<?php

namespace app\common;

use think\Db;

/**
 * 参考文献作者明细入库/读取（供引用堆叠等同作者精准统计）
 */
class ReferenceReferAuthorService
{
    /** @var BackgroundCheckService */
    private $bgCheck;

    /** @var CrossrefService */
    private $crossref;

    public function __construct()
    {
        $this->bgCheck = new BackgroundCheckService();
        $this->crossref = new CrossrefService([
            'mailto' => trim((string)\think\Env::get('crossref_mailto', '')),
        ]);
    }

    /**
     * Crossref enrichment 成功后：解析并覆盖写入作者明细
     *
     * @return int 写入作者条数
     */
    public function syncFromWorkSummary($pReferId, $pArticleId, $doi, array $summary)
    {
        $pReferId = intval($pReferId);
        $pArticleId = intval($pArticleId);
        if ($pReferId <= 0) {
            return 0;
        }

        $rows = $this->buildAuthorRows($doi, $summary);
        Db::name('production_article_refer_author')->where('p_refer_id', $pReferId)->delete();
        if (empty($rows)) {
            return 0;
        }

        $now = date('Y-m-d H:i:s');
        $insertRows = [];
        foreach ($rows as $row) {
            $insertRows[] = [
                'p_article_id'    => $pArticleId,
                'p_refer_id'      => $pReferId,
                'author_seq'      => intval($row['author_seq']),
                'author_position' => $this->clipField((string)$row['author_position'], 16),
                'is_first_author' => intval($row['is_first_author']),
                'family'          => $this->clipField((string)$row['family'], 128),
                'given'           => $this->clipField((string)$row['given'], 128),
                'display_name'    => $this->clipField((string)$row['display_name'], 256),
                'citation_name'   => $this->clipField((string)$row['citation_name'], 128),
                'orcid'           => $this->clipField((string)$row['orcid'], 32),
                'openalex_id'     => $this->clipField((string)$row['openalex_id'], 32),
                'identity_source' => $this->clipField((string)$row['identity_source'], 32),
                'created_at'      => $now,
                'updated_at'      => $now,
            ];
        }

        Db::name('production_article_refer_author')->insertAll($insertRows);
        return count($insertRows);
    }

    /**
     * 从 refer 表已有 author 字段解析并入库（Crossref/OpenAlex 均不可用时的兜底）
     *
     * @return int
     */
    public function syncFromReferAuthorField($pReferId, $pArticleId, $authorString)
    {
        $pReferId = intval($pReferId);
        $pArticleId = intval($pArticleId);
        if ($pReferId <= 0) {
            return 0;
        }

        $rows = $this->parseReferAuthorString($authorString);
        Db::name('production_article_refer_author')->where('p_refer_id', $pReferId)->delete();
        if (empty($rows)) {
            return 0;
        }

        $now = date('Y-m-d H:i:s');
        $insertRows = [];
        foreach ($rows as $row) {
            $insertRows[] = [
                'p_article_id'    => $pArticleId,
                'p_refer_id'      => $pReferId,
                'author_seq'      => intval($row['author_seq']),
                'author_position' => $this->clipField((string)$row['author_position'], 16),
                'is_first_author' => intval($row['is_first_author']),
                'family'          => '',
                'given'           => '',
                'display_name'    => $this->clipField((string)$row['display_name'], 256),
                'citation_name'   => $this->clipField((string)$row['citation_name'], 128),
                'orcid'           => '',
                'openalex_id'     => '',
                'identity_source' => 'refer_author',
                'created_at'      => $now,
                'updated_at'      => $now,
            ];
        }

        Db::name('production_article_refer_author')->insertAll($insertRows);
        return count($insertRows);
    }

    /**
     * 单条参考文献同步作者明细：有 DOI 走 Crossref+OpenAlex，否则解析 refer.author
     *
     * @param int   $pReferId
     * @param int   $pArticleId
     * @param array $refer 可传 production_article_refer 行；为空则从库读取
     * @return int 写入作者条数
     */
    public function syncOneRefer($pReferId, $pArticleId, array $refer = [])
    {
        $pReferId = intval($pReferId);
        $pArticleId = intval($pArticleId);
        if ($pReferId <= 0 || $pArticleId <= 0) {
            return 0;
        }

        if (empty($refer)) {
            $refer = Db::name('production_article_refer')
                ->where('p_refer_id', $pReferId)
                ->where('p_article_id', $pArticleId)
                ->where('state', 0)
                ->find();
            if (empty($refer)) {
                return 0;
            }
        }

        $refUtil = new ReferenceCheckService();
        $doi = $refUtil->extractDoiFromRefer($refer);
        $count = 0;

        if ($doi !== '') {
            $summary = $this->crossref->fetchWorkSummary($doi);
            if ($summary === null || empty($summary['doi'])) {
                $summary = ['doi' => $doi, 'raw' => []];
            }
            $count = $this->syncFromWorkSummary($pReferId, $pArticleId, $doi, $summary);
        }

        if ($count <= 0) {
            $count = $this->syncFromReferAuthorField(
                $pReferId,
                $pArticleId,
                (string)($refer['author'] ?? '')
            );
        }

        return $count;
    }

    /**
     * 按篇批量同步参考文献作者明细（有 DOI 则 Crossref + OpenAlex）
     *
     * @return array{total:int,synced:int,authors:int,skipped_no_doi:int,failed:int,errors:array}
     */
    public function syncByPArticleId($pArticleId, array $options = [])
    {
        $pArticleId = intval($pArticleId);
        if ($pArticleId <= 0) {
            throw new \InvalidArgumentException('p_article_id is required');
        }

        $sleepMs = max(0, intval($options['sleep_ms'] ?? 100));
        $refUtil = new ReferenceCheckService();

        $refers = Db::name('production_article_refer')
            ->field('p_refer_id,p_article_id,index,refer_doi,doilink,refer_content,refer_frag,author')
            ->where('p_article_id', $pArticleId)
            ->where('state', 0)
            ->order('index asc')
            ->select();

        $result = [
            'p_article_id'     => $pArticleId,
            'total'            => count($refers),
            'synced'           => 0,
            'authors'          => 0,
            'skipped_no_doi'   => 0,
            'failed'           => 0,
            'errors'           => [],
        ];

        foreach ($refers as $refer) {
            $pReferId = intval($refer['p_refer_id']);
            $doi = $refUtil->extractDoiFromRefer($refer);
            if ($doi === '') {
                $result['skipped_no_doi']++;
                continue;
            }

            try {
                $summary = $this->crossref->fetchWorkSummary($doi);
                if ($summary === null || empty($summary['doi'])) {
                    $summary = ['doi' => $doi, 'raw' => []];
                }

                $count = $this->syncFromWorkSummary($pReferId, $pArticleId, $doi, $summary);
                if ($count <= 0) {
                    $count = $this->syncFromReferAuthorField(
                        $pReferId,
                        $pArticleId,
                        (string)($refer['author'] ?? '')
                    );
                }

                if ($count > 0) {
                    $result['synced']++;
                    $result['authors'] += $count;
                } else {
                    $result['failed']++;
                    $result['errors'][] = [
                        'p_refer_id'   => $pReferId,
                        'reference_no' => intval($refer['index']) + 1,
                        'doi'          => $doi,
                        'msg'          => 'no author rows from Crossref/OpenAlex/refer.author',
                    ];
                }
            } catch (\Throwable $e) {
                $result['failed']++;
                $result['errors'][] = [
                    'p_refer_id'   => $pReferId,
                    'reference_no' => intval($refer['index']) + 1,
                    'doi'          => $doi,
                    'msg'          => $e->getMessage(),
                ];
            }

            if ($sleepMs > 0) {
                usleep($sleepMs * 1000);
            }
        }

        return $result;
    }

    /**
     * 单条参考文献：外网拉取作者并入库，再返回明细
     * 有 DOI → Crossref + OpenAlex；失败或无 DOI → 解析 refer.author
     *
     * @return array{
     *   p_article_id:int,
     *   p_refer_id:int,
     *   reference_no:int,
     *   doi:string,
     *   synced:int,
     *   refer:array|null,
     *   author_count:int,
     *   authors:array
     * }
     */
    public function fetchAuthorsByPReferId($pArticleId, $pReferId)
    {
        $pArticleId = intval($pArticleId);
        $pReferId = intval($pReferId);
        if ($pArticleId <= 0 || $pReferId <= 0) {
            throw new \InvalidArgumentException('p_article_id and p_refer_id are required');
        }

        $refer = Db::name('production_article_refer')
            ->where('p_refer_id', $pReferId)
            ->where('p_article_id', $pArticleId)
            ->where('state', 0)
            ->find();

        if (empty($refer)) {
            return [
                'p_article_id' => $pArticleId,
                'p_refer_id'   => $pReferId,
                'reference_no' => 0,
                'doi'          => '',
                'synced'       => 0,
                'refer'        => null,
                'author_count' => 0,
                'authors'      => [],
            ];
        }

        $refUtil = new ReferenceCheckService();
        $doi = $refUtil->extractDoiFromRefer($refer);
        $syncedCount = $this->syncOneRefer($pReferId, $pArticleId, $refer);
        $result = $this->getAuthorsByPReferId($pArticleId, $pReferId);
        $result['doi'] = $doi;
        $result['synced'] = $syncedCount > 0 ? 1 : 0;

        return $result;
    }

    /**
     * 按 p_article_id + p_refer_id 读取作者明细（只读本地库）
     *
     * @return array{p_article_id:int,p_refer_id:int,reference_no:int,refer:array|null,author_count:int,authors:array}
     */
    public function getAuthorsByPReferId($pArticleId, $pReferId)
    {
        $pArticleId = intval($pArticleId);
        $pReferId = intval($pReferId);
        if ($pArticleId <= 0 || $pReferId <= 0) {
            throw new \InvalidArgumentException('p_article_id and p_refer_id are required');
        }

        $refer = Db::name('production_article_refer')
            ->field('p_refer_id,p_article_id,index,author,title,joura,refer_doi,doilink,refer_type')
            ->where('p_refer_id', $pReferId)
            ->where('p_article_id', $pArticleId)
            ->where('state', 0)
            ->find();

        if (empty($refer)) {
            return [
                'p_article_id'  => $pArticleId,
                'p_refer_id'    => $pReferId,
                'reference_no'  => 0,
                'refer'         => null,
                'author_count'  => 0,
                'authors'       => [],
            ];
        }

        $rows = Db::name('production_article_refer_author')
            ->where('p_article_id', $pArticleId)
            ->where('p_refer_id', $pReferId)
            ->order('author_seq asc, id asc')
            ->field('author_seq,author_position,is_first_author,family,given,display_name,citation_name,orcid,openalex_id,identity_source')
            ->select();

        $authors = [];
        foreach ($rows as $row) {
            $authors[] = [
                'author_seq'      => intval($row['author_seq'] ?? 0),
                'author_position' => (string)($row['author_position'] ?? ''),
                'is_first_author' => intval($row['is_first_author'] ?? 0),
                'family'          => (string)($row['family'] ?? ''),
                'given'           => (string)($row['given'] ?? ''),
                'display_name'    => (string)($row['display_name'] ?? ''),
                'citation_name'   => (string)($row['citation_name'] ?? ''),
                'orcid'           => (string)($row['orcid'] ?? ''),
                'openalex_id'     => (string)($row['openalex_id'] ?? ''),
                'identity_source' => (string)($row['identity_source'] ?? ''),
            ];
        }

        return [
            'p_article_id' => $pArticleId,
            'p_refer_id'   => $pReferId,
            'reference_no' => intval($refer['index']) + 1,
            'refer'        => [
                'p_refer_id'   => $pReferId,
                'reference_no' => intval($refer['index']) + 1,
                'author'       => (string)($refer['author'] ?? ''),
                'title'        => (string)($refer['title'] ?? ''),
                'joura'        => (string)($refer['joura'] ?? ''),
                'refer_doi'    => (string)($refer['refer_doi'] ?? ''),
                'doilink'      => (string)($refer['doilink'] ?? ''),
                'refer_type'   => (string)($refer['refer_type'] ?? ''),
            ],
            'author_count' => count($authors),
            'authors'      => $authors,
        ];
    }

    /**
     * 读取已入库的作者身份（与 ReferenceAuthorIdentityService 结构兼容）
     *
     * @return array<int, array{openalex_id:string,orcid:string,display_name:string,author_position:string,is_corresponding:bool,identity_keys:string[]}>
     */
    public function loadAuthorshipsByPReferId($pReferId)
    {
        $pReferId = intval($pReferId);
        if ($pReferId <= 0) {
            return [];
        }

        $rows = Db::name('production_article_refer_author')
            ->where('p_refer_id', $pReferId)
            ->order('author_seq asc, id asc')
            ->select();

        $list = [];
        foreach ($rows as $row) {
            $openalexId = trim((string)($row['openalex_id'] ?? ''));
            $orcid = trim((string)($row['orcid'] ?? ''));
            $identityKeys = [];
            if ($openalexId !== '') {
                $identityKeys[] = 'openalex:' . $openalexId;
            }
            if ($orcid !== '') {
                $identityKeys[] = 'orcid:' . $orcid;
            }
            if (empty($identityKeys)) {
                continue;
            }

            $position = trim((string)($row['author_position'] ?? ''));
            if ($position === '' && intval($row['is_first_author'] ?? 0) === 1) {
                $position = 'first';
            }

            $list[] = [
                'openalex_id'      => $openalexId,
                'orcid'            => $orcid,
                'display_name'     => trim((string)($row['display_name'] ?? '')),
                'author_position'  => $position,
                'is_corresponding' => false,
                'identity_keys'    => $identityKeys,
            ];
        }

        return $list;
    }

    /**
     * @return array<int, array>
     */
    private function buildAuthorRows($doi, array $summary)
    {
        $doi = trim((string)$doi);
        $raw = is_array($summary['raw'] ?? null) ? $summary['raw'] : [];
        $crossrefAuthors = $this->parseCrossrefAuthorList($raw['author'] ?? []);
        $openalexList = $doi !== '' ? $this->fetchOpenAlexAuthorships($doi) : [];

        $max = max(count($crossrefAuthors), count($openalexList));
        if ($max <= 0) {
            return [];
        }

        $rows = [];
        for ($i = 0; $i < $max; $i++) {
            $cr = $crossrefAuthors[$i] ?? null;
            $oa = $openalexList[$i] ?? null;

            if (is_array($oa) && is_array($cr) && trim((string)($cr['orcid'] ?? '')) !== '' && trim((string)($oa['orcid'] ?? '')) === '') {
                $oa['orcid'] = trim((string)$cr['orcid']);
            }
            if (is_array($oa) && is_array($cr) && trim((string)($oa['display_name'] ?? '')) === '' && trim((string)($cr['display_name'] ?? '')) !== '') {
                $oa['display_name'] = trim((string)$cr['display_name']);
            }

            $row = $this->mergeOneAuthorRow($i, $cr, $oa);
            if ($row !== null) {
                $rows[] = $row;
            }
        }

        return $rows;
    }

    private function mergeOneAuthorRow($seq, $crossrefAuthor, $openalexAuthor)
    {
        $family = '';
        $given = '';
        $displayName = '';
        $citationName = '';
        $orcid = '';
        $openalexId = '';
        $position = '';
        $sources = [];

        if (is_array($crossrefAuthor)) {
            $family = trim((string)($crossrefAuthor['family'] ?? ''));
            $given = trim((string)($crossrefAuthor['given'] ?? ''));
            $displayName = trim((string)($crossrefAuthor['display_name'] ?? ''));
            $citationName = trim((string)($crossrefAuthor['citation_name'] ?? ''));
            $orcid = trim((string)($crossrefAuthor['orcid'] ?? ''));
            $position = trim((string)($crossrefAuthor['author_position'] ?? ''));
            $sources[] = 'crossref';
        }

        if (is_array($openalexAuthor)) {
            $openalexId = trim((string)($openalexAuthor['openalex_id'] ?? ''));
            if (trim((string)($openalexAuthor['orcid'] ?? '')) !== '') {
                $orcid = trim((string)$openalexAuthor['orcid']);
            }
            if (trim((string)($openalexAuthor['display_name'] ?? '')) !== '') {
                $displayName = trim((string)$openalexAuthor['display_name']);
            }
            if (trim((string)($openalexAuthor['author_position'] ?? '')) !== '') {
                $position = trim((string)$openalexAuthor['author_position']);
            }
            $sources[] = 'openalex';
        }

        if ($displayName === '' && ($family !== '' || $given !== '')) {
            $displayName = trim($given . ' ' . $family);
        }
        if ($citationName === '' && is_array($crossrefAuthor) && !empty($crossrefAuthor['raw_author'])) {
            $citationName = $this->crossref->getAuthorsCitation(['author' => [$crossrefAuthor['raw_author']]], 1);
        }
        if ($citationName === '' && $displayName !== '') {
            $citationName = $displayName;
        }

        if ($displayName === '' && $citationName === '' && $orcid === '' && $openalexId === '') {
            return null;
        }

        $sources = array_values(array_unique($sources));
        $isFirst = ($position === 'first') || ($seq === 0 && $position === '');

        return [
            'author_seq'      => intval($seq),
            'author_position' => $position,
            'is_first_author' => $isFirst ? 1 : 0,
            'family'          => $family,
            'given'           => $given,
            'display_name'    => $displayName,
            'citation_name'   => $citationName,
            'orcid'           => $orcid,
            'openalex_id'     => $openalexId,
            'identity_source' => implode('+', $sources),
        ];
    }

    /**
     * @return array<int, array>
     */
    private function parseCrossrefAuthorList($authorList)
    {
        if (empty($authorList) || !is_array($authorList)) {
            return [];
        }

        $parsed = $this->bgCheck->parseCrossRefAuthors($authorList);
        $rows = [];
        foreach ($parsed as $i => $item) {
            $rawAuthor = $authorList[$i] ?? [];
            if (!is_array($rawAuthor)) {
                $rawAuthor = [];
            }
            $family = trim((string)($item['family'] ?? ''));
            $given = trim((string)($item['given'] ?? ''));
            $displayName = trim((string)($item['name'] ?? ''));
            $position = trim((string)($rawAuthor['sequence'] ?? ''));
            if ($position === '' && $i === 0) {
                $position = 'first';
            }

            $rows[] = [
                'family'          => $family,
                'given'           => $given,
                'display_name'    => $displayName,
                'orcid'           => trim((string)($item['orcid'] ?? '')),
                'author_position' => $position,
                'citation_name'   => $this->crossref->getAuthorsCitation(['author' => [$rawAuthor]], 1),
                'raw_author'      => $rawAuthor,
            ];
        }

        return $rows;
    }

    /**
     * @return array<int, array{openalex_id:string,orcid:string,display_name:string,author_position:string}>
     */
    private function fetchOpenAlexAuthorships($doi)
    {
        $res = $this->bgCheck->fetchOpenAlexWorkByDoi($doi);
        if (empty($res['success']) || empty($res['work']) || !is_array($res['work'])) {
            return [];
        }

        $list = [];
        foreach ($res['work']['authorships'] ?? [] as $auth) {
            if (!is_array($auth)) {
                continue;
            }
            $author = is_array($auth['author'] ?? null) ? $auth['author'] : [];
            $openalexId = $this->bgCheck->extractOpenAlexId($author['id'] ?? '');
            $orcid = $this->bgCheck->cleanOrcid($author['orcid'] ?? '');
            $displayName = trim((string)($author['display_name'] ?? ''));
            if ($openalexId === '' && $orcid === '' && $displayName === '') {
                continue;
            }

            $list[] = [
                'openalex_id'      => $openalexId,
                'orcid'            => $orcid,
                'display_name'     => $displayName,
                'author_position'  => (string)($auth['author_position'] ?? ''),
                'is_corresponding' => !empty($auth['is_corresponding']),
            ];
        }

        return $list;
    }

    /**
     * @return array<int, array{author_seq:int,author_position:string,is_first_author:int,display_name:string,citation_name:string}>
     */
    private function parseReferAuthorString($authorString)
    {
        $authorString = trim((string)$authorString);
        if ($authorString === '') {
            return [];
        }

        $authorString = preg_replace('/\s+et\s+al\.?\s*$/iu', '', $authorString);
        $parts = preg_split('/\s*,\s*/u', $authorString);
        if (!is_array($parts)) {
            return [];
        }

        $rows = [];
        foreach ($parts as $i => $part) {
            $name = trim((string)$part);
            if ($name === '' || preg_match('/^et\s+al\.?$/iu', $name)) {
                continue;
            }
            $seq = count($rows);
            $rows[] = [
                'author_seq'      => $seq,
                'author_position' => $seq === 0 ? 'first' : 'additional',
                'is_first_author' => $seq === 0 ? 1 : 0,
                'display_name'    => $name,
                'citation_name'   => $name,
            ];
        }

        return $rows;
    }

    private function clipField($value, $maxLen)
    {
        $value = trim((string)$value);
        if ($value === '' || $maxLen <= 0) {
            return $value;
        }
        if (mb_strlen($value) <= $maxLen) {
            return $value;
        }
        return mb_substr($value, 0, $maxLen);
    }
}