package main

import (
	"bytes"
	"io"
	"os"
)

func expandEnvFiles() error {
	for _, path := range FlagExpandEnvFiles {
		tmpFile, err := os.CreateTemp("", "*")
		if err != nil {
			return err
		}
		defer tmpFile.Close()

		ExpandEnvFiles[path] = tmpFile.Name()

		file, err := os.Open(path)
		if err != nil {
			return err
		}
		defer file.Close()

		data, err := io.ReadAll(file)
		if err != nil {
			return err
		}
		file.Close()

		if _, err := io.Copy(tmpFile, bytes.NewReader(data)); err != nil {
			return err
		}

		newFile, err := os.Create(path)
		if err != nil {
			return err
		}
		defer newFile.Close()

		if _, err := newFile.WriteString(os.ExpandEnv(string(data))); err != nil {
			return err
		}
	}

	return nil
}

func restoreEnvFiles() error {
	for originalFilePath, tmpFilePath := range ExpandEnvFiles {
		originalFile, err := os.Create(originalFilePath)
		if err != nil {
			return err
		}
		defer originalFile.Close()

		tmpFile, err := os.Open(tmpFilePath)
		if err != nil {
			return err
		}
		defer tmpFile.Close()

		if _, err := io.Copy(originalFile, tmpFile); err != nil {
			return err
		}
	}

	return nil
}