<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use App\Models\Department;
use App\Models\Position;
use App\Models\Subject; 
use App\Models\User;
use App\Models\QuestionBank;
use App\Models\Exam;

class ExamManagementController extends Controller
{
    // ==============================================================================
    // 1. AREA MANAJEMEN UJIAN (CBT)
    // ==============================================================================

    public function index(Request $request)
    {
        $query = Exam::with('subject');

        if ($request->filled('search')) {
            $query->where('title', 'LIKE', '%' . $request->search . '%');
        }

        $exams = $query->latest()->paginate(20);
        return view('pages.admin.exams.index', compact('exams'));
    }

    public function create()
    {
        // Tarik data materi untuk Select2 Modul
        $subjects = Subject::orderBy('name', 'asc')->get();
        
        // Tarik data karyawan untuk Select2 Peserta (Bisa pilih banyak)
        $employees = User::orderBy('first_name', 'asc')->get(); 

        return view('pages.admin.exams.create', compact('subjects', 'employees'));
    }

    public function store(Request $request)
    {
        $request->validate([
            'training_type'   => 'required|in:matrix_plant,general,external',
            'is_random_order' => 'nullable|boolean',
        ]);

        if ($request->training_type === 'external') {
            return back()->with('info', 'Fitur External Training dengan database HR sedang dalam tahap pengembangan.');
        }

        // Validasi Tambahan: Peserta, Deadline, dan Array Ujian
        $request->validate([
            'employee_ids'             => 'required|array|min:1', // Wajib pilih minimal 1 peserta
            'employee_ids.*'           => 'exists:users,id',
            'deadline_date'            => 'required|date|after_or_equal:today', // Deadline tidak boleh masa lalu
            
            'exams'                    => 'required|array|min:1',
            'exams.*.subject_id'       => 'required|exists:subjects,id',
            'exams.*.title'            => 'nullable|string|max:255',
            'exams.*.duration_minutes' => 'required|integer|min:1',
            'exams.*.passing_grade'    => 'required|integer|min:1|max:100',
            'exams.*.max_retakes'      => 'required|integer|min:0',
        ]);

        $isRandom = $request->has('is_random_order');
        $trainingType = $request->training_type === 'general' ? 'product' : 'matrix_plant';

        // 1. Simpan setiap modul sebagai sesi ujian tersendiri
        foreach ($request->exams as $examData) {
            $exam = Exam::create([
                'title'            => $examData['title'] ?: Subject::find($examData['subject_id'])->name,
                'subject_id'       => $examData['subject_id'],
                'training_type'    => $trainingType,
                'duration_minutes' => $examData['duration_minutes'],
                'passing_grade'    => $examData['passing_grade'],
                'max_retakes'      => $examData['max_retakes'],
                'is_random_order'  => $isRandom,
                'is_active'        => true,
            ]);

            // 2. Tugaskan (Assign) ujian yang baru dibuat ini ke SEMUA karyawan yang dipilih
            $assignments = [];
            foreach ($request->employee_ids as $userId) {
                $assignments[] = [
                    'user_id'       => $userId,
                    'exam_id'       => $exam->id,
                    'deadline_date' => $request->deadline_date,
                    'status'        => 'pending',
                    'created_at'    => now(),
                    'updated_at'    => now(),
                ];
            }
            
            // Insert massal ke database agar prosesnya secepat kilat
            \Illuminate\Support\Facades\DB::table('exam_assignments')->insert($assignments);
        }

        return redirect()->route('admin.exams.index')
                         ->with('success', count($request->exams) . ' Modul Ujian berhasil dibuat dan ditugaskan ke ' . count($request->employee_ids) . ' Karyawan!');
    }


    // ==============================================================================
    // 2. AREA MANAJEMEN BANK SOAL
    // ==============================================================================

    public function questionBank(Request $request)
    {
        $creatorIds = QuestionBank::whereNotNull('created_by')->distinct()->pluck('created_by');
        $creators = User::whereIn('id', $creatorIds)->orderBy('first_name', 'asc')->get();

        $subjects = Subject::orderBy('name', 'asc')->get();
        $departments = Department::orderBy('name', 'asc')->get();
        $positions = Position::orderBy('name', 'asc')->get(); 

        $totalQuestions = QuestionBank::count();

        // Query utama dengan relasi
        $query = QuestionBank::with(['subject', 'department', 'creator', 'position']);

        // 1. FILTER GLOBAL SEARCH (Mencari di semua kolom & relasi)
        if ($request->filled('search')) {
            $search = $request->search;
            $query->where(function($q) use ($search) {
                // Cari di ID atau Teks Soal
                $q->where('id', 'LIKE', "%{$search}%")
                  ->orWhere('question_text', 'LIKE', "%{$search}%")
                  ->orWhere('question_type', 'LIKE', "%{$search}%")
                  ->orWhere('question_level', 'LIKE', "%{$search}%")
                  // Cari di Nama Materi
                  ->orWhereHas('subject', function($sub) use ($search) {
                      $sub->where('name', 'LIKE', "%{$search}%");
                  })
                  // Cari di Nama Departemen
                  ->orWhereHas('department', function($dep) use ($search) {
                      $dep->where('name', 'LIKE', "%{$search}%");
                  })
                  // Cari di Nama Jabatan
                  ->orWhereHas('position', function($pos) use ($search) {
                      $pos->where('name', 'LIKE', "%{$search}%");
                  })
                  // Cari di Nama Pembuat Soal
                  ->orWhereHas('creator', function($usr) use ($search) {
                      $usr->where('first_name', 'LIKE', "%{$search}%")
                          ->orWhere('last_name', 'LIKE', "%{$search}%");
                  });
            });
        }

        // 2. FILTER DROPDOWN SPESIFIK
        if ($request->filled('creator_id')) { $query->where('created_by', $request->creator_id); }
        if ($request->filled('subject_id')) { $query->where('subject_id', $request->subject_id); }
        if ($request->filled('department_id')) { $query->where('department_id', $request->department_id); }
        if ($request->filled('position_id')) { $query->where('position_id', $request->position_id); }
        if ($request->filled('question_type')) { $query->where('question_type', $request->question_type); }
        if ($request->filled('question_level')) { $query->where('question_level', $request->question_level); }

        // ==============================================================================
        // 3. INTERCEPTOR UNTUK EXPORT (Excel & PDF)
        // ==============================================================================
        if ($request->action === 'export_excel' || $request->action === 'export_pdf') {
            $exportData = $query->latest()->get();
            $exporterName = auth()->user()->first_name . ' ' . auth()->user()->last_name;
            $exportTime = now()->format('d F Y, H:i:s');
            
            // LOGIKA EXPORT EXCEL (Download Paksa)
            if ($request->action === 'export_excel') {
                $fileName = 'Data_Bank_Soal_' . now()->format('Ymd_His') . '.xls';
                
                return response()->streamDownload(function () use ($exportData, $exporterName, $exportTime, $request) {
                    echo view('pages.admin.question-banks.export-report', compact('exportData', 'exporterName', 'exportTime', 'request'))->render();
                }, $fileName, [
                    'Content-Type' => 'application/vnd.ms-excel',
                    'Content-Disposition' => 'attachment; filename="'.$fileName.'"',
                ]);
            }

            // LOGIKA EXPORT PDF (Menggunakan Facade DomPDF)
            if ($request->action === 'export_pdf') {
                $fileName = 'Data_Bank_Soal_' . now()->format('Ymd_His') . '.pdf';
                
                // Gunakan library PDF yang sudah ada di project Anda
                $pdf = \Barryvdh\DomPDF\Facade\Pdf::loadView('pages.admin.question-banks.export-report', compact('exportData', 'exporterName', 'exportTime', 'request'))
                    ->setPaper('a4', 'landscape'); // Format landscape agar tabel muat
                
                return $pdf->download($fileName);
            }
        }
        // 4. JIKA BUKAN EXPORT, LANJUTKAN KE TAMPILAN TABEL NORMAL DENGAN PAGINATION
        $questions = $query->latest()->paginate(20);

        return view('pages.admin.question-banks.question-bank', compact('questions', 'creators', 'subjects', 'departments', 'positions', 'totalQuestions'));
    }

    // Nama diubah agar tidak bentrok dengan create() ujian
    public function createQuestion()
    {
        $departments = Department::orderBy('name', 'asc')->get();
        $positions   = Position::orderBy('name', 'asc')->get();
        $subjects    = Subject::orderBy('name', 'asc')->get();

        return view('pages.admin.question-banks.create', compact('departments', 'positions', 'subjects'));
    }

    // Nama diubah agar spesifik untuk soal
    public function editQuestion($id)
    {
        $question    = QuestionBank::findOrFail($id);
        $departments = Department::orderBy('name', 'asc')->get();
        $positions   = Position::orderBy('name', 'asc')->get();
        $subjects    = Subject::orderBy('name', 'asc')->get();

        return view('pages.admin.question-banks.edit', compact('question', 'departments', 'positions', 'subjects'));
    }

    // Nama diubah agar spesifik untuk soal
    public function showQuestion($id)
    {
        $question = QuestionBank::with(['subject', 'department', 'position', 'creator'])->findOrFail($id);
        return view('pages.admin.question-banks.show', compact('question'));
    }

    public function bulkDelete(Request $request)
    {
        $request->validate([
            'question_ids'   => 'required|array',
            'question_ids.*' => 'exists:question_banks,id' // Diperbaiki dari tabel questions ke question_banks
        ]);

        try {
            // Diperbaiki dari model Question ke QuestionBank
            QuestionBank::whereIn('id', $request->question_ids)->delete();
            return back()->with('success', count($request->question_ids) . ' Soal berhasil dihapus secara massal.');
        } catch (\Exception $e) {
            return back()->with('error', 'Gagal menghapus soal: ' . $e->getMessage());
        }
    }

    public function importView()
    {
        return view('pages.admin.exams.questions.import');
    }

    // ==============================================================================
    // FUNGSI PROSES SIMPAN, EDIT, DAN HAPUS BANK SOAL
    // ==============================================================================

    public function storeQuestion(Request $request)
    {
        $request->validate([
            'subject_id'     => 'required|exists:subjects,id',
            'department_id'  => 'nullable|exists:departments,id',
            'position_id'    => 'nullable|exists:positions,id',
            // VALIDASI INI SUDAH DISAMAKAN DENGAN FORM UI
            'question_type'  => 'required|in:single,multiple,true_false,descriptive',
            'question_text'  => 'required|string',
            'score_weight'   => 'required|numeric|min:1',
            'duration'       => 'nullable|numeric',
            'passing_grade'  => 'nullable|numeric',
        ]);

        $data = $request->all();
        $data['created_by'] = auth()->id(); // Rekam siapa yang membuat soal

        // Bersihkan data yang tidak relevan berdasarkan jenis soal
        if ($request->question_type === 'descriptive') {
            $data['option_a'] = null; 
            $data['option_b'] = null; 
            $data['option_c'] = null;
            $data['option_d'] = null; 
            $data['option_e'] = null; 
            $data['correct_answer'] = null;
        } else {
            $data['essay_keywords'] = null;
        }

        // Jika tipe soal adalah Multiple (bisa centang lebih dari 1), ubah array menjadi JSON
        // if (isset($request->correct_answer) && is_array($request->correct_answer)) {
        //     $data['correct_answer'] = json_encode($request->correct_answer);
        // }

        QuestionBank::create($data);

        return redirect()->route('admin.question-bank.index')->with('success', 'Soal baru berhasil ditambahkan ke Bank Soal!');
    }

    public function updateQuestion(Request $request, $id)
    {
        $request->validate([
            'subject_id'     => 'required|exists:subjects,id',
            'department_id'  => 'nullable|exists:departments,id',
            'position_id'    => 'nullable|exists:positions,id',
            'question_type'  => 'required|in:single,multiple,true_false,descriptive',
            'question_text'  => 'required|string',
            'score_weight'   => 'required|numeric|min:1',
            'duration'       => 'nullable|numeric',
            'passing_grade'  => 'nullable|numeric',
        ]);

        $question = QuestionBank::findOrFail($id);
        $data = $request->all();

        // 1. Bersihkan data yang tidak relevan berdasarkan jenis soal
        if ($request->question_type === 'descriptive') {
            $data['option_a'] = null; 
            $data['option_b'] = null; 
            $data['option_c'] = null;
            $data['option_d'] = null; 
            $data['option_e'] = null; 
            $data['correct_answer'] = null;
        } else {
            $data['essay_keywords'] = null;
        }

        // 2. Jika tipe soal adalah Multiple (bisa centang lebih dari 1), ubah array menjadi JSON
        // if (is_array($request->correct_answer)) {
        //     $data['correct_answer'] = json_encode($request->correct_answer);
        // }

        // 3. Simpan pembaruan
        $question->update($data);

        return redirect()->route('admin.question-bank.index')->with('success', 'Perubahan soal berhasil disimpan!');
    }

    public function destroyQuestion($id)
    {
        try {
            $question = QuestionBank::findOrFail($id);
            $question->delete();
            return back()->with('success', 'Soal berhasil dihapus.');
        } catch (\Exception $e) {
            return back()->with('error', 'Gagal menghapus soal: ' . $e->getMessage());
        }
    }
}