pub mod field;
pub mod composite;
pub mod discrete;

use nom::{
    branch::alt,
    bytes::complete::is_not,
    combinator::{map, not, recognize},
    multi::many0,
    sequence::pair,
    IResult,
};

use crate::header::CompFieldList;
use crate::mime;
use crate::mime::mime::AnyMIME;
use crate::text::ascii::CRLF;
use crate::text::boundary::boundary;
use crate::text::whitespace::obs_crlf;
use crate::part::{composite::{Multipart, Message, multipart, message}, discrete::{Text, Binary}};

#[derive(Debug, PartialEq)]
pub enum AnyPart<'a> {
    Mult(Multipart<'a>),
    Msg(Message<'a>),
    Txt(Text<'a>),
    Bin(Binary<'a>),
}

pub fn to_anypart<'a>(m: AnyMIME<'a>, rpart: &'a [u8]) -> AnyPart<'a> {
    match m {
        AnyMIME::Mult(a) => map(multipart(a), AnyPart::Mult)(rpart)
            .map(|v| v.1)
            .unwrap_or(AnyPart::Txt(Text { interpreted: mime::mime::Text::default(), body: rpart })),
        AnyMIME::Msg(a) => map(message(a), AnyPart::Msg)(rpart)
            .map(|v| v.1)
            .unwrap_or(AnyPart::Txt(Text { interpreted: mime::mime::Text::default(), body: rpart })),
        AnyMIME::Txt(a) => AnyPart::Txt(Text { interpreted: a, body: rpart}),
        AnyMIME::Bin(a) => AnyPart::Bin(Binary{ interpreted: a, body: rpart }),
    }
}

pub fn part_raw<'a>(bound: &[u8]) -> impl Fn(&'a [u8]) -> IResult<&'a [u8], &'a [u8]> + '_ {
    move |input| {
        recognize(many0(pair(
            not(boundary(bound)),
            alt((is_not(CRLF), obs_crlf)),
        )))(input)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_preamble() {
        assert_eq!(
            part_raw(b"hello")(
                b"blip
bloup

blip
bloup--
--bim
--bim--

--hello
Field: Body
"
            ),
            Ok((
                &b"\n--hello\nField: Body\n"[..],
                &b"blip\nbloup\n\nblip\nbloup--\n--bim\n--bim--\n"[..],
            ))
        );
    }

    #[test]
    fn test_part_raw() {
        assert_eq!(
            part_raw(b"simple boundary")(b"Content-type: text/plain; charset=us-ascii

This is explicitly typed plain US-ASCII text.
It DOES end with a linebreak.

--simple boundary--
"),
            Ok((
                &b"\n--simple boundary--\n"[..], 
                &b"Content-type: text/plain; charset=us-ascii\n\nThis is explicitly typed plain US-ASCII text.\nIt DOES end with a linebreak.\n"[..],
            ))
        );
    }
}