package originclient

import (
	"path/filepath"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func withStubMachineID(t *testing.T, id string, err error) {
	t.Helper()
	original := machineIDFunc
	machineIDFunc = func() (string, error) { return id, err }
	t.Cleanup(func() { machineIDFunc = original })
}

func TestResolveMachineID_ExplicitOverrideWins(t *testing.T) {
	withStubMachineID(t, "os-machine-id", nil)
	got := ResolveMachineID("explicit-id", filepath.Join(t.TempDir(), "install-id"), nil)
	assert.Equal(t, "explicit-id", got)
}

func TestResolveMachineID_UsesOSMachineIDWhenAvailable(t *testing.T) {
	withStubMachineID(t, "os-machine-id", nil)
	got := ResolveMachineID("", filepath.Join(t.TempDir(), "install-id"), nil)
	assert.Equal(t, "os-machine-id", got)
}

func TestResolveMachineID_FallsBackAndPersistsWhenOSIDUnavailable(t *testing.T) {
	withStubMachineID(t, "", errMachineIDUnavailable)
	path := filepath.Join(t.TempDir(), "nested", "install-id")

	first := ResolveMachineID("", path, nil)
	assert.NotEmpty(t, first)

	second := ResolveMachineID("", path, nil)
	assert.Equal(t, first, second, "second call should read the persisted id rather than generating a new one")
}

func TestResolveMachineID_NilLoggerDoesNotPanic(t *testing.T) {
	withStubMachineID(t, "", errMachineIDUnavailable)
	assert.NotPanics(t, func() {
		ResolveMachineID("", filepath.Join(t.TempDir(), "install-id"), nil)
	})
}

func TestResolveMachineID_LogsWarningWhenOSIDUnavailable(t *testing.T) {
	withStubMachineID(t, "", errMachineIDUnavailable)
	var warned bool
	logger := LoggerFunc(func(msg string, err error) { warned = true })

	ResolveMachineID("", filepath.Join(t.TempDir(), "install-id"), logger)

	assert.True(t, warned)
}

func TestPersistInstallID(t *testing.T) {
	path := filepath.Join(t.TempDir(), "nested", "dir", "install-id")
	require.NoError(t, persistInstallID(path, "abc-123"))
}