package storage

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

// Encode serializes a value into JSON.
func Encode(value any) ([]byte, error) {
	return json.MarshalIndent(value, "", "  ")
}

// Decode deserializes JSON into the supplied value.
func Decode(data []byte, target any) error {
	return json.Unmarshal(data, target)
}

// Save writes a value to a JSON file.
func Save(path string, value any) error {
	data, err := Encode(value)
	if err != nil {
		return err
	}

	dir := filepath.Dir(path)

	if err := os.MkdirAll(dir, 0755); err != nil {
		return err
	}

	file, err := os.CreateTemp(dir, ".settings-*.tmp")
	if err != nil {
		return err
	}

	tempPath := file.Name()

	defer os.Remove(tempPath)

	if _, err := file.Write(data); err != nil {
		file.Close()
		return err
	}

	if err := file.Sync(); err != nil {
		file.Close()
		return err
	}

	if err := file.Close(); err != nil {
		return err
	}

	return os.Rename(tempPath, path)
}

// Load reads a JSON file into the supplied target.
func Load(path string, target any) error {
	data, err := os.ReadFile(path)
	if err != nil {
		return err
	}

	return Decode(data, target)
}