<?php

namespace app\common;

use think\Db;
use think\Env;
use think\Exception;
use think\Queue;

/**
 * 根据投稿记录 / 审稿人资料，用大模型总结用户主领域（中文）写入 field_ai。
 * 队列链：UserFieldAiFill → 处理一条 → enqueueNextFieldAi → 下一条。
 */
class UserFieldAiService
{
    const QUEUE_NAME = 'UserFieldAi';

    const STATUS_PENDING = 0;
    const STATUS_DONE = 1;
    const STATUS_INSUFFICIENT = 2;
    const STATUS_FAILED = 3;

    private $logFile;

    public function __construct()
    {
        $this->logFile = ROOT_PATH . 'runtime' . DS . 'user_field_ai.log';
    }

    /**
     * 启动链式处理（从 user_id=0 之后找第一个待处理用户）。
     *
     * @param bool $force  true 时重算已生成用户
     * @return bool 是否已推入首条 job
     */
    public function startChain($force = false, $delay = 1, $queue = '')
    {
        return $this->enqueueNextFieldAi($delay, $queue, 0, $force);
    }

    /**
     * 链式：找 user_id > $afterUserId 的下一位待处理用户并入队。
     */
    public function enqueueNextFieldAi($delay = 1, $queue = '', $afterUserId = 0, $force = false)
    {
        if ($queue === '') {
            $queue = self::QUEUE_NAME;
        }
        $afterUserId = intval($afterUserId);
        $userId = $this->findNextPendingUserId($afterUserId, $force);
        if ($userId <= 0) {
            $this->log('[FieldAi] chain finished after user_id=' . $afterUserId . ' force=' . ($force ? '1' : '0'));
            return false;
        }

        $data = [
            'user_id' => $userId,
            'queue'   => $queue,
            'force'   => $force ? 1 : 0,
        ];
        $jobClass = 'app\\api\\job\\UserFieldAiFill@fire';
        if ($delay > 0) {
            Queue::later($delay, $jobClass, $data, $queue);
        } else {
            Queue::push($jobClass, $data, $queue);
        }
        $this->log('[FieldAi] enqueued user_id=' . $userId . ' queue=' . $queue);
        return true;
    }

    /**
     * 处理单个用户（队列 Job 或同步调试）。
     *
     * @return array{ok:bool, skipped?:bool, insufficient?:bool, field_ai?:string, error?:string}
     */
    public function processUser($userId, $force = false)
    {
        $userId = intval($userId);
        if ($userId <= 0) {
            return ['ok' => false, 'error' => 'invalid user_id'];
        }

        $this->ensureReviewerInfoRow($userId);
        $uri = Db::name('user_reviewer_info')->where('reviewer_id', $userId)->find();
        if (!$uri) {
            return ['ok' => false, 'error' => 'reviewer_info missing'];
        }

        if (!$force && intval($uri['field_ai_status']) === self::STATUS_DONE && trim((string)$uri['field_ai']) !== '') {
            return ['ok' => true, 'skipped' => true, 'field_ai' => (string)$uri['field_ai']];
        }

        if (!$this->isEligible($userId, $uri)) {
            $this->updateFieldAi($userId, '', self::STATUS_INSUFFICIENT, 'insufficient profile/articles');
            return ['ok' => true, 'insufficient' => true];
        }

        try {
            $context = $this->buildContext($userId, $uri);
            $fieldAi = $this->summarizeWithLlm($context);
            if ($fieldAi === '') {
                throw new Exception('LLM returned empty field');
            }
            $this->updateFieldAi($userId, $fieldAi, self::STATUS_DONE, '');
            return ['ok' => true, 'field_ai' => $fieldAi];
        } catch (\Throwable $e) {
            $this->updateFieldAi($userId, '', self::STATUS_FAILED, mb_substr($e->getMessage(), 0, 500));
            $this->log('[FieldAi] user_id=' . $userId . ' fail: ' . $e->getMessage());
            return ['ok' => false, 'error' => $e->getMessage()];
        }
    }

    /**
     * 是否满足「可总结」：有投稿 或 审稿人资料较全。
     */
    public function isEligible($userId, $uri = null)
    {
        if ($this->hasSubmittedArticles($userId)) {
            return true;
        }
        if ($uri === null) {
            $uri = Db::name('user_reviewer_info')->where('reviewer_id', $userId)->find();
        }
        return $this->isReviewerProfileComplete($uri);
    }

    public function hasSubmittedArticles($userId)
    {
        $n = Db::name('article')
            ->where('user_id', intval($userId))
            ->where('title', '<>', '')
            ->count();
        return $n > 0;
    }

    /**
     * 审稿人资料字段填充数达到阈值视为「较全」。
     */
    public function isReviewerProfileComplete($uri)
    {
        if (!$uri || !is_array($uri)) {
            return false;
        }
        $minFilled = max(3, (int) Env::get('user_field_ai.min_profile_fields', 4));
        $keys = ['field', 'company', 'country', 'technical', 'introduction', 'department', 'website'];
        $filled = 0;
        foreach ($keys as $k) {
            if (!empty($uri[$k]) && trim((string)$uri[$k]) !== '') {
                $filled++;
            }
        }
        if (!empty($uri['major']) && trim((string)$uri['major']) !== '' && trim((string)$uri['major']) !== '0') {
            $filled++;
        }
        $majorCount = Db::name('major_to_user')->where('user_id', intval($uri['reviewer_id']))->where('state', 0)->count();
        if ($majorCount > 0) {
            $filled++;
        }
        return $filled >= $minFilled;
    }

    private function findNextPendingUserId($afterUserId, $force)
    {
        $batch = max(20, (int) Env::get('user_field_ai.scan_batch', 80));
        $cursor = intval($afterUserId);

        while (true) {
            $query = Db::name('user')->alias('u')
                ->leftJoin('t_user_reviewer_info uri', 'uri.reviewer_id = u.user_id')
                ->where('u.user_id', '>', $cursor);
            if (!$force) {
                $query->where(function ($q) {
                    $q->where('uri.field_ai_status', self::STATUS_PENDING)
                        ->whereOr('uri.field_ai_status', self::STATUS_FAILED)
                        ->whereOr('uri.reviewer_info_id', 'null');
                });
            }
            $ids = $query->order('u.user_id asc')->limit($batch)->column('u.user_id');

            if (empty($ids)) {
                return 0;
            }

            foreach ($ids as $uid) {
                $uid = intval($uid);
                $cursor = $uid;
                $this->ensureReviewerInfoRow($uid);
                $uri = Db::name('user_reviewer_info')->where('reviewer_id', $uid)->find();
                if (!$force && intval($uri['field_ai_status']) === self::STATUS_DONE) {
                    continue;
                }
                if (!$force && intval($uri['field_ai_status']) === self::STATUS_INSUFFICIENT) {
                    continue;
                }
                if ($this->isEligible($uid, $uri)) {
                    return $uid;
                }
                if (!$force) {
                    $this->updateFieldAi($uid, '', self::STATUS_INSUFFICIENT, 'auto skip: insufficient data');
                }
            }
        }
    }

    private function buildContext($userId, array $uri)
    {
        $user = Db::name('user')->where('user_id', $userId)->field('user_id,realname,email,account')->find();
        $majorTitles = $this->resolveMajorTitles($userId, $uri);

        $maxArticles = max(1, min(10, (int) Env::get('user_field_ai.max_articles', 5)));
        $articles = Db::name('article')
            ->where('user_id', $userId)
            ->where('title', '<>', '')
            ->order('article_id desc')
            ->limit($maxArticles)
            ->field('article_id,title,keywords,abstrart,journal_id,ctime')
            ->select();

        $journalNames = [];
        if (!empty($articles)) {
            $jids = array_unique(array_filter(array_column($articles, 'journal_id')));
            if (!empty($jids)) {
                $journalNames = Db::name('journal')->where('journal_id', 'in', $jids)->column('title', 'journal_id');
            }
        }

        $articleBlocks = [];
        foreach ($articles as $a) {
            $jid = intval($a['journal_id']);
            $articleBlocks[] = [
                'title'    => (string) $a['title'],
                'journal'  => isset($journalNames[$jid]) ? (string) $journalNames[$jid] : '',
                'keywords' => (string) ($a['keywords'] ?? ''),
                'abstract' => mb_substr(trim((string) ($a['abstrart'] ?? '')), 0, 800),
            ];
        }

        return [
            'user'     => [
                'realname' => $user ? (string) $user['realname'] : '',
                'email'    => $user ? (string) $user['email'] : '',
            ],
            'profile'  => [
                'field'        => trim((string) ($uri['field'] ?? '')),
                'technical'    => trim((string) ($uri['technical'] ?? '')),
                'company'      => trim((string) ($uri['company'] ?? '')),
                'department'   => trim((string) ($uri['department'] ?? '')),
                'country'      => trim((string) ($uri['country'] ?? '')),
                'introduction' => mb_substr(trim((string) ($uri['introduction'] ?? '')), 0, 1200),
                'website'      => trim((string) ($uri['website'] ?? '')),
                'majors'       => $majorTitles,
            ],
            'articles' => $articleBlocks,
        ];
    }

    private function resolveMajorTitles($userId, array $uri)
    {
        $titles = [];
        $ids = Db::name('major_to_user')->where('user_id', $userId)->where('state', 0)->column('major_id');
        if (!empty($ids)) {
            $titles = Db::name('reviewer_major')->where('major_id', 'in', $ids)->where('state', 0)->column('title');
        }
        if (empty($titles) && !empty($uri['major'])) {
            $legacy = array_filter(array_map('intval', explode(',', (string) $uri['major'])));
            if (!empty($legacy)) {
                $titles = Db::name('reviewer_major')->where('major_id', 'in', $legacy)->column('title');
            }
        }
        return array_values(array_unique(array_filter(array_map('trim', $titles))));
    }

    private function summarizeWithLlm(array $context)
    {
        $url = trim((string) Env::get('user_field_ai.chat_url', Env::get('expert_country_chat_url', Env::get('citation_chat_url', ''))));
        $model = trim((string) Env::get('user_field_ai.chat_model', Env::get('expert_country_chat_model', Env::get('citation_chat_model', 'gpt-4.1'))));
        $apiKey = trim((string) Env::get('user_field_ai.chat_api_key', Env::get('expert_country_chat_api_key', Env::get('citation_chat_api_key', ''))));
        if ($url === '' || $model === '') {
            throw new Exception('user_field_ai chat not configured (chat_url / chat_model)');
        }

        $payloadJson = json_encode($context, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
        $messages = [
            [
                'role'    => 'system',
                'content' => '你是学术领域分类助手。根据用户的投稿与个人资料，用简体中文给出该用户最主要的研究领域总结。'
                    . '要求：精确、简洁，1～3 个中文领域词或短短语，用顿号分隔；不要解释、不要英文、不要 JSON 以外的多余文字。'
                    . '只输出 JSON：{"field_ai":"..."}。',
            ],
            [
                'role'    => 'user',
                'content' => "请根据以下 JSON 资料总结该用户的主要研究领域：\n" . $payloadJson,
            ],
        ];

        $body = [
            'model'       => $model,
            'temperature' => 0.2,
            'messages'    => $messages,
        ];

        $ch = curl_init();
        curl_setopt_array($ch, [
            CURLOPT_URL            => $url,
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => json_encode($body, JSON_UNESCAPED_UNICODE),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_CONNECTTIMEOUT => 15,
            CURLOPT_TIMEOUT        => max(30, (int) Env::get('user_field_ai.timeout', 90)),
            CURLOPT_HTTPHEADER     => array_filter([
                'Content-Type: application/json',
                $apiKey !== '' ? 'Authorization: Bearer ' . $apiKey : null,
            ]),
        ]);
        $raw = curl_exec($ch);
        $code = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $err = curl_error($ch);
        curl_close($ch);

        if ($raw === false) {
            throw new Exception('LLM curl error: ' . $err);
        }
        if ($code < 200 || $code >= 300) {
            throw new Exception('LLM HTTP ' . $code . ': ' . mb_substr((string) $raw, 0, 400));
        }

        $data = json_decode($raw, true);
        $content = '';
        if (is_array($data) && isset($data['choices'][0]['message']['content'])) {
            $content = trim((string) $data['choices'][0]['message']['content']);
        } elseif (is_string($raw)) {
            $content = trim($raw);
        }

        $fieldAi = $this->parseFieldAiFromContent($content);
        if ($fieldAi === '' && $content !== '') {
            $fieldAi = $this->cleanFieldAiText($content);
        }
        return $fieldAi;
    }

    private function parseFieldAiFromContent($content)
    {
        $content = trim((string) $content);
        if ($content === '') {
            return '';
        }
        $content = preg_replace('/^```[a-zA-Z]*\s*|```$/m', '', $content);
        if (preg_match('/\{.*\}/s', $content, $m)) {
            $obj = json_decode($m[0], true);
            if (is_array($obj) && !empty($obj['field_ai'])) {
                return $this->cleanFieldAiText((string) $obj['field_ai']);
            }
        }
        $obj = json_decode($content, true);
        if (is_array($obj) && !empty($obj['field_ai'])) {
            return $this->cleanFieldAiText((string) $obj['field_ai']);
        }
        return '';
    }

    private function cleanFieldAiText($text)
    {
        $text = trim((string) $text);
        $text = trim($text, "\"' \t\n\r");
        $text = preg_replace('/\s+/u', '', $text);
        if (mb_strlen($text) > 200) {
            $text = mb_substr($text, 0, 200);
        }
        return $text;
    }

    public function ensureReviewerInfoRow($userId)
    {
        $exists = Db::name('user_reviewer_info')->where('reviewer_id', $userId)->find();
        if ($exists) {
            return;
        }
        Db::name('user_reviewer_info')->insert([
            'reviewer_id' => $userId,
            'ctime'       => time(),
            'state'       => 0,
        ]);
    }

    private function updateFieldAi($userId, $fieldAi, $status, $note)
    {
        $data = [
            'field_ai'        => mb_substr(trim((string) $fieldAi), 0, 512),
            'field_ai_status' => intval($status),
            'field_ai_utime'  => time(),
        ];
        Db::name('user_reviewer_info')->where('reviewer_id', $userId)->update($data);
        if ($note !== '') {
            $this->log('[FieldAi] user_id=' . $userId . ' status=' . $status . ' note=' . $note);
        }
    }

    public function log($msg)
    {
        $line = date('Y-m-d H:i:s') . ' ' . $msg . PHP_EOL;
        @file_put_contents($this->logFile, $line, FILE_APPEND);
    }
}