package source

import (
	"errors"
	"fmt"
	"testing"
)

func TestErrorKindThroughWrapping(t *testing.T) {
	base := errors.New("producer disappeared")
	wrapped := wrapError("read video", ErrorKindUnavailable, base)
	outer := fmt.Errorf("worker failed: %w", wrapped)

	if got := errorKind(outer); got != ErrorKindUnavailable {
		t.Fatalf("errorKind() = %v, want %v", got, ErrorKindUnavailable)
	}
	if !errors.Is(outer, base) {
		t.Fatal("wrapped error does not preserve its cause")
	}
	if wrapError("nil", 0, nil) != nil {
		t.Fatal("nil error is not wrapped as nil")
	}
}

func TestErrorKindUnknown(t *testing.T) {
	if got := errorKind(errors.New("ordinary error")); got != ErrorKindUnknown {
		t.Fatalf("errorKind() = %v, want %v", got, ErrorKindUnknown)
	}
}

func TestSourceErrorWithOperation(t *testing.T) {
	err := &SourceError{
		Op:   "read video",
		Kind: ErrorKindTemporary,
		Err:  errors.New("timeout"),
	}

	const want = "read video: timeout"
	if got := err.Error(); got != want {
		t.Fatalf("Error() = %q, want %q", got, want)
	}
}

func TestSourceErrorWithoutOperation(t *testing.T) {
	err := &SourceError{
		Kind: ErrorKindTemporary,
		Err:  errors.New("timeout"),
	}

	const want = "timeout"
	if got := err.Error(); got != want {
		t.Fatalf("Error() = %q, want %q", got, want)
	}
}