package plug

import (
	"context"
	"errors"
	"time"

	"git.anthrove.art/Anthrove/otter-space-sdk/v4/pkg/database"
	"git.anthrove.art/Anthrove/otter-space-sdk/v4/pkg/models"
	gRPC "git.anthrove.art/Anthrove/plug-sdk/v4/pkg/grpc"
	gonanoid "github.com/matoous/go-nanoid/v2"
	log "github.com/sirupsen/logrus"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
	"go.opentelemetry.io/otel/trace"
)

type server struct {
	gRPC.UnimplementedPlugConnectorServer
	ctx                   map[string]context.CancelFunc
	taskExecutionFunction TaskExecution
	sendMessageExecution  SendMessageExecution
	getMessageExecution   GetMessageExecution
	source                models.Source
}

func NewGrpcServer(source models.Source, taskExecutionFunction TaskExecution, sendMessageExecution SendMessageExecution, getMessageExecution GetMessageExecution) gRPC.PlugConnectorServer {
	return &server{
		ctx:                   make(map[string]context.CancelFunc),
		taskExecutionFunction: taskExecutionFunction,
		sendMessageExecution:  sendMessageExecution,
		getMessageExecution:   getMessageExecution,
		source:                source,
	}
}

func (s *server) TaskStart(ctx context.Context, creation *gRPC.PlugTaskCreation) (*gRPC.PlugTaskStatus, error) {
	ctx, span := tracer.Start(ctx, "TaskStart")
	defer span.End()

	var plugTaskState gRPC.PlugTaskStatus

	id, err := gonanoid.New(25)
	if err != nil {
		span.RecordError(err)
		span.SetStatus(codes.Error, err.Error())
		return nil, err
	}
	span.AddEvent("Generated task ID", trace.WithAttributes(attribute.String("task_id", id)))

	scrapeTaskHistory := models.ScrapeHistory{
		ScrapeTaskID: models.ScrapeTaskID(id),
		UserSourceID: models.UserSourceID(creation.UserSourceId),
	}
	scrapeTaskHistory, err = database.CreateScrapeHistory(ctx, scrapeTaskHistory)
	if err != nil {
		span.RecordError(err)
		span.SetStatus(codes.Error, err.Error())
		return nil, err
	}
	span.AddEvent("Creates ScrapeTaskHistory", trace.WithAttributes(
		attribute.String("user_source_id", creation.UserSourceId),
		attribute.String("scrape_task_id", id),
	))

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

	userSource, err := database.GetUserSourceByID(ctx, models.UserSourceID(creation.UserSourceId))
	if err != nil {
		span.RecordError(err)
		span.SetStatus(codes.Error, err.Error())

		dberr := database.UpdateScrapeHistory(ctx, models.ScrapeHistory{
			ScrapeTaskID: models.ScrapeTaskID(id),
			UserSourceID: userSource.ID,
			FinishedAt:   time.Now(),
			Error:        err.Error(),
		})

		return nil, errors.Join(err, dberr)
	}
	span.AddEvent("Retrieved user source", trace.WithAttributes(attribute.String("user_source_id", creation.UserSourceId)))

	if !userSource.AccountValidate {
		err = errors.New("user is not validated")

		log.WithContext(ctx).WithError(err).WithField("task_id", id).Error("Task execution failed")
		span.RecordError(err)
		span.SetStatus(codes.Error, err.Error())

		plugTaskState.TaskState = gRPC.PlugTaskState_STOPPED

		dberr := database.UpdateScrapeHistory(ctx, models.ScrapeHistory{
			ScrapeTaskID: models.ScrapeTaskID(id),
			UserSourceID: userSource.ID,
			FinishedAt:   time.Now(),
			Error:        err.Error(),
		})

		return &plugTaskState, errors.Join(err, dberr)
	}

	// 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 = trace.ContextWithSpanContext(context.Background(), trace.NewSpanContext(trace.SpanContextConfig{TraceID: span.SpanContext().TraceID()}))
	taskCtx, cancel := context.WithCancel(ctx)
	s.ctx[id] = cancel
	span.AddEvent("Created new context for task", trace.WithAttributes(attribute.String("task_id", id)))

	log.WithContext(taskCtx).WithFields(log.Fields{
		"task_id":        id,
		"user_source_id": creation.UserSourceId,
	}).Debug("Starting task")

	go func() {
		var err error
		taskSummery, err := s.taskExecutionFunction(taskCtx, userSource, creation.DeepScrape, creation.ApiKey)
		if err != nil {
			log.WithContext(taskCtx).WithError(err).WithField("task_id", id).Error("Task execution failed")
			span.RecordError(err)
			span.SetStatus(codes.Error, err.Error())
		} else {
			log.WithContext(taskCtx).WithField("task_id", id).Debug("Task completed successfully")
			span.AddEvent("Task completed successfully", trace.WithAttributes(attribute.String("task_id", id)))
		}

		err = database.UpdateScrapeHistory(taskCtx, models.ScrapeHistory{
			ScrapeTaskID: models.ScrapeTaskID(id),
			UserSourceID: userSource.ID,
			FinishedAt:   time.Now(),
			Error:        errorString(err),
			AddedPosts:   taskSummery.AddedPosts,
			DeletedPosts: taskSummery.DeletedPosts,
		})

		if err != nil {
			log.WithContext(taskCtx).WithError(err).WithField("task_id", id).Error("Task execution failed")
			span.RecordError(err)
			span.SetStatus(codes.Error, err.Error())
		}
		s.removeTask(id)
	}()

	span.SetAttributes(attribute.String("task_id", id))
	return &plugTaskState, nil
}

func (s *server) TaskStatus(ctx context.Context, task *gRPC.PlugTask) (*gRPC.PlugTaskStatus, error) {
	ctx, span := tracer.Start(ctx, "TaskStatus")
	defer span.End()

	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
	}
	span.AddEvent("Determined task state", trace.WithAttributes(attribute.String("task_id", task.TaskId), attribute.String("task_state", plugTaskState.TaskState.String())))

	log.WithContext(ctx).WithFields(log.Fields{
		"task_id":    task.TaskId,
		"task_state": plugTaskState.TaskState,
	}).Debug("Task status requested")

	span.SetAttributes(attribute.String("task_id", task.TaskId))
	return &plugTaskState, nil
}

func (s *server) TaskCancel(ctx context.Context, task *gRPC.PlugTask) (*gRPC.PlugTaskStatus, error) {
	ctx, span := tracer.Start(ctx, "TaskCancel")
	defer span.End()

	var plugTaskState gRPC.PlugTaskStatus

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

	s.removeTask(task.TaskId)
	span.AddEvent("Removed task", trace.WithAttributes(attribute.String("task_id", task.TaskId)))

	log.WithContext(ctx).WithFields(log.Fields{
		"task_id":    task.TaskId,
		"task_state": plugTaskState.TaskState,
	}).Debug("Task cancellation requested")

	span.SetAttributes(attribute.String("task_id", task.TaskId))
	return &plugTaskState, nil
}

func (s *server) GetUserMessages(ctx context.Context, message *gRPC.GetMessagesRequest) (*gRPC.GetMessagesResponse, error) {
	ctx, span := tracer.Start(ctx, "GetUserMessages")
	defer span.End()

	userSourceID := models.UserSourceID(message.UserSourceId)

	userSource, err := database.GetUserSourceByID(ctx, userSourceID)

	if err != nil {
		span.RecordError(err)
		span.SetStatus(codes.Error, err.Error())
		log.WithContext(ctx).WithError(err).Error("Getting userSource")
		return nil, err
	}

	messages, err := s.getMessageExecution(ctx, userSource)
	if err != nil {
		span.RecordError(err)
		span.SetStatus(codes.Error, err.Error())
		log.WithContext(ctx).WithError(err).Error("Execution function")
		return nil, err
	}

	var response gRPC.GetMessagesResponse
	for _, message := range messages {
		response.Messages = append(response.Messages, &gRPC.Message{
			FromUserSourceId: string(userSource.ID),
			CreatedAt:        message.CreatedAt,
			Body:             message.Body,
			Title:            message.Title,
		})
	}

	span.SetAttributes(
		attribute.String("user_source_id", string(userSource.ID)),
		attribute.String("user_id", string(userSource.UserID)),
		attribute.String("source_id", string(userSource.SourceID)),
	)

	fields := log.Fields{
		"user_source_id": userSource.ID,
		"user_id":        userSource.UserID,
		"source_id":      userSource.SourceID,
		"len_messages":   len(messages),
	}

	log.WithContext(ctx).WithFields(fields).Debug("Got User messages")

	return &response, err

}

func (s *server) SendMessage(ctx context.Context, message *gRPC.SendMessageRequest) (*gRPC.SendMessageResponse, error) {
	ctx, span := tracer.Start(ctx, "SendMessage")
	defer span.End()

	response := &gRPC.SendMessageResponse{
		Success: false,
	}

	sourceID := models.UserSourceID(message.UserSourceId)
	userSource := models.UserSource{BaseModel: models.BaseModel[models.UserSourceID]{ID: sourceID}}

	err := s.sendMessageExecution(ctx, userSource, message.Message)
	if err != nil {
		log.WithContext(ctx).WithError(err).Error("Sending message execution")
		span.RecordError(err)
		span.SetStatus(codes.Error, err.Error())

		return response, err
	}

	response.Success = true
	return response, err
}

func (s *server) Ping(ctx context.Context, ping *gRPC.PingRequest) (*gRPC.PongResponse, error) {
	ctx, span := tracer.Start(ctx, "Ping")
	defer span.End()

	var pong gRPC.PongResponse
	pong.Message = ping.Message
	pong.Timestamp = ping.Timestamp

	fields := log.Fields{
		"messsage":  ping.Message,
		"timestamp": ping.Timestamp,
	}
	log.WithContext(ctx).WithFields(fields).Trace("Got pinged")

	return &pong, nil
}

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

func errorString(err error) string {
	if err != nil {
		return err.Error()
	}
	return ""
}