database.go

package database

import (
	"context"
	"errors"
	"time"

	apiv0 "github.com/modelcontextprotocol/registry/pkg/api/v0"
)

// Common database errors
var (
	ErrNotFound          = errors.New("record not found")
	ErrAlreadyExists     = errors.New("record already exists")
	ErrInvalidInput      = errors.New("invalid input")
	ErrDatabase          = errors.New("database error")
	ErrInvalidVersion    = errors.New("invalid version: cannot publish duplicate version")
	ErrMaxServersReached = errors.New("maximum number of versions for this server reached (10000): please reach out at https://github.com/modelcontextprotocol/registry to explain your use case")
)

// ServerFilter defines filtering options for server queries
type ServerFilter struct {
	Name          *string    // for finding versions of same server
	RemoteURL     *string    // for duplicate URL detection
	UpdatedSince  *time.Time // for incremental sync filtering
	SubstringName *string    // for substring search on name
	Version       *string    // for exact version matching
	IsLatest      *bool      // for filtering latest versions only
}

// Database defines the interface for database operations
type Database interface {
	// Retrieve server entries with optional filtering
	List(ctx context.Context, filter *ServerFilter, cursor string, limit int) ([]*apiv0.ServerJSON, string, error)
	// Retrieve a single server by its ID
	GetByID(ctx context.Context, id string) (*apiv0.ServerJSON, error)
	// CreateServer adds a new server to the database
	CreateServer(ctx context.Context, server *apiv0.ServerJSON) (*apiv0.ServerJSON, error)
	// UpdateServer updates an existing server record
	UpdateServer(ctx context.Context, id string, server *apiv0.ServerJSON) (*apiv0.ServerJSON, error)
	// Close closes the database connection
	Close() error
	
	// Rate limiting methods
	IncrementPublishCount(ctx context.Context, authMethodSubject string) error
	GetPublishCount(ctx context.Context, authMethodSubject string, date time.Time) (int, error)
	// CheckAndIncrementPublishCount atomically checks if the count is under the limit and increments if so
	// Returns the current count and whether the increment was successful
	CheckAndIncrementPublishCount(ctx context.Context, authMethodSubject string, limit int) (currentCount int, incrementSuccessful bool, err error)
}

// ConnectionType represents the type of database connection
type ConnectionType string

const (
	// ConnectionTypeMemory represents an in-memory database connection
	ConnectionTypeMemory ConnectionType = "memory"
	// ConnectionTypePostgreSQL represents a PostgreSQL database connection
	ConnectionTypePostgreSQL ConnectionType = "postgresql"
)