use crate::optional_data_line;

use std::fmt;

#[derive(Clone, Debug, Eq, PartialEq)]
pub struct Dialogue {
    pub id: String,
    pub contents: String,
    pub name: Option<String>,
}

impl Dialogue {
    pub fn from_str(str: &str) -> Result<Dialogue, crate::Error> {
        let mut lines: Vec<&str> = str.lines().collect();
        let id = lines[0].replace("DLG ", "");

        let name = if lines.last().unwrap().starts_with("NAME ") {
            Some(lines.pop().unwrap().replace("NAME ", ""))
        } else {
            None
        };

        let contents = lines[1..].join("\n");

        Ok(Dialogue { id, contents, name })
    }
}

impl fmt::Display for Dialogue {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "DLG {}\n{}{}",
            self.id,
            self.contents,
            optional_data_line("NAME", self.name.as_ref())
        )
    }
}

#[cfg(test)]
mod test {
    use crate::Dialogue;

    #[test]
    fn dialogue_from_str() {
        let output = Dialogue::from_str(
            "DLG h\nhello\nNAME not a dialogue name\nNAME a dialogue name"
        ).unwrap();

        let expected = Dialogue {
            id: "h".to_string(),
            contents: "hello\nNAME not a dialogue name".to_string(),
            name: Some("a dialogue name".to_string())
        };

        assert_eq!(output, expected);
    }

    #[test]
    fn dialogue_to_string() {
        let output = Dialogue {
            id: "y".to_string(),
            contents: "This is a bit of dialogue,\nblah blah\nblah blah".to_string(),
            name: Some("a dialogue name".to_string())
        }.to_string();

        let expected = "DLG y\nThis is a bit of dialogue,\nblah blah\nblah blah\nNAME a dialogue name";

        assert_eq!(output, expected);
    }
}