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

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

trait ApprovalTransferTrait
{
    /** 查看某个实例的转交流水（按时间升序） */
    public function listTransfers(int $instanceId): array
    {
        $rows = Db::table('approval_transfers')
            ->where('instance_id', $instanceId)
            ->orderBy('id', 'asc')
            ->get()
            ->toArray();

        return array_map(function($r){
            return [
                'id'           => (int)$r->id,
                'instance_id'  => (int)$r->instance_id,
                'step_index'   => (int)$r->step_index,
                'record_id'    => (int)$r->record_id,
                'from_user_id' => (int)$r->from_user_id,
                'to_user_id'   => (int)$r->to_user_id,
                'reason'       => $r->reason,
                'created_at'   => $r->created_at,
            ];
        }, $rows);
    }

    /** 转交当前待办给他人 */
    public function transferApproval(
        int $instanceId,
        int $stepIndex,
        int $fromUserId,
        int $toUserId,
        string $reason = '',
        ?string $userNameColumn = null
    ): array {
        if ($fromUserId === $toUserId) {
            return ['status' => 'noop', 'msg' => '目标与来源相同，无需转交'];
        }

        return \support\Db::transaction(function () use ($instanceId, $stepIndex, $fromUserId, $toUserId, $reason, $userNameColumn) {
            // 锁实例，避免并发推进
            $instance = Db::table('approval_instances')->where('id', $instanceId)->lockForUpdate()->first();
            if (!$instance) throw new BusinessException('审批实例未找到');
            if ($instance->status !== 'processing') throw new BusinessException('流程非进行中，无法转交');

            // 锁定来源人的 pending 记录
            $record = Db::table('approval_records')
                ->where('instance_id', $instanceId)
                ->where('round', (int)$instance->round)
                ->where('step_index', $stepIndex)
                ->where('approver_id', $fromUserId)
                ->where('status', 'pending')
                ->lockForUpdate()
                ->first();
            if (!$record) throw new BusinessException('未找到可转交的待办或已处理');

            $now = date('Y-m-d H:i:s');

            // 若目标已有 pending：合并（本记录置为 skipped）
            $target = Db::table('approval_records')
                ->where('instance_id', $instanceId)
                ->where('round', (int)$instance->round)
                ->where('step_index', $stepIndex)
                ->where('approver_id', $toUserId)
                ->where('status', 'pending')
                ->lockForUpdate()
                ->first();

            if ($target) {
                Db::table('approval_records')->where('id', $record->id)->update([
                    'status'      => 'skipped',
                    'approved_at' => $now,
                    'updated_at'  => $now,
                    'comment'     => trim(($record->comment ?? '')."\n[转交给 {$toUserId}，目标已有待办，已合并]"),
                ]);
                $effectiveRecordId = (int)$target->id;
            } else {
                // 原地替换 approver_id
                Db::table('approval_records')->where('id', $record->id)->update([
                    'approver_id' => $toUserId,
                    'updated_at'  => $now,
                    'comment'     => trim(($record->comment ?? '')."\n[自 {$fromUserId} 转交]"),
                ]);
                $effectiveRecordId = (int)$record->id;
            }

            // 组织“转交来源/原因”文案（优先姓名）
            $fromLabel = (string)$fromUserId;
            $toLabel   = (string)$toUserId;
            if ($userNameColumn) {
                $fromName = Db::table('user')->where('id', $fromUserId)->value($userNameColumn);
                $toName   = Db::table('user')->where('id', $toUserId)->value($userNameColumn);
                if ($fromName) $fromLabel = $fromName;
                if ($toName)   $toLabel   = $toName;
            }
            $note = "【转交】{$fromLabel} → {$toLabel}";
            $r = trim($reason);
            if ($r !== '') $note .= "，原因：{$r}";

            // 通知被转交人（在内容里追加 note）
            $this->sendNotification([$toUserId], (object)[
                'id'           => (int)$instance->id,
                'flow_type'    => (string)$instance->flow_type,
                'biz_type'     => (string)$instance->biz_type,
                'biz_id'       => (string)$instance->biz_id,
                'initiator_id' => (int)$instance->initiator_id,
                'form_data'    => $instance->form_data,
            ], 'pending', false, ['note' => $note]);

            // 记转交流水
            Db::table('approval_transfers')->insert([
                'instance_id'  => (int)$instanceId,
                'step_index'   => (int)$stepIndex,
                'record_id'    => $effectiveRecordId,
                'from_user_id' => (int)$fromUserId,
                'to_user_id'   => (int)$toUserId,
                'reason'       => $reason,
                'created_at'   => $now,
            ]);

            $this->pushTodoChanged([$fromUserId, $toUserId]);
            return ['status' => 'ok', 'record_id' => $effectiveRecordId];
        });
    }
}