use crate::domain::author::Author;
use crate::domain::book::Book;
use std::path::PathBuf;

/// Parses a given file path into a vector containing a `Book` object.
///
/// # Arguments
///
/// * `path` - A reference to a `PathBuf` that represents the file path to be parsed.
///
/// # Returns
///
/// * `Result<Vec<Book>, String>` -
///   - On success, returns a `Vec<Book>` with a single `Book` object populated based on the input path.
///   - On failure, returns an error `String` describing the issue.
///
/// The function performs the following steps:
///
/// 1. Creates a new instance of `Book`.
/// 2. Sets the `title` of the `Book` to the string representation of the input path.
/// 3. Creates a new instance of `Author`.
/// 4. Sets the `first_name` of the `Author` to the string representation of the file extension of `path`.
/// 5. Pushes the `Author` into the `author` vector of the `Book`.
/// 6. Returns a `Vec<Book>` containing the newly created `Book`.
///
/// # Panics
///
/// The function will panic if the input path does not contain a file extension
/// (i.e., when `path.extension()` returns `None`).
///
/// # Example
///
/// ```ignore
/// use std::path::PathBuf;
///
/// let path = PathBuf::from("example.txt");
/// let books = parse(&path).unwrap();
///
/// assert_eq!(books.len(), 1);
/// assert_eq!(books[0].title, "example.txt");
/// assert_eq!(books[0].author[0].first_name, "txt");
/// ```
pub fn parse(path: &PathBuf) -> Result<Vec<Book>, String> {
    let mut book = Book::new();

    book.title = path.to_string_lossy().to_string();
    
    let mut author = Author::new();
    author.first_name = path.extension().unwrap().to_string_lossy().to_string();
    book.author.push(author);

    return Ok(vec![ book]);
}