package host

import (
	"testing"
	"time"

	"tower/internal/model"
)

func TestParseProcMeminfo(t *testing.T) {
	in := "MemTotal:       8000000 kB\nMemAvailable:  800000 kB\nSwapTotal:  2000000 kB\nSwapFree:  500000 kB\n"
	m := parseProcMeminfo(in)
	if m["MemTotal"] != 8000000 {
		t.Fatalf("MemTotal mismatch: %d", m["MemTotal"])
	}
	if m["MemAvailable"] != 800000 {
		t.Fatalf("MemAvailable mismatch: %d", m["MemAvailable"])
	}
}

func TestDesiredMemPriority(t *testing.T) {
	p, w := desiredMemPriority(16.0)
	if p != "" || w != 0 {
		t.Fatalf("expected none")
	}

	p, w = desiredMemPriority(15.0)
	if p != model.PriorityP2 || w != 60*time.Second {
		t.Fatalf("expected P2/60s got %v/%v", p, w)
	}
	p, w = desiredMemPriority(10.0)
	if p != model.PriorityP1 {
		t.Fatalf("expected P1 got %v", p)
	}
	p, w = desiredMemPriority(5.0)
	if p != model.PriorityP0 || w != 30*time.Second {
		t.Fatalf("expected P0/30s got %v/%v", p, w)
	}
}

func TestDesiredSwapPriority(t *testing.T) {
	// No swap configured.
	p, _ := desiredSwapPriority(4.0, 0, 90.0)
	if p != "" {
		t.Fatalf("expected none when SwapTotal=0")
	}

	p, w := desiredSwapPriority(4.0, 1000, 80.0)
	if p != model.PriorityP0 || w != 30*time.Second {
		t.Fatalf("expected P0/30s got %v/%v", p, w)
	}

	p, w = desiredSwapPriority(9.9, 1000, 50.0)
	if p != model.PriorityP1 || w != 60*time.Second {
		t.Fatalf("expected P1/60s got %v/%v", p, w)
	}

	// Swap high but RAM not tight => no issue.
	p, _ = desiredSwapPriority(20.0, 1000, 90.0)
	if p != "" {
		t.Fatalf("expected none when RAM not tight")
	}
}

func TestUpdateSustained(t *testing.T) {
	now := time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC)
	p, since := updateSustained(now, "", time.Time{}, model.PriorityP1)
	if p != model.PriorityP1 || !since.Equal(now) {
		t.Fatalf("expected set to P1 at now")
	}
	p2, since2 := updateSustained(now.Add(1*time.Second), p, since, model.PriorityP1)
	if p2 != model.PriorityP1 || !since2.Equal(since) {
		t.Fatalf("expected unchanged since")
	}
	p3, since3 := updateSustained(now.Add(2*time.Second), p2, since2, model.PriorityP0)
	if p3 != model.PriorityP0 || !since3.Equal(now.Add(2*time.Second)) {
		t.Fatalf("expected reset on priority change")
	}
	p4, since4 := updateSustained(now.Add(3*time.Second), p3, since3, "")
	if p4 != "" || !since4.IsZero() {
		t.Fatalf("expected cleared")
	}
}