<?php

namespace App\Models;

class Study extends SoftDeletesModel
{
    protected $table = 'studies';

    protected $casts = [
        'file' => 'array',
        'expire_day' => 'integer',
        'minute' => 'integer',
        'rate' => 'decimal:2',
    ];

    // 学习类型常量
    const TYPE_VISITOR = 1;        // 访客
    const TYPE_VISITOR_CAR = 2;    // 访客车辆
    const TYPE_LOGISTICS_CAR = 3;  // 物流车辆

    /**
     * 关联学习题目
     */
    public function studyAsks()
    {
        return $this->hasMany(StudyAsk::class, 'study_id');
    }

    /**
     * 获取学习类型文本
     */
    public function getTypeTextAttribute()
    {
        $types = [
            self::TYPE_VISITOR => '访客',
            self::TYPE_VISITOR_CAR => '访客车辆',
            self::TYPE_LOGISTICS_CAR => '物流车辆',
        ];
        return $types[$this->type] ?? '未知';
    }

    /**
     * 获取文件列表
     */
    public function getFilesAttribute()
    {
        if (!$this->file) {
            return [];
        }

        return Upload::whereIn('id', $this->file)->get();
    }

    /**
     * 检查学习是否有效
     */
    public function isValid()
    {
        return $this->expire_day > 0;
    }

    /**
     * 获取学习有效期（天数）
     */
    public function getExpireDays()
    {
        return $this->expire_day ?? 0;
    }

    /**
     * 获取最低学习时间（分钟）
     */
    public function getMinute()
    {
        return $this->minute ?? 0;
    }

    /**
     * 获取通过正确率
     */
    public function getPassRate()
    {
        return $this->rate ?? 0;
    }

    /**
     * 获取随机题目
     */
    public function getRandomQuestions($limit = 10)
    {
        return $this->studyAsks()
            ->inRandomOrder()
            ->limit($limit)
            ->get();
    }

    /**
     * 检查学习内容是否完整
     */
    public function isComplete()
    {
        return !empty($this->name) &&
            !empty($this->content) &&
            $this->studyAsks()->count() > 0;
    }

    /**
     * 获取学习统计信息
     */
    public function getStatistics()
    {
        return [
            'total_questions' => $this->studyAsks()->count(),
            'single_choice' => $this->studyAsks()->where('type', StudyAsk::TYPE_SINGLE)->count(),
            'multiple_choice' => $this->studyAsks()->where('type', StudyAsk::TYPE_MULTIPLE)->count(),
            'expire_days' => $this->getExpireDays(),
            'minute' => $this->getMinute(),
            'pass_rate' => $this->getPassRate(),
        ];
    }
}