// Package health provides the service readiness use case.
package health

import (
	"context"

	"gl/domain/ledger"
)

type Database interface {
	Ping(context.Context) error
}

type SettlementMonitor interface {
	Stats(context.Context) (ledger.SettlementStats, error)
}

type Status struct {
	Serving           bool
	DatabaseReady     bool
	SettlementEnabled bool
	SettlementReady   bool
	SettlementStats   ledger.SettlementStats
}

type Service struct {
	database          Database
	settlement        SettlementMonitor
	settlementEnabled bool
}

func NewService(database Database, settlement ...SettlementMonitor) *Service {
	service := &Service{database: database}
	if len(settlement) > 0 && settlement[0] != nil {
		service.settlement = settlement[0]
		service.settlementEnabled = true
	}
	return service
}

func (s *Service) Check(ctx context.Context) Status {
	status := Status{}
	if s.database != nil {
		status.DatabaseReady = s.database.Ping(ctx) == nil
	}
	status.Serving = status.DatabaseReady
	status.SettlementEnabled = s.settlementEnabled
	if status.DatabaseReady && s.settlementEnabled {
		stats, err := s.settlement.Stats(ctx)
		if err == nil {
			status.SettlementStats = stats
			status.SettlementReady = true
		}
	}
	return status
}