package monitor

import (
	"errors"
	"time"

	"github.com/influxdata/influxdb/monitor/diagnostics"
	"github.com/influxdata/influxdb/toml"
)

const (
	// DefaultStoreEnabled is whether the system writes gathered information in
	// an InfluxDB system for historical analysis.
	DefaultStoreEnabled = true

	// DefaultStoreDatabase is the name of the database where gathered information is written.
	DefaultStoreDatabase = "_internal"

	// DefaultStoreInterval is the period between storing gathered information.
	DefaultStoreInterval = 10 * time.Second
)

// Config represents the configuration for the monitor service.
type Config struct {
	StoreEnabled  bool          `toml:"store-enabled"`
	StoreDatabase string        `toml:"store-database"`
	StoreInterval toml.Duration `toml:"store-interval"`
}

// NewConfig returns an instance of Config with defaults.
func NewConfig() Config {
	return Config{
		StoreEnabled:  true,
		StoreDatabase: DefaultStoreDatabase,
		StoreInterval: toml.Duration(DefaultStoreInterval),
	}
}

// Validate validates that the configuration is acceptable.
func (c Config) Validate() error {
	if c.StoreInterval <= 0 {
		return errors.New("monitor store interval must be positive")
	}
	if c.StoreDatabase == "" {
		return errors.New("monitor store database name must not be empty")
	}
	return nil
}

// Diagnostics returns a diagnostics representation of a subset of the Config.
func (c Config) Diagnostics() (*diagnostics.Diagnostics, error) {
	if !c.StoreEnabled {
		return diagnostics.RowFromMap(map[string]interface{}{
			"store-enabled": false,
		}), nil
	}

	return diagnostics.RowFromMap(map[string]interface{}{
		"store-enabled":  true,
		"store-database": c.StoreDatabase,
		"store-interval": c.StoreInterval,
	}), nil
}