<?php
namespace App\Http\Controllers\Child;
use App\Http\Controllers\Controller;
use App\Models\{Quiz, QuizAttempt, QuizAttemptAnswer, QuizQuestion, Subject};
use Illuminate\Http\Request;

class QuizController extends Controller {

    public function index() {
        $subjects = Subject::all()->keyBy('id');
        $quizzes  = Quiz::with('subject')->where('active',true)
            ->withCount('questions')->get()->groupBy('subject_id');
        $bestScores = QuizAttempt::where('user_id',auth()->id())
            ->where('status','completed')
            ->selectRaw('quiz_id, MAX(score) as best')
            ->groupBy('quiz_id')->pluck('best','quiz_id');
        return view('child.quiz.index', compact('subjects','quizzes','bestScores'));
    }

    public function start(Quiz $quiz) {
        abort_unless($quiz->active, 403);
        $attempt = QuizAttempt::firstOrCreate(
            ['user_id'=>auth()->id(),'quiz_id'=>$quiz->id,'status'=>'in_progress'],
            ['score'=>0,'current_question'=>0,'started_at'=>now()]
        );
        return redirect()->route('quiz.question', $attempt);
    }

    public function question(QuizAttempt $attempt) {
        abort_unless($attempt->user_id === auth()->id(), 403);
        if ($attempt->status === 'completed') return redirect()->route('quiz.result', $attempt);
        $question        = $attempt->quiz->questions()->skip($attempt->current_question)->first();
        $pointsIfCorrect = QuizAttempt::POINTS[$attempt->current_question];
        return view('child.quiz.question', compact('attempt','question','pointsIfCorrect'));
    }

    public function answer(Request $r, QuizAttempt $attempt) {
        abort_unless($attempt->user_id === auth()->id(), 403);
        abort_if($attempt->status === 'completed', 400);

        $question      = $attempt->quiz->questions()->skip($attempt->current_question)->first();
        $possible      = QuizAttempt::POINTS[$attempt->current_question];
        $timedOut      = $r->input('timeout') === '1';
        $answerGiven   = $r->input('answer','');
        $isCorrect     = false;
        $pointsEarned  = 0;

        if (!$timedOut && $answerGiven !== '') {
            $isCorrect    = $this->check($question, $answerGiven);
            $pointsEarned = $isCorrect ? $possible : 0;
        }

        QuizAttemptAnswer::create([
            'quiz_attempt_id'  => $attempt->id,
            'quiz_question_id' => $question->id,
            'answer_given'     => $timedOut ? '__timeout__' : $answerGiven,
            'is_correct'       => $isCorrect,
            'points_earned'    => $pointsEarned,
        ]);

        session()->flash('last_answer', [
            'correct'  => $isCorrect,
            'points'   => $pointsEarned,
            'possible' => $possible,
            'timeout'  => $timedOut,
        ]);

        $next = $attempt->current_question + 1;
        $totalQuestions = $attempt->quiz->questions()->count();

        if ($next >= $totalQuestions || $next >= 10) {
            $total = QuizAttemptAnswer::where('quiz_attempt_id',$attempt->id)->sum('points_earned');
            $attempt->update(['score'=>$total,'current_question'=>$next,'status'=>'completed','completed_at'=>now()]);
            auth()->user()->increment('points', $total);
            return redirect()->route('quiz.result', $attempt);
        }
        $attempt->update(['current_question'=>$next]);
        return redirect()->route('quiz.question', $attempt);
    }

    public function result(QuizAttempt $attempt) {
        abort_unless($attempt->user_id === auth()->id(), 403);
        abort_unless($attempt->status === 'completed', 400);
        $answers = $attempt->answers()->with('question.answerOptions')->get();
        return view('child.quiz.result', compact('attempt','answers'));
    }

    private function check(QuizQuestion $q, string $answer): bool {
        return match($q->type) {
            'multiple_choice','exclusion' => ($opt = $q->answerOptions()->where('is_correct',true)->first())
                                              && (string)$opt->id === $answer,
            'true_false','free_text'      => strtolower(trim($answer)) === strtolower(trim((string)$q->correct_answer)),
            default                       => false,
        };
    }
}