fluvio-protocol-api 0.4.1

use std::default::Default;
use std::io::Error as IoError;
use std::io::ErrorKind;
use std::fs::File;
use std::io::Cursor;
use std::path::Path;
use std::io::Read;
use std::fmt::Debug;
use std::fmt;
use std::convert::TryFrom;

use tracing::debug;
use tracing::trace;

use crate::core::Decoder;
use crate::core::Encoder;
use crate::derive::Decoder;
use crate::derive::Encoder;
use crate::core::bytes::Buf;

pub trait Request: Encoder + Decoder + Debug {
    const API_KEY: u16;

    const DEFAULT_API_VERSION: i16 = 0;
    const MIN_API_VERSION: i16 = 0;
    const MAX_API_VERSION: i16 = -1;

    type Response: Encoder + Decoder + Debug;
}

pub trait ApiMessage: Sized + Default {
    type ApiKey: Decoder + Debug;

    fn decode_with_header<T>(src: &mut T, header: RequestHeader) -> Result<Self, IoError>
    where
        Self: Default + Sized,
        Self::ApiKey: Sized,
        T: Buf;

    fn decode_from<T>(src: &mut T) -> Result<Self, IoError>
    where
        T: Buf,
    {
        let header = RequestHeader::decode_from(src, 0)?;
        Self::decode_with_header(src, header)
    }

    fn decode_from_file<P: AsRef<Path>>(file_name: P) -> Result<Self, IoError> {
        debug!("decoding from file: {:#?}", file_name.as_ref());
        let mut f = File::open(file_name)?;
        let mut buffer: [u8; 1000] = [0; 1000];

        f.read_exact(&mut buffer)?;

        let data = buffer.to_vec();
        let mut src = Cursor::new(&data);

        let mut size: i32 = 0;
        size.decode(&mut src, 0)?;
        trace!("decoded request size: {} bytes", size);

        if src.remaining() < size as usize {
            return Err(IoError::new(
                ErrorKind::UnexpectedEof,
                "not enought bytes for request message",
            ));
        }

        Self::decode_from(&mut src)
    }
}

pub trait ApiKey: Sized + Encoder + Decoder + TryFrom<u16> {}

#[derive(Debug, Encoder, Decoder, Default)]
pub struct RequestHeader {
    api_key: u16,
    api_version: i16,
    correlation_id: i32,
    client_id: String,
}

impl fmt::Display for RequestHeader {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "api: {} client: {}", self.api_key, self.client_id)
    }
}

impl RequestHeader {
    pub fn new(api_key: u16) -> Self {
        // TODO: generate random client id
        Self::new_with_client(api_key, "dummy".to_owned())
    }

    pub fn new_with_client<T>(api_key: u16, client_id: T) -> Self
    where
        T: Into<String>,
    {
        RequestHeader {
            api_key,
            api_version: 1,
            correlation_id: 1,

            client_id: client_id.into(),
        }
    }

    pub fn api_key(&self) -> u16 {
        self.api_key
    }

    pub fn api_version(&self) -> i16 {
        self.api_version
    }

    pub fn set_api_version(&mut self, version: i16) -> &mut Self {
        self.api_version = version;
        self
    }

    pub fn correlation_id(&self) -> i32 {
        self.correlation_id
    }

    pub fn set_correlation_id(&mut self, id: i32) -> &mut Self {
        self.correlation_id = id;
        self
    }

    pub fn client_id(&self) -> &String {
        &self.client_id
    }

    pub fn set_client_id<T>(&mut self, client_id: T) -> &mut Self
    where
        T: Into<String>,
    {
        self.client_id = client_id.into();
        self
    }
}

impl From<&RequestHeader> for i32 {
    fn from(header: &RequestHeader) -> i32 {
        header.correlation_id()
    }
}