package application

import (
	"github.com/mudler/LocalAI/core/backend"
	"github.com/mudler/xlog"
)

// preloadModelByName is a seam over backend.PreloadModelByName so tests can
// substitute a controllable loader instead of touching real models/disk.
var preloadModelByName = backend.PreloadModelByName

// applyFailoverWarmTargets pins warm failover targets in the watchdog and
// loads them, so a switch does not wait for a cold load.
//
// SyncPinnedModelsToWatchdog runs synchronously: it is a cheap in-memory
// update, and the pin must land before the watchdog can evict a target that
// is about to become (or stay) a chain's active path. Preloading is not
// cheap — it can download or load a multi-GB model — and this callback runs
// on the failover manager's single scheduler goroutine (Sync, called from
// Tick, called from Run), before that tick's probes fire. A slow or hung
// load here would freeze probing and fail-back for every chain, so it runs
// in its own goroutine instead of blocking the scheduler loop.
func (a *Application) applyFailoverWarmTargets(warm []string) {
	a.SyncPinnedModelsToWatchdog()
	go func() {
		for _, name := range warm {
			if _, err := preloadModelByName(a.ApplicationConfig().Context, a.ModelConfigLoader(), a.ModelLoader(), a.ApplicationConfig(), name); err != nil {
				xlog.Warn("failover: could not preload warm target", "model", name, "error", err)
			}
		}
	}()
}