#![feature(const_type_id)]

use std::any::{Any, TypeId};

use xreflect_core::{Builder, EnumBuildable, EnumReflect, Reflect, ReflectError, StructType};

enum Test {
	Unit,
	Tuple(i32),
	Struct { field: u8 },
}

impl Reflect for Test {
	fn amount_of_fields(&self) -> usize {
		match self {
			Test::Unit => 0,
			Test::Tuple(_) => 1,
			Test::Struct { .. } => 1,
		}
	}

	fn try_get_index_of_field(&self, member_name: &str) -> Result<usize, ReflectError> {
		match self {
			Test::Unit => Err(ReflectError::FieldNotFound),
			Test::Tuple(_) => {
				match member_name {
					"0" => Ok(0),
					_ => Err(ReflectError::FieldNotFound),
				}
			}
			Test::Struct { .. } => {
				match member_name {
					"field" => Ok(0),
					_ => Err(ReflectError::FieldNotFound),
				}
			}
		}
	}
	fn try_get_field_at<T: 'static>(&self, index: usize) -> Result<&T, ReflectError> {
		match self {
			Self::Unit => {
				return Err(ReflectError::FieldNotFound);
			}
			Self::Struct { field } => match index {
				0 => (field as &dyn Any)
					.downcast_ref::<T>()
					.ok_or(ReflectError::WrongType),
				_ => Err(ReflectError::FieldNotFound),
			},
			Self::Tuple(field) => match index {
				0 => (field as &dyn Any)
					.downcast_ref::<T>()
					.ok_or(ReflectError::WrongType),
				_ => Err(ReflectError::FieldNotFound),
			},
		}
	}

	fn try_get_field_mut_at<T: 'static>(&mut self, index: usize) -> Result<&mut T, ReflectError> {
		match self {
			Self::Unit => {
				return Err(ReflectError::FieldNotFound);
			}
			Self::Struct { field } => match index {
				0 => (field as &mut dyn Any)
					.downcast_mut::<T>()
					.ok_or(ReflectError::WrongType),
				_ => Err(ReflectError::FieldNotFound),
			},
			Self::Tuple(field) => match index {
				0 => (field as &mut dyn Any)
					.downcast_mut::<T>()
					.ok_or(ReflectError::WrongType),
				_ => Err(ReflectError::FieldNotFound),
			},
		}
	}

	fn try_get_type_of_field_at(&self, field_index: usize) -> Result<TypeId, ReflectError> {
		match self {
			Self::Unit => {
				return Err(ReflectError::FieldNotFound);
			}
			Self::Struct { .. } => match field_index {
				0 => Ok(TypeId::of::<u8>()),
				_ => Err(ReflectError::FieldNotFound),
			},
			Self::Tuple(_) => match field_index {
				0 => Ok(TypeId::of::<i32>()),
				_ => Err(ReflectError::FieldNotFound),
			},
		}
	}
}

impl EnumBuildable for Test {
	fn build(enum_member_name: &'static str) -> impl Builder<Self> {
		match enum_member_name {
			"Unit" => {
				return __xreflect_builders::TestBuilder::Unit;
			}
			"Tuple" => {
				return __xreflect_builders::TestBuilder::Tuple(None);
			}
			"Struct" => {
				return __xreflect_builders::TestBuilder::Struct {
					field: None,
				};
			}
			_ => panic!(),
		}
	}
}
impl EnumReflect for Test {
	const MEMBER_NAMES: &'static [&'static str] = &["Unit", "Tuple", "Struct"];
	const MEMBER_TYPES: &'static [StructType] = &[
		StructType::Unit,
		StructType::Tuple(&[TypeId::of::<i32>()]),
		StructType::Record(&[("field", TypeId::of::<u8>())]),
	];

	fn get_index_of_member(member_name: &str) -> Result<usize, ReflectError> {
		match member_name {
			"Unit" => Ok(0),
			"Tuple" => Ok(1),
			"Struct" => Ok(2),
			_ => Err(ReflectError::EnumMemberNotFound),
		}
	}
}
mod __xreflect_builders {
	// reflect actual visibility
	pub(crate) enum TestBuilder {
		Unit,
		Tuple(Option<i32>),
		Struct { field: Option<u8> },
	}

	use ::xreflect_core::Builder;

	use super::Test;

	impl Builder<Test> for TestBuilder {
		fn with_field<T: 'static>(mut self, field_name: &'static str, field_value: T) -> Self {
			match self {
				Self::Unit => {}
				Self::Tuple(ref mut field0) => match field_name {
					"0" => {
						if std::any::TypeId::of::<i32>() == std::any::TypeId::of::<T>() {
							*field0 =
								Some(unsafe { std::mem::transmute_copy::<T, i32>(&field_value) });
						} else {
							panic!()
						}
					}
					_ => panic!(),
				},
				Self::Struct { ref mut field } => match field_name {
					"field" => {
						if std::any::TypeId::of::<u8>() == std::any::TypeId::of::<T>() {
							*field =
								Some(unsafe { std::mem::transmute_copy::<T, u8>(&field_value) });
						} else {
							panic!()
						}
					}
					_ => panic!(),
				},
			}
			self
		}

		fn with_field_at<T: 'static>(mut self, field_index: usize, field_value: T) -> Self {
			match self {
				Self::Unit => {}
				Self::Tuple(ref mut field0) => match field_index {
					0 => {
						if std::any::TypeId::of::<i32>() == std::any::TypeId::of::<T>() {
							*field0 =
								Some(unsafe { std::mem::transmute_copy::<T, i32>(&field_value) });
						} else {
							panic!()
						}
					}
					_ => panic!(),
				},
				Self::Struct { ref mut field } => match field_index {
					0 => {
						if std::any::TypeId::of::<u8>() == std::any::TypeId::of::<T>() {
							*field =
								Some(unsafe { std::mem::transmute_copy::<T, u8>(&field_value) });
						} else {
							panic!()
						}
					}
					_ => panic!(),
				},
			}
			self
		}

		fn try_build(self) -> Result<Test, ()> {
			match self {
				TestBuilder::Unit => Ok(Test::Unit),
				TestBuilder::Tuple(field0) => {
					let Some(field0) = field0 else { panic!() };
					Ok(Test::Tuple(field0))
				}
				TestBuilder::Struct { field } => {
					let Some(field) = field else { panic!() };
					Ok(Test::Struct { field })
				}
			}
		}
	}
}

#[test]
fn main() {
	let a = Test::Tuple(36);
	let b = a.get_field::<i32>("0");
	dbg!(b);
	Test::build("Tuple").with_field_at(0, 100i32).build();
}