package mailhold

import (
	"bytes"
	"errors"
	"log"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestHold_MarkerDecidesAndReleaseRemovesIt(t *testing.T) {
	dir := t.TempDir()
	buf := &bytes.Buffer{}
	h := New(dir, log.New(buf, "", 0))
	if h.Held() {
		t.Fatal("no marker: must not hold")
	}
	if err := h.Check("kernel notice", "c1"); err != nil {
		t.Fatalf("no marker: Check = %v", err)
	}
	if err := os.WriteFile(filepath.Join(dir, FileName), nil, 0o644); err != nil {
		t.Fatal(err)
	}
	if err := h.Check("kernel notice", "c1"); !errors.Is(err, ErrHeld) {
		t.Fatalf("marker present: Check = %v, want ErrHeld", err)
	}
	if got := buf.String(); !strings.Contains(got, "[WARN] MAIL-HOLD: not sending kernel notice to c1") {
		t.Fatalf("held mail log line missing: %q", got)
	}
	if err := h.Release(); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(filepath.Join(dir, FileName)); !os.IsNotExist(err) {
		t.Fatalf("Release left the marker: %v", err)
	}
	if err := h.Release(); err != nil {
		t.Fatalf("a second Release must be a no-op, got %v", err)
	}
}

// Fail-closed: a marker state that cannot be read (here: the data dir is a FILE, so stat says ENOTDIR) holds mail.
func TestHold_UnreadableStateHolds(t *testing.T) {
	f := filepath.Join(t.TempDir(), "not-a-dir")
	if err := os.WriteFile(f, nil, 0o644); err != nil {
		t.Fatal(err)
	}
	if !New(f, nil).Held() {
		t.Fatal("an unreadable marker state must count as HELD")
	}
}

func TestHold_NilNeverHolds(t *testing.T) {
	var h *Hold
	if h.Held() || h.Check("x", "y") != nil || h.Release() != nil {
		t.Fatal("a nil hold must never hold and never fail")
	}
}