package cmd

import (
	"encoding/json"
	"errors"
	"flag"
	"io"
	"os"
	"path/filepath"
	"testing"

	"github.com/stretchr/testify/require"
	"github.com/urfave/cli/v2"
)

func TestRunBackupRejectsMutuallyExclusiveModes(t *testing.T) {
	set := flag.NewFlagSet("backup", flag.ContinueOnError)
	set.Bool("db-only", true, "")
	set.Bool("images-only", true, "")

	err := runBackup(cli.NewContext(nil, set, nil))
	require.EqualError(t, err, "--db-only and --images-only cannot be used together")
}

func TestWriteFileAtomically(t *testing.T) {
	t.Run("success", func(t *testing.T) {
		dir := t.TempDir()
		target := filepath.Join(dir, "backup.sql")
		require.NoError(t, writeFileAtomically(target, func(w io.Writer) error {
			_, err := io.WriteString(w, "complete backup")
			return err
		}))

		content, err := os.ReadFile(target)
		require.NoError(t, err)
		require.Equal(t, "complete backup", string(content))
		requireNoPartFiles(t, dir)
	})

	t.Run("failure preserves previous backup", func(t *testing.T) {
		dir := t.TempDir()
		target := filepath.Join(dir, "backup.sql")
		require.NoError(t, os.WriteFile(target, []byte("known good"), 0o600))
		writeErr := errors.New("dump failed")

		err := writeFileAtomically(target, func(w io.Writer) error {
			_, _ = io.WriteString(w, "partial")
			return writeErr
		})
		require.ErrorIs(t, err, writeErr)

		content, err := os.ReadFile(target)
		require.NoError(t, err)
		require.Equal(t, "known good", string(content))
		requireNoPartFiles(t, dir)
	})

	t.Run("failure leaves no new backup", func(t *testing.T) {
		dir := t.TempDir()
		target := filepath.Join(dir, "backup.sql")
		writeErr := errors.New("dump failed")

		err := writeFileAtomically(target, func(w io.Writer) error {
			_, _ = io.WriteString(w, "partial")
			return writeErr
		})
		require.ErrorIs(t, err, writeErr)
		require.NoFileExists(t, target)
		requireNoPartFiles(t, dir)
	})
}

func requireNoPartFiles(t *testing.T, dir string) {
	t.Helper()
	matches, err := filepath.Glob(filepath.Join(dir, "*.part"))
	require.NoError(t, err)
	require.Empty(t, matches)
}

func TestImageManifestEntryIntegrityFields(t *testing.T) {
	entry := imageManifestEntry{
		Key:    "tamabox/image.webp",
		Size:   3,
		SHA256: "actual-content-sha256",
		ETag:   "provider-etag",
	}
	encoded, err := json.Marshal(entry)
	require.NoError(t, err)
	require.JSONEq(t, `{
		"key":"tamabox/image.webp",
		"size":3,
		"sha256":"actual-content-sha256",
		"etag":"provider-etag"
	}`, string(encoded))
	require.NotContains(t, string(encoded), "md5")
}