<?php

namespace App\Http\Controllers\student;

use App\Http\Controllers\Controller;
use App\Models\Course;
use App\Models\Lesson;
use App\Models\Question;
use App\Models\QuizSubmission;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Session;

class QuizController extends Controller
{
    public function quiz_submit(Request $request)
    {
        $quiz = Lesson::findOrFail($request->quiz_id);

        $retake = $quiz->retake;
        $submit = QuizSubmission::where('quiz_id', $quiz->id)
            ->where('user_id', auth()->user()->id)
            ->count();

        if ($submit >= $retake) {
            Session::flash('warning', get_phrase('Attempt has been over.'));
            return redirect()->back();
        }

        $inputs  = collect($request->all());
        $quiz_id = $inputs->pull('quiz_id');
        $inputs->forget(['_token', 'quiz_id']);

        $submits = $inputs->whereNotNull();
        foreach ($submits as $key => $submit) {
            if (is_string($submit) && ($submit != 'true' && $submit != 'false')) {
                $submits[$key] = array_column(json_decode($submit), 'value');
            }
        }

        $question_ids      = $submits->keys();
        $submitted_answers = $submits->values();
        $questions         = Question::whereIn('id', $question_ids)->get();

        $right_answers = $wrong_answers = [];

        foreach ($questions as $key => $question) {

            $correct_answer = json_decode($question->answer, true);
            $submitted      = $submitted_answers[$key];

            if ($question->type == 'mcq') {
                $isCorrect = empty(array_diff($correct_answer, $submitted))
                        && empty(array_diff($submitted, $correct_answer));
            } elseif ($question->type == 'fill_blanks') {
                $isCorrect = count($correct_answer) === count($submitted);
                if ($isCorrect) {
                    foreach ($correct_answer as $i => $answer) {
                        if (strtolower($answer) !== strtolower($submitted[$i])) {
                            $isCorrect = false;
                            break;
                        }
                    }
                }
            } elseif ($question->type == 'true_false') {
                $isCorrect = strtolower(json_encode($correct_answer)) === strtolower($submitted);
            }

            $isCorrect
                ? $right_answers[] = $question->id
                : $wrong_answers[] = $question->id;
        }

        QuizSubmission::create([
            'quiz_id'        => $quiz->id,
            'user_id'        => auth()->user()->id,
            'correct_answer' => $right_answers ? json_encode($right_answers) : null,
            'wrong_answer'   => $wrong_answers ? json_encode($wrong_answers) : null,
            'submits'        => $submits->count() ? json_encode($submits->toArray()) : null,
        ]);

        // ✅ HITUNG NILAI
        $total_questions   = $questions->count();
        $mark_per_question = $total_questions > 0
            ? ($quiz->total_mark / $total_questions)
            : 0;

        $obtained_mark = count($right_answers) * $mark_per_question;

        // ✅ JIKA LULUS → MARK LESSON COMPLETED
        if ($obtained_mark >= $quiz->pass_mark) {
            update_watch_history_manually(
                $quiz->id,
                $quiz->course_id,
                auth()->user()->id
            );

            Session::flash('success', get_phrase('Congratulations, you passed the quiz.'));
        } else {
            Session::flash('warning', get_phrase('You did not reach the minimum score.'));
        }

        return redirect()->back();
    }

    public function load_result(Request $request)
    {
        $page_data['quiz']      = Lesson::where('id', $request->quiz_id)->first();
        $page_data['questions'] = Question::where('quiz_id', $request->quiz_id)->get();
        $page_data['result']    = QuizSubmission::where('id', $request->submit_id)
            ->where('quiz_id', $request->quiz_id)
            ->where('user_id', auth()->user()->id)
            ->first();
        return view('course_player.quiz.result', $page_data);
    }

    public function load_questions(Request $request)
    {
        $page_data['quiz']      = Lesson::where('id', $request->quiz_id)->first();
        $page_data['questions'] = Question::where('quiz_id', $request->quiz_id)->get();
        $page_data['submits']   = QuizSubmission::where('quiz_id', $request->quiz_id)
            ->where('user_id', auth()->user()->id)
            ->get();
        $page_data['course_details'] = Course::where('id', $page_data['quiz']->course_id)->first();
        return view('course_player.quiz.questions', $page_data);
    }
}