<?php
/**
 * 前端自定义的导出类
 */

namespace App\Exports;

use App\Exceptions\ErrorException;
use Illuminate\Support\Collection;
use Maatwebsite\Excel\Concerns\FromCollection;

class BaseFormExport implements FromCollection
{
    public $fields;
    public $data;

    public function __construct($data, $exportFields)
    {
        // 需要导出的字段。格式：['name'=>'名字','user.sex'=>'性别']
        $this->fields = $exportFields;
        // 数据
        $this->data = $data;
    }


    /**
     * 数组转集合
     * @throws ErrorException
     */
    public function collection()
    {
        if (empty($this->fields)) {
            throw new ErrorException('导出字段不能为空');
        }
        if (!is_array($this->fields)) {
            throw new ErrorException('导出字段必须是数组');
        }
        // 获取表头
        $header = array_values($this->fields);
        // 获取字段指向
        $fields = array_keys($this->fields);
        $newList = [];
        foreach ($this->data as $info) {
            $temp = [];
            foreach ($fields as $field) {
                if ($field == 'idcard') {
                    $temp[$field] = ' ' . $this->getDotValue($info, $field);
                } else {
                    $temp[$field] = $this->getDotValue($info, $field);
                }
            }
            $newList[] = $temp;
        }
        array_unshift($newList, $header); //插入表头
        return new Collection($newList);
    }

    /**
     * .号转数组层级并返回对应的值
     * @param $key
     * @param null $default
     * @return mixed|null
     */
    function getDotValue($config, $key, $default = null)
    {
        // 如果在第一层，就直接返回
        if (isset($config[$key])) {
            return $config[$key];
        }
        // 如果找不到，直接返回默认值
        if (false === strpos($key, '.')) {
            return $default;
        }
        // 临时数组
        $tempArr = explode('.', $key);
        foreach ($tempArr as $segment) {
            if (!is_array($config) || !array_key_exists($segment, $config)) {
                return $default;
            }
            $config = $config[$segment];
        }
        return $config;
    }

}