package api

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

// A config file that exists but refuses a write is not writable. This is what a
// ConfigMap mounted into a pod looks like, and calling it writable made the
// console offer an editor whose every save failed.
func TestIsFileWritable(t *testing.T) {
	if os.Geteuid() == 0 {
		t.Skip("root can write a read-only file")
	}
	dir := t.TempDir()

	rw := filepath.Join(dir, "rw.yaml")
	if err := os.WriteFile(rw, []byte("x"), 0o644); err != nil {
		t.Fatal(err)
	}
	ro := filepath.Join(dir, "ro.yaml")
	if err := os.WriteFile(ro, []byte("x"), 0o444); err != nil {
		t.Fatal(err)
	}
	cases := map[string]struct {
		path string
		want bool
	}{
		"writable file":          {rw, true},
		"read-only file":         {ro, false},
		"missing file, open dir": {filepath.Join(dir, "new.yaml"), true},
		"missing file, no dir":   {filepath.Join(dir, "nodir", "x.yaml"), false},
		"no path":                {"", false},
	}
	for name, tc := range cases {
		if got := isFileWritable(tc.path); got != tc.want {
			t.Errorf("%s: isFileWritable(%q) = %v, want %v", name, tc.path, got, tc.want)
		}
	}

	// A directory that refuses new files makes a missing file unwritable too.
	locked := filepath.Join(dir, "locked")
	if err := os.Mkdir(locked, 0o555); err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })
	if isFileWritable(filepath.Join(locked, "x.yaml")) {
		t.Error("a file in a directory that refuses new files was reported writable")
	}
}