<?php

namespace App\Http\Controllers\Api;

use App\Models\Configuration;
use App\Models\LateSlipLog;
use App\Models\User;
use Carbon\Carbon;
use Dompdf\Dompdf;
use Dompdf\Options;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Response;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Session;
use Mike42\Escpos\Printer;
use Mike42\Escpos\PrintConnectors\NetworkPrintConnector;
use Mike42\Escpos\PrintConnectors\UsbPrintConnector;
use Mike42\Escpos\PrintConnectors\WindowsPrintConnector;
use Symfony\Component\HttpFoundation\BinaryFileResponse;
use Symfony\Component\HttpFoundation\Response as SymfonyResponse;

class SlipPrinterController extends BaseApiController
{
    protected Configuration $config;
    protected LateSlipLog $log;
    protected User $user;
    protected string $schoolYear;
    protected string $semester;

    public function __construct()
    {
        parent::__construct();
        $this->config = model(Configuration::class);
        $this->log    = model(LateSlipLog::class);
        $this->user   = model(User::class);
        $this->schoolYear  = (string) ($this->config->getConfig('school_year') ?? '');
        $this->semester    = (string) ($this->config->getConfig('semester') ?? '');
    }

    /**
     * POST /api/v1/slips/print
     * Generate and return a PDF late slip
     */
    public function print(): SymfonyResponse|JsonResponse
    {
        $data = $this->payloadData();

        $slipData = [
            'school_year' => trim((string) ($data['school_year'] ?? $this->schoolYear ?: '')),
            'student_name' => trim((string) ($data['student_name'] ?? '')),
            'date'        => trim((string) ($data['date'] ?? date('m/d/Y'))),
            'time_in'     => trim((string) ($data['time_in'] ?? date('h:i A'))),
            'grade'       => trim((string) ($data['grade'] ?? '')),
            'reason'      => trim((string) ($data['reason'] ?? '')),
            'admin_name'  => trim((string) ($data['admin_name'] ?? '')),
        ];

        // Always prefer current logged-in user's full name from DB
        $adminFromDb = $this->currentAdminName();
        if ($adminFromDb !== '') {
            $slipData['admin_name'] = $adminFromDb;
        }

        // Validate minimal fields
        if ($slipData['student_name'] === '') {
            return $this->error('Student name is required.', SymfonyResponse::HTTP_UNPROCESSABLE_ENTITY);
        }

        try {
            // Persist a log (best-effort) before generating PDF
            try {
                $printedBy = $this->getCurrentUserId();
                $logData = [
                    'school_year'  => $slipData['school_year'],
                    'semester'     => $this->semester,
                    'student_name' => $slipData['student_name'],
                    'slip_date'    => $this->toDbDate($slipData['date']),
                    'time_in'      => $this->toDbTime($slipData['time_in']),
                    'grade'        => $slipData['grade'],
                    'reason'       => $slipData['reason'],
                    'admin_name'   => $slipData['admin_name'],
                ];
                $this->log->logSlip($logData, $printedBy);
            } catch (\Throwable $e) {
                Log::error('Late slip log insert failed: ' . $e->getMessage());
            }

            // Generate and return PDF
            return $this->renderSlipPdfResponse($slipData);
        } catch (\Throwable $e) {
            Log::error('Late slip PDF generation failed: ' . $e->getMessage());
            return $this->error('Printing failed.', SymfonyResponse::HTTP_INTERNAL_SERVER_ERROR, [
                'details' => $e->getMessage(),
            ]);
        }
    }

    /**
     * GET/POST /api/v1/slips/preview
     * Show preview of late slips (GET returns list, POST returns JSON preview)
     */
    public function preview(): JsonResponse
    {
        try {
            // Resolve current school year
            $currentYear = trim((string) ($this->schoolYear ?? ''));
            if ($currentYear === '') {
                $latest = $this->log->newQuery()
                    ->select('school_year')
                    ->orderBy('id', 'DESC')
                    ->first();
                $currentYear = $latest['school_year'] ?? (date('Y') . '-' . (date('Y') + 1));
            }

            $data = $this->payloadData();
            $selectedYear = trim((string) ($data['school_year'] ?? $currentYear));
            $selectedSemester = strtolower(trim((string) ($data['semester'] ?? '')));

            $previewData = [
                'school_year'  => $selectedYear,
                'student_name' => trim((string) ($data['student_name'] ?? '')),
                'date'         => trim((string) ($data['date'] ?? date('m/d/Y'))),
                'time_in'      => trim((string) ($data['time_in'] ?? date('h:i A'))),
                'grade'        => trim((string) ($data['grade'] ?? '')),
                'reason'       => trim((string) ($data['reason'] ?? '')),
                'admin_name'   => trim((string) ($data['admin_name'] ?? '')),
            ];

            // Prefer logged-in admin name
            $adminFromDb = $this->currentAdminName();
            if ($adminFromDb !== '') {
                $previewData['admin_name'] = $adminFromDb;
            }

            // Handle GET (return list of recent slips)
            if (strtolower($this->laravelRequest->method()) === 'get') {
                $builder = $this->log->newQuery();

                // Filter by school year if not empty
                if ($selectedYear !== '') {
                    $builder->where('school_year', $selectedYear);
                }

                // Normalize and apply semester filter
                $hasFilter = false;
                if ($selectedSemester !== '') {
                    $hasFilter = true;
                    if ($selectedSemester === 'fall') {
                        $builder->where(function ($q) {
                            $q->where('semester', 'fall')
                              ->orWhere('semester', '1')
                              ->orWhere('semester', 1);
                        });
                    } elseif ($selectedSemester === 'spring') {
                        $builder->where(function ($q) {
                            $q->where('semester', 'spring')
                              ->orWhere('semester', '2')
                              ->orWhere('semester', 2);
                        });
                    }
                }

                // Execute query
                $logs = $builder->orderBy('id', 'DESC')->limit(50)->get()->toArray();

                // Only use fallback when no filters are selected
                if (empty($logs) && !$hasFilter && $selectedYear === '') {
                    $logs = $this->log->newQuery()->orderBy('id', 'DESC')->limit(50)->get()->toArray();
                }

                // Format rows
                $rows = [];
                foreach ($logs as $r) {
                    $dispDate = '';
                    if (!empty($r['slip_date'])) {
                        $ts = strtotime($r['slip_date']);
                        $dispDate = $ts ? date('m/d/Y', $ts) : '';
                    }

                    $dispTime = '';
                    if (!empty($r['time_in'])) {
                        $t = strtotime($r['time_in']) ?: strtotime('today ' . $r['time_in']);
                        $dispTime = $t ? date('h:i A', $t) : '';
                    }

                    $rows[] = [
                        'id'           => (int) ($r['id'] ?? 0),
                        'school_year'  => (string) ($r['school_year'] ?? ''),
                        'semester'     => (string) ($r['semester'] ?? ''),
                        'student_name' => (string) ($r['student_name'] ?? ''),
                        'date'         => $dispDate,
                        'time_in'      => $dispTime,
                        'grade'        => (string) ($r['grade'] ?? ''),
                        'reason'       => (string) ($r['reason'] ?? ''),
                        'admin_name'   => (string) ($r['admin_name'] ?? ''),
                    ];
                }

                return $this->success([
                    'rows' => $rows,
                    'school_year' => $selectedYear,
                    'semester' => $selectedSemester,
                ], 'Late slip logs retrieved');
            }

            // POST mode (JSON preview for printer)
            $cfg = $this->printerConfig();
            $lineWidth = (int) ($cfg['chars_per_line'] ?? 48);
            $feedLines = (int) ($cfg['feed_lines'] ?? 3);

            $header = "Al Rahma School at ISGL\nSchool Year: {$previewData['school_year']}\n\n";
            $body   = implode("\n", $this->buildSlipLines($previewData, $lineWidth));
            $footer = str_repeat("\n", $feedLines);
            $full   = $header . $body . $footer;

            return $this->success([
                'ok'     => true,
                'text'   => $full,
                'width'  => $lineWidth,
            ], 'Preview generated');
        } catch (\Throwable $e) {
            Log::error('Late slip preview failed: ' . $e->getMessage());
            return $this->error('Preview failed.', SymfonyResponse::HTTP_INTERNAL_SERVER_ERROR, [
                'details' => $e->getMessage(),
            ]);
        }
    }

    /**
     * POST /api/v1/slips/reprint/{id}
     * Reprint a late slip from a saved log row
     */
    public function reprint($id = null): SymfonyResponse|JsonResponse
    {
        $id = (int) ($id ?? 0);
        if ($id <= 0) {
            return $this->error('Invalid slip id.', SymfonyResponse::HTTP_BAD_REQUEST);
        }

        try {
            $row = $this->log->find($id);
        } catch (\Throwable $e) {
            $row = null;
        }

        if (!$row) {
            return $this->error('Slip not found.', SymfonyResponse::HTTP_NOT_FOUND);
        }

        // Map DB row to print payload
        $dateDisplay = '';
        if (!empty($row['slip_date'])) {
            $ts = strtotime($row['slip_date']);
            $dateDisplay = $ts ? date('m/d/Y', $ts) : '';
        }
        if ($dateDisplay === '') {
            $dateDisplay = date('m/d/Y');
        }

        $timeDisplay = '';
        if (!empty($row['time_in'])) {
            $ts = strtotime($row['time_in']);
            if ($ts === false) {
                $ts = strtotime('today ' . $row['time_in']);
            }
            $timeDisplay = $ts ? date('h:i A', $ts) : '';
        }
        if ($timeDisplay === '') {
            $timeDisplay = date('h:i A');
        }

        $data = [
            'school_year' => (string) ($row['school_year'] ?? ''),
            'student_name' => (string) ($row['student_name'] ?? ''),
            'date'        => $dateDisplay,
            'time_in'     => $timeDisplay,
            'grade'       => (string) ($row['grade'] ?? ''),
            'reason'      => (string) ($row['reason'] ?? ''),
            'admin_name'  => (string) ($row['admin_name'] ?? ''),
        ];

        // Always prefer current logged-in user's full name from DB
        $adminFromDb = $this->currentAdminName();
        if ($adminFromDb !== '') {
            $data['admin_name'] = $adminFromDb;
        }

        try {
            // Log again (best-effort) for audit trail
            try {
                $printedBy = $this->getCurrentUserId();
                $logData = [
                    'school_year'  => $data['school_year'],
                    'semester'     => $this->semester,
                    'student_name' => $data['student_name'],
                    'slip_date'    => $this->toDbDate($data['date']),
                    'time_in'      => $this->toDbTime($data['time_in']),
                    'grade'        => $data['grade'],
                    'reason'       => $data['reason'],
                    'admin_name'   => $data['admin_name'],
                ];
                $this->log->logSlip($logData, $printedBy);
            } catch (\Throwable $e) {
                Log::error('Late slip reprint log insert failed: ' . $e->getMessage());
            }

            // Generate and return PDF
            return $this->renderSlipPdfResponse($data);
        } catch (\Throwable $e) {
            Log::error('Reprint failed: ' . $e->getMessage());
            return $this->error('Reprint failed: ' . $e->getMessage(), SymfonyResponse::HTTP_INTERNAL_SERVER_ERROR);
        }
    }

    /**
     * Build monospaced slip lines for receipt printing
     */
    private function buildSlipLines(array $data, ?int $lineWidth = null): array
    {
        $cfgWidth = (int) ($this->printerConfig()['chars_per_line'] ?? 0);
        $w = $lineWidth ?? ($cfgWidth > 0 ? $cfgWidth : 32);

        $lines = [];
        $lines[] = $this->fitLine('Student Name: ' . (string) ($data['student_name'] ?? ''), $w);
        $lines[] = $this->fitLine('Date: ' . (string) ($data['date'] ?? '') . '  ' . 'Time In: ' . (string) ($data['time_in'] ?? ''), $w);
        $lines[] = $this->fitLine('Grade: ' . (string) ($data['grade'] ?? ''), $w);
        $lines[] = $this->fitLine('Reason: ' . (string) ($data['reason'] ?? ''), $w);
        $lines[] = $this->fitLine('Admin: ' . (string) ($data['admin_name'] ?? ''), $w);

        return $lines;
    }

    /**
     * Create and return a configured Printer instance
     */
    private function makePrinter(): Printer
    {
        $cfg  = $this->printerConfig();
        $mode = strtolower((string) ($cfg['mode'] ?? 'network'));

        if ($mode === 'windows') {
            if (stripos(PHP_OS_FAMILY, 'Windows') !== false) {
                $name = (string) ($cfg['windows_name'] ?? 'POS-80');
                $connector = new WindowsPrintConnector($name);
                return new Printer($connector);
            }
            Log::warning('PRINTER_MODE=windows on non-Windows OS; falling back to network.');
            $mode = 'network';
        }

        if ($mode === 'usb') {
            if (stripos(PHP_OS_FAMILY, 'Windows') !== false) {
                $name = (string) ($cfg['windows_name'] ?? 'POS-80');
                $connector = new WindowsPrintConnector($name);
                return new Printer($connector);
            }
            $vidStr = (string) ($cfg['usb_vid'] ?? '');
            $pidStr = (string) ($cfg['usb_pid'] ?? '');
            if ($vidStr === '' || $pidStr === '') {
                throw new \RuntimeException('USB mode requires PRINTER_USB_VID and PRINTER_USB_PID');
            }
            $vid = $this->hexToInt($vidStr);
            $pid = $this->hexToInt($pidStr);
            $connector = new UsbPrintConnector($vid, $pid);
            return new Printer($connector);
        }

        // Default: network
        $host = (string) ($cfg['host'] ?? '192.168.1.100');
        $port = (int) ($cfg['port'] ?? 9100);
        $connector = new NetworkPrintConnector($host, $port);
        return new Printer($connector);
    }

    /**
     * Ensure any line is exactly $width characters
     */
    private function fitLine(string $line, int $width): string
    {
        $line = (string) $line;
        if (strlen($line) > $width) {
            return substr($line, 0, $width);
        }
        return $line . str_repeat(' ', $width - strlen($line));
    }

    /**
     * Convert hex string to int
     */
    private function hexToInt(string $hexOrDec): int
    {
        $hexOrDec = trim($hexOrDec);
        if ($hexOrDec === '') {
            return 0;
        }
        if (stripos($hexOrDec, '0x') === 0) {
            return intval($hexOrDec, 16);
        }
        return (int) $hexOrDec;
    }

    /**
     * Get printer configuration from environment
     */
    private function printerConfig(): array
    {
        $get = function ($keys, $default = null) {
            $keys = is_array($keys) ? $keys : [$keys];
            foreach ($keys as $k) {
                $v = env($k);
                if ($v !== null && $v !== '') {
                    return $v;
                }
            }
            return $default;
        };

        return [
            'mode'            => strtolower((string) $get(['printer.mode', 'PRINTER_MODE'], 'network')),
            'host'            => (string) $get(['printer.host', 'PRINTER_HOST'], '192.168.1.100'),
            'port'            => (int)    $get(['printer.port', 'PRINTER_PORT'], 9100),
            'usb_vid'         => (string) $get(['printer.usb.vid', 'PRINTER_USB_VID'], ''),
            'usb_pid'         => (string) $get(['printer.usb.pid', 'PRINTER_USB_PID'], ''),
            'windows_name'    => (string) $get(['printer.windows.name', 'PRINTER_WINDOWS_NAME'], 'POS-80'),
            'chars_per_line'  => (int)    $get(['printer.chars_per_line', 'PRINTER_CHARS_PER_LINE'], 48),
            'feed_lines'      => (int)    $get(['printer.feed_lines', 'PRINTER_FEED_LINES'], 3),
        ];
    }

    /**
     * Convert user-provided date/time strings into DB formats
     */
    private function toDbDate(?string $s): ?string
    {
        $s = trim((string) $s);
        if ($s === '') {
            return null;
        }
        $ts = strtotime($s);
        return $ts ? date('Y-m-d', $ts) : null;
    }

    private function toDbTime(?string $s): ?string
    {
        $s = trim((string) $s);
        if ($s === '') {
            return null;
        }
        $ts = strtotime($s);
        return $ts ? date('H:i:s', $ts) : null;
    }

    /**
     * Get current admin full name using session user_id
     */
    private function currentAdminName(): string
    {
        try {
            $uid = $this->getCurrentUserId();
            if ($uid && $uid > 0) {
                $user = $this->user->select('firstname', 'lastname')->find($uid);
                if ($user) {
                    $full = trim((string) ($user['firstname'] ?? '') . ' ' . (string) ($user['lastname'] ?? ''));
                    if ($full !== '') {
                        return $full;
                    }
                }
            }
        } catch (\Throwable $e) {
            // ignore and fall back
        }

        $first = trim((string) (Session::get('firstname') ?? ''));
        $last  = trim((string) (Session::get('lastname') ?? ''));
        $full  = trim($first . ' ' . $last);
        if ($full !== '') {
            return $full;
        }

        return (string) (Session::get('user_name') ?? '');
    }

    /**
     * Render the slip as a PDF and return it as a response
     */
    private function renderSlipPdfResponse(array $data): SymfonyResponse
    {
        // Determine paper size (mm)
        $paper = strtolower((string) ($this->laravelRequest->input('paper') ?? env('SLIP_PAPER', 'card')));

        // Estimate dynamic height
        $fontPt = (float) ($this->laravelRequest->input('font_pt') ?? env('SLIP_FONT_PT', 13.0));
        $lineH  = (float) ($this->laravelRequest->input('line_h') ?? env('SLIP_LINE_H', 2.0));
        $linesCount = (int) ($this->laravelRequest->input('rows') ?? 8);
        if ($linesCount < 1) {
            $linesCount = 8;
        }

        $ptPerLine = $fontPt * $lineH;
        $mmPerPt   = 25.4 / 72.0;
        $contentMm = $ptPerLine * $linesCount * $mmPerPt;
        $pageMarginsMm = 3.0 * 2;
        $fudgeMm = (float) ($this->laravelRequest->input('fudge_mm') ?? env('SLIP_FUDGE_MM', 12.0));
        $dynHeightMm = $contentMm + $pageMarginsMm + $fudgeMm;

        switch ($paper) {
            case 'cardp':
            case 'card-portrait':
                $wMm = 53.98;
                $hMm = max($dynHeightMm, 40.0);
                $wChars = 30;
                break;
            case 'receipt80':
                $wMm = 72.0;
                $hMm = 90.0;
                $wChars = 30;
                break;
            case 'receipt58':
                $wMm = 58.0;
                $hMm = 80.0;
                $wChars = 24;
                break;
            case 'card':
            default:
                $wMm = 85.60;
                $hMm = max($dynHeightMm, 40.0);
                $wChars = 40;
        }

        // Optional manual override
        $hOverride = $this->laravelRequest->input('height_mm') ?? $this->laravelRequest->input('h');
        if (is_numeric($hOverride)) {
            $hMm = max(30.0, min(200.0, (float) $hOverride));
        }

        // Build lines
        $w = $wChars;
        $lines = [];
        $lines[] = $this->fitLine('Al Rahma School at ISGL ' . ($data['school_year'] ?? ''), $w);
        $lines[] = $this->fitLine('Student Name: ' . (string) ($data['student_name'] ?? ''), $w);
        $lines[] = $this->fitLine('Date: ' . (string) ($data['date'] ?? ''), $w);
        $lines[] = $this->fitLine('Time In: ' . (string) ($data['time_in'] ?? ''), $w);
        $lines[] = $this->fitLine('Grade: ' . (string) ($data['grade'] ?? ''), $w);
        $lines[] = $this->fitLine('Reason: ' . (string) ($data['reason'] ?? ''), $w);
        $lines[] = $this->fitLine('Admin: ' . (string) ($data['admin_name'] ?? ''), $w);

        // Generate HTML for PDF
        $html = $this->generateSlipHtml($data, $lines, ['w_mm' => $wMm, 'h_mm' => $hMm]);

        $options = new Options();
        $options->set('isRemoteEnabled', true);
        $options->set('defaultFont', 'Courier');

        $dompdf = new Dompdf($options);
        $dompdf->loadHtml($html, 'UTF-8');

        if ($hMm < $dynHeightMm) {
            $hMm = $dynHeightMm;
        }

        // Set paper size
        $mmToPt = 72 / 25.4;
        $wPt = $wMm * $mmToPt;
        $hPt = $hMm * $mmToPt;
        $dompdf->setPaper([0, 0, $wPt, $hPt]);
        $dompdf->render();

        $filename = 'LateSlip_' . preg_replace('/[^A-Za-z0-9]+/', '_', (string) ($data['student_name'] ?? 'slip')) . '_' . date('Ymd_His') . '.pdf';

        return response($dompdf->output(), 200, [
            'Content-Type' => 'application/pdf',
            'Content-Disposition' => 'inline; filename="' . $filename . '"',
        ]);
    }

    /**
     * Generate HTML for the slip PDF
     */
    private function generateSlipHtml(array $data, array $lines, array $page): string
    {
        $wMm = $page['w_mm'];
        $hMm = $page['h_mm'];

        $html = '<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <style>
        @page {
            margin: 0;
            size: ' . $wMm . 'mm ' . $hMm . 'mm;
        }
        body {
            margin: 3mm;
            font-family: "Courier New", Courier, monospace;
            font-size: 13pt;
            line-height: 2.0;
        }
        .line {
            white-space: pre;
        }
    </style>
</head>
<body>';

        foreach ($lines as $line) {
            $html .= '<div class="line">' . htmlspecialchars($line, ENT_QUOTES, 'UTF-8') . '</div>';
        }

        $html .= '</body>
</html>';

        return $html;
    }
}