/**************************************************************************/
/*  gdscript_language_protocol.h                                          */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* Permission is hereby granted, free of charge, to any person obtaining  */
/* a copy of this software and associated documentation files (the        */
/* "Software"), to deal in the Software without restriction, including    */
/* without limitation the rights to use, copy, modify, merge, publish,    */
/* distribute, sublicense, and/or sell copies of the Software, and to     */
/* permit persons to whom the Software is furnished to do so, subject to  */
/* the following conditions:                                              */
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/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
/*                                                                        */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
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#pragma once

#include "gdscript_text_document.h"
#include "gdscript_workspace.h"
#include "scene_cache.h"

#include "core/io/stream_peer_tcp.h"
#include "core/io/tcp_server.h"

#include "modules/jsonrpc/jsonrpc.h"

#define LSP_MAX_BUFFER_SIZE 4194304
#define LSP_MAX_CLIENTS 8

#define LSP_NO_CLIENT -1

class GDScriptLanguageProtocol : public JSONRPC {
	GDCLASS(GDScriptLanguageProtocol, JSONRPC)

	friend class TestGDScriptLanguageProtocolInitializer;

private:
	struct LSPeer : RefCounted {
		Ref<StreamPeerTCP> connection;

		uint8_t req_buf[LSP_MAX_BUFFER_SIZE];
		int req_pos = 0;
		bool has_header = false;
		bool has_content = false;
		int content_length = 0;
		Vector<CharString> res_queue;
		int res_sent = 0;

		Error handle_data();
		Error send_data();

		/**
		 * Tracks all files that the client claimed, however for files deemed not relevant
		 * to the server the `text` might not be persisted.
		 */
		HashMap<String, LSP::TextDocumentItem> managed_files;
		HashMap<String, ExtendGDScriptParser *> parse_results;

		void remove_cached_parser(const String &p_path);
		ExtendGDScriptParser *parse_script(const String &p_path);

		~LSPeer();

	private:
		void clear_stale_parsers();
		// Paths of parsers which we can't cache longterm.
		// Can be cleared up using `clear_stale_parsers()`.
		HashSet<String> stale_parsers;
	};

	enum LSPErrorCode {
		RequestCancelled = -32800,
		ContentModified = -32801,
	};

	static GDScriptLanguageProtocol *singleton;

	HashMap<int, Ref<LSPeer>> clients;
	SceneCache scene_cache;
	Ref<TCPServer> server;
	int latest_client_id = LSP_NO_CLIENT;
	int next_client_id = 0;

	int next_server_id = 0;

	Ref<GDScriptTextDocument> text_document;
	Ref<GDScriptWorkspace> workspace;

	Error on_client_connected();
	void on_client_disconnected(const int &p_client_id);

	String process_message(const String &p_text);
	String format_output(const String &p_text);

	bool _initialized = false;

protected:
	static void _bind_methods();

	Dictionary initialize(const Dictionary &p_params);
	void initialized(const Variant &p_params);

public:
	_FORCE_INLINE_ static GDScriptLanguageProtocol *get_singleton() { return singleton; }
	_FORCE_INLINE_ Ref<GDScriptWorkspace> get_workspace() { return workspace; }
	_FORCE_INLINE_ Ref<GDScriptTextDocument> get_text_document() { return text_document; }
	_FORCE_INLINE_ SceneCache *get_scene_cache() { return &scene_cache; }

	_FORCE_INLINE_ bool is_initialized() const { return _initialized; }

	void poll(int p_limit_usec);
	Error start(int p_port, const IPAddress &p_bind_ip);
	void stop();

	void notify_client(const String &p_method, const Variant &p_params = Variant(), int p_client_id = -1);
	void request_client(const String &p_method, const Variant &p_params = Variant(), int p_client_id = -1);

	bool is_smart_resolve_enabled() const;
	bool is_goto_native_symbols_enabled() const;

	// Text Document Synchronization
	void lsp_did_open(const Dictionary &p_params);
	void lsp_did_change(const Dictionary &p_params);
	void lsp_did_close(const Dictionary &p_params);

	/**
	 * Returns a list of symbols that might be related to the document position.
	 *
	 * The result fulfills no semantic guarantees, nor is it guaranteed to be complete.
	 * Should only be used for "smart resolve".
	 */
	void resolve_related_symbols(const LSP::TextDocumentPositionParams &p_doc_pos, List<const LSP::DocumentSymbol *> &r_list);

	/**
	 * Returns parse results for the given path, using the cache if available.
	 * If no such file exists, or the file is not a GDScript file a `nullptr` is returned.
	 */
	ExtendGDScriptParser *get_parse_result(const String &p_path);

	GDScriptLanguageProtocol();
	~GDScriptLanguageProtocol() {
		clients.clear();
	}
};
