record-query 1.0.4

use std::io;

use ordered_float;
use rmpv;

use crate::error;
use crate::value;

#[derive(Debug)]
pub struct MessagePackSource<R>(R)
where
    R: io::Read;

#[derive(Debug)]
pub struct MessagePackSink<W>(W)
where
    W: io::Write;

#[inline]
pub fn source<R>(r: R) -> MessagePackSource<R>
where
    R: io::Read,
{
    MessagePackSource(r)
}

#[inline]
pub fn sink<W>(w: W) -> MessagePackSink<W>
where
    W: io::Write,
{
    MessagePackSink(w)
}

impl<R> value::Source for MessagePackSource<R>
where
    R: io::Read,
{
    #[inline]
    fn read(&mut self) -> error::Result<Option<value::Value>> {
        use rmpv::decode::Error;

        match rmpv::decode::value::read_value(&mut self.0) {
            Ok(v) => Ok(Some(value_from_message_pack(v)?)),
            Err(Error::InvalidMarkerRead(ref e)) if e.kind() == io::ErrorKind::UnexpectedEof => {
                Ok(None)
            }
            Err(e) => Err(error::Error::MessagePackDecode(e)),
        }
    }
}

impl<W> value::Sink for MessagePackSink<W>
where
    W: io::Write,
{
    #[inline]
    fn write(&mut self, v: value::Value) -> error::Result<()> {
        rmpv::encode::write_value(&mut self.0, &value_to_message_pack(v)).map_err(From::from)
    }
}

fn value_from_message_pack(value: rmpv::Value) -> error::Result<value::Value> {
    use rmpv::Value;
    match value {
        Value::Nil => Ok(value::Value::Unit),
        Value::Boolean(v) => Ok(value::Value::Bool(v)),
        Value::Integer(i) if i.is_u64() => Ok(value::Value::U64(i.as_u64().unwrap())),
        Value::Integer(i) if i.is_i64() => Ok(value::Value::I64(i.as_i64().unwrap())),
        Value::Integer(_) => unreachable!(),
        Value::F32(v) => Ok(value::Value::from_f32(v)),
        Value::F64(v) => Ok(value::Value::from_f64(v)),
        Value::String(v) => {
            if v.is_err() {
                Err(error::Error::Format {
                    msg: v.as_err().unwrap().to_string(),
                })
            } else {
                Ok(value::Value::String(v.into_str().unwrap()))
            }
        }
        Value::Ext(_, v) | Value::Binary(v) => Ok(value::Value::Bytes(v)),
        Value::Array(v) => Ok(value::Value::Sequence(
            v.into_iter()
                .map(value_from_message_pack)
                .collect::<error::Result<_>>()?,
        )),
        Value::Map(v) => Ok(value::Value::Map(
            v.into_iter()
                .map(|(k, v)| Ok((value_from_message_pack(k)?, value_from_message_pack(v)?)))
                .collect::<error::Result<_>>()?,
        )),
    }
}

fn value_to_message_pack(value: value::Value) -> rmpv::Value {
    use rmpv::Value;
    match value {
        value::Value::Unit => Value::Nil,
        value::Value::Bool(v) => Value::Boolean(v),

        value::Value::I8(v) => Value::Integer(v.into()),
        value::Value::I16(v) => Value::Integer(v.into()),
        value::Value::I32(v) => Value::Integer(v.into()),
        value::Value::I64(v) => Value::Integer(v.into()),

        value::Value::U8(v) => Value::Integer(v.into()),
        value::Value::U16(v) => Value::Integer(v.into()),
        value::Value::U32(v) => Value::Integer(v.into()),
        value::Value::U64(v) => Value::Integer(v.into()),

        value::Value::F32(ordered_float::OrderedFloat(v)) => Value::F32(v),
        value::Value::F64(ordered_float::OrderedFloat(v)) => Value::F64(v),

        value::Value::Char(v) => Value::String(format!("{}", v).into()),
        value::Value::String(v) => Value::String(v.into()),
        value::Value::Bytes(v) => Value::Binary(v),

        value::Value::Sequence(v) => {
            Value::Array(v.into_iter().map(value_to_message_pack).collect())
        }
        value::Value::Map(v) => Value::Map(
            v.into_iter()
                .map(|(k, v)| (value_to_message_pack(k), value_to_message_pack(v)))
                .collect(),
        ),
    }
}