<?php
namespace app\common\utils\approval\service\traits;

use support\Db;
use support\exception\BusinessException;

trait ApprovalDiscussionTrait
{
    /** 是否该实例参与者 */
    private function isParticipantOfInstance(int $instanceId, int $userId): bool
    {
        $inst = Db::table('approval_instances')->where('id', $instanceId)->first();
        if (!$inst) return false;
        if ((int)$inst->initiator_id === $userId) return true;

        $inRecords = Db::table('approval_records')
            ->where('instance_id', $instanceId)->where('approver_id', $userId)->exists();
        if ($inRecords) return true;

        $inCc = Db::table('approval_ccs')
            ->where('instance_id', $instanceId)->where('user_id', $userId)->exists();
        return $inCc;
    }

    /** 是否该实例任一步的审批人 */
    private function isApproverOfInstance(int $instanceId, int $userId): bool
    {
        return Db::table('approval_records')
            ->where('instance_id', $instanceId)
            ->where('approver_id', $userId)
            ->exists();
    }

    /** 获取讨论受众 */
    private function getDiscussionAudienceUserIds(int $instanceId, bool $approversOnly, int $excludeUserId): array
    {
        $uids = [];
        if (!$approversOnly) {
            $inst = Db::table('approval_instances')->where('id', $instanceId)->first();
            if ($inst) $uids[] = (int)$inst->initiator_id;
            $ccs = Db::table('approval_ccs')->where('instance_id', $instanceId)->pluck('user_id')->toArray();
            foreach ($ccs as $u) $uids[] = (int)$u;
        }
        $approvers = Db::table('approval_records')
            ->where('instance_id', $instanceId)
            ->distinct()->pluck('approver_id')->toArray();
        foreach ($approvers as $u) $uids[] = (int)$u;

        $uids = array_values(array_unique(array_filter($uids, fn($u) => $u !== $excludeUserId)));
        return $uids;
    }

    /** 发表讨论 */
    public function postDiscussion(
        int $instanceId,
        int $userId,
        string $content,
        bool $isInternal = false,
        array $attachments = [],
        ?string $userNameColumn = null
    ): array {
        $content = trim($content);
        if ($content === '') throw new BusinessException('讨论内容不能为空');
        if (!$this->isParticipantOfInstance($instanceId, $userId)) {
            throw new BusinessException('无权参与该实例的讨论');
        }
        if ($isInternal && !$this->isApproverOfInstance($instanceId, $userId)) {
            throw new BusinessException('仅审批人可发布内部讨论');
        }

        $now = date('Y-m-d H:i:s');
        $id = Db::table('approval_discussions')->insertGetId([
            'instance_id' => $instanceId,
            'user_id'     => $userId,
            'is_internal' => $isInternal ? 1 : 0,
            'content'     => $content,
            'attachments' => empty($attachments) ? null : json_encode($attachments, JSON_UNESCAPED_UNICODE|JSON_UNESCAPED_SLASHES),
            'created_at'  => $now,
            'updated_at'  => $now,
        ]);

        // 通知其他人
        $inst = Db::table('approval_instances')->where('id', $instanceId)->first();
        if ($inst) {
            $audience = $this->getDiscussionAudienceUserIds($instanceId, $isInternal, $userId);
            // 发言人姓名（可选）
            $speaker = (string)$userId;
            if ($userNameColumn) {
                $name = Db::table('user')->where('id', $userId)->value($userNameColumn);
                if ($name) $speaker = $name;
            }
            $snippet = function_exists('mb_strimwidth') ? mb_strimwidth($content, 0, 80, '...', 'UTF-8') : $content;
            $extra   = ['note' => "【讨论】{$speaker}：{$snippet}"];

            $this->sendNotification(
                $audience,
                (object)[
                    'id'           => (int)$inst->id,
                    'flow_type'    => (string)$inst->flow_type,
                    'initiator_id' => (int)$inst->initiator_id,
                    'form_data'    => $inst->form_data,
                    'biz_type'     => (string)$inst->biz_type,
                    'biz_id'       => (string)$inst->biz_id,
                ],
                'pending',
                false,
                $extra
            );
        }

        return [
            'id'           => (int)$id,
            'instance_id'  => $instanceId,
            'user_id'      => $userId,
            'is_internal'  => (bool)$isInternal,
            'content'      => $content,
            'attachments'  => $attachments,
            'created_at'   => $now,
        ];
    }

    /** 获取讨论列表 */
    public function listDiscussions(int $instanceId, ?int $afterId = null, int $limit = 50, ?string $userNameColumn = null): array
    {
        $q = Db::table('approval_discussions as d')->where('d.instance_id', $instanceId);
        if ($afterId) $q->where('d.id', '>', $afterId);
        $q->orderBy('d.id', 'asc')->limit(max(1, min(200, $limit)));

        if ($userNameColumn) {
            $rows = $q->leftJoin('user as u', 'd.user_id', '=', 'u.id')
                ->select('d.*', Db::raw("u.`{$userNameColumn}` as user_name"))
                ->get()->toArray();
        } else {
            $rows = $q->select('d.*')->get()->toArray();
        }

        return array_map(function($r){
            return [
                'id'          => (int)$r->id,
                'instance_id' => (int)$r->instance_id,
                'user_id'     => (int)$r->user_id,
                'is_internal' => (bool)$r->is_internal,
                'content'     => $r->content,
                'attachments' => $r->attachments ? json_decode($r->attachments, true) : [],
                'created_at'  => $r->created_at,
                'updated_at'  => $r->updated_at,
                'user_name'   => property_exists($r, 'user_name') ? $r->user_name : null,
            ];
        }, $rows);
    }
}