package com.ruoyi.approve.utils;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.ruoyi.approve.pojo.ApprovalInstance;
import com.ruoyi.approve.pojo.ApprovalInstanceNode;
import com.ruoyi.approve.pojo.ApprovalRecord;
import com.ruoyi.approve.pojo.ApprovalTask;
import com.ruoyi.approve.pojo.ApprovalTemplateNode;
import com.ruoyi.approve.pojo.ApprovalTemplateNodeApprover;
import com.ruoyi.approve.service.ApprovalInstanceNodeService;
import com.ruoyi.approve.service.ApprovalRecordService;
import com.ruoyi.approve.service.ApprovalTaskService;
import com.ruoyi.approve.service.ApprovalTemplateNodeApproverService;
import com.ruoyi.approve.service.ApprovalTemplateNodeService;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

/**
 * 审批流程节点工具类
 */
@Component
@RequiredArgsConstructor
public class ApproveProcessConfigNodeUtils {

    private final ApprovalInstanceNodeService instanceNodeService;
    private final ApprovalTaskService approvalTaskService;
    private final ApprovalRecordService approvalRecordService;
    private final ApprovalTemplateNodeService approvalTemplateNodeService;
    private final ApprovalTemplateNodeApproverService approvalTemplateNodeApproverService;

    /**
     * 按当前层级创建审批节点和审批任务。
     * 该重载会同时写入一条发起审批记录。
     */
    @Transactional(rollbackFor = Exception.class)
    public ApprovalInstanceNode createCurrentNodeAndTasks(ApprovalInstance instance) {
        return createCurrentNodeAndTasks(instance, true);
    }

    /**
     * 按当前层级创建审批节点和审批任务。
     *
     * @param instance 审批实例
     * @param createSubmitRecord 是否创建发起审批记录
     * @return 创建出的当前节点实例
     */
    @Transactional(rollbackFor = Exception.class)
    public ApprovalInstanceNode createCurrentNodeAndTasks(ApprovalInstance instance, boolean createSubmitRecord) {
        if (instance == null || instance.getId() == null) {
            throw new RuntimeException("审批实例不能为空");
        }
        if (instance.getTemplateId() == null) {
            throw new RuntimeException("审批模板不能为空");
        }

        Integer currentLevel = instance.getCurrentLevel() == null ? 1 : instance.getCurrentLevel();

        ApprovalInstanceNode existsNode = instanceNodeService.getOne(
                new LambdaQueryWrapper<ApprovalInstanceNode>()
                        .eq(ApprovalInstanceNode::getInstanceId, instance.getId())
                        .eq(ApprovalInstanceNode::getLevelNo, currentLevel)
                        .eq(ApprovalInstanceNode::getDeleted, 0)
                        .last("LIMIT 1")
        );
        if (existsNode != null) {
            return existsNode;
        }

        ApprovalTemplateNode templateNode = approvalTemplateNodeService.getOne(
                new LambdaQueryWrapper<ApprovalTemplateNode>()
                        .eq(ApprovalTemplateNode::getTemplateId, instance.getTemplateId())
                        .eq(ApprovalTemplateNode::getLevelNo, currentLevel)
                        .orderByAsc(ApprovalTemplateNode::getId)
                        .last("LIMIT 1")
        );
        if (templateNode == null) {
            throw new RuntimeException("未找到当前层级对应的审批模板节点");
        }

        List<ApprovalTemplateNodeApprover> approvers = approvalTemplateNodeApproverService.list(
                new LambdaQueryWrapper<ApprovalTemplateNodeApprover>()
                        .eq(ApprovalTemplateNodeApprover::getTemplateId, instance.getTemplateId())
                        .eq(ApprovalTemplateNodeApprover::getNodeId, templateNode.getId())
                        .eq(ApprovalTemplateNodeApprover::getDeleted, 0L)
                        .orderByAsc(ApprovalTemplateNodeApprover::getSortNo)
        );
        if (approvers == null || approvers.isEmpty()) {
            throw new RuntimeException("当前审批节点未配置审批人");
        }

        ApprovalInstanceNode instanceNode = new ApprovalInstanceNode();
        instanceNode.setInstanceId(instance.getId());
        instanceNode.setLevelNo(templateNode.getLevelNo());
        instanceNode.setApproveType(templateNode.getApproveType());
        instanceNode.setStatus("PENDING");
        instanceNode.setStartTime(LocalDateTime.now());
        instanceNode.setDeleted((byte) 0);
        instanceNodeService.save(instanceNode);

        List<ApprovalTask> taskList = new ArrayList<>(approvers.size());
        for (ApprovalTemplateNodeApprover approver : approvers) {
            ApprovalTask task = new ApprovalTask();
            task.setInstanceId(instance.getId());
            task.setNodeId(instanceNode.getId());
            task.setLevelNo(instanceNode.getLevelNo());
            task.setApproverId(approver.getApproverId());
            task.setApproverName(approver.getApproverName());
            task.setTaskStatus("PENDING");
            task.setIsRead((byte) 0);
            task.setDeleted((byte) 0);
            taskList.add(task);
        }
        approvalTaskService.saveBatch(taskList);

        if (createSubmitRecord) {
            ApprovalRecord record = new ApprovalRecord();
            record.setInstanceId(instance.getId());
            record.setNodeId(instanceNode.getId());
            record.setOperatorId(instance.getApplicantId());
            record.setOperatorName(instance.getApplicantName());
            record.setAction("SUBMIT");
            record.setComment("发起审批");
            record.setDeleted((byte) 0);
            approvalRecordService.save(record);
        }

        return instanceNode;
    }

    /**
     * 查询当前待处理节点。
     */
    public ApprovalInstanceNode getCurrentNode(Long instanceId) {
        if (instanceId == null) {
            return null;
        }

        return instanceNodeService.getOne(
                new LambdaQueryWrapper<ApprovalInstanceNode>()
                        .eq(ApprovalInstanceNode::getInstanceId, instanceId)
                        .eq(ApprovalInstanceNode::getStatus, "PENDING")
                        .eq(ApprovalInstanceNode::getDeleted, 0)
                        .orderByAsc(ApprovalInstanceNode::getLevelNo)
                        .last("LIMIT 1")
        );
    }

    /**
     * 查询当前审批层级。
     */
    public Integer getCurrentLevel(Long instanceId) {
        ApprovalInstanceNode currentNode = getCurrentNode(instanceId);
        return currentNode != null ? currentNode.getLevelNo() : null;
    }

    /**
     * 查询当前节点下的待审批任务。
     */
    public List<ApprovalTask> getCurrentPendingTasks(Long instanceId) {
        if (instanceId == null) {
            return List.of();
        }

        ApprovalInstanceNode currentNode = getCurrentNode(instanceId);
        if (currentNode == null) {
            return List.of();
        }

        return approvalTaskService.list(
                new LambdaQueryWrapper<ApprovalTask>()
                        .eq(ApprovalTask::getInstanceId, instanceId)
                        .eq(ApprovalTask::getNodeId, currentNode.getId())
                        .eq(ApprovalTask::getTaskStatus, "PENDING")
                        .eq(ApprovalTask::getDeleted, 0)
                        .orderByAsc(ApprovalTask::getLevelNo)
        );
    }

    /**
     * 查询当前用户在当前节点上的待审批任务。
     */
    public ApprovalTask getCurrentUserTask(Long instanceId, Long userId) {
        if (instanceId == null || userId == null) {
            return null;
        }

        ApprovalInstanceNode currentNode = getCurrentNode(instanceId);
        if (currentNode == null) {
            return null;
        }

        return approvalTaskService.getOne(
                new LambdaQueryWrapper<ApprovalTask>()
                        .eq(ApprovalTask::getInstanceId, instanceId)
                        .eq(ApprovalTask::getNodeId, currentNode.getId())
                        .eq(ApprovalTask::getApproverId, userId)
                        .eq(ApprovalTask::getTaskStatus, "PENDING")
                        .eq(ApprovalTask::getDeleted, 0)
                        .last("LIMIT 1")
        );
    }

    /**
     * 判断当前用户是否是当前审批人。
     */
    public boolean isCurrentApprover(Long instanceId, Long userId) {
        return getCurrentUserTask(instanceId, userId) != null;
    }

    /**
     * 查询当前节点的审批人 ID 列表。
     */
    public List<Long> getCurrentNodeApproverIds(Long instanceId) {
        return getCurrentPendingTasks(instanceId).stream()
                .map(ApprovalTask::getApproverId)
                .distinct()
                .collect(Collectors.toList());
    }

    /**
     * 查询当前节点剩余待审批人数。
     */
    public int getRemainingApproverCount(Long instanceId) {
        return getCurrentPendingTasks(instanceId).size();
    }

    /**
     * 查询当前节点已同意人数。
     */
    public int getApprovedCount(Long instanceId) {
        if (instanceId == null) {
            return 0;
        }

        ApprovalInstanceNode currentNode = getCurrentNode(instanceId);
        if (currentNode == null) {
            return 0;
        }

        return Math.toIntExact(approvalTaskService.count(
                new LambdaQueryWrapper<ApprovalTask>()
                        .eq(ApprovalTask::getInstanceId, instanceId)
                        .eq(ApprovalTask::getNodeId, currentNode.getId())
                        .eq(ApprovalTask::getTaskStatus, "APPROVED")
                        .eq(ApprovalTask::getDeleted, 0)
        ));
    }

    /**
     * 查询当前节点已拒绝人数。
     */
    public int getRejectedCount(Long instanceId) {
        if (instanceId == null) {
            return 0;
        }

        ApprovalInstanceNode currentNode = getCurrentNode(instanceId);
        if (currentNode == null) {
            return 0;
        }

        return Math.toIntExact(approvalTaskService.count(
                new LambdaQueryWrapper<ApprovalTask>()
                        .eq(ApprovalTask::getInstanceId, instanceId)
                        .eq(ApprovalTask::getNodeId, currentNode.getId())
                        .eq(ApprovalTask::getTaskStatus, "REJECTED")
                        .eq(ApprovalTask::getDeleted, 0)
        ));
    }

    /**
     * 判断当前节点是否可以流转到下一层。
     */
    public boolean canProceedToNextLevel(Long instanceId, String approveType) {
        if (instanceId == null || approveType == null) {
            return false;
        }

        if (getRejectedCount(instanceId) > 0) {
            return false;
        }

        int totalApproverCount = getCurrentPendingTasks(instanceId).size() + getApprovedCount(instanceId);
        int approvedCount = getApprovedCount(instanceId);

        if ("AND".equalsIgnoreCase(approveType)) {
            return approvedCount > 0 && approvedCount == totalApproverCount;
        }
        if ("OR".equalsIgnoreCase(approveType)) {
            return approvedCount > 0;
        }
        return false;
    }

    /**
     * 查询当前用户在当前节点上的任务状态。
     */
    public String getUserTaskStatus(Long instanceId, Long userId) {
        if (instanceId == null || userId == null) {
            return null;
        }

        ApprovalInstanceNode currentNode = getCurrentNode(instanceId);
        if (currentNode == null) {
            return null;
        }

        ApprovalTask task = approvalTaskService.getOne(
                new LambdaQueryWrapper<ApprovalTask>()
                        .eq(ApprovalTask::getInstanceId, instanceId)
                        .eq(ApprovalTask::getNodeId, currentNode.getId())
                        .eq(ApprovalTask::getApproverId, userId)
                        .eq(ApprovalTask::getDeleted, 0)
                        .last("LIMIT 1")
        );

        return task != null ? task.getTaskStatus() : null;
    }

    /**
     * 查询指定用户的全部待审批任务。
     */
    public List<ApprovalTask> getUserAllPendingTasks(Long userId) {
        if (userId == null) {
            return List.of();
        }

        return approvalTaskService.list(
                new LambdaQueryWrapper<ApprovalTask>()
                        .eq(ApprovalTask::getApproverId, userId)
                        .eq(ApprovalTask::getTaskStatus, "PENDING")
                        .eq(ApprovalTask::getDeleted, 0)
                        .orderByDesc(ApprovalTask::getCreateTime)
        );
    }

    /**
     * 查询审批实例的进度摘要。
     */
    public String getApprovalProgress(Long instanceId) {
        if (instanceId == null) {
            return "无效的审批实例";
        }

        ApprovalInstanceNode currentNode = getCurrentNode(instanceId);
        if (currentNode == null) {
            return "审批已完成或尚未开始";
        }

        int approvedCount = getApprovedCount(instanceId);
        int rejectedCount = getRejectedCount(instanceId);
        int pendingCount = getRemainingApproverCount(instanceId);
        int totalCount = approvedCount + rejectedCount + pendingCount;

        return String.format(
                "第%d级审批：总人数=%d，已同意=%d，已拒绝=%d，待审批=%d",
                currentNode.getLevelNo(),
                totalCount,
                approvedCount,
                rejectedCount,
                pendingCount
        );
    }
}