package main

import (
	"encoding/json"
	"errors"
	"os"
	"path/filepath"
)

func atomicWriteJSON(path string, value any, mode os.FileMode) error {
	if path == "" {
		return nil
	}
	dir := filepath.Dir(path)
	if err := os.MkdirAll(dir, 0o700); err != nil {
		return err
	}
	data, err := json.MarshalIndent(value, "", "  ")
	if err != nil {
		return err
	}
	temp, err := os.CreateTemp(dir, ".diple-*")
	if err != nil {
		return err
	}
	name := temp.Name()
	defer os.Remove(name)
	if err := temp.Chmod(mode); err != nil {
		_ = temp.Close()
		return err
	}
	if _, err := temp.Write(data); err != nil {
		_ = temp.Close()
		return err
	}
	if err := temp.Sync(); err != nil {
		_ = temp.Close()
		return err
	}
	if err := temp.Close(); err != nil {
		return err
	}
	if err := os.Rename(name, path); err != nil {
		return err
	}
	if directory, err := os.Open(dir); err == nil {
		defer directory.Close()
		if syncErr := directory.Sync(); syncErr != nil && !errors.Is(syncErr, os.ErrInvalid) {
			return syncErr
		}
	}
	return nil
}