protify 0.1.4

use crate::*;
use proto_types::field_descriptor_proto::Type as DescriptorType;

/// A trait that specifies the protobuf type to which a rust type should be mapped.
///
/// Automatically implemented for all primitive types, as well as the targets of the [`proto_message`], [`proto_oneof`] and [`proto_enum`] macros, and all the types exported from the [`proto-types`](crate::proto_types) crate.
pub trait AsProtoType {
	/// The protobuf type to which this rust type should be mapped.
	fn proto_type() -> ProtoType;
}

/// A trait that specifies the protobuf field type to which a rust type should be mapped (i.e. single, optional, repeated, map).
///
/// Automatically implemented for the types that implement [`AsProtoType`].
pub trait AsProtoField {
	fn as_proto_field() -> FieldType;
}

impl<T> AsProtoField for Option<T>
where
	T: AsProtoType,
{
	#[inline]
	fn as_proto_field() -> FieldType {
		let type_ = T::proto_type();

		if type_.is_message() {
			FieldType::Normal(type_)
		} else {
			FieldType::Optional(type_)
		}
	}
}

impl<T: AsProtoType> AsProtoField for T {
	#[inline]
	fn as_proto_field() -> FieldType {
		FieldType::Normal(T::proto_type())
	}
}

/// The types in which a protobuf field can be represented.
#[derive(Debug, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub enum FieldType {
	Normal(ProtoType),
	Map {
		keys: ProtoMapKey,
		values: ProtoType,
	},
	Repeated(ProtoType),
	Optional(ProtoType),
}

pub(crate) struct Sealed;

/// A sealed trait that defines the kind of protobuf map key that a rust type maps to.
pub trait AsProtoMapKey {
	fn as_proto_map_key() -> ProtoMapKey;

	#[doc(hidden)]
	#[allow(private_interfaces)]
	const SEALED: Sealed;
}

/// An enum representing the types that are supported as map keys in protobuf.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub enum ProtoMapKey {
	String,
	Bool,
	Int32,
	Int64,
	Sint32,
	Sint64,
	Sfixed32,
	Sfixed64,
	Fixed32,
	Fixed64,
	Uint32,
	Uint64,
}

impl ProtoMapKey {
	/// Converts to [`ProtoType`].
	#[must_use]
	pub fn into_type(self) -> ProtoType {
		self.into()
	}
}

impl From<ProtoMapKey> for ProtoType {
	fn from(value: ProtoMapKey) -> Self {
		Self::Scalar(value.into())
	}
}

impl From<ProtoMapKey> for ProtoScalar {
	fn from(value: ProtoMapKey) -> Self {
		match value {
			ProtoMapKey::String => Self::String,
			ProtoMapKey::Bool => Self::Bool,
			ProtoMapKey::Int32 => Self::Int32,
			ProtoMapKey::Int64 => Self::Int64,
			ProtoMapKey::Sint32 => Self::Sint32,
			ProtoMapKey::Sint64 => Self::Sint64,
			ProtoMapKey::Sfixed32 => Self::Sfixed32,
			ProtoMapKey::Sfixed64 => Self::Sfixed64,
			ProtoMapKey::Fixed32 => Self::Fixed32,
			ProtoMapKey::Fixed64 => Self::Fixed64,
			ProtoMapKey::Uint32 => Self::Uint32,
			ProtoMapKey::Uint64 => Self::Uint64,
		}
	}
}

impl Display for ProtoMapKey {
	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
		match self {
			Self::Int32 => write!(f, "int32"),
			Self::Int64 => write!(f, "int64"),
			Self::Uint32 => write!(f, "uint32"),
			Self::Uint64 => write!(f, "uint64"),
			Self::Sint32 => write!(f, "sint32"),
			Self::Sint64 => write!(f, "sint64"),
			Self::Fixed32 => write!(f, "fixed32"),
			Self::Fixed64 => write!(f, "fixed64"),
			Self::Sfixed32 => write!(f, "sfixed32"),
			Self::Sfixed64 => write!(f, "sfixed64"),
			Self::Bool => write!(f, "bool"),
			Self::String => write!(f, "string"),
		}
	}
}

/// An enum representing the scalar types in protobuf.
#[derive(Debug, Clone, PartialEq, Eq, Copy)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub enum ProtoScalar {
	Double,
	Float,
	Int32,
	Int64,
	Uint32,
	Uint64,
	Sint32,
	Sint64,
	Fixed32,
	Fixed64,
	Sfixed32,
	Sfixed64,
	Bool,
	String,
	Bytes,
}

impl From<ProtoScalar> for DescriptorType {
	#[inline]
	fn from(value: ProtoScalar) -> Self {
		match value {
			ProtoScalar::Double => Self::Double,
			ProtoScalar::Float => Self::Float,
			ProtoScalar::Int32 => Self::Int32,
			ProtoScalar::Int64 => Self::Int64,
			ProtoScalar::Uint32 => Self::Uint32,
			ProtoScalar::Uint64 => Self::Uint64,
			ProtoScalar::Sint32 => Self::Sint32,
			ProtoScalar::Sint64 => Self::Sint64,
			ProtoScalar::Fixed32 => Self::Fixed32,
			ProtoScalar::Fixed64 => Self::Fixed64,
			ProtoScalar::Sfixed32 => Self::Sfixed32,
			ProtoScalar::Sfixed64 => Self::Sfixed64,
			ProtoScalar::Bool => Self::Bool,
			ProtoScalar::String => Self::String,
			ProtoScalar::Bytes => Self::Bytes,
		}
	}
}

impl Display for ProtoScalar {
	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
		match self {
			Self::Double => write!(f, "double"),
			Self::Float => write!(f, "float"),
			Self::Int32 => write!(f, "int32"),
			Self::Int64 => write!(f, "int64"),
			Self::Uint32 => write!(f, "uint32"),
			Self::Uint64 => write!(f, "uint64"),
			Self::Sint32 => write!(f, "sint32"),
			Self::Sint64 => write!(f, "sint64"),
			Self::Fixed32 => write!(f, "fixed32"),
			Self::Fixed64 => write!(f, "fixed64"),
			Self::Sfixed32 => write!(f, "sfixed32"),
			Self::Sfixed64 => write!(f, "sfixed64"),
			Self::Bool => write!(f, "bool"),
			Self::String => write!(f, "string"),
			Self::Bytes => write!(f, "bytes"),
		}
	}
}

/// An enum representing a protobuf type.
#[derive(Debug, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub enum ProtoType {
	Scalar(ProtoScalar),
	Message(ProtoPath),
	Enum(ProtoPath),
}

impl From<ProtoType> for DescriptorType {
	#[inline]
	fn from(value: ProtoType) -> Self {
		match value {
			ProtoType::Scalar(scalar) => scalar.into(),
			ProtoType::Message(_) => Self::Message,
			ProtoType::Enum(_) => Self::Enum,
		}
	}
}

impl Display for ProtoType {
	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
		match self {
			Self::Scalar(proto_scalar) => write!(f, "{proto_scalar}"),
			Self::Message(proto_path) | Self::Enum(proto_path) => write!(f, "{proto_path}"),
		}
	}
}

impl ProtoType {
	/// Returns `true` if the proto type is [`Message`].
	///
	/// [`Message`]: ProtoType::Message
	#[must_use]
	pub const fn is_message(&self) -> bool {
		matches!(self, Self::Message { .. })
	}

	/// Returns `true` if the proto type is [`Enum`].
	///
	/// [`Enum`]: ProtoType::Enum
	#[must_use]
	pub const fn is_enum(&self) -> bool {
		matches!(self, Self::Enum(..))
	}
}

impl FieldType {
	pub(crate) fn render(&self, current_package: &FixedStr) -> Cow<'_, str> {
		let name = self.render_name(current_package);

		match self {
			Self::Normal(_) | Self::Map { .. } => name,
			Self::Repeated(_) => format!("repeated {name}").into(),
			Self::Optional(inner) => {
				if inner.is_message() {
					name
				} else {
					format!("optional {name}").into()
				}
			}
		}
	}

	pub(crate) fn render_name(&self, current_package: &FixedStr) -> Cow<'_, str> {
		match self {
			Self::Normal(type_info) | Self::Repeated(type_info) | Self::Optional(type_info) => {
				type_info.render_name(current_package)
			}
			Self::Map { keys, values } => format!(
				"map<{}, {}>",
				keys.into_type().render_name(current_package),
				values.render_name(current_package)
			)
			.into(),
		}
	}
}

impl ProtoType {
	pub(crate) fn render_name(&self, current_package: &FixedStr) -> Cow<'_, str> {
		match self {
			Self::Scalar(scalar) => scalar.to_string().into(),
			Self::Message(path) | Self::Enum(path) => {
				if *path.package == **current_package {
					path.name.as_ref().into()
				} else {
					format!("{}.{}", path.package, path.name).into()
				}
			}
		}
	}

	pub(crate) fn register_import(&self, imports: &mut FileImports) {
		match self {
			Self::Scalar { .. } => {}
			Self::Message(path) | Self::Enum(path) => imports.insert_from_path(path),
		}
	}
}

impl ProtoPath {
	pub(crate) fn render_name(&self, current_package: &FixedStr) -> Cow<'_, str> {
		if self.package == *current_package {
			self.name.as_ref().into()
		} else {
			format!("{}.{}", self.package, self.name).into()
		}
	}
}

/// A struct that represents a path to an item (message or enum) in a protobuf package.
#[derive(Debug, Clone, PartialEq, Eq)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct ProtoPath {
	pub name: FixedStr,
	pub package: FixedStr,
	pub file: FixedStr,
}

impl Display for ProtoPath {
	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
		let Self { name, package, .. } = self;

		write!(f, "{package}.{name}")
	}
}