package updater

import (
	"encoding/base64"
	"encoding/json"
	"io"
	"log/slog"
	"os"
	"path/filepath"
	"testing"

	"github.com/docker/docker/api/types/registry"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func writeDockerConfig(t *testing.T, body string) string {
	t.Helper()
	dir := t.TempDir()
	require.NoError(t, os.WriteFile(filepath.Join(dir, "config.json"), []byte(body), 0o600))
	return dir
}

func decodeAuth(t *testing.T, enc string) registry.AuthConfig {
	t.Helper()
	raw, err := base64.URLEncoding.DecodeString(enc)
	require.NoError(t, err)
	var ac registry.AuthConfig
	require.NoError(t, json.Unmarshal(raw, &ac))
	return ac
}

func TestRegistryAuth(t *testing.T) {
	user := base64.StdEncoding.EncodeToString([]byte("bob:s3cret"))
	log := slog.New(slog.NewTextHandler(io.Discard, nil))

	t.Run("docker hub spellings", func(t *testing.T) {
		for _, key := range []string{"https://index.docker.io/v1/", "index.docker.io", "docker.io", "registry-1.docker.io"} {
			dir := writeDockerConfig(t, `{"auths":{"`+key+`":{"auth":"`+user+`"}}}`)
			a, err := LoadRegistryAuth(dir, log)
			require.NoError(t, err)
			for _, repo := range []string{"gitea/gitea", "docker.io/library/nginx", "nginx"} {
				ac := decodeAuth(t, a.For(repo))
				assert.Equal(t, "bob", ac.Username, "%s for %s", key, repo)
				assert.Equal(t, "s3cret", ac.Password)
			}
			assert.Empty(t, a.For("gitea.shcizo.se/shcizo/slusk"))
		}
	})
	t.Run("custom registry with scheme", func(t *testing.T) {
		dir := writeDockerConfig(t, `{"auths":{"https://gitea.shcizo.se":{"auth":"`+user+`"},"ghcr.io":{"identitytoken":"tok"}}}`)
		a, err := LoadRegistryAuth(dir, log)
		require.NoError(t, err)
		assert.Equal(t, "bob", decodeAuth(t, a.For("gitea.shcizo.se/shcizo/slusk")).Username)
		assert.Equal(t, "tok", decodeAuth(t, a.For("ghcr.io/x/y")).IdentityToken)
		assert.Empty(t, a.For("registry.example.com/x"))
	})
	t.Run("empty dir is anonymous", func(t *testing.T) {
		a, err := LoadRegistryAuth("", log)
		require.NoError(t, err)
		assert.Nil(t, a)
		assert.Empty(t, a.For("gitea/gitea"))
	})
	t.Run("malformed json", func(t *testing.T) {
		_, err := LoadRegistryAuth(writeDockerConfig(t, "{"), log)
		assert.Error(t, err)
	})
	t.Run("missing file", func(t *testing.T) {
		_, err := LoadRegistryAuth(t.TempDir(), log)
		assert.Error(t, err)
	})
}