<?php

namespace app\common;

use think\Db;
use think\Queue;

/**
 * Expert 领域总结（方案 C）
 * 阶段1：通过 email 关联 t_user / t_user_reviewer_info，复用 user.field_ai
 * 阶段2（后续）：对 field_ai_status=4 的记录走 LLM 总结
 */
class ExpertFieldAiService
{
    const QUEUE_NAME = 'ExpertFieldAi';

    const STATUS_PENDING = 0;
    const STATUS_DONE = 1;
    const STATUS_INSUFFICIENT = 2;
    const STATUS_FAILED = 3;
    const STATUS_NO_USER_LINK = 4;

    const SOURCE_USER_LINK = 'user_link';
    const SOURCE_AI = 'ai';

    private $logFile;

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

    /**
     * 启动链式关联（从 expert_id=0 之后找下一位待处理专家）。
     */
    public function startLinkChain($force = false, $delay = 1, $queue = '')
    {
        return $this->enqueueNextLink($delay, $queue, 0, $force);
    }

    /**
     * 链式：处理 expert_id > $afterExpertId 的下一位。
     */
    public function enqueueNextLink($delay = 1, $queue = '', $afterExpertId = 0, $force = false)
    {
        if ($queue === '') {
            $queue = self::QUEUE_NAME;
        }
        $afterExpertId = intval($afterExpertId);
        $expertId = $this->findNextLinkExpertId($afterExpertId, $force);
        if ($expertId <= 0) {
            $this->log('[ExpertFieldAi] link chain finished after expert_id=' . $afterExpertId);
            return false;
        }

        $data = [
            'expert_id' => $expertId,
            'queue'     => $queue,
            'force'     => $force ? 1 : 0,
            'mode'      => 'link',
        ];
        $jobClass = 'app\\api\\job\\ExpertFieldAiFill@fire';
        if ($delay > 0) {
            Queue::later($delay, $jobClass, $data, $queue);
        } else {
            Queue::push($jobClass, $data, $queue);
        }
        $this->log('[ExpertFieldAi] enqueued expert_id=' . $expertId . ' queue=' . $queue);
        return true;
    }

    /**
     * 单个 expert：尝试从 user 邮箱关联 field_ai。
     *
     * @return array{ok:bool, linked?:bool, skipped?:bool, field_ai?:string, user_id?:int, error?:string}
     */
    public function linkFromUser($expertId, $force = false)
    {
        $expertId = intval($expertId);
        if ($expertId <= 0) {
            return ['ok' => false, 'error' => 'invalid expert_id'];
        }

        $expert = Db::name('expert')->where('expert_id', $expertId)->find();
        if (!$expert) {
            return ['ok' => false, 'error' => 'expert not found'];
        }

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

        $email = strtolower(trim((string)($expert['email'] ?? '')));
        if ($email === '') {
            $this->updateFieldAi($expertId, '', self::STATUS_NO_USER_LINK, '', 'no email');
            return ['ok' => true, 'linked' => false, 'reason' => 'empty email'];
        }

        $user = Db::name('user')
            ->where('email', $email)
            ->where('state', 0)
            ->field('user_id,email,realname')
            ->find();

        if (!$user) {
            $this->updateFieldAi($expertId, '', self::STATUS_NO_USER_LINK, '', 'no matching user');
            return ['ok' => true, 'linked' => false, 'reason' => 'user not found'];
        }

        $uri = Db::name('user_reviewer_info')
            ->where('reviewer_id', intval($user['user_id']))
            ->where('state', 0)
            ->find();

        $fieldAi = $uri ? trim((string)($uri['field_ai'] ?? '')) : '';
        $userStatus = $uri ? intval($uri['field_ai_status']) : 0;

        if ($fieldAi === '' || $userStatus !== UserFieldAiService::STATUS_DONE) {
            $this->updateFieldAi($expertId, '', self::STATUS_NO_USER_LINK, '', 'user field_ai not ready');
            return [
                'ok'      => true,
                'linked'  => false,
                'user_id' => intval($user['user_id']),
                'reason'  => 'user has no field_ai',
            ];
        }

        $this->updateFieldAi($expertId, $fieldAi, self::STATUS_DONE, self::SOURCE_USER_LINK, 'linked from user_id=' . $user['user_id']);
        return [
            'ok'       => true,
            'linked'   => true,
            'field_ai' => $fieldAi,
            'user_id'  => intval($user['user_id']),
            'source'   => self::SOURCE_USER_LINK,
        ];
    }

    /**
     * 批量同步（同步执行，适合小批量调试）。
     */
    public function batchLinkFromUser(array $expertIds, $force = false)
    {
        $linked = 0;
        $skipped = 0;
        $noLink = 0;
        $failed = 0;
        $details = [];

        foreach ($expertIds as $expertId) {
            $expertId = intval($expertId);
            if ($expertId <= 0) {
                continue;
            }
            $result = $this->linkFromUser($expertId, $force);
            if (empty($result['ok'])) {
                $failed++;
            } elseif (!empty($result['skipped'])) {
                $skipped++;
            } elseif (!empty($result['linked'])) {
                $linked++;
            } else {
                $noLink++;
            }
            $details[] = array_merge(['expert_id' => $expertId], $result);
        }

        return [
            'total'   => count($details),
            'linked'  => $linked,
            'skipped' => $skipped,
            'no_link' => $noLink,
            'failed'  => $failed,
            'details' => $details,
        ];
    }

    /**
     * 预览：expert 是否可关联到 user.field_ai。
     */
    public function previewLink($expertId)
    {
        $expertId = intval($expertId);
        $expert = Db::name('expert')->where('expert_id', $expertId)->find();
        if (!$expert) {
            return ['ok' => false, 'error' => 'expert not found'];
        }

        $email = strtolower(trim((string)($expert['email'] ?? '')));
        $user = null;
        $uri = null;
        if ($email !== '') {
            $user = Db::name('user')->where('email', $email)->where('state', 0)->field('user_id,email,realname')->find();
            if ($user) {
                $uri = Db::name('user_reviewer_info')
                    ->where('reviewer_id', intval($user['user_id']))
                    ->where('state', 0)
                    ->find();
            }
        }

        $canLink = $user && $uri
            && trim((string)($uri['field_ai'] ?? '')) !== ''
            && intval($uri['field_ai_status']) === UserFieldAiService::STATUS_DONE;

        return [
            'ok'                    => true,
            'expert_id'             => $expertId,
            'expert_email'          => $email,
            'expert_field_ai'       => (string)($expert['field_ai'] ?? ''),
            'expert_field_ai_status'=> intval($expert['field_ai_status'] ?? 0),
            'matched_user_id'       => $user ? intval($user['user_id']) : 0,
            'matched_user_name'     => $user ? (string)$user['realname'] : '',
            'user_field_ai'         => $uri ? (string)($uri['field_ai'] ?? '') : '',
            'user_field_ai_status'  => $uri ? intval($uri['field_ai_status']) : 0,
            'can_link'              => $canLink,
        ];
    }

    /**
     * user 生成 field_ai 后，反向同步到同邮箱 expert（可选调用）。
     */
    public function syncExpertsByUserId($userId, $force = false)
    {
        $userId = intval($userId);
        $user = Db::name('user')->where('user_id', $userId)->where('state', 0)->field('user_id,email')->find();
        if (!$user || trim((string)$user['email']) === '') {
            return ['ok' => false, 'error' => 'user not found'];
        }

        $email = strtolower(trim((string)$user['email']));
        $expertIds = Db::name('expert')
            ->where('email', $email)
            ->where('state', '<>', 5)
            ->column('expert_id');

        if (empty($expertIds)) {
            return ['ok' => true, 'synced' => 0, 'msg' => 'no expert with same email'];
        }

        return array_merge(['ok' => true], $this->batchLinkFromUser($expertIds, $force));
    }

    private function findNextLinkExpertId($afterExpertId, $force)
    {
        $batch = 50;
        $cursor = intval($afterExpertId);

        while (true) {
            $query = Db::name('expert')
                ->where('expert_id', '>', $cursor)
                ->where('state', '<>', 5);

            if (!$force) {
                $query->where(function ($q) {
                    $q->where('field_ai_status', self::STATUS_PENDING)
                        ->whereOr('field_ai_status', self::STATUS_FAILED);
                });
            }

            $ids = $query->order('expert_id asc')->limit($batch)->column('expert_id');
            if (empty($ids)) {
                return 0;
            }

            foreach ($ids as $expertId) {
                $expertId = intval($expertId);
                $cursor = $expertId;

                if (!$force) {
                    $row = Db::name('expert')->where('expert_id', $expertId)->field('field_ai,field_ai_status')->find();
                    if ($row
                        && intval($row['field_ai_status']) === self::STATUS_DONE
                        && trim((string)$row['field_ai']) !== '') {
                        continue;
                    }
                }

                return $expertId;
            }
        }
    }

    private function updateFieldAi($expertId, $fieldAi, $status, $source, $note)
    {
        $data = [
            'field_ai'        => mb_substr(trim((string)$fieldAi), 0, 512),
            'field_ai_status' => intval($status),
            'field_ai_utime'  => time(),
            'field_ai_source' => mb_substr(trim((string)$source), 0, 32),
        ];
        Db::name('expert')->where('expert_id', intval($expertId))->update($data);
        if ($note !== '') {
            $this->log('[ExpertFieldAi] expert_id=' . $expertId . ' status=' . $status . ' note=' . $note);
        }
    }

    public function statusLabel($status)
    {
        $map = [
            self::STATUS_PENDING      => 'pending',
            self::STATUS_DONE         => 'done',
            self::STATUS_INSUFFICIENT => 'insufficient',
            self::STATUS_FAILED       => 'failed',
            self::STATUS_NO_USER_LINK => 'no_user_link',
        ];
        return isset($map[$status]) ? $map[$status] : 'unknown';
    }

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