#[doc(hidden)]
pub use tokenizer::Tokenizer;

use super::{request, response};
use crate::{common::Version, Error, Headers, Request, Response};
use std::convert::{TryFrom, TryInto};

/// SipMessage reprsents a generic SIP message, which could either be a [Request](crate::Request)
/// or a [Response](crate::Response).
///
/// A SipMessage can be converted to a `String`, `&str`, or `Bytes`, all using the underlying `Debug`
/// trait.
///
/// A SipMessage can be taken using the `TryFrom` convertions from a `String`, an `&str` or
/// `Bytes`, all using the underlying Tokenizer. If a convertion fails, the tokenizer will give you
/// a relevant underlying nom error wrapped in [rsip::Error](crate::Error).
///
/// In order to access specific [headers](crate::headers::untyped), you should take a look on the
/// [HeadersExt](crate::message::HeadersExt) trait that is automatically implemented for any type
/// that has implemented the [HasHeaders](crate::message::HasHeaders) trait, which SipMessage
/// implements it.
#[derive(Debug, PartialEq, Eq, Clone)]
pub enum SipMessage {
    Request(Request),
    Response(Response),
}

impl SipMessage {
    pub fn is_request(&self) -> bool {
        matches!(self, Self::Request(_))
    }

    pub fn is_response(&self) -> bool {
        matches!(self, Self::Response(_))
    }

    pub fn version(&self) -> &Version {
        match self {
            Self::Request(request) => request.version(),
            Self::Response(response) => response.version(),
        }
    }

    pub fn body(&self) -> &Vec<u8> {
        match self {
            Self::Request(request) => request.body(),
            Self::Response(response) => response.body(),
        }
    }

    pub fn body_mut(&mut self) -> &mut Vec<u8> {
        match self {
            Self::Request(request) => request.body_mut(),
            Self::Response(response) => response.body_mut(),
        }
    }
}

impl From<Request> for SipMessage {
    fn from(request: Request) -> Self {
        Self::Request(request)
    }
}

impl From<Response> for SipMessage {
    fn from(response: Response) -> Self {
        Self::Response(response)
    }
}

impl super::HasHeaders for SipMessage {
    fn headers(&self) -> &Headers {
        match self {
            Self::Request(request) => request.headers(),
            Self::Response(response) => response.headers(),
        }
    }

    fn headers_mut(&mut self) -> &mut Headers {
        match self {
            Self::Request(request) => request.headers_mut(),
            Self::Response(response) => response.headers_mut(),
        }
    }
}

impl std::fmt::Display for SipMessage {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Request(request) => write!(f, "{}", request),
            Self::Response(response) => write!(f, "{}", response),
        }
    }
}

impl TryFrom<&[u8]> for SipMessage {
    type Error = Error;

    fn try_from(from: &[u8]) -> Result<Self, Self::Error> {
        Tokenizer::tokenize(from)?.1.try_into()
    }
}

impl TryFrom<Vec<u8>> for SipMessage {
    type Error = Error;

    fn try_from(from: Vec<u8>) -> Result<Self, Self::Error> {
        Tokenizer::tokenize(&from)?.1.try_into()
    }
}

impl TryFrom<&str> for SipMessage {
    type Error = Error;

    fn try_from(from: &str) -> Result<Self, Self::Error> {
        Tokenizer::tokenize(from.as_bytes())?.1.try_into()
    }
}

impl TryFrom<String> for SipMessage {
    type Error = Error;

    fn try_from(from: String) -> Result<Self, Self::Error> {
        Tokenizer::tokenize(&from.as_bytes())?.1.try_into()
    }
}

impl TryFrom<bytes::Bytes> for SipMessage {
    type Error = Error;

    fn try_from(from: bytes::Bytes) -> Result<Self, Self::Error> {
        Tokenizer::tokenize(&from)?.1.try_into()
    }
}

impl From<SipMessage> for String {
    fn from(msg: SipMessage) -> Self {
        msg.to_string()
    }
}

impl From<SipMessage> for Vec<u8> {
    fn from(msg: SipMessage) -> Self {
        msg.to_string().into_bytes()
    }
}

impl From<SipMessage> for bytes::Bytes {
    fn from(msg: SipMessage) -> Self {
        bytes::Bytes::from(msg.to_string())
    }
}

#[doc(hidden)]
pub mod tokenizer {
    use super::{request, response, SipMessage};
    use crate::{Error, NomError};
    use std::convert::TryInto;

    impl<'a> TryInto<SipMessage> for Tokenizer<'a> {
        type Error = Error;

        fn try_into(self) -> Result<SipMessage, Error> {
            match self {
                Tokenizer::Request(tokenizer) => Ok(SipMessage::Request(tokenizer.try_into()?)),
                Tokenizer::Response(tokenizer) => Ok(SipMessage::Response(tokenizer.try_into()?)),
            }
        }
    }

    #[derive(Debug, PartialEq, Eq)]
    pub enum Tokenizer<'a> {
        Request(request::Tokenizer<'a>),
        Response(response::Tokenizer<'a>),
    }

    impl<'a> From<request::Tokenizer<'a>> for Tokenizer<'a> {
        fn from(tokenizer: request::Tokenizer<'a>) -> Self {
            Self::Request(tokenizer)
        }
    }

    impl<'a> From<response::Tokenizer<'a>> for Tokenizer<'a> {
        fn from(tokenizer: response::Tokenizer<'a>) -> Self {
            Self::Response(tokenizer)
        }
    }

    impl<'a> Tokenizer<'a> {
        pub fn tokenize(part: &'a [u8]) -> Result<(&'a [u8], Self), NomError<'a>> {
            use nom::{branch::alt, combinator::map};

            let (_, message) = alt((
                map(response::Tokenizer::tokenize, |r| r.into()),
                map(request::Tokenizer::tokenize, |r| r.into()),
            ))(part)?;

            Ok((&[], message))
        }
    }
}