// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package overlay

import (
	"time"

	"github.com/spacemonkeygo/monkit/v3"
	"github.com/zeebo/errs"

	"storj.io/common/memory"
)

var (
	mon = monkit.Package()
	// Error represents an overlay error.
	Error = errs.Class("overlay")
)

// Config is a configuration for overlay service.
type Config struct {
	Node                  NodeSelectionConfig
	NodeSelectionCache    UploadSelectionCacheConfig
	UpdateStatsBatchSize  int           `help:"number of update requests to process per transaction" default:"100"`
	NodeCheckInWaitPeriod time.Duration `help:"the amount of time to wait before accepting a redundant check-in from a node (unmodified info since last check-in)" default:"2h" testDefault:"30s"`
}

// AsOfSystemTimeConfig is a configuration struct to enable 'AS OF SYSTEM TIME' for CRDB queries.
type AsOfSystemTimeConfig struct {
	Enabled         bool          `help:"enables the use of the AS OF SYSTEM TIME feature in CRDB" default:"true"`
	DefaultInterval time.Duration `help:"default duration for AS OF SYSTEM TIME" devDefault:"-1ms" releaseDefault:"-10s" testDefault:"-1µs"`
}

// NodeSelectionConfig is a configuration struct to determine the minimum
// values for nodes to select.
type NodeSelectionConfig struct {
	NewNodeFraction  float64       `help:"the fraction of new nodes allowed per request" releaseDefault:"0.05" devDefault:"1"`
	MinimumVersion   string        `help:"the minimum node software version for node selection queries" default:""`
	OnlineWindow     time.Duration `help:"the amount of time without seeing a node before its considered offline" default:"4h" testDefault:"1m"`
	DistinctIP       bool          `help:"require distinct IPs when choosing nodes for upload" releaseDefault:"true" devDefault:"false"`
	MinimumDiskSpace memory.Size   `help:"how much disk space a node at minimum must have to be selected for upload" default:"500.00MB" testDefault:"100.00MB"`

	AsOfSystemTime AsOfSystemTimeConfig
}

func (aost *AsOfSystemTimeConfig) isValid() error {
	if aost.Enabled {
		if aost.DefaultInterval >= 0 {
			return errs.New("AS OF SYSTEM TIME interval must be a negative number")
		}
		if aost.DefaultInterval > -time.Microsecond {
			return errs.New("AS OF SYSTEM TIME interval cannot be in nanoseconds")
		}
	}

	return nil
}