<?php

namespace App\Services;

use App\Models\Question;
use App\Models\QuestionBlank;
use App\Models\QuestionChoice;
use App\Models\QuestionGroup;
use App\Models\QuestionType;
use Illuminate\Support\Facades\DB;

class QuestionService
{

    public function __construct(
        QuestionGroupService $questionGroupService
    )
    {
        $this->questionGroupService = $questionGroupService;
    }

    public function createQuestion($data, $exerciseId)
    {
        $now = now();
        $groupData = [];
        $dataQuestion = [];
        $dataQuestionChoices = [];
        $dataQuestionBlank = [];
        $questionMap = [];

        DB::beginTransaction();
        try {
            // 1. Chuẩn bị groupData
            foreach ($data as $groupKey => $value) {
                $groupData[] = [
                    'content'                 => $value->title,
                    'exercise_id'             => $exerciseId,
                    'is_question_order_fixed' => $value->is_question_order_fixed,
                    'is_option_order_fixed'   => $value->is_option_order_fixed,
                    'position'                => $groupKey + 1,
                    'paragraph'               => $value->paragraph,
                    'created_at'              => $now,
                    'updated_at'              => $now,
                ];
            }

            // 2. Insert group & lấy lại id
            QuestionGroup::insert($groupData);
            $groupIds = QuestionGroup::where('exercise_id', $exerciseId)
                ->orderByDesc('id')
                ->take(count($groupData))
                ->get()
                ->reverse()
                ->pluck('id')
                ->values()
                ->toArray();

            // 3. Chuẩn bị question
            $questionIndex = 0;
            foreach ($data as $groupKey => $value) {
                $groupId = $groupIds[$groupKey];
                foreach ($value->questions as $qIndex => $question) {
                    $questionType = QuestionType::where('code', $question->type)->first();
                    $questionTypeId = $questionType ? $questionType->id : 1;
                    $dataQuestion[] = [
                        'exercise_id'      => $exerciseId,
                        'content'          => $question->content,
                        'description'      => $question->description ?? null,
                        'group_id'         => $groupId,
                        'question_type_id' => $questionTypeId,
                        'level'            => 2,
                        'score'            => $question->score ?? null,
                        'explanation'      => $question->explanation ?? null,
                        'hint'             => $question->hint ?? null,
                        'created_at'       => $now,
                        'updated_at'       => $now
                    ];
                    $questionMap["{$groupKey}_{$qIndex}"] = [
                        'type'    => $question->type,
                        'options' => $question->options ?? [],
                        'answers' => $question->answers ?? [],
                    ];
                    $questionIndex++;
                }
            }

            // 4. Insert question & lấy lại theo custom_key
            Question::insert($dataQuestion);

            $questions = Question::where('exercise_id', $exerciseId)->get();
//            $questionsByKey = $questions->keyBy(function ($item) {
//                return "{$item->group_id}_{$item->position}"; // hoặc dùng custom_key nếu có
//            });

            // 5. Mapping lại options/answers
            $qIndex = 0;
            foreach ($questionMap as $key => $meta) {
                $questionId = $questions[$qIndex]->id ?? null;
                if (!$questionId) continue;

                if ($meta['type'] == 'multiple_choice') {
                    foreach ($meta['options'] as $optKey => $option) {
                        $dataQuestionChoices[] = [
                            'question_id' => $questionId,
                            'label'       => $option->label,
                            'content'     => $option->content,
                            'is_correct'  => $option->is_correct,
                            'position'    => $optKey + 1,
                            'created_at'  => $now,
                            'updated_at'  => $now,
                        ];
                    }
                } else {
                    foreach ($meta['answers'] as $ansKey => $answer) {
                        $dataQuestionBlank[] = [
                            'question_id'     => $questionId,
                            'correct_answer'  => $answer->answer_true,
                            'other_answers'   => json_encode($answer->other_answers),
                            'position'        => $ansKey + 1,
                            'created_at'      => $now,
                            'updated_at'      => $now,
                        ];
                    }
                }

                $qIndex++;
            }

            if (!empty($dataQuestionChoices)) {
                QuestionChoice::insert($dataQuestionChoices);
            }

            if (!empty($dataQuestionBlank)) {
                QuestionBlank::insert($dataQuestionBlank);
            }

            DB::commit();
        } catch (\Throwable $e) {
            DB::rollBack();
            throw $e;
        }
    }

}