config.go

package sqliteproxy

import (
	"fmt"
	"log/slog"
	"sort"
	"time"
)

// SQLiteProxyOption configures the SQLiteProxy
type SQLiteProxyOption func(*SQLiteProxy)

// WithDSNResolver sets a custom DSN resolver function
func WithDSNResolver(resolver func(orgID, baseDsnInfo string) string) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.dsnResolver = resolver
	}
}

// WithOrgIDKey sets the context key used to extract organization ID
func WithOrgIDKey(key OrgIDKey) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.orgIDKey = key
	}
}

// WithMaxOpenConns sets the maximum number of open connections per database
func WithMaxOpenConns(n int) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.maxOpenConns = n
	}
}

// WithMaxIdleConns sets the maximum number of idle connections per database
func WithMaxIdleConns(n int) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.maxIdleConns = n
	}
}

// WithConnMaxLifetime sets the maximum lifetime of connections
func WithConnMaxLifetime(d time.Duration) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.connMaxLife = d
	}
}

// WithConnMaxIdleTime sets the maximum idle time for connections
func WithConnMaxIdleTime(d time.Duration) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.connMaxIdle = d
	}
}

// WithEviction enables connection eviction with the specified parameters
func WithEviction(maxConnections int, evictionInterval, idleTimeout time.Duration) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.evictionEnabled = true
		p.maxConnections = maxConnections
		p.evictionInterval = evictionInterval
		p.idleTimeout = idleTimeout
	}
}

// WithResourceLimits sets global resource limits
func WithResourceLimits(maxTotalConnections int64, maxMemoryPerTenant, maxTotalMemory int64) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.maxTotalConnections = maxTotalConnections
		p.maxMemoryPerTenant = maxMemoryPerTenant
		p.maxTotalMemory = maxTotalMemory
	}
}

// WithLogger sets a custom structured logger
func WithLogger(logger *slog.Logger) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.logger = logger
	}
}

// WithShutdownTimeout sets the graceful shutdown timeout
func WithShutdownTimeout(timeout time.Duration) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.shutdownTimeout = timeout
	}
}

// WithQueryTimeout sets a timeout that applies to all database operations
// If timeout is 0, no timeout is applied (database/sql default behavior)
func WithQueryTimeout(timeout time.Duration) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.queryTimeout = timeout
	}
}

// WithMigrations configures the proxy with schema migrations
func WithMigrations(migrations ...Migration) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		// Sort migrations by version
		sorted := make([]Migration, len(migrations))
		copy(sorted, migrations)
		sort.Slice(sorted, func(i, j int) bool {
			return sorted[i].Version < sorted[j].Version
		})
		
		// Validate migrations
		for i, m := range sorted {
			if m.Version <= 0 {
				panic(fmt.Sprintf("migration version must be positive, got %d", m.Version))
			}
			if i > 0 && sorted[i-1].Version == m.Version {
				panic(fmt.Sprintf("duplicate migration version: %d", m.Version))
			}
			if m.Up == "" {
				panic(fmt.Sprintf("migration %d has empty Up SQL", m.Version))
			}
		}
		
		p.migrations = sorted
		if len(sorted) > 0 {
			p.targetSchemaVersion = sorted[len(sorted)-1].Version
		}
	}
}

// WithMigrationMode sets how migrations are applied
func WithMigrationMode(mode MigrationMode) SQLiteProxyOption {
	return func(p *SQLiteProxy) {
		p.migrationMode = mode
	}
}