package main

import (
	"os"
	"os/exec"
)

// InputFromEditor retrieves user input by opening an editor on a temporary
// file. Once the editor closes, the contents of the temporary file are
// returned. If the contents exactly match the placeholder (no edits to the
// file were made), then an empty string is returned.
// Example patten: message.*.md
func InputFromEditor(placeholder string, pattern string) (string, error) {
	msgFile, _ := os.CreateTemp("/tmp", pattern)
	defer os.Remove(msgFile.Name())

	os.WriteFile(msgFile.Name(), []byte(placeholder), os.ModeAppend)

	editor := os.Getenv("EDITOR")
	if editor == "" {
		editor = "vim" // default to vim if no EDITOR env variable
	}

	execCmd := exec.Command(editor, msgFile.Name())
	execCmd.Stdin = os.Stdin
	execCmd.Stdout = os.Stdout
	execCmd.Stderr = os.Stderr

	if err := execCmd.Run(); err != nil {
		return "", err
	}

	bytes, _ := os.ReadFile(msgFile.Name())
	content := string(bytes)

	if content == placeholder {
		return "", nil
	}

	return content, nil
}