coverage page set per QCR-enabled proposal.
     * Each page shows only the "Quote Asked" column (2-col table like original).
     *
     * @return list<array{title:string,rows:list<array{particular:string,value:string}>}>
     */
    private function buildCoveragePages(array $qcrJson, ?array $selectedProposals = null): array
    {
        $proposalMeta = $qcrJson['proposal_data']['over_all_column_data'] ?? [];
        $headers      = $qcrJson['table_data']['headers'] ?? [];
        $dataRows     = $qcrJson['table_data']['data'] ?? [];

        // Collect QCR-enabled proposals that have a Quote Asked column
        $proposals = [];
        foreach ($headers as $header) {
            $parent = (string) ($header['parentHeader'] ?? '');
            if (in_array($parent, ['Sno', 'Item Key', 'Particulars', 'Action', ''], true)) {
                continue;
            }
            $meta = $proposalMeta[$parent] ?? null;
            $proposalQcr = $meta === null ? 1 : (int) ($meta['qcr'] ?? 0);
            if ($proposalQcr !== 1) {
                continue;
            }
            // Filter by user-selected proposals if provided
            if ($selectedProposals !== null && ! in_array($parent, $selectedProposals, true)) {
                continue;
            }
            $subs = $header['subHeaders'] ?? [];
            if (in_array('Quote Asked', $subs, true) && ! isset($proposals[$parent])) {
                $proposals[$parent] = true;
            }
        }

        $pages = [];
        foreach (array_keys($proposals) as $proposalName) {
            $rows = [];
            foreach ($dataRows as $row) {
                $actionQcr  = 1;
                $particular = '';
                $value      = '';

                foreach (($row['data'] ?? []) as $cell) {
                    $parent = (string) ($cell['parentth'] ?? '');
                    $sub    = (string) ($cell['subth'] ?? '');
                    $raw    = $cell['value'] ?? $cell['input_value'] ?? '';
                    if (is_array($raw)) {
                        if (isset($raw['qcr'])) {
                            $actionQcr = (int) $raw['qcr'];
                        }
                        $raw = '';
                    }
                    $text = trim(html_entity_decode(strip_tags((string) $raw)));

                    if ($parent === 'Particulars') {
                        $particular = $text;
                    } elseif ($parent === $proposalName && $sub === 'Quote Asked') {
                        $value = $text;
                    } elseif ($parent === 'Action' && is_array($cell['value'] ?? $cell['input_value'] ?? null)) {
                        $actionQcr = (int) (($cell['value'] ?? $cell['input_value'] ?? [])['qcr'] ?? 1);
                    }
                }

                if ($actionQcr !== 1 || $particular === '') {
                    continue;
                }
                $rows[] = ['particular' => $particular, 'value' => $value];
            }

            if (! empty($rows)) {
                $pages[] = [
                    'title' => 'GMC Policy Coverage ' . $proposalName,
                    'rows'  => $rows,
                ];
            }
        }

        return $pages;
    }

    /**
     * Build Quote Comparison sections from premium_data — insurers only (not Quote Asked).
     *
     * @return list<array{title:string,rows:list<array{insurer:string,premium:string,gst:string,total:string}>}>
     */
    private function buildPremiumSections(array $qcrJson, ?array $selectedProposals = null): array
    {
        $premiumData  = $qcrJson['premium_data']['data'] ?? [];
        $proposalMeta = $qcrJson['proposal_data']['over_all_column_data'] ?? [];
        if (! is_array($premiumData) || empty($premiumData)) {
            return [];
        }

        $sections = [];
        foreach ($proposalMeta as $proposalName => $meta) {
            if ((int) ($meta['qcr'] ?? 0) !== 1) {
                continue;
            }
            if ($selectedProposals !== null && ! in_array($proposalName, $selectedProposals, true)) {
                continue;
            }
            $insMap = $premiumData[$proposalName] ?? [];
            if (! is_array($insMap)) {
                continue;
            }
            $sectionRows = [];
            foreach ($insMap as $insurerName => $metrics) {
                if ($insurerName === 'Quote Asked' || $insurerName === '' || ! is_array($metrics)) {
                    continue;
                }
                $premium = trim((string) ($metrics['Premium'] ?? ''));
                $gst     = trim((string) ($metrics['GST Amount (₹)'] ?? $metrics['GST Amount'] ?? ''));
                $total   = trim((string) ($metrics['Total'] ?? ''));
                if ($premium === '' && $total === '') {
                    continue;
                }
                if ($premium === 'Premium') {
                    continue;
                }
                $sectionRows[] = [
                    'insurer' => $insurerName,
                    'premium' => $premium,
                    'gst'     => $gst,
                    'total'   => $total,
                ];
            }
            if (! empty($sectionRows)) {
                $sections[] = [
                    'title' => 'GMC Quote – ' . $proposalName,
                    'rows'  => $sectionRows,
                ];
            }
        }

        return $sections;
    }

    private function importPdfPages(Mpdf $mpdf, string $pdfPath, string $tempDir): void
    {
        helper('merge_pdf');
        try {
            merge_ticket_pdf_add_pdf_pages($mpdf, $pdfPath, $tempDir);
        } catch (\Throwable $e) {
            // Fallback: import page-by-page with explicit sheet size
            $pageCount = $mpdf->setSourceFile($pdfPath);
            for ($p = 1; $p <= $pageCount; $p++) {
                $tplId = $mpdf->importPage($p);
                $mpdf->AddPageByArray($this->pageArray());
                $mpdf->useTemplate($tplId, 0, 0, self::PAGE_W_MM, self::PAGE_H_MM, false);
            }
        }
    }

    private function persistGeneratedPath(array $lead, string $storedName, string $downloadName): void
    {
        $misc = [];
        if (! empty($lead['misc'])) {
            $decoded = json_decode($lead['misc'], true);
            if (is_array($decoded)) {
                $misc = $decoded;
            }
        }

        // Remove previous file if present
        if (! empty($misc['gmc_qcr_pdf'])) {
            $old = rtrim(WRITEPATH, '/\\') . DIRECTORY_SEPARATOR . 'uploads' . DIRECTORY_SEPARATOR . 'qcr_pdf' . DIRECTORY_SEPARATOR . $misc['gmc_qcr_pdf'];
            if (is_file($old) && $misc['gmc_qcr_pdf'] !== $storedName) {
                @unlink($old);
            }
        }

        $misc['gmc_qcr_pdf'] = $storedName;
        $misc['gmc_qcr_pdf_download_name'] = $downloadName;
        $misc['gmc_qcr_pdf_generated_at'] = date('Y-m-d H:i:s');

        $this->leadsModel->update((int) $lead['id'], [
            'misc' => json_encode($misc),
        ]);
    }

    private function escape(string $value): string
    {
        return htmlspecialchars($value, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
    }

    private function renderCoverHtml(string $clientName, ?string $logoPath, string $nhanceLogo): string
    {
        $logoHtml = '';
        if ($logoPath) {
            $logoHtml = '<div style="margin-bottom:8mm;"><img src="' . $this->escape($logoPath) . '" style="max-height:55mm;max-width:100mm;" /></div>';
        }

        $nhance = is_file($nhanceLogo)
            ? '<img src="' . $this->escape($nhanceLogo) . '" style="height:10mm;" />'
            : '<span style="color:#0aa3a0;font-size:14pt;font-weight:bold;">Nhance</span>';

        return '
<html><head><style>
@page { margin: 0; }
body { margin:0; padding:0; font-family: freeserif, DejaVu Serif, serif; }
.wrap { width:100%; height:190mm; position:relative; text-align:center; }
.spacer { height:48mm; }
.client { color:#0b7f7c; font-size:16pt; margin-bottom:6mm; font-family: freeserif, DejaVu Serif, serif; }
.title { font-size:24pt; color:#1a2744; font-family: freeserif, DejaVu Serif, serif; }
.title em { color:#0b7f7c; font-style:italic; }
.footer-logo { position:absolute; left:12mm; bottom:8mm; }
.footer-bar { position:absolute; right:0; bottom:0; width:28mm; height:8mm; background:#0aa3a0; }
</style></head><body>
<div class="wrap">
  <div class="spacer">&nbsp;</div>
  ' . $logoHtml . '
  <div class="client">' . $this->escape($clientName) . '</div>
  <div class="title"><strong>Group</strong> <em>Medical Insurance</em> <strong>Quote</strong></div>
  <div class="footer-logo">' . $nhance . '</div>
  <div class="footer-bar"></div>
</div>
</body></html>';
    }

    /**
     * Render a coverage page (2-column: Particulars + value) matching original style.
     *
     * @param list<array{particular:string,value:string}> $rows
     */
    private function renderCoverageHtml(string $title, array $rows, string $nhanceLogo, bool $showTitle): string
    {
        $nhance = is_file($nhanceLogo)
            ? '<img src="' . $this->escape($nhanceLogo) . '" style="height:8mm;" />'
            : '<span style="color:#0aa3a0;font-size:11pt;font-weight:bold;">Nhance</span>';

        $thead = '<tr><th style="width:55%;">Particulars</th><th style="width:45%;">Expiring</th></tr>';

        $tbody = '';
        $i = 0;
        foreach ($rows as $row) {
            $bg = ($i % 2 === 0) ? '#ffffff' : '#f7fafa';
            $tbody .= '<tr style="background:' . $bg . ';">';
            $tbody .= '<td class="part">' . $this->escape($row['particular']) . '</td>';
            $tbody .= '<td>' . $this->escape($row['value']) . '</td>';
            $tbody .= '</tr>';
            $i++;
        }

        $titleBlock = $showTitle
            ? '<div class="title"><span class="bar"></span><strong>GMC</strong> <em>' . $this->escape(str_replace('GMC ', '', $title)) . '</em></div>'
            : '<div class="title-sm"><strong>GMC</strong> <em>' . $this->escape(str_replace('GMC ', '', $title)) . '</em> <span style="color:#666;font-size:9pt;">(continued)</span></div>';

        return '
<html><head><style>
body { margin:0; padding:0; font-family: dejavusans, sans-serif; color:#222; }
.page { padding:8mm 14mm 14mm 14mm; }
.title { font-family: freeserif, DejaVu Serif, serif; color:#1a2744; font-size:20pt; margin:0 0 5mm 0; padding-left:5mm; border-left:3mm solid #0aa3a0; }
.title em { color:#0aa3a0; font-style:italic; }
.title-sm { font-family: freeserif, DejaVu Serif, serif; color:#1a2744; font-size:16pt; margin:0 0 4mm 0; padding-left:5mm; border-left:3mm solid #0aa3a0; }
.title-sm em { color:#0aa3a0; font-style:italic; }
table { width:100%; border-collapse:collapse; table-layout:fixed; margin-top:2mm; }
th { background:#1a7a6e; color:#fff; font-size:9pt; padding:2.8mm 3mm; text-align:center; vertical-align:middle; font-family: dejavusans, sans-serif; }
td { font-size:8pt; padding:2.2mm 3mm; border-bottom:0.15mm solid #e0eded; text-align:center; vertical-align:middle; word-wrap:break-word; }
td.part { text-align:center; color:#333; }
.footer { position:absolute; left:12mm; bottom:5mm; }
</style></head><body>
<div class="page">
  ' . $titleBlock . '
  <table><thead>' . $thead . '</thead><tbody>' . $tbody . '</tbody></table>
</div>
<div class="footer">' . $nhance . '</div>
</body></html>';
    }

    /**
     * @param list<array{title:string,rows:list<array{insurer:string,premium:string,gst:string,total:string}>}> $sections
     */
    private function renderPremiumHtml(array $sections, string $nhanceLogo): string
    {
        $nhance = is_file($nhanceLogo)
            ? '<img src="' . $this->escape($nhanceLogo) . '" style="height:8mm;" />'
            : '<span style="color:#0aa3a0;font-size:11pt;font-weight:bold;">Nhance</span>';

        $body = '';
        foreach ($sections as $section) {
            $body .= '<div class="section-title">' . $this->escape($section['title']) . '</div>';
            $body .= '<table><thead><tr>
                <th style="width:40%;">Insurer Name</th>
                <th style="width:20%;">Premium</th>
                <th style="width:20%;">GST</th>
                <th style="width:20%;">Total Premium</th>
            </tr></thead><tbody>';
            $i = 0;
            foreach ($section['rows'] as $row) {
                $bg = ($i % 2 === 0) ? '#ffffff' : '#f7fafa';
                $body .= '<tr style="background:' . $bg . ';">
                    <td class="left">' . $this->escape($row['insurer']) . '</td>
                    <td>' . $this->escape($row['premium']) . '</td>
                    <td>' . $this->escape($row['gst']) . '</td>
                    <td>' . $this->escape($row['total']) . '</td>
                </tr>';
                $i++;
            }
            $body .= '</tbody></table>';
        }

        return '
<html><head><style>
body { margin:0; padding:0; font-family: dejavusans, sans-serif; color:#222; }
.page { padding:8mm 14mm 14mm 14mm; }
.title { font-family: freeserif, DejaVu Serif, serif; color:#1a2744; font-size:20pt; margin:0 0 6mm 0; border-left:3mm solid #0aa3a0; padding-left:5mm; }
.title em { color:#0aa3a0; font-style:italic; }
.section-title { font-size:10pt; font-weight:bold; margin:5mm 0 2mm 0; font-family: dejavusans, sans-serif; }
table { width:100%; border-collapse:collapse; margin-bottom:4mm; }
th { background:#1a7a6e; color:#fff; font-size:9pt; padding:2.8mm 3mm; text-align:center; font-family: dejavusans, sans-serif; }
td { font-size:8.5pt; padding:2.5mm 3mm; border-bottom:0.15mm solid #e0eded; text-align:center; }
td.left { text-align:left; }
.footer { position:absolute; left:12mm; bottom:5mm; }
</style></head><body>
<div class="page">
  <div class="title"><strong>Quote</strong> <em>Comparison</em></div>
  ' . $body . '
</div>
<div class="footer">' . $nhance . '</div>
</body></html>';
    }
}