package plug

import (
	"context"
	"google.golang.org/protobuf/types/known/timestamppb"
	"log"

	"git.dragse.it/anthrove/otter-space-sdk/pkg/graph"
	"git.dragse.it/anthrove/otter-space-sdk/pkg/models"
	gRPC "git.dragse.it/anthrove/plug-sdk/pkg/grpc"
	gonanoid "github.com/matoous/go-nanoid/v2"
)

type server struct {
	gRPC.UnimplementedPlugConnectorServer
	ctx                   map[string]context.CancelFunc
	database              graph.OtterSpace
	taskExecutionFunction TaskExecution
}

func NewGrpcServer(database graph.OtterSpace, taskExecutionFunction TaskExecution) gRPC.PlugConnectorServer {
	return &server{
		ctx:                   make(map[string]context.CancelFunc),
		database:              database,
		taskExecutionFunction: taskExecutionFunction,
	}
}

func (s *server) TaskStart(ctx context.Context, creation *gRPC.PlugTaskCreation) (*gRPC.PlugTaskStatus, error) {
	var anthroveUser models.AnthroveUser
	var plugTaskState gRPC.PlugTaskStatus
	var err error

	id, err := gonanoid.New()
	if err != nil {
		return nil, err
	}

	plugTaskState.TaskId = id
	plugTaskState.TaskState = gRPC.PlugTaskState_RUNNING

	anthroveUser.UserID = models.AnthroveUserID(creation.UserId)

	// gRPC closes the context after the call ended. So the whole scrapping stopped without waiting
	// by using this method we assign a new context to each new request we get.
	// This can be used for example to close the context with the given id
	ctx, cancel := context.WithCancel(context.Background())
	s.ctx[id] = cancel

	go func() {
		// FIXME: better implement this methode, works for now but needs refactoring
		err := s.taskExecutionFunction(ctx, s.database, creation.UserSourceName, anthroveUser, creation.DeepScrape, func() {
			s.removeTask(id)
		})
		if err != nil {
			log.Print(err)
		}
	}()

	return &plugTaskState, nil
}

func (s *server) TaskStatus(_ context.Context, task *gRPC.PlugTask) (*gRPC.PlugTaskStatus, error) {
	var plugTaskState gRPC.PlugTaskStatus

	_, found := s.ctx[task.TaskId]
	plugTaskState.TaskId = task.TaskId

	plugTaskState.TaskState = gRPC.PlugTaskState_RUNNING

	if !found {
		plugTaskState.TaskState = gRPC.PlugTaskState_UNKNOWN
	}
	return &plugTaskState, nil
}

func (s *server) TaskCancel(_ context.Context, task *gRPC.PlugTask) (*gRPC.PlugTaskStatus, error) {
	var plugTaskState gRPC.PlugTaskStatus

	plugTaskState.TaskState = gRPC.PlugTaskState_STOPPED
	plugTaskState.TaskId = task.TaskId

	s.removeTask(task.TaskId)

	return &plugTaskState, nil
}

func (s *server) removeTask(taskID string) {
	fn, exists := s.ctx[taskID]
	if !exists {
		return
	}
	fn()
	delete(s.ctx, taskID)
}

func (s *server) Ping(_ context.Context, request *gRPC.PingRequest) (*gRPC.PongResponse, error) {
	response := gRPC.PongResponse{
		Message:   request.Message,
		Timestamp: timestamppb.Now(),
	}
	return &response, nil
}