// Code generated by ent, DO NOT EDIT.

package hook

import (
	"context"
	"fmt"

	"github.com/Wei-Shaw/sub2api/ent"
)

// The APIKeyFunc type is an adapter to allow the use of ordinary
// function as APIKey mutator.
type APIKeyFunc func(context.Context, *ent.APIKeyMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f APIKeyFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.APIKeyMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.APIKeyMutation", m)
}

// The AccountFunc type is an adapter to allow the use of ordinary
// function as Account mutator.
type AccountFunc func(context.Context, *ent.AccountMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f AccountFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.AccountMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.AccountMutation", m)
}

// The AccountGroupFunc type is an adapter to allow the use of ordinary
// function as AccountGroup mutator.
type AccountGroupFunc func(context.Context, *ent.AccountGroupMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f AccountGroupFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.AccountGroupMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.AccountGroupMutation", m)
}

// The AnnouncementFunc type is an adapter to allow the use of ordinary
// function as Announcement mutator.
type AnnouncementFunc func(context.Context, *ent.AnnouncementMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f AnnouncementFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.AnnouncementMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.AnnouncementMutation", m)
}

// The AnnouncementReadFunc type is an adapter to allow the use of ordinary
// function as AnnouncementRead mutator.
type AnnouncementReadFunc func(context.Context, *ent.AnnouncementReadMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f AnnouncementReadFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.AnnouncementReadMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.AnnouncementReadMutation", m)
}

// The AuthIdentityFunc type is an adapter to allow the use of ordinary
// function as AuthIdentity mutator.
type AuthIdentityFunc func(context.Context, *ent.AuthIdentityMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f AuthIdentityFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.AuthIdentityMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.AuthIdentityMutation", m)
}

// The AuthIdentityChannelFunc type is an adapter to allow the use of ordinary
// function as AuthIdentityChannel mutator.
type AuthIdentityChannelFunc func(context.Context, *ent.AuthIdentityChannelMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f AuthIdentityChannelFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.AuthIdentityChannelMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.AuthIdentityChannelMutation", m)
}

// The ChannelMonitorFunc type is an adapter to allow the use of ordinary
// function as ChannelMonitor mutator.
type ChannelMonitorFunc func(context.Context, *ent.ChannelMonitorMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f ChannelMonitorFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.ChannelMonitorMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.ChannelMonitorMutation", m)
}

// The ChannelMonitorDailyRollupFunc type is an adapter to allow the use of ordinary
// function as ChannelMonitorDailyRollup mutator.
type ChannelMonitorDailyRollupFunc func(context.Context, *ent.ChannelMonitorDailyRollupMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f ChannelMonitorDailyRollupFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.ChannelMonitorDailyRollupMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.ChannelMonitorDailyRollupMutation", m)
}

// The ChannelMonitorHistoryFunc type is an adapter to allow the use of ordinary
// function as ChannelMonitorHistory mutator.
type ChannelMonitorHistoryFunc func(context.Context, *ent.ChannelMonitorHistoryMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f ChannelMonitorHistoryFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.ChannelMonitorHistoryMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.ChannelMonitorHistoryMutation", m)
}

// The ChannelMonitorRequestTemplateFunc type is an adapter to allow the use of ordinary
// function as ChannelMonitorRequestTemplate mutator.
type ChannelMonitorRequestTemplateFunc func(context.Context, *ent.ChannelMonitorRequestTemplateMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f ChannelMonitorRequestTemplateFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.ChannelMonitorRequestTemplateMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.ChannelMonitorRequestTemplateMutation", m)
}

// The ErrorPassthroughRuleFunc type is an adapter to allow the use of ordinary
// function as ErrorPassthroughRule mutator.
type ErrorPassthroughRuleFunc func(context.Context, *ent.ErrorPassthroughRuleMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f ErrorPassthroughRuleFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.ErrorPassthroughRuleMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.ErrorPassthroughRuleMutation", m)
}

// The GroupFunc type is an adapter to allow the use of ordinary
// function as Group mutator.
type GroupFunc func(context.Context, *ent.GroupMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f GroupFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.GroupMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.GroupMutation", m)
}

// The IdempotencyRecordFunc type is an adapter to allow the use of ordinary
// function as IdempotencyRecord mutator.
type IdempotencyRecordFunc func(context.Context, *ent.IdempotencyRecordMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f IdempotencyRecordFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.IdempotencyRecordMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.IdempotencyRecordMutation", m)
}

// The IdentityAdoptionDecisionFunc type is an adapter to allow the use of ordinary
// function as IdentityAdoptionDecision mutator.
type IdentityAdoptionDecisionFunc func(context.Context, *ent.IdentityAdoptionDecisionMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f IdentityAdoptionDecisionFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.IdentityAdoptionDecisionMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.IdentityAdoptionDecisionMutation", m)
}

// The PaymentAuditLogFunc type is an adapter to allow the use of ordinary
// function as PaymentAuditLog mutator.
type PaymentAuditLogFunc func(context.Context, *ent.PaymentAuditLogMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f PaymentAuditLogFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.PaymentAuditLogMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.PaymentAuditLogMutation", m)
}

// The PaymentOrderFunc type is an adapter to allow the use of ordinary
// function as PaymentOrder mutator.
type PaymentOrderFunc func(context.Context, *ent.PaymentOrderMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f PaymentOrderFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.PaymentOrderMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.PaymentOrderMutation", m)
}

// The PaymentProviderInstanceFunc type is an adapter to allow the use of ordinary
// function as PaymentProviderInstance mutator.
type PaymentProviderInstanceFunc func(context.Context, *ent.PaymentProviderInstanceMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f PaymentProviderInstanceFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.PaymentProviderInstanceMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.PaymentProviderInstanceMutation", m)
}

// The PendingAuthSessionFunc type is an adapter to allow the use of ordinary
// function as PendingAuthSession mutator.
type PendingAuthSessionFunc func(context.Context, *ent.PendingAuthSessionMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f PendingAuthSessionFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.PendingAuthSessionMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.PendingAuthSessionMutation", m)
}

// The PromoCodeFunc type is an adapter to allow the use of ordinary
// function as PromoCode mutator.
type PromoCodeFunc func(context.Context, *ent.PromoCodeMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f PromoCodeFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.PromoCodeMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.PromoCodeMutation", m)
}

// The PromoCodeUsageFunc type is an adapter to allow the use of ordinary
// function as PromoCodeUsage mutator.
type PromoCodeUsageFunc func(context.Context, *ent.PromoCodeUsageMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f PromoCodeUsageFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.PromoCodeUsageMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.PromoCodeUsageMutation", m)
}

// The ProxyFunc type is an adapter to allow the use of ordinary
// function as Proxy mutator.
type ProxyFunc func(context.Context, *ent.ProxyMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f ProxyFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.ProxyMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.ProxyMutation", m)
}

// The RedeemCodeFunc type is an adapter to allow the use of ordinary
// function as RedeemCode mutator.
type RedeemCodeFunc func(context.Context, *ent.RedeemCodeMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f RedeemCodeFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.RedeemCodeMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.RedeemCodeMutation", m)
}

// The SecuritySecretFunc type is an adapter to allow the use of ordinary
// function as SecuritySecret mutator.
type SecuritySecretFunc func(context.Context, *ent.SecuritySecretMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f SecuritySecretFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.SecuritySecretMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.SecuritySecretMutation", m)
}

// The SettingFunc type is an adapter to allow the use of ordinary
// function as Setting mutator.
type SettingFunc func(context.Context, *ent.SettingMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f SettingFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.SettingMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.SettingMutation", m)
}

// The SubscriptionPlanFunc type is an adapter to allow the use of ordinary
// function as SubscriptionPlan mutator.
type SubscriptionPlanFunc func(context.Context, *ent.SubscriptionPlanMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f SubscriptionPlanFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.SubscriptionPlanMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.SubscriptionPlanMutation", m)
}

// The TLSFingerprintProfileFunc type is an adapter to allow the use of ordinary
// function as TLSFingerprintProfile mutator.
type TLSFingerprintProfileFunc func(context.Context, *ent.TLSFingerprintProfileMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f TLSFingerprintProfileFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.TLSFingerprintProfileMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.TLSFingerprintProfileMutation", m)
}

// The UsageCleanupTaskFunc type is an adapter to allow the use of ordinary
// function as UsageCleanupTask mutator.
type UsageCleanupTaskFunc func(context.Context, *ent.UsageCleanupTaskMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f UsageCleanupTaskFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.UsageCleanupTaskMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.UsageCleanupTaskMutation", m)
}

// The UsageLogFunc type is an adapter to allow the use of ordinary
// function as UsageLog mutator.
type UsageLogFunc func(context.Context, *ent.UsageLogMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f UsageLogFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.UsageLogMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.UsageLogMutation", m)
}

// The UserFunc type is an adapter to allow the use of ordinary
// function as User mutator.
type UserFunc func(context.Context, *ent.UserMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f UserFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.UserMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.UserMutation", m)
}

// The UserAllowedGroupFunc type is an adapter to allow the use of ordinary
// function as UserAllowedGroup mutator.
type UserAllowedGroupFunc func(context.Context, *ent.UserAllowedGroupMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f UserAllowedGroupFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.UserAllowedGroupMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.UserAllowedGroupMutation", m)
}

// The UserAttributeDefinitionFunc type is an adapter to allow the use of ordinary
// function as UserAttributeDefinition mutator.
type UserAttributeDefinitionFunc func(context.Context, *ent.UserAttributeDefinitionMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f UserAttributeDefinitionFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.UserAttributeDefinitionMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.UserAttributeDefinitionMutation", m)
}

// The UserAttributeValueFunc type is an adapter to allow the use of ordinary
// function as UserAttributeValue mutator.
type UserAttributeValueFunc func(context.Context, *ent.UserAttributeValueMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f UserAttributeValueFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.UserAttributeValueMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.UserAttributeValueMutation", m)
}

// The UserSubscriptionFunc type is an adapter to allow the use of ordinary
// function as UserSubscription mutator.
type UserSubscriptionFunc func(context.Context, *ent.UserSubscriptionMutation) (ent.Value, error)

// Mutate calls f(ctx, m).
func (f UserSubscriptionFunc) Mutate(ctx context.Context, m ent.Mutation) (ent.Value, error) {
	if mv, ok := m.(*ent.UserSubscriptionMutation); ok {
		return f(ctx, mv)
	}
	return nil, fmt.Errorf("unexpected mutation type %T. expect *ent.UserSubscriptionMutation", m)
}

// Condition is a hook condition function.
type Condition func(context.Context, ent.Mutation) bool

// And groups conditions with the AND operator.
func And(first, second Condition, rest ...Condition) Condition {
	return func(ctx context.Context, m ent.Mutation) bool {
		if !first(ctx, m) || !second(ctx, m) {
			return false
		}
		for _, cond := range rest {
			if !cond(ctx, m) {
				return false
			}
		}
		return true
	}
}

// Or groups conditions with the OR operator.
func Or(first, second Condition, rest ...Condition) Condition {
	return func(ctx context.Context, m ent.Mutation) bool {
		if first(ctx, m) || second(ctx, m) {
			return true
		}
		for _, cond := range rest {
			if cond(ctx, m) {
				return true
			}
		}
		return false
	}
}

// Not negates a given condition.
func Not(cond Condition) Condition {
	return func(ctx context.Context, m ent.Mutation) bool {
		return !cond(ctx, m)
	}
}

// HasOp is a condition testing mutation operation.
func HasOp(op ent.Op) Condition {
	return func(_ context.Context, m ent.Mutation) bool {
		return m.Op().Is(op)
	}
}

// HasAddedFields is a condition validating `.AddedField` on fields.
func HasAddedFields(field string, fields ...string) Condition {
	return func(_ context.Context, m ent.Mutation) bool {
		if _, exists := m.AddedField(field); !exists {
			return false
		}
		for _, field := range fields {
			if _, exists := m.AddedField(field); !exists {
				return false
			}
		}
		return true
	}
}

// HasClearedFields is a condition validating `.FieldCleared` on fields.
func HasClearedFields(field string, fields ...string) Condition {
	return func(_ context.Context, m ent.Mutation) bool {
		if exists := m.FieldCleared(field); !exists {
			return false
		}
		for _, field := range fields {
			if exists := m.FieldCleared(field); !exists {
				return false
			}
		}
		return true
	}
}

// HasFields is a condition validating `.Field` on fields.
func HasFields(field string, fields ...string) Condition {
	return func(_ context.Context, m ent.Mutation) bool {
		if _, exists := m.Field(field); !exists {
			return false
		}
		for _, field := range fields {
			if _, exists := m.Field(field); !exists {
				return false
			}
		}
		return true
	}
}

// If executes the given hook under condition.
//
//	hook.If(ComputeAverage, And(HasFields(...), HasAddedFields(...)))
func If(hk ent.Hook, cond Condition) ent.Hook {
	return func(next ent.Mutator) ent.Mutator {
		return ent.MutateFunc(func(ctx context.Context, m ent.Mutation) (ent.Value, error) {
			if cond(ctx, m) {
				return hk(next).Mutate(ctx, m)
			}
			return next.Mutate(ctx, m)
		})
	}
}

// On executes the given hook only for the given operation.
//
//	hook.On(Log, ent.Delete|ent.Create)
func On(hk ent.Hook, op ent.Op) ent.Hook {
	return If(hk, HasOp(op))
}

// Unless skips the given hook only for the given operation.
//
//	hook.Unless(Log, ent.Update|ent.UpdateOne)
func Unless(hk ent.Hook, op ent.Op) ent.Hook {
	return If(hk, Not(HasOp(op)))
}

// FixedError is a hook returning a fixed error.
func FixedError(err error) ent.Hook {
	return func(ent.Mutator) ent.Mutator {
		return ent.MutateFunc(func(context.Context, ent.Mutation) (ent.Value, error) {
			return nil, err
		})
	}
}

// Reject returns a hook that rejects all operations that match op.
//
//	func (T) Hooks() []ent.Hook {
//		return []ent.Hook{
//			Reject(ent.Delete|ent.Update),
//		}
//	}
func Reject(op ent.Op) ent.Hook {
	hk := FixedError(fmt.Errorf("%s operation is not allowed", op))
	return On(hk, op)
}

// Chain acts as a list of hooks and is effectively immutable.
// Once created, it will always hold the same set of hooks in the same order.
type Chain struct {
	hooks []ent.Hook
}

// NewChain creates a new chain of hooks.
func NewChain(hooks ...ent.Hook) Chain {
	return Chain{append([]ent.Hook(nil), hooks...)}
}

// Hook chains the list of hooks and returns the final hook.
func (c Chain) Hook() ent.Hook {
	return func(mutator ent.Mutator) ent.Mutator {
		for i := len(c.hooks) - 1; i >= 0; i-- {
			mutator = c.hooks[i](mutator)
		}
		return mutator
	}
}

// Append extends a chain, adding the specified hook
// as the last ones in the mutation flow.
func (c Chain) Append(hooks ...ent.Hook) Chain {
	newHooks := make([]ent.Hook, 0, len(c.hooks)+len(hooks))
	newHooks = append(newHooks, c.hooks...)
	newHooks = append(newHooks, hooks...)
	return Chain{newHooks}
}

// Extend extends a chain, adding the specified chain
// as the last ones in the mutation flow.
func (c Chain) Extend(chain Chain) Chain {
	return c.Append(chain.hooks...)
}
