package eventstore

import (
	"context"
	"fmt"

	"github.com/nbd-wtf/go-nostr"
)

type RelayWrapper struct {
	Store
}

var _ nostr.RelayStore = (*RelayWrapper)(nil)

func (w RelayWrapper) Publish(ctx context.Context, evt nostr.Event) error {
	if nostr.IsEphemeralKind(evt.Kind) {
		// do not store ephemeral events
		return nil
	}

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	if nostr.IsRegularKind(evt.Kind) {
		// regular events are just saved directly
		if err := w.SaveEvent(ctx, &evt); err != nil && err != ErrDupEvent {
			return fmt.Errorf("failed to save: %w", err)
		}
	}

	// from now on we know they are replaceable or addressable
	filter := nostr.Filter{Limit: 1, Kinds: []int{evt.Kind}, Authors: []string{evt.PubKey}}
	if nostr.IsAddressableKind(evt.Kind) {
		// when addressable, add the "d" tag to the filter
		filter.Tags = nostr.TagMap{"d": []string{evt.Tags.GetD()}}
	}

	// now we fetch the event, whatever it is, delete it and then save the new
	ch, err := w.Store.QueryEvents(ctx, filter)
	if err != nil {
		return fmt.Errorf("failed to query before replacing: %w", err)
	}

	shouldStore := true
	for previous := range ch {
		if previous == nil {
			continue
		}
		if isOlder(previous, &evt) {
			if err := w.Store.DeleteEvent(ctx, previous); err != nil {
				return fmt.Errorf("failed to delete event for replacing: %w", err)
			}
		} else {
			// already, newer event is stored.
			shouldStore = false
		}
	}
	if shouldStore {
		if err := w.SaveEvent(ctx, &evt); err != nil && err != ErrDupEvent {
			return fmt.Errorf("failed to save: %w", err)
		}
	}

	return nil
}

func (w RelayWrapper) QuerySync(ctx context.Context, filter nostr.Filter) ([]*nostr.Event, error) {
	ch, err := w.Store.QueryEvents(ctx, filter)
	if err != nil {
		return nil, fmt.Errorf("failed to query: %w", err)
	}

	n := filter.Limit
	if n == 0 {
		n = 500
	}

	results := make([]*nostr.Event, 0, n)
	for evt := range ch {
		results = append(results, evt)
	}

	return results, nil
}