package services

import (
	"time"

	"fmt"
	"strings"

	"github.com/engigu/taskpool/internal/constant"
	"github.com/engigu/taskpool/internal/database"
	"github.com/engigu/taskpool/internal/eventbus"
	"github.com/engigu/taskpool/internal/logger"
	"github.com/engigu/taskpool/internal/models"
	"github.com/engigu/taskpool/internal/utils"
)

type LogRetentionConfig struct {
	Days     int `json:"days"`
	MaxCount int `json:"max_count"`
}

type AppLogService struct {
	settingsService *SettingsService
}

func NewAppLogService() *AppLogService {
	return &AppLogService{
		settingsService: NewSettingsService(),
	}
}

func (s *AppLogService) Add(log *models.AppLog) error {
	if log.ID == "" {
		log.ID = utils.GenerateID()
	}
	err := database.DB.Create(log).Error
	if err == nil {
		eventbus.DefaultBus.Publish(eventbus.Event{
			Type:    constant.EventAppLogAdded,
			Payload: log,
		})
	}
	return err
}

func (s *AppLogService) List(category string, status string, level string, page, pageSize int, keyword string) ([]models.AppLog, int64, error) {
	var logs []models.AppLog
	var total int64
	db := database.DB

	// 如果是推送日志，尝试关联查询渠道名称
	if category == constant.LogCategoryPushLog {
		db = db.Table(models.AppLog{}.TableName() + " AS al").
			Select("al.*, nw.name as channel_name").
			Joins(fmt.Sprintf("LEFT JOIN %s AS nw ON al.ref_id = nw.id", models.NotifyWay{}.TableName()))
	} else {
		db = db.Model(&models.AppLog{})
	}

	if category != "" {
		if category == constant.LogCategoryPushLog {
			db = db.Where("al.category = ?", category)
		} else {
			db = db.Where("category = ?", category)
		}
	}
	if status != "" {
		field := "status"
		if category == constant.LogCategoryPushLog {
			field = "al.status"
		}
		db = db.Where(field+" = ?", status)
	}
	if level != "" {
		field := "level"
		if category == constant.LogCategoryPushLog {
			field = "al.level"
		}
		db = db.Where(field+" = ?", level)
	}
	if keyword != "" {
		if category == constant.LogCategoryPushLog {
			db = db.Where("(al.title LIKE ? OR al.content LIKE ?)", "%"+keyword+"%", "%"+keyword+"%")
		} else {
			db = db.Where("(title LIKE ? OR content LIKE ?)", "%"+keyword+"%", "%"+keyword+"%")
		}
	}

	db.Count(&total)
	offset := (page - 1) * pageSize
	order := "created_at desc"
	if category == constant.LogCategoryPushLog {
		order = "al.created_at desc"
	}
	err := db.Order(order).Offset(offset).Limit(pageSize).Scan(&logs).Error
	return logs, total, err
}

func (s *AppLogService) MarkAsRead(id string) error {
	now := models.LocalTime(time.Now())
	return database.DB.Model(&models.AppLog{}).Where("id = ?", id).Updates(map[string]interface{}{
		"status":  constant.LogStatusRead,
		"read_at": &now,
	}).Error
}

func (s *AppLogService) MarkAllAsRead(category string) error {
	now := models.LocalTime(time.Now())
	return database.DB.Model(&models.AppLog{}).Where("category = ? AND status = ?", category, constant.LogStatusUnread).Updates(map[string]interface{}{
		"status":  constant.LogStatusRead,
		"read_at": &now,
	}).Error
}

func (s *AppLogService) Clear(category string) error {
	query := database.DB.Model(&models.AppLog{})
	if category != "" {
		query = query.Where("category = ?", category)
	}
	return query.Delete(&models.AppLog{}).Error
}

func (s *AppLogService) GetRetentionConfigs() map[string]LogRetentionConfig {
	configs := map[string]LogRetentionConfig{
		constant.LogCategorySystemNotice: {
			Days:     utils.ToInt(s.settingsService.Get(constant.SectionSystem, constant.KeySystemNoticeDays), 30),
			MaxCount: utils.ToInt(s.settingsService.Get(constant.SectionSystem, constant.KeySystemNoticeMaxCount), 500),
		},
		constant.LogCategoryPushLog: {
			Days:     utils.ToInt(s.settingsService.Get(constant.SectionSystem, constant.KeyPushLogDays), 15),
			MaxCount: utils.ToInt(s.settingsService.Get(constant.SectionSystem, constant.KeyPushLogMaxCount), 5000),
		},
		constant.LogCategoryLoginLog: {
			Days:     utils.ToInt(s.settingsService.Get(constant.SectionSystem, constant.KeyLoginLogDays), 30),
			MaxCount: utils.ToInt(s.settingsService.Get(constant.SectionSystem, constant.KeyLoginLogMaxCount), 1000),
		},
		constant.LogCategorySchedulerLog: {
			Days:     utils.ToInt(s.settingsService.Get(constant.SectionSystem, constant.KeySchedulerLogDays), 30),
			MaxCount: utils.ToInt(s.settingsService.Get(constant.SectionSystem, constant.KeySchedulerLogMaxCount), 10000),
		},
		constant.LogCategoryDefault: {
			Days:     30,
			MaxCount: 10000,
		},
	}
	return configs
}

func (s *AppLogService) AddSchedulerLog(title, content, level string) error {
	if level == "" {
		level = constant.LogLevelInfo
	}
	return s.Add(&models.AppLog{
		Category: constant.LogCategorySchedulerLog,
		Title:    title,
		Content:  models.BigText(content),
		Level:    level,
		Status:   constant.LogStatusRead,
	})
}

func (s *AppLogService) CleanUp() {
	configs := s.GetRetentionConfigs()
	categories := []string{constant.LogCategorySystemNotice, constant.LogCategoryPushLog, constant.LogCategoryLoginLog, constant.LogCategorySchedulerLog}

	var totalDeleted int64
	var summaryBuilder strings.Builder

	for _, cat := range categories {
		cfg, ok := configs[cat]
		if !ok {
			cfg = configs[constant.LogCategoryDefault]
		}

		var daysDeleted int64
		if cfg.Days > 0 {
			deadline := time.Now().AddDate(0, 0, -cfg.Days)
			res := database.DB.Where("category = ? AND created_at < ?", cat, deadline).Delete(&models.AppLog{})
			if res.Error == nil {
				daysDeleted = res.RowsAffected
			}
		}

		var countDeleted int64
		if cfg.MaxCount > 0 {
			var total int64
			database.DB.Model(&models.AppLog{}).Where("category = ?", cat).Count(&total)
			if total > int64(cfg.MaxCount) {
				deleteCount := total - int64(cfg.MaxCount)
				var ids []string
				database.DB.Model(&models.AppLog{}).Where("category = ?", cat).Order("created_at asc").Limit(int(deleteCount)).Pluck("id", &ids)
				if len(ids) > 0 {
					res := database.DB.Where("id IN ?", ids).Delete(&models.AppLog{})
					if res.Error == nil {
						countDeleted = res.RowsAffected
					}
				}
			}
		}

		catTotal := daysDeleted + countDeleted
		if catTotal > 0 {
			totalDeleted += catTotal
			var catLabel string
			switch cat {
			case constant.LogCategorySystemNotice:
				catLabel = "系统通知"
			case constant.LogCategoryPushLog:
				catLabel = "推送日志"
			case constant.LogCategoryLoginLog:
				catLabel = "登录日志"
			case constant.LogCategorySchedulerLog:
				catLabel = "调度日志"
			default:
				catLabel = cat
			}
			summaryBuilder.WriteString(fmt.Sprintf("分类 [%s]: 过期清理 %d 条，溢出限制清理 %d 条；\n", catLabel, daysDeleted, countDeleted))
		}
	}

	if totalDeleted > 0 {
		logger.Infof("[AppLog] 周期巡检完成清理，共删除 %d 条陈旧日志", totalDeleted)
		eventbus.DefaultBus.Publish(eventbus.Event{
			Type: constant.EventSystemNotice,
			Payload: map[string]interface{}{
				"title":   "系统日志定时容量收敛",
				"content": fmt.Sprintf("后台巡检已自动执行日志容量清理，共计清除陈旧或溢出记录 %d 条。\n详情明细:\n%s", totalDeleted, summaryBuilder.String()),
				"level":   constant.LogLevelInfo,
			},
		})
	} else {
		logger.Debugf("[AppLog] 完成应用日志清理策略，未检测到需要剔除的陈旧记录")
	}
}

func (s *AppLogService) SubscribeEvents(bus *eventbus.EventBus) {
	// 1. [订阅] 系统通知 -> 存储到数据库表现为红点消息
	bus.Subscribe(constant.EventSystemNotice, func(e eventbus.Event) {
		payload, ok := e.Payload.(map[string]interface{})
		if !ok {
			return
		}

		title, _ := payload["title"].(string)
		content, _ := payload["content"].(string)
		level, _ := payload["level"].(string)
		if level == "" {
			level = constant.LogLevelInfo
		}

		s.Add(&models.AppLog{
			Category: constant.LogCategorySystemNotice,
			Title:    title,
			Content:  models.BigText(content),
			Level:    level,
			Status:   constant.LogStatusUnread,
		})
	})

	// 2. [订阅] 推送结果 -> 存储到数据库供推送日志查看
	bus.Subscribe(constant.EventNotifySent, func(e eventbus.Event) {
		payload, ok := e.Payload.(map[string]interface{})
		if !ok {
			return
		}

		title, _ := payload["title"].(string)
		content, _ := payload["content"].(string)
		success, _ := payload["success"].(bool)
		errorMsg, _ := payload["error_msg"].(string)
		channelID, _ := payload["channel_id"].(string)

		status := constant.LogStatusSuccess
		level := constant.LogLevelInfo
		if !success {
			status = constant.LogStatusFailed
			level = constant.LogLevelError
		}

		s.Add(&models.AppLog{
			Category: constant.LogCategoryPushLog,
			Title:    title,
			Content:  models.BigText(content),
			Level:    level,
			Status:   status,
			RefID:    channelID,
			ErrorMsg: models.BigText(errorMsg),
		})
	})

	// 3. 将某些业务事件转化为系统内部通知 (自动出现在小铃铛)
	/*
		bus.Subscribe(constant.EventTaskFailed, func(e eventbus.Event) {
			payload, ok := e.Payload.(map[string]interface{})
			if !ok {
				return
			}
			taskName, _ := payload["task_name"].(string)
			errMsg, _ := payload["error"].(string)

			bus.Publish(eventbus.Event{
				Type: constant.EventSystemNotice,
				Payload: map[string]interface{}{
					"title":   fmt.Sprintf("任务 [%s] 执行失败", taskName),
					"content": fmt.Sprintf("错误详情: %s", errMsg),
					"level":   constant.LogLevelError,
				},
			})
		})

		bus.Subscribe(constant.EventTaskTimeout, func(e eventbus.Event) {
			payload, ok := e.Payload.(map[string]interface{})
			if !ok {
				return
			}
			taskName, _ := payload["task_name"].(string)

			bus.Publish(eventbus.Event{
				Type: constant.EventSystemNotice,
				Payload: map[string]interface{}{
					"title":   fmt.Sprintf("任务 [%s] 执行超时", taskName),
					"content": "任务已经超过预设的运行时间并被系统强制中止。",
					"level":   constant.LogLevelWarning,
				},
			})
		})
	*/

	bus.Subscribe(constant.EventPasswordChanged, func(e eventbus.Event) {
		payload, ok := e.Payload.(map[string]interface{})
		if !ok {
			return
		}
		username, _ := payload["username"].(string)

		bus.Publish(eventbus.Event{
			Type: constant.EventSystemNotice,
			Payload: map[string]interface{}{
				"title":   "账户安全提醒",
				"content": fmt.Sprintf("用户 %s 的账号密码已被修改。", username),
				"level":   constant.LogLevelInfo,
			},
		})
	})

	// 4. [订阅] 调度日志写入
	bus.Subscribe(constant.EventSchedulerLog, func(e eventbus.Event) {
		payload, ok := e.Payload.(map[string]interface{})
		if !ok {
			return
		}
		title, _ := payload["title"].(string)
		content, _ := payload["content"].(string)
		level, _ := payload["level"].(string)
		s.AddSchedulerLog(title, content, level)
	})
}