package storage

import (
	"context"
	"fmt"

	pb "northwest.io/nostr-grpc/api/nostr/v1"
)

const KindDeletion = 5

func (s *Storage) ProcessDeletion(ctx context.Context, deletionEvent *pb.Event) error {
	if deletionEvent.Kind != KindDeletion {
		return fmt.Errorf("not a deletion event")
	}

	var eventIDsToDelete []string
	for _, tag := range deletionEvent.Tags {
		if len(tag.Values) >= 2 && tag.Values[0] == "e" {
			eventIDsToDelete = append(eventIDsToDelete, tag.Values[1])
		}
	}

	if len(eventIDsToDelete) == 0 {
		return nil
	}

	tx, err := s.db.BeginTx(ctx, nil)
	if err != nil {
		return fmt.Errorf("failed to begin transaction: %w", err)
	}
	defer tx.Rollback()

	for _, eventID := range eventIDsToDelete {
		var eventPubkey string
		err := tx.QueryRowContext(ctx,
			"SELECT pubkey FROM events WHERE id = ? AND deleted = 0",
			eventID,
		).Scan(&eventPubkey)

		if err != nil {
			continue
		}

		if eventPubkey != deletionEvent.Pubkey {
			continue
		}

		_, err = tx.ExecContext(ctx,
			"UPDATE events SET deleted = 1 WHERE id = ?",
			eventID,
		)
		if err != nil {
			return fmt.Errorf("failed to mark event as deleted: %w", err)
		}

		_, err = tx.ExecContext(ctx,
			"INSERT OR IGNORE INTO deletions (deleted_event_id, deletion_event_id, pubkey, created_at) VALUES (?, ?, ?, ?)",
			eventID,
			deletionEvent.Id,
			deletionEvent.Pubkey,
			deletionEvent.CreatedAt,
		)
		if err != nil {
			return fmt.Errorf("failed to record deletion: %w", err)
		}
	}

	return tx.Commit()
}