package models

import (
	"context"
	"log"
	"sync"
	"time"
)

// HealthTickInterval is exported so focused tests can exercise the same
// lifecycle with a short interval.
var HealthTickInterval = time.Minute

var serverHealthTickerOnce sync.Once

// StartServerHealthTicker periodically refreshes derived server health. The
// first production tick is delayed to keep CLI migration paths side-effect
// free; assignment/pause paths recompute synchronously.
func StartServerHealthTicker(parent context.Context) {
	serverHealthTickerOnce.Do(func() {
		go func() {
			ticker := time.NewTicker(HealthTickInterval)
			defer ticker.Stop()
			for {
				select {
				case <-parent.Done():
					return
				case <-ticker.C:
					var ids []int64
					if err := DB().Model(&Server{}).Pluck("id", &ids).Error; err != nil {
						log.Printf("server health: list: %v", err)
						continue
					}
					for _, id := range ids {
						if err := HealthForServer(id); err != nil {
							log.Printf("server health %d: %v", id, err)
						}
					}
				}
			}
		}()
	})
}