package msgsvc

import (
	"context"
	"time"
)

// This file defines a set of interfaces that wrap the actual pub sub implementation
// This enables much easier unit testing of msgsvc public functions, without
// depending on the actual pub sub implementation

// Each type from pubsub that we require should have an associated interface
// defined in this file. Methods associated with these interfaces should always
// return an interface defined in here or a stdlib type.
// msgsvc.go should never directly depend on pubsub types.
// Once an interface is defined in this file, an associated struct should be
// created in pubsub.go, which wraps the associated pubsub type and implements
// the interface defined here. Only pubsub.go should depend on the pubsub library
// If access to fields on pubsub types is required, a getter/setter should be
// added to the interface definition here, and implemented in the wrapper struct
// in pubsub.go, e.g. the SetOrdering method on topicInt interface
// Interfaces should be named `<unexported pubsub type>Itfc`, and the associated
// wrapper struct should be named <unexported pubsub type>, e.g. for the pubsub
// type `Client` the interface should be `clientInt` and the struct should be
// `client`

// struct wrappers in pubsub.go should be as simple as possible as only msgsvc.go
// is unit tested, wrappers in pubsub.go should depend on integration testing to
// verify their behaviour

type publishResultItfc interface {
	Get(ctx context.Context) (serverID string, err error)
}

type topicItfc interface {
	Publish(ctx context.Context, msg messageItfc) publishResultItfc
	SetOrdering(bool)
	ID() string
	Stop()
}

type subscriptionItfc interface {
	Receive(context.Context, func(ctx context.Context, msg messageItfc)) error
	Delete(context.Context) error
}

type subscriptionInProjecter interface {
	SubscriptionInProject(id string, projectID string) subscriptionItfc
}

type topicInProjecter interface {
	TopicInProject(id string, projectID string) topicItfc
}

type clientItfc interface {
	subscriptionInProjecter
	topicInProjecter
	CreateSubscription(context.Context, string, subscriptionCfg) (subscriptionItfc, error)
}

type messageItfc interface {
	Ack()
	Nack()
	ID() string
	Data() []byte
	Attributes() map[string]string
	OrderingKey() string
	SetOrderingKey(key string)
}

type subscriptionCfg struct {
	topicName         string
	projectID         string
	retentionDuration time.Duration
	expirationPolicy  time.Duration
	filter            string
}