serde-pbx 0.1.0

use serde::{ser, Serialize};
use std::fmt;

// largely based on serde_json's serialiser

pub fn to_string<T>(value: &T) -> Result<String>
where
	T: Serialize,
{
	let mut serializer = Serializer {
		output: String::new(),
		indent_level: 0,
	};
	value.serialize(&mut serializer)?;
	Ok(serializer.output)
}

pub struct Serializer {
	indent_level: i32,
	output: String,
}

impl Serializer {
	pub fn begin_line(&mut self) {
		self.output += "\n";
		for _ in 0..self.indent_level {
			self.output += "\t";
		}
	}

	pub fn indent(&mut self) {
		self.indent_level += 1;
	}

	pub fn dedent(&mut self) {
		self.indent_level -= 1;
	}
}

#[derive(Debug)]
pub struct Error;

impl fmt::Display for Error {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		f.write_str("Error")
	}
}

impl std::error::Error for Error {}

impl serde::ser::Error for Error {
	fn custom<T>(_msg: T) -> Self
	where
		T: fmt::Display,
	{
		Self
	}
}

type Result<T> = std::result::Result<T, Error>;

impl<'a> ser::Serializer for &'a mut Serializer {
	type Ok = ();
	type Error = 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.output += if v { "true" } else { "false" };
		Ok(())
	}

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

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

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

	fn serialize_i64(self, v: i64) -> Result<()> {
		self.output += &v.to_string();
		Ok(())
	}

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

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

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

	fn serialize_u64(self, v: u64) -> Result<()> {
		self.output += &v.to_string();
		Ok(())
	}

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

	fn serialize_f64(self, v: f64) -> Result<()> {
		self.output += &v.to_string();
		Ok(())
	}

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

	fn serialize_str(self, v: &str) -> Result<()> {
		self.output += "\"";
		self.output += v;
		self.output += "\"";
		Ok(())
	}

	fn serialize_bytes(self, v: &[u8]) -> Result<()> {
		use serde::ser::SerializeSeq;
		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.serialize_unit()
	}

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

	fn serialize_unit(self) -> Result<()> {
		self.output += "null";
		Ok(())
	}

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

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

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

	fn serialize_newtype_variant<T>(
		self,
		_name: &'static str,
		_variant_index: u32,
		variant: &'static str,
		value: &T,
	) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		self.output += "{";
		variant.serialize(&mut *self)?;
		self.output += ":";
		value.serialize(&mut *self)?;
		self.output += "}";
		Ok(())
	}

	fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
		self.output += "(";
		self.indent();
		Ok(self)
	}

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

	fn serialize_tuple_struct(self, _name: &'static str, len: usize) -> Result<Self::SerializeTupleStruct> {
		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.output += "{";
		variant.serialize(&mut *self)?;
		self.output += ":[";
		Ok(self)
	}

	fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
		self.output += "{";
		self.indent();
		Ok(self)
	}

	fn serialize_struct(self, _name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
		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.output += "{";
		variant.serialize(&mut *self)?;
		self.output += ":{";
		Ok(self)
	}
}

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

	fn serialize_element<T>(&mut self, value: &T) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		self.begin_line();
		value.serialize(&mut **self)?;
		self.output += ",";
		Ok(())
	}

	fn end(self) -> Result<()> {
		self.dedent();
		self.begin_line();
		self.output += ")";
		Ok(())
	}
}

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

	fn serialize_element<T>(&mut self, value: &T) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		if !self.output.ends_with('[') {
			self.output += ",";
		}
		value.serialize(&mut **self)
	}

	fn end(self) -> Result<()> {
		self.output += "]";
		Ok(())
	}
}

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

	fn serialize_field<T>(&mut self, value: &T) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		if !self.output.ends_with('[') {
			self.output += ",";
		}
		value.serialize(&mut **self)
	}

	fn end(self) -> Result<()> {
		self.output += "]";
		Ok(())
	}
}

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

	fn serialize_field<T>(&mut self, value: &T) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		if !self.output.ends_with('[') {
			self.output += ",";
		}
		value.serialize(&mut **self)
	}

	fn end(self) -> Result<()> {
		self.output += "]}";
		Ok(())
	}
}

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

	fn serialize_key<T>(&mut self, key: &T) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		self.begin_line();
		key.serialize(&mut **self)
	}

	fn serialize_value<T>(&mut self, value: &T) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		self.output += " = ";
		value.serialize(&mut **self)?;
		self.output += ";";
		Ok(())
	}

	fn end(self) -> Result<()> {
		self.dedent();
		self.begin_line();
		self.output += "}";
		Ok(())
	}
}

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

	fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		self.begin_line();
		self.output += key;
		self.output += " = ";
		value.serialize(&mut **self)?;
		self.output += ";";
		Ok(())
	}

	fn end(self) -> Result<()> {
		self.dedent();
		self.begin_line();
		self.output += "}";
		Ok(())
	}
}

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

	fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
	where
		T: ?Sized + Serialize,
	{
		if !self.output.ends_with('{') {
			self.output += ",";
		}
		key.serialize(&mut **self)?;
		self.output += ":";
		value.serialize(&mut **self)
	}

	fn end(self) -> Result<()> {
		self.output += "}}";
		Ok(())
	}
}