open Typecore
open TType
open TUnification
open TFunctions

let unify_cf map_type c cf el =
	let monos = List.map (fun _ -> mk_mono()) cf.cf_params in
	match follow (apply_params cf.cf_params monos (map_type cf.cf_type)) with
		| TFun(tl'',ret) as tf ->
			let rec loop2 acc el tl = match el,tl with
				| e :: el,(_,o,t) :: tl ->
					begin try
						Type.unify e.etype t;
						loop2 (e :: acc) el tl
					with _ ->
						if Type.ExtType.is_rest (follow t) then
							match follow t,tl with
							| TAbstract({a_path=["haxe"],"Rest"},[t]),[] ->
								begin try
									let el = List.map (fun e -> unify t e.etype; e) el in
									let fcc = make_field_call_candidate ((List.rev acc) @ el) ret monos tf cf (c,cf,monos) in
									Some fcc
								with _ ->
									None
								end
							| _ ->
								Globals.die "" __LOC__
						else
							None
					end
				| [],[] ->
					let fcc = make_field_call_candidate (List.rev acc) ret monos tf cf (c,cf,monos) in
					Some fcc
				| _ ->
					None
			in
			loop2 [] el tl''
		| t ->
			None

let find_overload map_type c cf el =
	ExtList.List.filter_map (fun cf -> unify_cf map_type c cf el) (cf :: cf.cf_overloads)

let filter_overloads candidates =
	match Overloads.Resolution.reduce_compatible candidates with
	| [fcc] -> Some(fcc.fc_data)
	| [] -> None
	| ((fcc) :: _) (* as resolved *) ->
		(* let st = s_type (print_context()) in
		print_endline (Printf.sprintf "Ambiguous overload for %s(%s)" name (String.concat ", " (List.map (fun e -> st e.etype) el)));
		List.iter (fun (_,t,(c,cf)) ->
			print_endline (Printf.sprintf "\tCandidate: %s.%s(%s)" (s_type_path c.cl_path) cf.cf_name (st t));
		) resolved; *)
		Some(fcc.fc_data)

let resolve_instance_overload is_ctor map_type c name el =
	let candidates = ref [] in
	let has_function t1 fcc2 =
		begin match follow t1,fcc2.fc_type with
		| TFun(tl1,_),TFun(tl2,_) -> type_iseq (TFun(tl1,t_dynamic)) (TFun(tl2,t_dynamic))
		| _ -> false
		end
	in
	let rec loop map_type c =
		begin try
			let cf = if is_ctor then
				(match c.cl_constructor with Some cf -> cf | None -> raise Not_found)
			else
				PMap.find name c.cl_fields
			in
			begin match find_overload map_type c cf el with
			| [] -> raise Not_found
			| l ->
				List.iter (fun fcc ->
					if not (List.exists (has_function fcc.fc_type) !candidates) then candidates := fcc :: !candidates
				) l
			end;
			if has_class_field_flag cf CfOverload || cf.cf_overloads <> [] then raise Not_found
		with Not_found ->
			if (has_class_flag c CInterface) then
				List.iter (fun (c,tl) -> loop (apply_params c.cl_params (List.map map_type tl)) c) c.cl_implements
			else match c.cl_super with
			| None -> ()
			| Some(c,tl) -> loop (apply_params c.cl_params (List.map map_type tl)) c
		end;
	in
	loop map_type c;
	filter_overloads (List.rev !candidates)

let maybe_resolve_instance_overload is_ctor map_type c cf el =
	if has_class_field_flag cf CfOverload || cf.cf_overloads <> [] then
		resolve_instance_overload is_ctor map_type c cf.cf_name el
	else match unify_cf map_type c cf el with
		| Some fcc -> Some (fcc.fc_data)
		| None -> Some(c,cf,extract_param_types cf.cf_params)

let maybe_resolve_constructor_overload c tl el =
	let cf,c,tl = get_constructor_class c tl in
	maybe_resolve_instance_overload true (apply_params c.cl_params tl) c cf el
