/*
	This file is part of solidity.

	solidity is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	solidity is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
*/
// SPDX-License-Identifier: GPL-3.0
#pragma once

#include <libsolidity/ast/AST.h>
#include <libsolidity/formal/ModelCheckerSettings.h>
#include <libsolidity/interface/CompilerStack.h>
#include <libsolidity/interface/StandardCompiler.h>
#include <libsolidity/interface/FileReader.h>
#include <libsolidity/interface/ImportRemapper.h>
#include <libsolidity/lsp/LSPTypes.h>
#include <libsolidity/lsp/ReferenceCollector.h>
#include <libsolidity/lsp/Transport.h>

#include <liblangutil/SourceReferenceExtractor.h>

#include <fmt/format.h>

#include <json/value.h>

#include <boost/filesystem/path.hpp>

#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <optional>
#include <ostream>
#include <set>
#include <string>
#include <string_view>
#include <unordered_map>
#include <variant>
#include <vector>

namespace solidity::lsp
{

enum class ErrorCode;

/// Solidity Language Server, managing one LSP client.
///
/// This implements a subset of LSP version 3.16 that can be found at:
///     https://microsoft.github.io/language-server-protocol/specifications/specification-3-16/
class LanguageServer
{
public:
	/// @param _transport Customizable transport layer.
	explicit LanguageServer(std::unique_ptr<Transport> _transport);

	/// Compiles the source behind path @p _file and updates the diagnostics pushed to the client.
	///
	/// update diagnostics and also pushes any updates to the client.
	void compileSourceAndReport(std::string const& _file);

	/// Loops over incoming messages via the transport layer until shutdown condition is met.
	///
	/// The standard shutdown condition is when the maximum number of consecutive failures
	/// has been exceeded.
	///
	/// @return boolean indicating normal or abnormal termination.
	bool run();

	/// Initiates the main event loop to terminate as soon as possible.
	void terminate();

	Transport& transport() noexcept { return *m_client; }

protected:
	void handleInitialize(MessageID _id, Json::Value const& _args);
	void handleWorkspaceDidChangeConfiguration(MessageID _id, Json::Value const& _args);
	void handleTextDocumentDidOpen(MessageID _id, Json::Value const& _args);
	void handleTextDocumentDidChange(MessageID _id, Json::Value const& _args);
	void handleTextDocumentHover(MessageID _id, Json::Value const& _args);
	void handleTextDocumentHighlight(MessageID _id, Json::Value const& _args);
	void handleTextDocumentReferences(MessageID _id, Json::Value const& _args);
	void handleGotoDefinition(MessageID _id, Json::Value const& _args);
	void semanticTokensFull(MessageID _id, Json::Value const& _args);

	/**
	 * Constructs some tooltip (hover) text.
	 *
	 * The resulting text string should be in markdown format.
	 */
	std::string symbolHoverInformation(frontend::ASTNode const* _node);

	/// Invoked when the server user-supplied configuration changes (initiated by the client).
	void changeConfiguration(Json::Value const&);

	/// Find all semantically equivalent occurrences of the symbol the current cursor is located at.
	///
	/// @returns a list of ranges to highlight as well as their use kind (read fraom, written to, other text).
	std::vector<DocumentHighlight> semanticHighlight(frontend::ASTNode const* _node, std::string const& _path);

	/// Finds all references of the current symbol at the given document position.
	///
	/// @returns all references as document ranges as well as their use kind (read fraom, written to, other text).
	std::vector<langutil::SourceLocation> references(DocumentPosition _documentPosition);

	/// Requests compilation of given client path.
	/// @returns false if the file was not found.
	bool compile(std::string const& _path);

	frontend::ASTNode const* requestASTNode(DocumentPosition _filePos);

	std::optional<langutil::SourceLocation> declarationPosition(frontend::Declaration const* _declaration);

	std::vector<langutil::SourceLocation> findAllReferences(
		frontend::Declaration const* _declaration,
		std::string const& _sourceIdentifierName,
		frontend::SourceUnit const& _sourceUnit
	);

	void findAllReferences(
		frontend::Declaration const* _declaration,
		std::string const& _sourceIdentifierName,
		frontend::SourceUnit const& _sourceUnit,
		std::vector<langutil::SourceLocation>& _output
	);

	DocumentPosition extractDocumentPosition(Json::Value const& _json) const;
	Json::Value toRange(langutil::SourceLocation const& _location) const;
	Json::Value toJson(langutil::SourceLocation const& _location) const;

	/// Translates an LSP client path to the internal source unit name for the compiler.
	std::string clientPathToSourceUnitName(std::string const& _path) const;
	/// @returns true if we store the source for given the LSP client path.
	bool clientPathSourceKnown(std::string const& _path) const;

	// LSP related member fields
	using Handler = std::function<void(MessageID, Json::Value const&)>;
	using HandlerMap = std::unordered_map<std::string, Handler>;

	std::unique_ptr<Transport> m_client;
	HandlerMap m_handlers;
	bool m_shutdownRequested = false;
	bool m_exitRequested = false;

	/// FileReader is used for reading files during comilation phase but is also used as VFS for the LSP.
	frontend::FileReader m_fileReader;
	/// Mapping from LSP client path to source unit name.
	std::map<std::string, std::string> m_fileMappings;

	frontend::CompilerStack m_compilerStack;
	Json::Value m_settingsObject;
};

} // namespace solidity