<?php
namespace app\api\controller;
use app\api\controller\Base;
use think\Db;
class Crossrefdoi extends Base{

    public function __construct(\think\Request $request = null) {
        parent::__construct($request);
    }
    // 配置项
    private $mailto; // 邮箱（提升优先级）
    private $timeout = 15; // 请求超时（秒）
    private $maxRetry = 2; // 单个DOI最大重试次数
    private $crossrefUrl = "https://api.crossref.org/works/"; //接口地址
    /**
     * 批量查询DOI信息（核心方法）
     * @param array $dois DOI列表
     * @return array 包含所有DOI的查询结果
     */
    public function get($aParam = []){

        //获取参数
        $aParam = empty($aParam) ? $this->request->post() : $aParam;

        $iPReferId = empty($aParam['p_refer_id']) ? 0 : $aParam['p_refer_id'];
        if(empty($iPReferId)){
            return json_encode(['status' => 2,'msg' => 'Please select the reference to be queried']);
        }
        $aWhere = ['p_refer_id' => $iPReferId,'state' => ['in', [0,2]]];
        $aRefer = Db::name('production_article_refer')->field('title,joura,author,refer_doi,doilink,cs')->where($aWhere)->find();
        if(empty($aRefer['refer_doi'])){
            return json_encode(['status' => 3,'msg' => 'The doi of the reference is empty']);
        }

        $finalResult = [];
        $sDoi = empty($aRefer['refer_doi']) ? '' : $aRefer['refer_doi'];
        $sCheckDoi = $this->filterValidDoi($sDoi); // 过滤非法DOI
        if(empty($sCheckDoi)){
            return json_encode(['status' => 4,'msg' => 'Doi does not comply with the rules']);
        }

        // 调用单DOI查询（带重试）
        $aDoiInfo = $this->fetchSingleDoiWithRetry($sCheckDoi);
        if (!$aDoiInfo) {
            $result['status'] = 'fail';
            $result['fail_reason'] = "请求失败（重试{$this->maxRetry}次后仍失败）";
        }
        // 提取核心字段
        $sTitle = $this->getTitle($aDoiInfo);
        //期刊信息
        $aPublisher = $this->getPublisher($aDoiInfo);
        $sJoura = empty($aPublisher['title']) ? $aPublisher['short_title'] : $aPublisher['title'];
        //作者信息
        $aAuthor = $this->getAuthors($aDoiInfo);
        $sAuthor = empty($aAuthor) ? '' : implode(',', $aAuthor);
        $sDateno = $this->getVolumeIssuePages($aDoiInfo);
        
        // 识别撤稿状态
        $aRetractInfo = $this->checkRetracted($aDoiInfo);
        $bIsRetracted = 2;
        if($aRetractInfo['is_retracted'] == true){
            $bIsRetracted = 1;
        }
        $sRetractReason = empty($aRetractInfo['reason']) ? '' : $aRetractInfo['reason'];
        //获取dolink
        $sDolink = $this->getDolink($aDoiInfo);
        $sDolink = empty($sDolink) ? 'https://doi.org/' . $sCheckDoi : $sDolink;

        //数据处理更新数据库
        $aUpdate = [];
        if(!empty($sTitle) && empty($aRefer['title'])){
            $aUpdate['title'] = $sTitle;
        }
        if(!empty($sJoura) && empty($aRefer['joura'])){
            $aUpdate['joura'] = $sJoura;
        }
        if(!empty($sAuthor) && empty($aRefer['author'])){
            $aUpdate['author'] = $sAuthor;
        }
        if(!empty($sDateno)){
            $aUpdate['dateno'] = $sDateno;
        }
        if($bIsRetracted == 1){
            $aUpdate['is_retracted'] = 1;
        }
        if(!empty($sDolink) && empty($aRefer['doilink'])){
            $aUpdate['doilink'] = $sDolink;
        }
        if(empty($aUpdate)){
            return json_encode(['status' => 5,'msg' => 'No update information available']);
        }
        $aUpdate['update_time'] = time();
        $aUpdate['cs'] = 1;
        $aWhere = ['p_refer_id' => $iPReferId];
        $result = Db::name('production_article_refer')->where($aWhere)->limit(1)->update($aUpdate);
        if($result === false){
            return json_encode(['status' => 6,'msg' => 'Update failed-Cs']);
        }
        return json_encode(['status' => 1,'msg' => 'Update successful']);
    }

    /**
     * 过滤非法DOI（仅保留10.xxxx/xxx格式）
     */
    private function filterValidDoi($doi = ''){
        $doi = trim($doi);
        if (empty($doi)) return '';
        // 正则匹配：10. + 至少4位数字 + / + 任意字符
        if (preg_match('/^10\.\d{4,}\/.+/', $doi)) {
            return $doi;
        }
        return '';
    }

    /**
     * 单DOI查询
     */
    private function fetchSingleDoiWithRetry($doi){
        $retryCount = 0;
        while ($retryCount < $this->maxRetry) {
            $url = $this->crossrefUrl. rawurlencode($doi) . "?mailto=" . rawurlencode($this->mailto);
            
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_TIMEOUT, $this->timeout);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_HTTPHEADER, [
                "User-Agent: DOI-Fetcher/1.0 (mailto:{$this->mailto})"
            ]);
            $response = curl_exec($ch);
            $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
            curl_close($ch);

            // 成功返回
            if ($httpCode == 200) {
                $data = json_decode($response, true);
                return $data['status'] == 'ok' ? $data['message'] : null;
            }

            // 429速率限制：延长等待后重试
            if ($httpCode == 429) {
                sleep(5);
                $retryCount++;
                continue;
            }

            $retryCount++;
            sleep(1); // 普通失败，1秒后重试
        }
        return null;
    }

    /**
     * 提取标题
     */
    private function getTitle($aDoiInfo = []){
        return $aDoiInfo['title'][0] ?? '';
    }

    /**
     * 提取出版社名
     */
    private function getPublisher($aDoiInfo = []){
        $aJournal = [
            'title'      => isset($aDoiInfo['container-title'][0]) ? $aDoiInfo['container-title'][0] : '',
            'short_title'=> isset($aDoiInfo['short-container-title'][0]) ? $aDoiInfo['short-container-title'][0] : '',
            'ISSN'       => $aDoiInfo['ISSN'] ?? [],
            'publisher'  => $aDoiInfo['publisher'] ?? '',
        ];
        return $aJournal;
    }

    /**
     * 提取作者
     */
    private function getAuthors($aDoiInfo = []){
        $authors = [];
        if (!empty($aDoiInfo['author'])) {
            foreach ($aDoiInfo['author'] as $author) {
                $name = $author['family'] ?? '';
                if (!empty($author['given'])) {
                    $name = $author['given'] . ' ' . $name;
                }
                if (!empty($name)) {
                    $authors[] = $name;
                }
            }
        }
        return $authors;
    }

    /**
     * 提取发表年份
     */
    private function getPublishYear($aDoiInfo = []){
        if (!empty($aDoiInfo['issued']['date-parts'][0][0])) {
            return (string)$aDoiInfo['issued']['date-parts'][0][0];
        }
        return '';
    }

    /**
     * 提取卷(期):起始页-终止页（格式：2024;10(2):100-120）
     */
    private function getVolumeIssuePages($aDoiInfo = []){
        $parts = [];
        // 年
        $year = $this->getPublishYear($aDoiInfo);
        if ($year) $parts[] = $year;
        
        // 卷(期)
        $volume = $aDoiInfo['volume'] ?? '';
        $issue = $aDoiInfo['issue'] ?? '';
        if ($volume) {
            $volumeIssue = $volume . ($issue ? "({$issue})" : '');
            $parts[] = $volumeIssue;
        }
        
        // 起始页-终止页
        $pageStart = $aDoiInfo['page']['start'] ?? ($aDoiInfo['first-page'] ?? '');
        $pageEnd = $aDoiInfo['page']['end'] ?? ($aDoiInfo['last-page'] ?? '');
        $pages = '';
        if ($pageStart) {
            $pages = $pageStart . ($pageEnd ? "-{$pageEnd}" : '');
        }else{
            $pages = $aDoiInfo['page'] ?? '';
        }
        if ($pages) $parts[] = $pages;

        return implode(':', $parts);
    }

    /**
     * 识别撤稿文章
     */
    private function checkRetracted($aDoiInfo = []){
        $isRetracted = false;
        $reason = "未撤稿";

        // 1. 文章类型为撤稿声明type/subtype
        $sType = strtolower($aDoiInfo['type'] ?? '');
        $sSubtype = strtolower($aDoiInfo['subtype'] ?? '');
        if (isset($sType) && in_array($sType, ['retraction', 'correction'])) {
            $isRetracted = true;
            $reason = "文章类型为{$sType}（撤稿/更正声明）";
        }

        if (isset($sSubtype) && in_array($sSubtype, ['retraction', 'correction'])) {
            $isRetracted = true;
            $reason = "文章类型为{$sSubtype}（撤稿/更正声明）";
        }
        // 2. update-type包含撤稿
        if (isset($aDoiInfo['update-type']) && in_array('retraction', $aDoiInfo['update-type'])) {
            $isRetracted = true;
            $reason = "官方标记为撤稿（update-type: retraction）";
        }

        // 3. 关联撤稿文章
        if (isset($aDoiInfo['relation']) && !empty($aDoiInfo['relation'])) {
            foreach ($aDoiInfo['relation'] as $relType => $relItems) {
                if (in_array($relType, ['is-retraction-of', 'corrects'])) {
                    $isRetracted = true;
                    $relatedDoi = $relItems[0]['id'] ?? '未知';
                    $reason = "关联撤稿文章{$relatedDoi}（关系：{$relType}）";
                    break;
                }
            }
        }

        // 4. update-to 字段
        if (isset($aDoiInfo['update-to']) && is_array($aDoiInfo['update-to'])) {
            foreach ($aDoiInfo['update-to'] as $update) {
                $updateType = strtolower($update['type'] ?? '');
                $updateLabel = strtolower($update['label'] ?? '');
                if (strpos($updateType, 'retract') !== false || strpos($updateLabel, 'retract') !== false) {
                    $isRetracted = true;
                    $retractionDetail['retraction_notice'] = [
                        'type'  => $update['type'] ?? '',
                        'label' => $update['label'] ?? '',
                        'DOI'   => $update['DOI'] ?? '',
                        'date'  => isset($update['updated']) ? $this->parseDateParts($update['updated']) : '',
                    ];
                    break;
                }
            }
        }
        //5.title 关键词
        $aTitles = $aDoiInfo['title'] ?? [];
        foreach ($aTitles as $value) {
            $sTitleLower = strtolower($value);
            if (strpos($sTitleLower, 'retraction') !== false || strpos($sTitleLower, 'retracted') !== false
                || strpos($sTitleLower, 'withdrawal') !== false || strpos($sTitleLower, 'withdrawn') !== false) {
                $isRetracted = true;
                $retractionDetail['title_keyword'] = $value;
                break;
            }
        }
        return [
            'is_retracted' => $isRetracted,
            'reason' => $reason
        ];
    }
    /**
     * 识别doi链接
     */
    private function getDolink($aDoiInfo = []){
        return $aDoiInfo['URL'] ?? '';
    }
}