<?php

namespace App\Http\Controllers;

use App\Models\KehadiranTaklimat;
use App\Models\SesiTaklimat;
use App\Models\Sppm\PetugasPermohonan;
use App\Support\SimpleXlsx;
use Illuminate\Http\Request;
use Symfony\Component\HttpFoundation\Response;

class EksportKehadiranController extends Controller
{
    /**
     * Susunan jawatan dalam laporan: PPM dahulu, kemudian mengikut Saluran
     * (KTM sebelum KP), dan akhir sekali PPAPM.
     */
    private const JAWATAN_KUMPULAN = [
        'PPM' => 0,
        'KTM' => 1,
        'KP_KMU' => 1,
        'PPAPM_MANUAL' => 2,
        'PPAPM_KOMPUTER' => 2,
        'PPAPM_BERGERAK' => 2,
    ];

    private const PENGEPALA = [
        'Bil', 'DUN', 'Pusat Mengundi', 'Saluran', 'Jawatan', 'Nama', 'No. KP', 'No. Telefon', 'Emel', 'Tarikh Hadir',
    ];

    /**
     * Eksport kehadiran semua petugas merentas semua sesi taklimat yang
     * dilihat pengguna, dikumpul kepada satu fail Excel: worksheet "Hadir"
     * dan "Tidak Hadir".
     */
    public function __invoke(Request $request): Response
    {
        $user = $request->user();

        $sesiSemua = SesiTaklimat::with('dun')
            ->when($user->isPengurus(), fn ($q) => $q->where('dun_id', $user->dun_id))
            ->get();

        $hadir = [];
        $tidakHadir = [];

        foreach ($sesiSemua->groupBy('dun_id') as $sesiDun) {
            $dun = $sesiDun->first()->dun;
            $dunLabel = trim(($dun->code ?? '').' '.($dun->nama ?? ''));
            $sesiIds = $sesiDun->pluck('id');

            // Tarikh hadir paling awal bagi setiap petugas merentas sesi DUN ini.
            $tarikhHadir = [];
            $rekodKehadiran = KehadiranTaklimat::whereIn('sesi_taklimat_id', $sesiIds)
                ->orderBy('hadir_at')
                ->get(['permohonan_id', 'sesi_taklimat_id']);

            foreach ($rekodKehadiran as $rekod) {
                if (! array_key_exists($rekod->permohonan_id, $tarikhHadir)) {
                    $tarikhHadir[$rekod->permohonan_id] = optional(
                        $sesiDun->firstWhere('id', $rekod->sesi_taklimat_id)?->tarikh
                    )->format('d/m/Y') ?? '';
                }
            }

            $petugas = PetugasPermohonan::assignedUntukDun((int) $sesiDun->first()->dun_id)
                ->with(['assignments' => fn ($q) => $q->orderBy('urutan')->with(['pusatMengundi', 'saluran', 'jawatan'])])
                ->get();

            foreach ($petugas as $p) {
                $baris = $this->barisPetugas($p, $dunLabel);

                if (array_key_exists($p->id, $tarikhHadir)) {
                    $baris['tarikh_hadir'] = $tarikhHadir[$p->id];
                    $hadir[] = $baris;
                } else {
                    $tidakHadir[] = $baris;
                }
            }
        }

        $hadir = $this->susun($hadir);
        $tidakHadir = $this->susun($tidakHadir);

        $xlsx = (new SimpleXlsx)
            ->addSheet('Hadir', $this->keBaris($hadir))
            ->addSheet('Tidak Hadir', $this->keBaris($tidakHadir));

        $namaFail = 'Kehadiran-Taklimat-'.now()->format('Ymd-His').'.xlsx';

        return response($xlsx->toString(), 200, [
            'Content-Type' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
            'Content-Disposition' => 'attachment; filename="'.$namaFail.'"',
        ]);
    }

    /**
     * Hasilkan satu baris data petugas berserta kunci susunan.
     *
     * @return array<string,mixed>
     */
    private function barisPetugas(PetugasPermohonan $p, string $dunLabel): array
    {
        $assignment = $p->assignmentUtama();

        $pusatNama = $assignment?->pusatMengundi?->nama ?? '';
        $saluranNo = $assignment?->saluran?->nombor_saluran;
        $kod = $assignment?->jawatan?->kod ?? '';

        $kumpulan = self::JAWATAN_KUMPULAN[$kod] ?? 9;
        // Dalam kumpulan Saluran, KTM (0) didahulukan sebelum KP (1).
        $subJawatan = $kod === 'KTM' ? 0 : 1;

        return [
            'dun' => $dunLabel,
            'pusat' => $pusatNama,
            'saluran' => $saluranNo !== null ? 'Saluran '.$saluranNo : '',
            'jawatan' => $assignment?->jawatan?->nama ?? '-',
            'nama' => $p->nama_ic ?? '',
            'no_kp' => $p->no_kp ?? '',
            'no_telefon' => $p->no_telefon ?? '',
            'emel' => $p->emel ?? '',
            'tarikh_hadir' => '',
            '_sort' => [
                $dunLabel,
                $pusatNama,
                $kumpulan,
                $kumpulan === 1 ? (int) ($saluranNo ?? 0) : 0,
                $subJawatan,
                $p->nama_ic ?? '',
            ],
        ];
    }

    /**
     * Susun mengikut pusat mengundi > PPM > Saluran (KTM > KP) > PPAPM.
     *
     * @param  array<int,array<string,mixed>>  $baris
     * @return array<int,array<string,mixed>>
     */
    private function susun(array $baris): array
    {
        usort($baris, function ($a, $b) {
            return $a['_sort'] <=> $b['_sort'];
        });

        return $baris;
    }

    /**
     * Tukar baris data kepada matriks (pengepala + sel) untuk worksheet.
     *
     * @param  array<int,array<string,mixed>>  $baris
     * @return array<int,array<int,string>>
     */
    private function keBaris(array $baris): array
    {
        $rows = [self::PENGEPALA];

        foreach ($baris as $i => $b) {
            $rows[] = [
                $i + 1,
                $b['dun'],
                $b['pusat'],
                $b['saluran'],
                $b['jawatan'],
                $b['nama'],
                $b['no_kp'],
                $b['no_telefon'],
                $b['emel'],
                $b['tarikh_hadir'],
            ];
        }

        return $rows;
    }
}