<?php

namespace App\Services;

use App\Models\Question;

class QuestionPayloadMapper
{
    /**
     * @param array<int, string> $fallbackKpCodes
     * @return array<string, mixed>
     */
    public function fromArray(array $question, array $fallbackKpCodes = []): array
    {
        $type = $this->normalizeQuestionType(
            (string) ($question['question_type'] ?? $question['type'] ?? '')
        ) ?? $this->guessType($question);

        $kpCode = (string) ($question['kp_code']
            ?? $question['kp']
            ?? $question['knowledge_point']
            ?? $question['knowledge_point_code']
            ?? ($fallbackKpCodes[0] ?? ''));

        $id = $question['id'] ?? $question['question_id'] ?? $question['question_bank_id'] ?? null;

        return [
            'id' => $id,
            'question_id' => $question['question_id'] ?? $id,
            'question_type' => $type,
            'stem' => $question['stem'] ?? $question['content'] ?? ($question['question_text'] ?? ''),
            'content' => $question['content'] ?? $question['stem'] ?? '',
            'options' => $question['options'] ?? ($question['choices'] ?? []),
            'answer' => $question['answer'] ?? $question['correct_answer'] ?? '',
            'solution' => $question['solution'] ?? '',
            'difficulty' => $this->normalizeDifficulty($question['difficulty'] ?? null),
            'score' => $question['score'] ?? $this->defaultScore($type),
            'estimated_time' => $question['estimated_time'] ?? 300,
            'kp' => $kpCode,
            'kp_code' => $kpCode,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    public function fromModel(Question $question): array
    {
        return $this->fromArray([
            'id' => $question->id,
            'question_id' => $question->id,
            'question_type' => $question->question_type,
            'stem' => $question->stem,
            'content' => $question->stem,
            'options' => $question->options ?? [],
            'answer' => $question->answer,
            'solution' => $question->solution,
            'difficulty' => $question->difficulty,
            'kp_code' => $question->kp_code,
        ]);
    }

    public function normalizeQuestionType(?string $type): ?string
    {
        $type = strtolower(trim((string) $type));
        if (in_array($type, ['choice', 'single_choice', 'multiple_choice', '选择题', '单选', '多选'], true)) {
            return 'choice';
        }
        if (in_array($type, ['fill', 'fill_in_the_blank', 'blank', '填空题', '填空'], true)) {
            return 'fill';
        }
        if (in_array($type, ['answer', 'calculation', 'word_problem', 'proof', '解答题', '计算题'], true)) {
            return 'answer';
        }

        return null;
    }

    public function normalizeDifficulty(mixed $difficulty): float
    {
        if ($difficulty === null || $difficulty === '') {
            return 0.5;
        }

        $value = (float) $difficulty;
        if ($value > 1) {
            $value = $value / 5;
        }

        return max(0.0, min(1.0, $value));
    }

    private function guessType(array $question): string
    {
        if (! empty($question['options']) && is_array($question['options'])) {
            return 'choice';
        }

        $content = $question['stem'] ?? $question['content'] ?? '';
        if (is_string($content) && (str_contains($content, '____') || str_contains($content, '（）'))) {
            return 'fill';
        }

        return 'answer';
    }

    private function defaultScore(string $type): int
    {
        return match ($type) {
            'choice', 'fill' => 5,
            default => 10,
        };
    }
}