use crate::prelude::*;

use atom_syndication::Link;
use std::fs::OpenOptions;
use std::io::prelude::*;

pub fn add(link: &Link, file_name: &str) -> Result<()> {
    let mut file = OpenOptions::new()
        .write(true)
        .append(true)
        .create(true)
        .open(file_name)
        .unwrap();

    writeln!(file, "{}", link.href)?;
    Ok(())
}

#[cfg(test)]
mod tests {

    use crate::{
        history::Link,
        test_utils::{create_text_file, read_text_file},
    };

    use super::*;

    #[test]
    fn creates_file_if_missing() -> Result<()> {
        //given
        let (dir, file_name) =
            create_text_file("download.txt", include_bytes!("../../test/data/empty.txt"))?;
        std::fs::remove_file(&file_name)?;

        let link = Link {
            href: "foo".to_string(),
            rel: "bar".to_string(),
            hreflang: None,
            mime_type: None,
            title: None,
            length: None,
        };
        //when
        add(&link, &file_name)?;

        //then
        let content: Vec<String> = read_text_file(&file_name)?;
        drop(dir);

        let expected = vec!["foo".to_string()];
        assert_eq!(content, expected);

        Ok(())
    }

    #[test]
    fn appends_to_exising_file() -> Result<()> {
        // given
        let (dir, file_name) = create_text_file(
            "download.txt",
            include_bytes!("../../test/data/downloads.txt"),
        )?;

        let link = Link {
            href: "foo".to_string(),
            rel: "bar".to_string(),
            hreflang: None,
            mime_type: None,
            title: None,
            length: None,
        };
        //when
        add(&link, &file_name)?;

        //then
        let content: Vec<String> = read_text_file(&file_name)?;
        drop(dir);

        let expected = vec![
            "line-1".to_string(),
            "line-2".to_string(),
            "foo".to_string(),
        ];
        assert_eq!(content, expected);

        Ok(())
    }
}