serde_shon 0.1.0

use serde::{ser, ser::SerializeSeq, Serialize};

#[derive(Default)]
pub struct Serializer {
    output: Vec<String>,
    empty_struct: bool,
}

pub fn to_string<T>(value: &T) -> crate::Result<String>
where
    T: Serialize,
{
    let mut serializer = Serializer {
        output: Vec::new(),
        ..Default::default()
    };
    value.serialize(&mut serializer)?;
    Ok(serializer.output.join(" "))
}

pub fn to_params<T>(value: &T) -> crate::Result<Vec<String>>
where
    T: Serialize,
{
    let mut serializer = Serializer {
        output: Vec::new(),
        ..Default::default()
    };
    value.serialize(&mut serializer)?;
    Ok(serializer.output)
}

impl<'a> ser::Serializer for &'a mut Serializer {
    type Ok = ();

    type Error = crate::Error;

    type SerializeSeq = Self;
    type SerializeTuple = Self;
    type SerializeTupleStruct = Self;
    type SerializeTupleVariant = Self;
    type SerializeMap = Self;
    type SerializeStruct = Self;
    type SerializeStructVariant = Self;

    fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error> {
        self.output.push(match v {
            true => "-t".to_string(),
            false => "-f".to_string(),
        });
        Ok(())
    }

    fn serialize_i8(self, v: i8) -> Result<Self::Ok, Self::Error> {
        self.serialize_i64(i64::from(v))
    }

    fn serialize_i16(self, v: i16) -> Result<Self::Ok, Self::Error> {
        self.serialize_i64(i64::from(v))
    }

    fn serialize_i32(self, v: i32) -> Result<Self::Ok, Self::Error> {
        self.serialize_i64(i64::from(v))
    }

    fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> {
        self.output.push(v.to_string());
        Ok(())
    }

    fn serialize_u8(self, v: u8) -> Result<Self::Ok, Self::Error> {
        self.serialize_u64(u64::from(v))
    }

    fn serialize_u16(self, v: u16) -> Result<Self::Ok, Self::Error> {
        self.serialize_u64(u64::from(v))
    }

    fn serialize_u32(self, v: u32) -> Result<Self::Ok, Self::Error> {
        self.serialize_u64(u64::from(v))
    }

    fn serialize_u64(self, v: u64) -> Result<Self::Ok, Self::Error> {
        self.output.push(v.to_string());
        Ok(())
    }

    fn serialize_f32(self, v: f32) -> Result<Self::Ok, Self::Error> {
        self.serialize_f64(f64::from(v))
    }

    fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error> {
        self.output.push(v.to_string());
        Ok(())
    }

    fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error> {
        self.serialize_str(&v.to_string())
    }

    fn serialize_str(self, v: &str) -> Result<Self::Ok, Self::Error> {
        let result = shell_escape::unix::escape(v.into());
        if result == "-"
            || result == "--"
            || result.parse::<i64>().is_ok()
            || result.parse::<f64>().is_ok()
        {
            self.output.push("--".to_string());
        }
        self.output.push(result.to_string());
        Ok(())
    }

    fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok, Self::Error> {
        let mut seq = self.serialize_seq(Some(v.len()))?;
        for byte in v {
            seq.serialize_element(byte)?;
        }
        seq.end()
    }

    fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
        self.serialize_unit()
    }

    fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
    where
        T: Serialize,
    {
        value.serialize(self)
    }

    fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
        self.output.push("-n".to_string());
        Ok(())
    }

    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
        self.serialize_unit()
    }

    fn serialize_unit_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
    ) -> Result<Self::Ok, Self::Error> {
        self.serialize_str(variant)
    }

    fn serialize_newtype_struct<T: ?Sized>(
        self,
        _name: &'static str,
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
        T: Serialize,
    {
        value.serialize(self)
    }

    fn serialize_newtype_variant<T: ?Sized>(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        value: &T,
    ) -> Result<Self::Ok, Self::Error>
    where
        T: Serialize,
    {
        use serde::ser::SerializeMap;
        let mut map = self.serialize_map(Some(1))?;
        map.serialize_key(variant)?;
        map.serialize_value(value)?;
        SerializeMap::end(map)
    }

    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
        self.output.push("[".to_string());
        Ok(self)
    }

    fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple, Self::Error> {
        self.serialize_seq(Some(len))
    }

    fn serialize_tuple_struct(
        self,
        _name: &'static str,
        len: usize,
    ) -> Result<Self::SerializeTupleStruct, Self::Error> {
        self.serialize_seq(Some(len))
    }

    fn serialize_tuple_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        _len: usize,
    ) -> Result<Self::SerializeTupleVariant, Self::Error> {
        self.output.push("[".to_string());
        self.output.push(format!("--{}", variant)); // TODO key formatter
        self.output.push("[".to_string());
        Ok(self)
    }

    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
        self.output.push("[".to_string());
        Ok(self)
    }

    fn serialize_struct(
        self,
        _name: &'static str,
        len: usize,
    ) -> Result<Self::SerializeStruct, Self::Error> {
        match len {
            0 => {
                self.output.push("[--]".to_string());
                self.empty_struct = true;
                Ok(self)
            }
            _ => self.serialize_map(Some(len)),
        }
    }

    fn serialize_struct_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        _len: usize,
    ) -> Result<Self::SerializeStructVariant, Self::Error> {
        self.output.push("[".to_string());
        self.output.push(format!("--{}", variant)); // TODO key formatter
        self.output.push("[".to_string());
        Ok(self)
    }
}

impl<'a> ser::SerializeSeq for &'a mut Serializer {
    type Ok = ();

    type Error = crate::Error;

    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> std::result::Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> std::result::Result<Self::Ok, Self::Error> {
        self.output.push("]".to_string());
        Ok(())
    }
}

impl<'a> ser::SerializeTuple for &'a mut Serializer {
    type Ok = ();

    type Error = crate::Error;

    fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        self.output.push("]".to_string());
        Ok(())
    }
}

impl<'a> ser::SerializeTupleStruct for &'a mut Serializer {
    type Ok = ();

    type Error = crate::Error;

    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        self.output.push("]".to_string());
        Ok(())
    }
}

impl<'a> ser::SerializeTupleVariant for &'a mut Serializer {
    type Ok = ();
    type Error = crate::Error;

    fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        self.output.push("]".to_string());
        self.output.push("]".to_string());
        Ok(())
    }
}

impl<'a> ser::SerializeMap for &'a mut Serializer {
    type Ok = ();
    type Error = crate::Error;

    fn serialize_key<T: ?Sized>(&mut self, key: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        // TODO: implement custom keyserialiezr that only serializes str instead of... this
        key.serialize(&mut **self)?;
        let mut key = self.output.pop().unwrap();
        if key.starts_with('\'') {
            key.remove(0);
            self.output.push(format!("'--{}", key));
        } else {
            self.output.push(format!("--{}", key));
        }
        Ok(())
    }

    fn serialize_value<T: ?Sized>(&mut self, value: &T) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        self.output.push("]".to_string());
        Ok(())
    }
}

impl<'a> ser::SerializeStruct for &'a mut Serializer {
    type Ok = ();
    type Error = crate::Error;

    fn serialize_field<T: ?Sized>(
        &mut self,
        key: &'static str,
        value: &T,
    ) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        self.output.push(format!("--{}", key)); // TODO key formatter
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        if self.empty_struct {
            self.empty_struct = false;
            return Ok(());
        }
        self.output.push("]".to_string());
        Ok(())
    }
}

impl<'a> ser::SerializeStructVariant for &'a mut Serializer {
    type Ok = ();
    type Error = crate::Error;

    fn serialize_field<T: ?Sized>(
        &mut self,
        key: &'static str,
        value: &T,
    ) -> Result<(), Self::Error>
    where
        T: Serialize,
    {
        self.output.push(format!("--{}", key)); // TODO key formatter
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<Self::Ok, Self::Error> {
        self.output.push("]".to_string());
        self.output.push("]".to_string());
        Ok(())
    }
}

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

    #[test]
    fn test_struct() {
        #[derive(Serialize)]
        struct Test {
            int: u32,
            seq: Vec<&'static str>,
        }

        let test = Test {
            int: 1,
            seq: vec!["hello world", "b"],
        };
        let expected = r#"[ --int 1 --seq [ 'hello world' b ] ]"#;
        assert_eq!(to_string(&test).unwrap(), expected);
    }

    #[test]
    fn test_unit_struct() {
        #[derive(Serialize)]
        struct Test {}
        let test = Test {};
        let expected = r#"[--]"#;
        assert_eq!(to_string(&test).unwrap(), expected);
    }

    #[test]
    fn test_enum() {
        #[derive(Serialize)]
        enum E {
            Unit,
            Newtype(u32),
            Tuple(u32, u32),
            Struct { a: u32 },
        }

        let u = E::Unit;
        let expected = r#"Unit"#;
        assert_eq!(to_string(&u).unwrap(), expected);

        let n = E::Newtype(1);
        let expected = r#"[ --Newtype 1 ]"#;
        assert_eq!(to_string(&n).unwrap(), expected);

        let t = E::Tuple(1, 2);
        let expected = r#"[ --Tuple [ 1 2 ] ]"#;
        assert_eq!(to_string(&t).unwrap(), expected);

        let s = E::Struct { a: 1 };
        let expected = r#"[ --Struct [ --a 1 ] ]"#;
        assert_eq!(to_string(&s).unwrap(), expected);
    }
}