<?php

namespace App\Support;

use OpenSpout\Common\Entity\Row as SpoutRow;
use OpenSpout\Reader\CSV\Reader as CsvReader;
use OpenSpout\Reader\XLSX\Reader as XlsxReader;
use OpenSpout\Writer\CSV\Writer as CsvWriter;
use OpenSpout\Writer\XLSX\Writer as XlsxWriter;
use Symfony\Component\HttpFoundation\StreamedResponse;

class Spreadsheet
{
    /**
     * Baca fail CSV/XLSX menjadi senarai baris bersekutu (keyed by header).
     * Header dinormalkan: huruf kecil, ruang/sempang -> underscore.
     *
     * @return array<int, array<string, string>>
     */
    public static function read(string $path, ?string $extension = null): array
    {
        $extension = strtolower($extension ?? pathinfo($path, PATHINFO_EXTENSION));
        $reader = $extension === 'csv' ? new CsvReader() : new XlsxReader();

        $reader->open($path);

        $headers = [];
        $rows = [];

        foreach ($reader->getSheetIterator() as $sheet) {
            foreach ($sheet->getRowIterator() as $index => $row) {
                $cells = array_map(
                    static fn ($v) => is_string($v) ? trim($v) : (is_null($v) ? '' : (string) $v),
                    $row->toArray()
                );

                if ($index === 1) {
                    $headers = array_map(self::normalizeHeader(...), $cells);
                    continue;
                }

                // Langkau baris kosong sepenuhnya
                if (count(array_filter($cells, static fn ($v) => $v !== '')) === 0) {
                    continue;
                }

                $assoc = [];
                foreach ($headers as $i => $key) {
                    if ($key === '') {
                        continue;
                    }
                    $assoc[$key] = $cells[$i] ?? '';
                }
                $rows[] = $assoc;
            }
            break; // hanya sheet pertama
        }

        $reader->close();

        return $rows;
    }

    private static function normalizeHeader(string $header): string
    {
        $header = strtolower(trim($header));
        $header = preg_replace('/[\s\-]+/', '_', $header);
        return preg_replace('/[^a-z0-9_]/', '', $header);
    }

    /**
     * Hantar muat turun XLSX (atau CSV) terus ke pelayar.
     *
     * @param  array<int, string>  $headings
     * @param  iterable<int, array<int, scalar|null>>  $rows
     */
    public static function download(string $filename, array $headings, iterable $rows, string $format = 'xlsx'): StreamedResponse
    {
        return response()->streamDownload(function () use ($headings, $rows, $format) {
            $writer = $format === 'csv' ? new CsvWriter() : new XlsxWriter();
            $writer->openToFile('php://output');
            $writer->addRow(SpoutRow::fromValues($headings));
            foreach ($rows as $row) {
                $writer->addRow(SpoutRow::fromValues($row));
            }
            $writer->close();
        }, $filename, [
            'Content-Type' => $format === 'csv'
                ? 'text/csv'
                : 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
        ]);
    }
}