package pubsub

import (
	"context"
	"time"

	"cloud.google.com/go/pubsub/pstest"
	"google.golang.org/api/option"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"

	pubSub "cloud.google.com/go/pubsub"

	"edge-infra.dev/pkg/lib/gcp/pubsub"
)

type MockPubsubServerResponse struct {
	PubsubServer *pstest.Server
	Conn         *grpc.ClientConn
}

func SetupMockPubsubServer() (*MockPubsubServerResponse, error) {
	pubsubsrv := pstest.NewServer()
	conn, err := grpc.NewClient(pubsubsrv.Addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		return nil, err
	}
	return &MockPubsubServerResponse{
		PubsubServer: pubsubsrv,
		Conn:         conn,
	}, nil
}

// NewMockPubsubServer creates a new mock pubsub server and returns a client option.
func NewMockPubsubServer() (option.ClientOption, error) {
	res, err := SetupMockPubsubServer()
	if err != nil {
		return nil, err
	}
	pubsubGrpcClient := option.WithGRPCConn(res.Conn)
	return pubsubGrpcClient, nil
}

// CreateMockTopic creates a mock pubsub topic.
func CreateMockTopic(ctx context.Context, projectID, topicID string, opts ...option.ClientOption) (*pubSub.Topic, error) {
	pubSubService, err := pubsub.NewWithOptions(ctx, projectID, opts...)
	if err != nil {
		return nil, err
	}
	return pubSubService.CreateTopic(ctx, topicID)
}

// SendMessage publishes a pubsub message to the specified topic.
func SendMessage(ctx context.Context, projectID, topicID, message string, attributes map[string]string, opts ...option.ClientOption) error {
	pubSubService, err := pubsub.NewWithOptions(ctx, projectID, opts...)
	if err != nil {
		return err
	}
	return pubSubService.Send(ctx, topicID, []byte(message), attributes)
}

// CreateMockSubscription creates a mock pubsub subscription and receives an assertion function to assert the pubsub message.
func CreateMockSubscription(ctx context.Context, done chan<- bool, projectID, topicID, subscriptionID string, deadline time.Duration, filter string, assert func(msg *pubSub.Message), opts ...option.ClientOption) error {
	pubSubService, err := pubsub.NewWithOptions(ctx, projectID, opts...)
	if err != nil {
		return err
	}
	subscription, err := pubSubService.CreateSubscription(ctx, topicID, subscriptionID, deadline, filter)
	if err != nil {
		return err
	}
	return subscription.Receive(ctx, func(_ context.Context, msg *pubSub.Message) {
		assert(msg)
		done <- true
		msg.Ack()
	})
}