package icon

import (
	"bytes"
	"os"
	"path/filepath"
	"testing"
)

// TestInstall: the icon lands in the directory, is left alone when current,
// and is repaired when the file on disk differs.
func TestInstall(t *testing.T) {
	if len(PNG) < 8 || !bytes.HasPrefix(PNG, []byte("\x89PNG")) {
		t.Fatalf("embedded icon is not a PNG (%d bytes)", len(PNG))
	}
	dir := filepath.Join(t.TempDir(), "talk")
	path, err := Install(dir)
	if err != nil {
		t.Fatal(err)
	}
	if path != filepath.Join(dir, FileName) {
		t.Errorf("path = %q", path)
	}
	got, err := os.ReadFile(path)
	if err != nil || !bytes.Equal(got, PNG) {
		t.Fatalf("installed file differs (err %v)", err)
	}
	first, _ := os.Stat(path)
	if _, err := Install(dir); err != nil {
		t.Fatal(err)
	}
	second, _ := os.Stat(path)
	if !second.ModTime().Equal(first.ModTime()) {
		t.Error("unchanged icon was rewritten")
	}
	if err := os.WriteFile(path, []byte("stale"), 0o644); err != nil {
		t.Fatal(err)
	}
	if _, err := Install(dir); err != nil {
		t.Fatal(err)
	}
	got, _ = os.ReadFile(path)
	if !bytes.Equal(got, PNG) {
		t.Error("stale icon was not replaced")
	}
	if _, err := Install(""); err == nil {
		t.Error("Install(\"\") succeeded")
	}
}