use rbx_dom_weak::WeakDom;

use super::vector3::Vector3;

pub struct Instance{
	referent:rbx_types::Ref,
}

impl From<crate::script::Script> for Instance{
	fn from(value:crate::script::Script)->Self{
		Self{referent:value.script}
	}
}

impl Instance{
	pub const fn new(referent:rbx_types::Ref)->Self{
		Self{referent}
	}
	pub fn get<'a>(&'a self,dom:&'a WeakDom)->mlua::Result<&'a rbx_dom_weak::Instance>{
		dom.get_by_ref(self.referent).ok_or(mlua::Error::runtime("Instance missing"))
	}
	pub fn get_mut<'a>(&'a self,dom:&'a mut WeakDom)->mlua::Result<&'a mut rbx_dom_weak::Instance>{
		dom.get_by_ref_mut(self.referent).ok_or(mlua::Error::runtime("Instance missing"))
	}
}

// LMAO look at this function!
fn dom<T>(lua:&mlua::Lua,mut f:impl FnMut(&mut WeakDom)->mlua::Result<T>)->mlua::Result<T>{
	f(&mut *lua.app_data_mut::<WeakDom>().ok_or(mlua::Error::runtime("DataModel missing"))?)
}

impl mlua::UserData for Instance{
	fn add_fields<'lua,F:mlua::UserDataFields<'lua,Self>>(fields:&mut F){
		fields.add_field_method_get("Parent",|lua,this|{
			dom(lua,|dom|{
				let instance=this.get(dom)?;
				Ok(Instance::new(instance.parent()))
			})
		});
		fields.add_field_method_set("Parent",|lua,this,val:Self|{
			dom(lua,|dom|{
				dom.transfer_within(this.referent,val.referent);
				Ok(())
			})
		});
	}

	fn add_methods<'lua,M:mlua::UserDataMethods<'lua,Self>>(methods:&mut M){
		methods.add_meta_function(mlua::MetaMethod::NewIndex,|lua,(this,index,value):(Self,mlua::String,mlua::Value)|
			dom(lua,|dom|{
				let instance=this.get_mut(dom)?;
				let index_str=index.to_str()?;
				let class=rbx_reflection_database::get().classes.get(instance.class.as_str()).ok_or(mlua::Error::runtime("Class missing"))?;
				let property=class.default_properties.get(index_str).ok_or(mlua::Error::runtime(format!("Property '{index_str}' missing on class '{}'",class.name)))?;
				match property{
					rbx_types::Variant::Vector3(_)=>{
						let typed_value:Vector3=value.as_userdata().ok_or(mlua::Error::runtime("Expected Userdata"))?.take()?;
						instance.properties.insert(index_str.to_owned(),rbx_types::Variant::Vector3(typed_value.into()));
					},
					rbx_types::Variant::Float64(_)=>{
						let typed_value:f64=value.as_f64().ok_or(mlua::Error::runtime("Expected f64"))?;
						instance.properties.insert(index_str.to_owned(),rbx_types::Variant::Float64(typed_value));
					},
					_=>unimplemented!(),
				}
				Ok(())
			})
		);
	}
}

impl<'lua> mlua::FromLua<'lua> for Instance{
	fn from_lua(value:mlua::prelude::LuaValue<'lua>,_lua:&'lua mlua::prelude::Lua)->mlua::prelude::LuaResult<Self>{
		match value{
			mlua::Value::UserData(ud)=>ud.take(),
			other=>Err(mlua::Error::runtime(format!("Expected Instance got {:?}",other))),
		}
	}
}