package labels

import (
	"context"
	"fmt"

	"github.com/jackc/pgx/v5/pgxpool"
)

// LabelService handles address labeling
type LabelService struct {
	db *pgxpool.Pool
}

// NewLabelService creates a new label service
func NewLabelService(db *pgxpool.Pool) *LabelService {
	return &LabelService{db: db}
}

// AddLabel adds a label to an address
func (l *LabelService) AddLabel(ctx context.Context, chainID int, address, label, labelType string, userID *string) error {
	query := `
		INSERT INTO address_labels (chain_id, address, label, label_type, user_id)
		VALUES ($1, $2, $3, $4, $5)
		ON CONFLICT (chain_id, address, label_type, user_id) DO UPDATE SET
			label = $3,
			updated_at = NOW()
	`

	_, err := l.db.Exec(ctx, query, chainID, address, label, labelType, userID)
	return err
}

// GetLabels gets labels for an address
func (l *LabelService) GetLabels(ctx context.Context, chainID int, address string) ([]Label, error) {
	query := `
		SELECT label, label_type, user_id, source, created_at
		FROM address_labels
		WHERE chain_id = $1 AND address = $2
		ORDER BY created_at DESC
	`

	rows, err := l.db.Query(ctx, query, chainID, address)
	if err != nil {
		return nil, fmt.Errorf("failed to query labels: %w", err)
	}
	defer rows.Close()

	var labels []Label
	for rows.Next() {
		var label Label
		var userID *string
		if err := rows.Scan(&label.Label, &label.LabelType, &userID, &label.Source, &label.CreatedAt); err != nil {
			continue
		}
		if userID != nil {
			label.UserID = *userID
		}
		labels = append(labels, label)
	}

	return labels, nil
}

// Label represents an address label
type Label struct {
	Label     string
	LabelType string
	UserID    string
	Source    string
	CreatedAt string
}