package internal

import (
	"context"
	"encoding/json"
	"sync"

	"github.com/rs/zerolog/log"

	pb "homelab.lan/music-agregator/gen/music_agregator/v1"
	"homelab.lan/music-agregator/internal/database"
	"homelab.lan/music-agregator/internal/eventbus"
)

type EventPublisher interface {
	PublishStatus(ctx context.Context, step pb.MonitorStep, msg string, data interface{}) error
	PublishError(ctx context.Context, step pb.MonitorStep, err error, recoverable bool) error
	PublishResult(ctx context.Context, result *pb.MonitorAlbumResponse) error
	SetAlbumID(albumID string)
	SetWorkflowRunID(id string)
}

type dbEventPublisher struct {
	mu            sync.Mutex
	workflowRunID string
	albumID       string
	quality       string
	events        *database.AlbumEventRepository
	bus           *eventbus.EventBus
	topic         string
}

func newDBEventPublisher(albumID, quality string, events *database.AlbumEventRepository, bus *eventbus.EventBus, topic string) *dbEventPublisher {
	return &dbEventPublisher{
		albumID: albumID,
		quality: quality,
		events:  events,
		bus:     bus,
		topic:   topic,
	}
}

func (p *dbEventPublisher) SetAlbumID(albumID string) {
	p.mu.Lock()
	defer p.mu.Unlock()
	p.albumID = albumID
}

func (p *dbEventPublisher) getAlbumID() string {
	p.mu.Lock()
	defer p.mu.Unlock()
	return p.albumID
}

func (p *dbEventPublisher) SetWorkflowRunID(id string) {
	p.mu.Lock()
	defer p.mu.Unlock()
	p.workflowRunID = id
}

func (p *dbEventPublisher) getWorkflowRunID() string {
	p.mu.Lock()
	defer p.mu.Unlock()
	return p.workflowRunID
}

func (p *dbEventPublisher) PublishStatus(ctx context.Context, step pb.MonitorStep, msg string, data interface{}) error {
	var dataJSON []byte
	if data != nil {
		var err error
		dataJSON, err = json.Marshal(data)
		if err != nil {
			log.Warn().Err(err).Msg("failed to marshal status data to JSON")
			dataJSON = nil
		}
	}

	albumID := p.getAlbumID()
	workflowRunID := p.getWorkflowRunID()

	var seq int64
	if albumID != "" {
		event := &database.AlbumEvent{
			WorkflowRunID: workflowRunID,
			AlbumID:       albumID,
			EventType:     "status",
			Step:          step.String(),
			Message:       msg,
			DataJSON:      dataJSON,
		}

		if err := p.events.Create(ctx, event); err != nil {
			log.Error().Err(err).Msg("failed to persist status event")
		} else {
			seq = event.Seq
		}
	}

	p.bus.Publish(p.topic, &eventbus.Event{
		Seq:           seq,
		WorkflowRunID: workflowRunID,
		AlbumID:       albumID,
		Quality:       p.quality,
		EventType:     "status",
		Step:          step.String(),
		Message:       msg,
		Data:          data,
	})

	return nil
}

func (p *dbEventPublisher) PublishError(ctx context.Context, step pb.MonitorStep, err error, recoverable bool) error {
	albumID := p.getAlbumID()
	workflowRunID := p.getWorkflowRunID()

	var seq int64
	if albumID != "" {
		event := &database.AlbumEvent{
			WorkflowRunID: workflowRunID,
			AlbumID:       albumID,
			EventType:     "error",
			Step:          step.String(),
			Message:       err.Error(),
		}

		if dbErr := p.events.Create(ctx, event); dbErr != nil {
			log.Error().Err(dbErr).Msg("failed to persist error event")
		} else {
			seq = event.Seq
		}
	}

	p.bus.Publish(p.topic, &eventbus.Event{
		Seq:           seq,
		WorkflowRunID: workflowRunID,
		AlbumID:       albumID,
		Quality:       p.quality,
		EventType:     "error",
		Step:          step.String(),
		Message:       err.Error(),
		Data:          map[string]bool{"recoverable": recoverable},
	})

	return nil
}

func (p *dbEventPublisher) PublishResult(ctx context.Context, result *pb.MonitorAlbumResponse) error {
	var dataJSON []byte
	if result != nil {
		var err error
		dataJSON, err = json.Marshal(result)
		if err != nil {
			log.Warn().Err(err).Msg("failed to marshal result to JSON")
			dataJSON = nil
		}
	}

	albumID := p.getAlbumID()
	workflowRunID := p.getWorkflowRunID()

	var seq int64
	if albumID != "" {
		event := &database.AlbumEvent{
			WorkflowRunID: workflowRunID,
			AlbumID:       albumID,
			EventType:     "result",
			Step:          pb.MonitorStep_MONITOR_STEP_COMPLETE.String(),
			Message:       "workflow completed",
			DataJSON:      dataJSON,
		}

		if err := p.events.Create(ctx, event); err != nil {
			log.Error().Err(err).Msg("failed to persist result event")
		} else {
			seq = event.Seq
		}
	}

	p.bus.Publish(p.topic, &eventbus.Event{
		Seq:           seq,
		WorkflowRunID: workflowRunID,
		AlbumID:       albumID,
		Quality:       p.quality,
		EventType:     "result",
		Step:          pb.MonitorStep_MONITOR_STEP_COMPLETE.String(),
		Message:       "workflow completed",
		Data:          result,
	})

	return nil
}

type streamEventPublisher struct {
	*dbEventPublisher
	stream pb.MusicAgregatorService_MonitorAlbumStreamServer
}

func newStreamEventPublisher(db *dbEventPublisher, stream pb.MusicAgregatorService_MonitorAlbumStreamServer) *streamEventPublisher {
	return &streamEventPublisher{
		dbEventPublisher: db,
		stream:           stream,
	}
}

func (p *streamEventPublisher) PublishStatus(ctx context.Context, step pb.MonitorStep, msg string, data interface{}) error {
	if err := p.dbEventPublisher.PublishStatus(ctx, step, msg, data); err != nil {
		return err
	}

	select {
	case <-ctx.Done():
		return ctx.Err()
	default:
	}

	status := &pb.StatusUpdate{
		Step:    step,
		Message: msg,
	}

	switch v := data.(type) {
	case *pb.StreamAlbumInfo:
		status.Data = &pb.StatusUpdate_AlbumInfo{AlbumInfo: v}
	case *pb.TorrentList:
		status.Data = &pb.StatusUpdate_Torrents{Torrents: v}
	case *pb.ReleaseInfo:
		status.Data = &pb.StatusUpdate_ReleaseInfo{ReleaseInfo: v}
	}

	return p.stream.Send(&pb.MonitorAlbumStreamResponse{
		Message: &pb.MonitorAlbumStreamResponse_Status{Status: status},
	})
}

func (p *streamEventPublisher) PublishError(ctx context.Context, step pb.MonitorStep, err error, recoverable bool) error {
	if dbErr := p.dbEventPublisher.PublishError(ctx, step, err, recoverable); dbErr != nil {
		return dbErr
	}

	return p.stream.Send(&pb.MonitorAlbumStreamResponse{
		Message: &pb.MonitorAlbumStreamResponse_Error{
			Error: &pb.ErrorUpdate{
				FailedStep:  step,
				Message:     err.Error(),
				Recoverable: recoverable,
			},
		},
	})
}

func (p *streamEventPublisher) PublishResult(ctx context.Context, result *pb.MonitorAlbumResponse) error {
	if err := p.dbEventPublisher.PublishResult(ctx, result); err != nil {
		return err
	}

	return p.stream.Send(&pb.MonitorAlbumStreamResponse{
		Message: &pb.MonitorAlbumStreamResponse_Result{Result: result},
	})
}