package com.designhub.service;

import com.designhub.entity.*;
import com.designhub.mapper.UserMapper;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.HashSet;
import java.util.Set;

/**
 * 任务状态变更通知服务
 * 负责在任务状态变化时通知需求人
 */
@Service
@Slf4j
@RequiredArgsConstructor
public class TaskStatusNotificationService {

    private final NotificationService notificationService;
    private final UserMapper userMapper;

    private static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");

    /**
     * 通知需求人：任务已解锁（排队中 → 抢单中）
     */
    @Async
    public void notifyTaskUnlocked(TaskItem item, Task mainTask) {
        if (mainTask == null) {
            log.warn("通知任务解锁失败：主任务为空");
            return;
        }

        Set<Long> demandUserIds = getDemandUserIds(mainTask);
        if (demandUserIds.isEmpty()) {
            log.warn("通知任务解锁失败：没有找到需求人");
            return;
        }

        String content = String.format(
            "您发布的任务《%s》已完成排队，现已开放设计师抢单。\n" +
            "任务编号：%s\n" +
            "发布时间：%s\n" +
            "设计师正在抢单中，请耐心等待...",
            mainTask.getTitle(),
            item.getItemNo(),
            formatTime(mainTask.getCreateTime())
        );

        for (Long userId : demandUserIds) {
            try {
                Notification notification = new Notification();
                notification.setReceiverId(userId);
                notification.setNotificationType("task_status");
                notification.setTitle("📢 任务已开放抢单");
                notification.setContent(content);
                notification.setRelatedId(item.getId());
                notification.setRelatedType("task_item");
                notification.setPriority(1);  // 普通优先级
                notification.setPushDingtalk(1);  // 推送钉钉
                notificationService.sendNotification(notification);

                log.info("已通知需求人 {} 任务 {} 已解锁开放抢单", userId, item.getItemNo());
            } catch (Exception e) {
                log.error("通知需求人 {} 任务解锁失败: {}", userId, e.getMessage());
            }
        }
    }

    /**
     * 通知需求人：任务已被接单（抢单中 → 进行中）
     */
    @Async
    public void notifyTaskGrabbed(TaskItem item, Task mainTask, User designer) {
        if (mainTask == null || designer == null) {
            log.warn("通知任务接单失败：主任务或设计师信息为空");
            return;
        }

        Set<Long> demandUserIds = getDemandUserIds(mainTask);
        if (demandUserIds.isEmpty()) {
            return;
        }

        String content = String.format(
            "您发布的任务《%s》已被设计师接单。\n" +
            "任务编号：%s\n" +
            "接单设计师：%s\n" +
            "预计完成：%s\n" +
            "如有问题可联系设计师沟通。",
            mainTask.getTitle(),
            item.getItemNo(),
            designer.getRealName(),
            item.getDeadline() != null ? formatTime(item.getDeadline()) : "待定"
        );

        for (Long userId : demandUserIds) {
            // 不通知自己（如果设计师就是需求人）
            if (userId.equals(designer.getId())) {
                continue;
            }

            try {
                Notification notification = new Notification();
                notification.setReceiverId(userId);
                notification.setNotificationType("task_status");
                notification.setTitle("🎉 任务已被接单");
                notification.setContent(content);
                notification.setRelatedId(item.getId());
                notification.setRelatedType("task_item");
                notification.setPriority(1);
                notification.setPushDingtalk(1);
                notificationService.sendNotification(notification);

                log.info("已通知需求人 {} 任务 {} 已被 {} 接单", userId, item.getItemNo(), designer.getRealName());
            } catch (Exception e) {
                log.error("通知需求人 {} 任务接单失败: {}", userId, e.getMessage());
            }
        }
    }

    /**
     * 通知需求人：任务已完成
     */
    @Async
    public void notifyTaskCompleted(TaskItem item, Task mainTask, User designer) {
        if (mainTask == null || designer == null) {
            log.warn("通知任务完成失败：主任务或设计师信息为空");
            return;
        }

        Set<Long> demandUserIds = getDemandUserIds(mainTask);
        if (demandUserIds.isEmpty()) {
            return;
        }

        String content = String.format(
            "您发布的任务《%s》已完成。\n" +
            "任务编号：%s\n" +
            "完成设计师：%s\n" +
            "完成时间：%s\n" +
            "请及时查收并确认交付物。",
            mainTask.getTitle(),
            item.getItemNo(),
            designer.getRealName(),
            formatTime(item.getCompleteTime() != null ? item.getCompleteTime() : LocalDateTime.now())
        );

        for (Long userId : demandUserIds) {
            try {
                Notification notification = new Notification();
                notification.setReceiverId(userId);
                notification.setNotificationType("task_status");
                notification.setTitle("✅ 任务已完成");
                notification.setContent(content);
                notification.setRelatedId(item.getId());
                notification.setRelatedType("task_item");
                notification.setPriority(2);  // 重要
                notification.setPushDingtalk(1);
                notificationService.sendNotification(notification);

                log.info("已通知需求人 {} 任务 {} 已完成", userId, item.getItemNo());
            } catch (Exception e) {
                log.error("通知需求人 {} 任务完成失败: {}", userId, e.getMessage());
            }
        }
    }

    /**
     * 批量通知任务解锁
     */
    @Async
    public void batchNotifyTasksUnlocked(java.util.List<TaskItem> items, java.util.Map<Long, Task> taskMap) {
        if (items == null || items.isEmpty()) {
            return;
        }

        // 按主任务分组，避免同一任务的多个子任务重复通知
        java.util.Map<Long, java.util.List<TaskItem>> groupedByTask = items.stream()
            .collect(java.util.stream.Collectors.groupingBy(TaskItem::getTaskId));

        for (java.util.Map.Entry<Long, java.util.List<TaskItem>> entry : groupedByTask.entrySet()) {
            Long taskId = entry.getKey();
            java.util.List<TaskItem> taskItems = entry.getValue();
            Task mainTask = taskMap.get(taskId);

            if (mainTask == null) {
                continue;
            }

            Set<Long> demandUserIds = getDemandUserIds(mainTask);
            if (demandUserIds.isEmpty()) {
                continue;
            }

            // 构建通知内容
            String itemNos = taskItems.stream()
                .map(TaskItem::getItemNo)
                .collect(java.util.stream.Collectors.joining(", "));

            String content = String.format(
                "您发布的任务《%s》有 %d 个子任务已完成排队，现已开放设计师抢单。\n" +
                "子任务编号：%s\n" +
                "设计师正在抢单中，请耐心等待...",
                mainTask.getTitle(),
                taskItems.size(),
                itemNos
            );

            for (Long userId : demandUserIds) {
                try {
                    Notification notification = new Notification();
                    notification.setReceiverId(userId);
                    notification.setNotificationType("task_status");
                    notification.setTitle("📢 任务已开放抢单");
                    notification.setContent(content);
                    notification.setRelatedId(taskId);
                    notification.setRelatedType("task");
                    notification.setPriority(1);
                    notification.setPushDingtalk(1);
                    notificationService.sendNotification(notification);
                } catch (Exception e) {
                    log.error("批量通知任务解锁失败: {}", e.getMessage());
                }
            }
        }
    }

    /**
     * 获取任务的所有需求人（发布者 + 详情填写人 + 一级发起人）
     */
    private Set<Long> getDemandUserIds(Task task) {
        Set<Long> userIds = new HashSet<>();

        // 发布者
        if (task.getPublisherId() != null) {
            userIds.add(task.getPublisherId());
        }

        // 详情填写人
        if (task.getDetailCompleterId() != null) {
            userIds.add(task.getDetailCompleterId());
        }

        // 一级发起人
        if (task.getPrimaryPublisherId() != null) {
            userIds.add(task.getPrimaryPublisherId());
        }

        return userIds;
    }

    /**
     * 格式化时间
     */
    private String formatTime(LocalDateTime time) {
        if (time == null) {
            return "未知";
        }
        return time.format(DATE_TIME_FORMATTER);
    }
}