package randomsource

import (
	"context"
	crand "crypto/rand"
	"io"
	"math/big"
	"sync"
	"time"
)

func NewService(ch chan [10]int, interval time.Duration, maxInt int64) *Service {
	return &Service{
		interval: interval,
		ch:       ch,
		rand:     crand.Reader,
		maxInt:   maxInt,
	}
}

type Service struct {
	interval time.Duration
	rand     io.Reader
	ch       chan [10]int
	maxInt   int64
}

func (s *Service) SourceCh() <-chan [10]int {
	return s.ch
}

func (s *Service) Start(ctx context.Context, wg *sync.WaitGroup) {
	defer wg.Done()

	var res [10]int

	ticker := time.NewTicker(s.interval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return

		case <-ticker.C:
			for i := 0; i < 10; i++ {
				v, err := crand.Int(s.rand, big.NewInt(s.maxInt))
				if err != nil {
					panic(err)
				}

				res[i] = int(v.Int64())
			}

			s.ch <- res
		}
	}
}