package agent

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

func writeJSONAtomic(path string, value any) error {
	data, err := json.MarshalIndent(value, "", "  ")
	if err != nil {
		return err
	}
	file, err := os.CreateTemp(filepath.Dir(path), ".state-*.tmp")
	if err != nil {
		return err
	}
	tmp := file.Name()
	defer os.Remove(tmp)
	if _, err := file.Write(append(data, '\n')); err != nil {
		_ = file.Close()
		return err
	}
	if err := file.Sync(); err != nil {
		_ = file.Close()
		_ = os.Remove(tmp)
		return err
	}
	if err := file.Close(); err != nil {
		_ = os.Remove(tmp)
		return err
	}
	if err := os.Rename(tmp, path); err != nil {
		_ = os.Remove(tmp)
		return err
	}
	return syncDirectory(filepath.Dir(path))
}

func syncDirectory(path string) error {
	dir, err := os.Open(path)
	if err != nil {
		return err
	}
	syncErr := dir.Sync()
	return firstError(syncErr, dir.Close())
}

func validateName(name string) error {
	if name == "" || name == "." || name == ".." || strings.ContainsAny(name, `/\\`) || strings.Contains(name, "..") || strings.TrimSpace(name) != name {
		return fmt.Errorf("unsafe file name %q", name)
	}
	return nil
}

func firstError(errs ...error) error {
	for _, err := range errs {
		if err != nil {
			return err
		}
	}
	return nil
}