package server

import (
	"testing"
	"time"
)

func TestQueueETASeconds(t *testing.T) {
	// No speed → can't extrapolate.
	if got := queueETASeconds(100, 3600, 0); got != 0 {
		t.Errorf("speed 0: got %d, want 0", got)
	}
	// current remaining 600s + 1800s of queued source at 0.5x (=3600s) = 4200s.
	if got := queueETASeconds(600, 1800, 0.5); got != 4200 {
		t.Errorf("got %d, want 4200", got)
	}
	// At 2x, 1800s of source encodes in 900s; + 600 remaining = 1500.
	if got := queueETASeconds(600, 1800, 2); got != 1500 {
		t.Errorf("got %d, want 1500", got)
	}
	// Empty queue → just the current job's remaining.
	if got := queueETASeconds(600, 0, 1); got != 600 {
		t.Errorf("got %d, want 600", got)
	}
}

// waitCached polls Get (the probe resolves on a background goroutine).
func waitCached(c *durationCache, p string, mt time.Time) (float64, bool) {
	for i := 0; i < 200; i++ {
		if sec, ok := c.Get(p, mt); ok {
			return sec, true
		}
		time.Sleep(2 * time.Millisecond)
	}
	return 0, false
}

func TestDurationCache(t *testing.T) {
	c := newDurationCache(func(p string) (float64, error) { return 42, nil })

	mt := time.Unix(1000, 0)
	if _, ok := c.Get("/a.mkv", mt); ok {
		t.Fatal("first Get should miss")
	}
	if sec, ok := waitCached(c, "/a.mkv", mt); !ok || sec != 42 {
		t.Fatalf("after probe: got %v ok=%v, want 42 true", sec, ok)
	}

	// A changed mtime invalidates the entry.
	if _, ok := c.Get("/a.mkv", time.Unix(2000, 0)); ok {
		t.Error("changed mtime should miss")
	}
	if _, ok := waitCached(c, "/a.mkv", time.Unix(2000, 0)); !ok {
		t.Fatal("re-probe under new mtime should cache")
	}

	// Retain drops entries for paths not in the keep set.
	c.Retain([]string{"/b.mkv"})
	if _, ok := c.Get("/a.mkv", time.Unix(2000, 0)); ok {
		t.Error("Retain should have dropped /a.mkv")
	}
}