package task

import (
	"context"
	"encoding/json"
	"fmt"
	"time"
	"tyapi-server/internal/domains/article/entities"
	"tyapi-server/internal/domains/article/repositories"

	"github.com/hibiken/asynq"
	"go.uber.org/zap"
)

// AsynqClient Asynq 客户端
type AsynqClient struct {
	client              *asynq.Client
	logger              *zap.Logger
	scheduledTaskRepo   repositories.ScheduledTaskRepository
}

// NewAsynqClient 创建 Asynq 客户端
func NewAsynqClient(redisAddr string, scheduledTaskRepo repositories.ScheduledTaskRepository, logger *zap.Logger) *AsynqClient {
	client := asynq.NewClient(asynq.RedisClientOpt{Addr: redisAddr})
	return &AsynqClient{
		client:            client,
		logger:            logger,
		scheduledTaskRepo: scheduledTaskRepo,
	}
}

// Close 关闭客户端
func (c *AsynqClient) Close() error {
	return c.client.Close()
}

// ScheduleArticlePublish 调度文章定时发布任务
func (c *AsynqClient) ScheduleArticlePublish(ctx context.Context, articleID string, publishTime time.Time) (string, error) {
	payload := map[string]interface{}{
		"article_id": articleID,
	}

	payloadBytes, err := json.Marshal(payload)
	if err != nil {
		c.logger.Error("序列化任务载荷失败", zap.Error(err))
		return "", fmt.Errorf("创建任务失败: %w", err)
	}

	task := asynq.NewTask(TaskTypeArticlePublish, payloadBytes)

	// 计算延迟时间
	delay := publishTime.Sub(time.Now())
	if delay <= 0 {
		return "", fmt.Errorf("定时发布时间不能早于当前时间")
	}

	// 设置任务选项
	opts := []asynq.Option{
		asynq.ProcessIn(delay),
		asynq.MaxRetry(3),
		asynq.Timeout(5 * time.Minute),
	}

	info, err := c.client.Enqueue(task, opts...)
	if err != nil {
		c.logger.Error("调度定时发布任务失败",
			zap.String("article_id", articleID),
			zap.Time("publish_time", publishTime),
			zap.Error(err))
		return "", fmt.Errorf("调度任务失败: %w", err)
	}

	// 创建任务状态记录
	scheduledTask := entities.ScheduledTask{
		TaskID:      info.ID,
		TaskType:    TaskTypeArticlePublish,
		ArticleID:   articleID,
		Status:      entities.TaskStatusPending,
		ScheduledAt: publishTime,
	}

	if _, err := c.scheduledTaskRepo.Create(ctx, scheduledTask); err != nil {
		c.logger.Error("创建任务状态记录失败", zap.String("task_id", info.ID), zap.Error(err))
		// 不返回错误，因为Asynq任务已经创建成功
	}

	c.logger.Info("定时发布任务调度成功",
		zap.String("article_id", articleID),
		zap.Time("publish_time", publishTime),
		zap.String("task_id", info.ID))

	return info.ID, nil
}

// CancelScheduledTask 取消已调度的任务
func (c *AsynqClient) CancelScheduledTask(ctx context.Context, taskID string) error {
	c.logger.Info("标记定时任务为已取消",
		zap.String("task_id", taskID))
	
	// 标记数据库中的任务状态为已取消
	if err := c.scheduledTaskRepo.MarkAsCancelled(ctx, taskID); err != nil {
		c.logger.Warn("标记任务状态为已取消失败", zap.String("task_id", taskID), zap.Error(err))
		// 不返回错误，因为Asynq任务可能已经执行完成
	}
	
	// Asynq不支持直接取消任务，我们通过数据库状态来标记
	// 任务执行时会检查文章状态，如果已取消则跳过执行
	return nil
}

// RescheduleArticlePublish 重新调度文章定时发布任务
func (c *AsynqClient) RescheduleArticlePublish(ctx context.Context, articleID string, oldTaskID string, newPublishTime time.Time) (string, error) {
	// 1. 取消旧任务（标记为已取消）
	if err := c.CancelScheduledTask(ctx, oldTaskID); err != nil {
		c.logger.Warn("取消旧任务失败",
			zap.String("old_task_id", oldTaskID),
			zap.Error(err))
	}

	// 2. 创建新任务
	newTaskID, err := c.ScheduleArticlePublish(ctx, articleID, newPublishTime)
	if err != nil {
		return "", fmt.Errorf("重新调度任务失败: %w", err)
	}

	c.logger.Info("重新调度定时发布任务成功",
		zap.String("article_id", articleID),
		zap.String("old_task_id", oldTaskID),
		zap.String("new_task_id", newTaskID),
		zap.Time("new_publish_time", newPublishTime))

	return newTaskID, nil
}