package polling

import (
	"context"
	"time"

	"github.com/bytedance/sonic"
	"github.com/hibiken/asynq"
	"github.com/redis/go-redis/v9"
	"go.uber.org/zap"
	"gorm.io/gorm"

	"github.com/break/junhong_cmp_fiber/internal/model"
	packagepkg "github.com/break/junhong_cmp_fiber/internal/service/package"
	"github.com/break/junhong_cmp_fiber/internal/store/postgres"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
)

// PackageActivationHandler 套餐激活检查处理器
// 任务 19: 处理主套餐过期、加油包级联失效、待生效主套餐激活
type PackageActivationHandler struct {
	db                *gorm.DB
	redis             *redis.Client
	queueClient       *asynq.Client
	packageUsageStore *postgres.PackageUsageStore
	activationService *packagepkg.ActivationService
	logger            *zap.Logger
}

// PackageActivationPayload 套餐激活任务载荷
type PackageActivationPayload struct {
	PackageUsageID uint   `json:"package_usage_id"`
	CarrierType    string `json:"carrier_type"` // "iot_card" 或 "device"
	CarrierID      uint   `json:"carrier_id"`
	ActivationType string `json:"activation_type"` // "queue" 或 "realname"
	Timestamp      int64  `json:"timestamp"`
}

// NewPackageActivationHandler 创建套餐激活检查处理器
func NewPackageActivationHandler(
	db *gorm.DB,
	redis *redis.Client,
	queueClient *asynq.Client,
	activationService *packagepkg.ActivationService,
	logger *zap.Logger,
) *PackageActivationHandler {
	return &PackageActivationHandler{
		db:                db,
		redis:             redis,
		queueClient:       queueClient,
		packageUsageStore: postgres.NewPackageUsageStore(db, redis),
		activationService: activationService,
		logger:            logger,
	}
}

// HandlePackageActivationCheck 任务 19.2-19.5: 处理套餐激活检查
// 每 10 秒调度一次，检查过期主套餐并激活下一个待生效主套餐
func (h *PackageActivationHandler) HandlePackageActivationCheck(ctx context.Context) error {
	startTime := time.Now()

	// 任务 19.2: 查询已过期的主套餐（status=1 AND expires_at <= NOW）
	expiredPackages, err := h.findExpiredMainPackages(ctx)
	if err != nil {
		h.logger.Error("查询过期主套餐失败", zap.Error(err))
		return err
	}

	if len(expiredPackages) == 0 {
		return nil
	}

	h.logger.Info("发现过期主套餐",
		zap.Int("count", len(expiredPackages)),
		zap.Duration("check_duration", time.Since(startTime)))

	// 处理每个过期的主套餐
	for _, pkg := range expiredPackages {
		if err := h.processExpiredPackage(ctx, pkg); err != nil {
			h.logger.Error("处理过期套餐失败",
				zap.Uint("package_usage_id", pkg.ID),
				zap.Error(err))
			// 继续处理下一个，不中断
			continue
		}
	}

	h.logger.Info("套餐激活检查完成",
		zap.Int("processed", len(expiredPackages)),
		zap.Duration("total_duration", time.Since(startTime)))

	return nil
}

// findExpiredMainPackages 任务 19.2: 查询已过期的主套餐
func (h *PackageActivationHandler) findExpiredMainPackages(ctx context.Context) ([]*model.PackageUsage, error) {
	var packages []*model.PackageUsage
	now := time.Now()

	// 查询 status=1 (生效中) AND expires_at <= NOW AND master_usage_id IS NULL (主套餐)
	err := h.db.WithContext(ctx).
		Where("status = ?", constants.PackageUsageStatusActive).
		Where("expires_at <= ?", now).
		Where("master_usage_id IS NULL"). // 主套餐没有 master_usage_id
		Limit(1000).                      // 每次最多处理 1000 个，避免长事务
		Find(&packages).Error

	return packages, err
}

// processExpiredPackage 处理单个过期套餐
func (h *PackageActivationHandler) processExpiredPackage(ctx context.Context, pkg *model.PackageUsage) error {
	return h.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		// 任务 19.3: 更新过期主套餐状态为 Expired (status=3)
		if err := tx.Model(pkg).Update("status", constants.PackageUsageStatusExpired).Error; err != nil {
			return err
		}

		h.logger.Info("主套餐已过期",
			zap.Uint("package_usage_id", pkg.ID),
			zap.Time("expires_at", pkg.ExpiresAt))

		// 任务 19.4: 加油包级联失效
		if err := h.invalidateAddons(ctx, tx, pkg.ID); err != nil {
			h.logger.Warn("加油包级联失效失败",
				zap.Uint("master_usage_id", pkg.ID),
				zap.Error(err))
			// 不返回错误，继续处理
		}

		// 任务 19.5: 查询并激活下一个待生效主套餐
		carrierType, carrierID := h.getCarrierInfo(pkg)
		if carrierType != "" && carrierID > 0 {
			if err := h.activateNextPackage(ctx, tx, carrierType, carrierID); err != nil {
				h.logger.Warn("激活下一个待生效套餐失败",
					zap.String("carrier_type", carrierType),
					zap.Uint("carrier_id", carrierID),
					zap.Error(err))
				// 不返回错误，继续处理
			}
		}

		return nil
	})
}

// invalidateAddons 任务 19.4: 加油包级联失效
func (h *PackageActivationHandler) invalidateAddons(ctx context.Context, tx *gorm.DB, masterUsageID uint) error {
	// 查询主套餐下的所有加油包（status IN (0,1,2) 的加油包）
	result := tx.Model(&model.PackageUsage{}).
		Where("master_usage_id = ?", masterUsageID).
		Where("status IN ?", []int{
			constants.PackageUsageStatusPending,
			constants.PackageUsageStatusActive,
			constants.PackageUsageStatusDepleted,
		}).
		Update("status", constants.PackageUsageStatusInvalidated)

	if result.Error != nil {
		return result.Error
	}

	if result.RowsAffected > 0 {
		h.logger.Info("加油包已级联失效",
			zap.Uint("master_usage_id", masterUsageID),
			zap.Int64("invalidated_count", result.RowsAffected))
	}

	return nil
}

// getCarrierInfo 获取载体信息
func (h *PackageActivationHandler) getCarrierInfo(pkg *model.PackageUsage) (string, uint) {
	if pkg.IotCardID > 0 {
		return "iot_card", pkg.IotCardID
	}
	if pkg.DeviceID > 0 {
		return "device", pkg.DeviceID
	}
	return "", 0
}

// activateNextPackage 任务 19.5: 激活下一个待生效主套餐
func (h *PackageActivationHandler) activateNextPackage(ctx context.Context, tx *gorm.DB, carrierType string, carrierID uint) error {
	// 查询下一个待生效主套餐
	// WHERE status=0 AND master_usage_id IS NULL ORDER BY priority ASC LIMIT 1
	var nextPkg model.PackageUsage
	query := tx.Where("status = ?", constants.PackageUsageStatusPending).
		Where("master_usage_id IS NULL"). // 主套餐
		Order("priority ASC").
		Limit(1)

	if carrierType == "iot_card" {
		query = query.Where("iot_card_id = ?", carrierID)
	} else if carrierType == "device" {
		query = query.Where("device_id = ?", carrierID)
	}

	if err := query.First(&nextPkg).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			// 没有待生效套餐，正常情况
			return nil
		}
		return err
	}

	// 提交 Asynq 任务进行激活（避免长事务）
	return h.enqueueActivationTask(ctx, nextPkg.ID, carrierType, carrierID, "queue")
}

// enqueueActivationTask 提交套餐激活任务到 Asynq
func (h *PackageActivationHandler) enqueueActivationTask(ctx context.Context, packageUsageID uint, carrierType string, carrierID uint, activationType string) error {
	payload := PackageActivationPayload{
		PackageUsageID: packageUsageID,
		CarrierType:    carrierType,
		CarrierID:      carrierID,
		ActivationType: activationType,
		Timestamp:      time.Now().Unix(),
	}

	payloadBytes, err := sonic.Marshal(payload)
	if err != nil {
		return err
	}

	task := asynq.NewTask(constants.TaskTypePackageQueueActivation, payloadBytes,
		asynq.MaxRetry(3),
		asynq.Timeout(30*time.Second),
		asynq.Queue(constants.QueueDefault),
	)

	_, err = h.queueClient.Enqueue(task)
	if err != nil {
		h.logger.Error("提交套餐激活任务失败",
			zap.Uint("package_usage_id", packageUsageID),
			zap.Error(err))
		return err
	}

	h.logger.Info("已提交套餐激活任务",
		zap.Uint("package_usage_id", packageUsageID),
		zap.String("activation_type", activationType))

	return nil
}

// HandlePackageQueueActivation 处理套餐排队激活任务（Asynq Handler）
// 任务 23: 由 Asynq 调用，执行实际的套餐激活逻辑
func (h *PackageActivationHandler) HandlePackageQueueActivation(ctx context.Context, t *asynq.Task) error {
	var payload PackageActivationPayload
	if err := sonic.Unmarshal(t.Payload(), &payload); err != nil {
		h.logger.Error("解析套餐激活任务载荷失败", zap.Error(err))
		return nil // 不重试
	}

	h.logger.Info("开始执行套餐激活",
		zap.Uint("package_usage_id", payload.PackageUsageID),
		zap.String("activation_type", payload.ActivationType))

	// 查询套餐使用记录
	var pkg model.PackageUsage
	if err := h.db.First(&pkg, payload.PackageUsageID).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			h.logger.Warn("套餐使用记录不存在", zap.Uint("package_usage_id", payload.PackageUsageID))
			return nil
		}
		return err
	}

	// 幂等性检查：如果已经是生效状态，跳过
	if pkg.Status == constants.PackageUsageStatusActive {
		h.logger.Info("套餐已激活，跳过",
			zap.Uint("package_usage_id", payload.PackageUsageID))
		return nil
	}

	// 调用 ActivationService 执行激活
	if h.activationService != nil {
		if err := h.activationService.ActivateQueuedPackage(ctx, payload.CarrierType, payload.CarrierID); err != nil {
			h.logger.Error("套餐激活失败",
				zap.Uint("package_usage_id", payload.PackageUsageID),
				zap.String("carrier_type", payload.CarrierType),
				zap.Uint("carrier_id", payload.CarrierID),
				zap.Error(err))
			return err
		}
	} else {
		// ActivationService 未注入，直接更新状态
		now := time.Now()
		if err := h.db.Model(&pkg).Updates(map[string]interface{}{
			"status":       constants.PackageUsageStatusActive,
			"activated_at": now,
		}).Error; err != nil {
			return err
		}
	}

	h.logger.Info("套餐激活成功",
		zap.Uint("package_usage_id", payload.PackageUsageID))

	return nil
}

// HandlePackageFirstActivation 处理首次实名激活任务（Asynq Handler）
// 任务 22: 由 Asynq 调用，执行首次实名后的套餐激活
func (h *PackageActivationHandler) HandlePackageFirstActivation(ctx context.Context, t *asynq.Task) error {
	var payload PackageActivationPayload
	if err := sonic.Unmarshal(t.Payload(), &payload); err != nil {
		h.logger.Error("解析首次实名激活任务载荷失败", zap.Error(err))
		return nil // 不重试
	}

	h.logger.Info("开始执行首次实名激活",
		zap.Uint("package_usage_id", payload.PackageUsageID),
		zap.String("carrier_type", payload.CarrierType),
		zap.Uint("carrier_id", payload.CarrierID))

	// 任务 22.4: 幂等性检查
	var pkg model.PackageUsage
	if err := h.db.First(&pkg, payload.PackageUsageID).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			h.logger.Warn("套餐使用记录不存在", zap.Uint("package_usage_id", payload.PackageUsageID))
			return nil
		}
		return err
	}

	// 检查 pending_realname_activation 是否已为 false（已处理过）
	if !pkg.PendingRealnameActivation {
		h.logger.Info("套餐已处理过首次实名激活，跳过",
			zap.Uint("package_usage_id", payload.PackageUsageID))
		return nil
	}

	// 如果已经是生效状态，跳过
	if pkg.Status == constants.PackageUsageStatusActive {
		h.logger.Info("套餐已激活，跳过",
			zap.Uint("package_usage_id", payload.PackageUsageID))
		return nil
	}

	// 任务 22.3: 调用 ActivationService.ActivateByRealname 激活套餐
	if h.activationService != nil {
		if err := h.activationService.ActivateByRealname(ctx, payload.CarrierType, payload.CarrierID); err != nil {
			h.logger.Error("首次实名激活失败",
				zap.Uint("package_usage_id", payload.PackageUsageID),
				zap.String("carrier_type", payload.CarrierType),
				zap.Uint("carrier_id", payload.CarrierID),
				zap.Error(err))
			return err
		}
	} else {
		// ActivationService 未注入，直接更新状态（备用逻辑）
		now := time.Now()
		if err := h.db.Model(&pkg).Updates(map[string]any{
			"status":                      constants.PackageUsageStatusActive,
			"activated_at":                now,
			"pending_realname_activation": false,
		}).Error; err != nil {
			return err
		}
	}

	h.logger.Info("首次实名激活成功",
		zap.Uint("package_usage_id", payload.PackageUsageID))

	return nil
}